HK1178829B

HK1178829B - Personal height rescue apparatus

Info

Publication number: HK1178829B
Application number: HK13106534.5A
Authority: HK
Inventors: J．E．伦顿; P．T．M．诺特
Original assignee: 安全降落有限公司
Priority date: 2004-05-15
Filing date: 2013-06-04
Publication date: 2015-12-18

Description

High-altitude rescue device for personnel

The application is a divisional application of an invention patent application named as a high-altitude rescue device for people, wherein the international application date is 2005-5-13, the international application number is PCT/GB2005/001862, and the national application number is 200580021299.8.

Technical Field

The invention relates to a personnel high-altitude rescue device which can descend a person connected with a falling prevention device to a safe place after the person falls off and is braked and suspended at high altitude. In particular, the invention relates to a personal height rescue apparatus which is physically connected to a person working at height, and which enables the person to descend to a safe location, whether the ground or some other safe height, in the event that the person is braked after falling from height.

Background

Personnel working at height often need to wear body harnesses. The body harness wraps around portions of the wearer's body to ensure that the wearer's body is securely held within the body harness. The body harness is typically attached to one end of a lanyard, and then the other end of the lanyard is attached to a secure anchorage. An alternative arrangement is for the whole body harness to be connected to a line which can be withdrawn or retracted from the drum which can be rotated within the housing which is connected to a secure anchorage. The withdrawal of the cord from the drum is normally achieved by pulling the cord, and the retraction of the cord into the drum occurs automatically, since the action of the torsion spring tends to rotate the drum to retract the cord. If the cord is rapidly withdrawn from the drum (as would be the case in a fall), a pawl in the housing engages on the drum and prevents any further rotation of the drum until the load on the cord due to the pulling action is relieved. The safety anchorage may be any suitable anchorage on the arrangement or building or it may be part of another fall arrest system such as a cable system whereby the safety anchorage is able to move along the length of the cable whilst the anchorage is securely connected to the cable thereby allowing access to an area near the length of the cable. In either fall arrest arrangement, typically an energy absorber is connected between the full body harness and the safety anchorage, and this energy absorber is deployed within specified load limits to limit the load on the falling person's body. Many lanyards have a flat rectangular cross-section and energy absorbers are achieved by folding a portion of the length of the lanyard and then stitching it together so that when the lanyard is subjected to a sufficient tensile load at either end, while such tensile load continues, the stitching progressively breaks, causing the effective length of the lanyard to elongate, thereby absorbing energy. An energy absorber associated with the cord being withdrawn or retracted from the drum onto the drum is often contained between the drum and its housing such that the cord is withdrawn from the drum by allowing the drum to rotate after the pawl has been engaged if the tensile load on the cord exceeds a threshold limit less than the specified load limit on the body of the fall. The threshold load is typically determined mechanically by the friction applied between the drum and its housing, whereby the drum can rotate as long as the load on the cord is sufficient to overcome the resistance load due to friction.

Fall arrest systems and devices typically allow personnel access to the edge of a building or arrangement where there is a possibility of a fall. In the unfortunate event of an accidental fall of a person, the fall arrest device arrests the fall of the falling person, suspending the falling person aloft close to the edge of the building or arrangement. The falling person is secured within the harness, which is then connected to the lanyard or retractable cord, which is then connected to the secure anchorage. During fall arrest, the energy absorber located between the falling person and the safety anchorage will typically deploy in accordance with the fall energy that needs to be absorbed, thereby limiting the load on the body of the falling person. While the falling person is safely arrested and the load placed on the falling person's body is limited, the physical requirements placed on the person during the fall event are particularly important if the falling person is light or in a relatively poor health condition. However, a falling person suspended in a harness at high altitudes after a fall event can experience more serious complications. A stationary suspension in a sling, even for a short time, causes a blood venous retention effect, which becomes dangerous in as little as ten minutes, thereby leading to loss of consciousness and gradual death. Various investigations have been carried out to verify the risk of a stationary suspension, and it is now a general consensus that it is crucial to rescue and recover the falling person as quickly as possible to avoid the onset of serious fatal complications.

Various methods are currently used to rescue a fall victim, but none of these methods is generally satisfactory. The most common method is to call out the fire brigade. The speed of reaction depends on many factors such as the location where the fall occurs and the distance of the location from the nearest fire station, the availability of fire brigade resources in the event of a fall and whether the nearest fire station has special equipment for rescuing people suspended at high altitudes, such as mobile platforms and lifting equipment. Specialized equipment tends to be expensive and less expensive than standard fire fighting equipment and is generally available only at selected fire stations. All of these factors make it difficult to predict how long it will take for a fire department to descend a suspended person to the ground from the time of alarming a fall event to the arrival at the scene. Typically, the reaction time varies widely from about 10 minutes at the fastest to up to 1 hour. Another problem may be reaching a specific location on the perimeter of the building where the fall occurred. Many buildings are located adjacent to the building or there are obstacles such as fences, all of which prevent rescue equipment of appropriate height from quickly reaching the fall location.

Another rescue method is for the rescuer to be equipped with a lowering device that descends, or for the rescuer to lower himself alongside the falling person and to connect the falling person's harness to the lowering device. The rescuer then cuts the lanyard of the falling person, usually with a knife, so that the weight of the falling person is transferred to the lowering device. After the belayer's lanyard is cut, the rescuer descends with the falling person. This method has a number of disadvantages, at least requiring the rescuer to place himself at considerable risk. The rescuer will also need to receive basic technical and physical training in order to perform the rescue method. This training is often expensive and therefore tends to be limited to a small number of people, thereby increasing the likelihood that a person with the appropriate ability to perform such a rescue procedure will not be able to reach immediately in the event of a fall.

Another rescue method is to connect the harness of the fall occupant to a lifting device such as that provided in GB2376009 and lift the fall occupant to the top of the building or to the initial position of the cable fall arrest system. There are a number of problems with this approach. First, the harness attachment point from a person suspended at high altitude after a fall has been arrested may be two or more meters below the building edge. Any attempt to connect the lifting cable to the connection point from a position at the top of the building will typically compromise the rescuer's safety. GB2376009 describes a strong and convenient anchorage point in the form of a top-hung beam. It is unlikely that there will be a convenient and suitable anchorage at the most typical location where personnel associated with the fall arrest system or apparatus will perform work that is sufficiently above the edge of the falling person and building to enable a suspended falling person to be lifted over the edge before returning to the height from which the fall occurs. The time required to erect such a beam after a fall event will be considerable. However, even if the falling person were to be successfully lifted and recovered, the problem still remains of transporting him or her easily and safely to the ground in order to enable him or her to obtain appropriate emergency services in the possible case of injury to him or her.

In any of the aforementioned rescue methods, which do not include a method using a fire brigade, it is necessary to find and transport the rescue system device to the place where the fall occurred and to turn on and prepare the device before starting the rescue work. Since the need to undertake rescue is extremely rare, there is a likely problem that it may lead to further delays, such as finding the rescue device, ensuring that the packaging containing the device is complete and that the rescue equipment is properly maintained. Moreover, as already mentioned, rescue methods often require training of high levels of personnel, and therefore it is necessary to ensure that a rescuer is always properly qualified at hand when performing high-altitude access operations.

In view of all of the above, it is quite advantageous to arrange the rescue apparatus as an integral part of the personal equipment of the falling person, so that the apparatus is immediately available at the place of fall and ready for operation by the falling person and/or rescuer.

Disclosure of Invention

It is therefore an object of the invention to provide a personnel height rescue apparatus which is part of personal equipment associated with personnel working at height, the rescue apparatus being capable of withstanding dynamic fall arrest loads if the personnel falls and is arrested by a fall arrest device, the rescue apparatus then being ready to be used to lower the personnel to the ground or other safe height after the fall has been arrested. Another object of the invention is that the personal height rescue apparatus should be light weight and compact so as to have minimal impact on the performance of the activities of the persons using the device, and to make the manufacture of the personal height rescue apparatus economical.

It is a further object of the invention to provide a personal high altitude rescue apparatus which enables a person to descend to the ground or other safe height without delay after a fall has been arrested. The invention may be operated by a fall occupant equipped with the device, although it is contemplated that the device may be operated by or in conjunction with another participant, such as a rescuer. If the falling person loses consciousness, it will be important to be operated by a rescuer. Furthermore, in order to avoid obstacles and to route the wind during descent with regard to wind influences, one or more rescuers have to assist. Alternatively or additionally, the personal high altitude rescue apparatus may operate automatically after a person is arrested from a fall, particularly if the person is injured or results in loss of consciousness during the fall. Injuries involving the head are common, especially with the use of fall arrest devices having considerable resilience, so that the falling person is subjected to a number of fall oscillations before reaching a stop, with each oscillation increasing the likelihood of the falling person colliding with surrounding objects.

According to the present invention there is provided a personal height rescue apparatus comprising a load cell with means for attachment to one end of a safety line (e.g. a lanyard or other type of safety line) the other end of which is connected to a safety anchorage, such as a building or other structure, the apparatus also comprising a harness attachment means for attachment to a safety harness worn by a person, and a connector with releasable means and means for releasing said releasable means, whereby said connector is securely attached between the load cell and the harness attachment means, the connector being of sufficient strength to maintain its attachment to the load cell and harness attachment means so as to carry the load between the load cell and harness attachment means during the process of the person being arrested from said fall in the event that the person is arrested from high altitude, the device further comprising a length of flexible elongate member which is safely connected at one end to the load element and a portion of its length is held in a store, the device also comprising at least one speed control means arranged in the personal height rescue device such that it controls the speed at which the length of flexible elongate member moves relative to the harness connection part such that in the event of a person falling and fall arrest being arrested, a fall arrest load between the load element and the harness connection part is taken up by the connector with the releasable means and then such that the person is suspended at high altitude, and then to lower the person to a safe location after the fall is arrested the means for operating the releasable means of the connector is operated such that the connector is released, thereby releasing the connection between the load element and the harness connection part, whereby the load between the load element and the strap connecting member is then transferred to the length of flexible elongate member causing the flexible elongate member to unwind from the store relative to the strap connecting member at a rate controlled by the at least one speed control member, thereby lowering the person at a controlled descent rate.

In most embodiments, the personal height rescue apparatus has a housing that provides a convenient base for connecting and containing components. In the exemplary embodiment both the strap attachment component and the speed control component are attached to the housing, such that the housing effectively provides a connection between the two components. Furthermore, the housing provides a convenient enclosure for storing the length of flexible elongate member and for protecting it from environmental influences and possible accidental damage. The housing also serves to store the connector with the releasable component and may include a portion or all of a mechanism for releasing the component of the connector.

The load applied between the load cell and the strap connecting part during the course of a fall arrest from high altitude is typically significantly higher than when lowering a person after being suspended stationary following a fall arrest event. An energy absorber between the person and the safety anchorage limits the load on the person's body in the event of a fall arrest. The magnitude of the required load limit varies between international ranges. The maximum physical limit in europe is 6kN, while in the us the limit is typically 4 kN. Therefore, applying a factor of safety of two, a connector with a releasable component would need to be able to withstand a load of at least 12kN on it. However, once the connector is released, the tensile load in the flexible elongate member will correspond substantially to the static weight of the person being lowered, typically around 1 kN. Therefore, applying a safety factor of up to 4 times to account for the deceleration effect of any braking during descent, the flexible elongate member and any speed control means for controlling the speed at which the flexible elongate member is deployed relative to the harness connecting member will only need to withstand tensile loads of up to 4kN between the load element and the harness connecting member rather than higher dynamic fall loads of up to 12kN, so that the personal height rescue apparatus can be relatively compact and lightweight.

Although the use of a load cell with a releasable connector is advantageous in enabling both the flexible elongate member and any speed control component for controlling the deployment speed of the flexible elongate member to avoid dynamic fall arrest loads in the event of a fall, and is therefore compact and lightweight, the invention may also include embodiments with a releasable arrangement which substantially prevents any speed control component from operating under such dynamic fall arrest loads. Such dynamic fall arrest loads may be prevented from being applied to any speed control component by various means, for example applying a releasable stop or brake to the flexible elongate member or to a component for deploying the flexible elongate member, rather than using a releasable connector to act on a load element connected to one of the flexible elongate members. For example, such an embodiment may comprise a length of flexible elongate member, whereby a first end thereof is connected to a drum on which a majority of its length is helically wound and a second end thereof is connected to a safety line or directly to a safety anchorage, the drum being mounted on a central shaft and free to rotate about the central shaft, the central shaft being fixedly connected to a cloth structure which is fixedly connected to or may be integral with the harness connection part, such an embodiment further comprising a releasable stop or brake with a release means for releasing the stop or brake such that the releasable stop or brake may act on the drum to prevent it from rotating until the stop or brake is released, such an embodiment also comprising at least one speed control means for controlling the speed at which the flexible elongate member is unwound relative to the harness connection part, such that in the event of a person falling and the fall being arrested, the flexible elongate member is prevented from unwinding from the drum by the releasable stop or brake, thereby also preventing the application of dynamic fall arrest loads between the flexible elongate member and the harness attachment member to the at least one speed control member. When the fall is arrested, the releasable stop or brake may be released by operating its release means, and the load between the flexible elongate member and the strap attachment means is then transferred to the at least one speed control means, thereby enabling the flexible elongate member to be deployed from the drum to lower the person to the ground or other safe level at a controlled rate of descent. The operation of the release member to release the stop or brake may be similar to any of the foregoing and subsequent embodiments in connection with releasable connectors including manual, automatic and remote releases. However, applying a stop or brake to a flexible elongate member or to a means for unwinding the flexible elongate member from its store has the disadvantage that dynamic fall loads can be applied to at least a portion of the length of the flexible elongate member, and in embodiments where a drum is used as the store for example, the arrangement of the dynamic fall load also being applied to the drum, its axis and the axis connecting the axis to the sling attachment means results in these means needing to be relatively strong and therefore potentially heavier and larger than using a load cell with a connector where dynamic loads are only applied between the load cell and the sling attachment means and not to the flexible elongate member. The size and weight of the flexible elongate member can be optimised by arranging a portion of the flexible elongate member subjected to a greater dynamic fall load to have a suitably larger cross-sectional area or to consist of more than one parallel length of flexible elongate member.

In any or all embodiments of the personal height rescue apparatus, the invention may include an energy absorber as described above which limits the load on the body of a person when arrested from a fall, wherein the load limit is less than 6kN in europe and less than 4kN in the united states. Typically, the energy absorber will be incorporated in either the connector between the load cell and the strap attachment member or between the load cell and the connector or between the strap attachment member and the connector.

The operation of the means for releasing the connector may be effected by manual operation, ideally by a person being lowered after the fall. In many cases the personal rescue apparatus will be located behind the head of the falling person during suspension after the fall, so that the release control member is extended to a convenient position for operation by the falling person. Typical components of operation are provided by a cable that is connected to a suitable mechanism for initiating release of the connector. Often regulatory authorities require that the release of a connector under safety critical conditions, where the release may be accidentally initiated, have two or more different actions in order to accomplish the release function. Thus, while the release member may be operated with a single operating action, such as pulling the cord once, various other embodiments of release operations providing more than one different action are possible. A simple manual release operating embodiment may be to provide a lanyard that requires only one pulling action to release the connector, but requires access to the cord by opening the lanyard bag, so that opening the lanyard bag and pulling the lanyard are two different actions. Another release operating arrangement may utilize two or more pull cables that need to be pulled together, pulled in sequence, or pulled in sequence but in a prescribed sequence in order to release the connector. Another release operating arrangement may be to use only one cable that is pulled a specified number of times before releasing the connector. Other safety measures may be applied when a person is suspended from after a fall is arrested rather than during or before the fall event, which only allow continued operation of the components to release the connector. In addition, many different embodiments are possible. For example, the release mechanism may be operable only within a predetermined range of load magnitude between the load element and the strap connecting part, so as to be releasable only when the load equals the weight of the suspended person. Another embodiment may have a release mechanism that is releasable only when the actual static load between the load element and the strap connecting part lasts for a predetermined duration or such a substantially static load equals the weight of the suspended person and has lasted for a predetermined duration.

If the falling person is unable to operate the connector release member due to injury or loss of consciousness resulting from the fall event, the personal height rescue apparatus may include one or more mechanisms which enable the connector to be released by the rescuer or helper. This may be achieved by using an additional release member which extends to ground or other safe height when the person is arrested from the fall, or by attaching the extension to the fall occupant's own manual release member which is then operated by the rescuer or helper, or by using a device such as a lever with a hook at one end whereby the hook may be used to actuate the release member, or by any other suitable means. Another option is for the rescuer to be equipped with a personal rescue device to lower himself or herself alongside the unintended falling person and to operate the manual release member of the falling person for the falling person.

In some embodiments, automatically operating the connector release member is advantageous, particularly in the event that a suspended person is injured in his head and becomes unconscious after a fall has been arrested. It is often important to ensure that automatic release of the connector does not occur until the process of arresting a fall from high altitude is completed, to avoid the possibility of higher dynamic loads during such a fall being transferred to the length of flexible elongate member and the at least one speed control component. Embodiments with an automatic release means for releasing the connector may include a release means that automatically releases the connector in response to a load applied between the load element and the harness connecting member, wherein the magnitude of such load is within upper and lower limits typically associated with the respective weights of the heaviest and lightest users of the personal height rescue apparatus. Also, such automatic release means may include means to delay release of the connector for a short period of time (e.g. 30 seconds) after initial detection of the load between the upper and lower load limits to ensure that activation occurs after the fall event is completed. Many falls involve not only the initial fall but also subsequent dynamic motion, which is usually caused by the resilience in the fall arrest system, causing the fall arrest person to bounce before reaching a stop, so it is important to ensure that the connector is only released when or after the dynamic motion in the vertical plane has substantially stopped. A safety feature may be arranged to prevent the release feature from being accidentally activated to release the connector such that the release feature is only activated after a load within upper and lower limits of magnitude between the load cell and the strap connecting member has been within such magnitude limits for a specified period of time (e.g. 30 seconds). Typically, if the load lasts for less than a certain period of time, e.g. 30 seconds, within certain upper and lower magnitude limits, the start-up process may stop as if the load between the load element and the strap connecting member were not applied. In other embodiments, the start-up process will stop if such a load decreases below a certain lower limit, as if the load were not applied. However, if such a load increases above a certain upper limit, the start-up procedure may be suspended and subsequently continued if such a load falls below a certain upper limit. Such an automatic release feature may be implemented mechanically using a mechanical device for providing a prescribed time delay.

More sophisticated automatic release features for releasing the connector may be implemented using typical standard electronic components that electronically activate an actuator that then releases the connector. Such an actuator may be a motor, a solenoid, a pyrotechnic device, or any other suitable type of actuator. Pyrotechnic actuators are widely used in the automotive industry for activating airbags and pretensioning seat belts and have excellent records that are reliable for a long time in various environments. They also have the advantage that they can be detonated by relatively small currents while generating a high level of mechanical energy after detonation, which can then be used to release the connector. A potential problem with relying on power in a safety-critical device is to ensure that sufficient power is available when it is needed. Power is typically taken from batteries or other suitable portable power storage in combination with a personal height rescue device. To minimize power usage, the circuit including the battery may be arranged so that it remains open and does not draw any power on the battery until a load is applied between the load cell and the harness connection component, which occurs when a person is suspended after a fall arrest event. The magnitude of the load is typically greater than a prescribed lower limit in order to minimize the likelihood of the circuit being accidentally closed. The lower limit magnitude may be related to the weight of the lightest user of the personal high altitude rescue apparatus. When the load between the load element and the strap connecting member is greater than a specified lower limit, the circuit will be closed so that power from the battery can be used to activate the actuator. To ensure that the electrically activated actuator releases the connector only after the fall event is complete and the fall occupant is substantially stationary, a standard electronic timer may be used to provide a predetermined time delay, for example 30 seconds, between the circuit being closed and the actuator being activated to release the connector, so that if the load between the load cell and strap connecting member is removed or its magnitude is below the lower limit, the circuit will be opened and the activation process will stop as if the load was not applied. In some workplace applications, when a worker uses his harness, lanyard and safety anchorage to limit his position, particularly when working on inclinedly sloped surfaces, a relatively large load may be applied between the load cell and the harness connection member. A relatively heavy worker may apply a restraining load that may exceed the lower limit of the load magnitude between the load cell and the strap connecting member, thus activating the circuit. Although this is unlikely, the circuit may contain a sensor that detects the load between the load cell and the strap connection member or the acceleration force of the personal high altitude rescue apparatus during a dynamic fall event, such that the connector is released only after a relatively large threshold limit of the load magnitude is exceeded. This will effectively ensure that the connector is only released after a relatively severe fall event, where the falling person may be injured or cause loss of consciousness. Such a personal height rescue apparatus would have a manual release feature to enable a falling person to operate his own manual release feature in the event of a less severe fall. The manual release member may be a simple electrical switch that activates the electrical actuator or it may be a mechanical arrangement or any other suitable arrangement. Means for detecting loads above a relatively high threshold limit may also be provided mechanically.

In any embodiment where the release means for releasing the releasable connector or releasable stop or brake is operated automatically or manually by means of an extended pull cord, the personal height rescue apparatus may be located anywhere between the person wearing the harness and a safe anchorage on the structure or building to which the person is connected, as there is no need for the personal height rescue apparatus to be in proximity to such a person. For example, the personal height rescue apparatus may be directly connected to a secure anchorage, which bears the weight of the personal height rescue apparatus, rather than the harness of the person. In embodiments where the personal height rescue apparatus is connected directly to the secure anchorage, it is preferred that the harness connection member may be otherwise connected to the harness, to the anchorage, and that the load cell and/or the flexible elongate member are connected to a safety line arranged between the harness and the secure anchorage of the person, such that only the flexible elongate member is moved away from the secure anchorage when the flexible elongate member is deployed, thereby reducing the likelihood of the deployment being impeded by obstacles in the path of descent.

In any of the preceding or subsequent embodiments using electrical energy, a further back-up release member may be provided mechanically to prevent the electrical release member from failing for some reason.

An add-on useful for either of the foregoing or subsequent arrangements using electrical energy may be the inclusion of an electronic sound generator which may be activated to sound an audible alarm of a fall of a person. Such a sounder may also be used to indicate that power is being drawn from the battery. An electrically powered sound generator may also be incorporated in any of the arrangements described previously or subsequently, but such a sound generator is powered by an electrical energy source such as a battery. Alternatively, a sounder may be provided mechanically in various arrangements, including modifying at least one speed control mechanism so that its operation is clearly audible as an alarm that a person is descending after a fall arrest event.

An alternative embodiment of the invention using typical standard electronic components would enable the release of the connector to be performed remotely by a rescuer or helper. In an injury-causing fall event where the falling person requires medical attention, it is desirable for the rescuer or helper to activate the release member of the falling person, and then prepare to receive and deliver assistance when the falling person reaches the ground. An embodiment of the invention is therefore where the rescuer or helper is provided with a typical standard wireless transmitter so that the rescuer or helper can send a wireless signal to a wireless receiver contained in the personnel height rescue apparatus of the falling person so that the signal can initiate electrical activation of an actuator (e.g. a motor, solenoid, pyrotechnic device or some other suitable actuator) in order to release the connector. As previously mentioned, power may be provided by a battery or some other suitable power store, and to minimise power usage, the circuit including the battery may be arranged such that it remains open and does not draw on any power on the battery until a predetermined threshold of load is applied between the load cell and the harness connection member (which occurs if a person is suspended after a fall). A time delay device may also be included to ensure that the connector is not released until the fall event is substantially complete. The falling person may also be equipped with a wireless transmitter to activate his own release member after the fall without injury or loss of consciousness. In another situation it is advantageous, where the roles are interchanged, the falling person becomes a rescuer, and he then performs a remote rescue with his own wireless transmitter. Alternatively, the falling person may actuate his own release member with a simple manual electrical switch directly connected to the circuitry in his personal height rescue apparatus or with some other suitable release member (e.g., a mechanical release member independent of any circuitry).

In an exemplary embodiment, the invention has a speed control component that automatically controls and limits the rate of descent of the person. Other embodiments may however have another speed control member which can be manually operated by the person being lowered to reduce the rate of lowering and which can also be caused to stop their lowering if required. The further speed control component may have the capability of being operated by a rescuer in addition to or instead of being operated by the person who is descending. It is useful to be operated by a rescuer in the event that the person being descended is unconscious. Both automatic and manual speed control components are typically close together for convenience. In practice, pulling or releasing one or more control cords has been found to be a suitable method of operating a manual speed control member. However, it is controversial as to whether the speed of the control rope or ropes will be reduced by pulling or releasing it. Pulling is a conscious action and is therefore often most relevant to reducing speed, especially in situations where the person is unconscious, where it is vital to lower the person to a safe place as quickly as possible. For convenience and to minimize the possibility of confusion, the operation of the manual speed control feature is often, but not necessarily, used in conjunction with the operation of the release feature for releasing the connector. In another exemplary embodiment of the manual speed control device means are provided for manually operating the speed control device to stop the flexible elongate member from unwinding at any stage during the descent and to remain stationary after the stop without requiring any continued or further operation of the manual speed control device. This is useful in situations where a rescuer equipped personal high-altitude rescue apparatus needs to lower himself alongside a person who is unconscious and suspended after being arrested from a fall and who is also equipped with a personal high-altitude rescue apparatus, and where the rescuer needs to remain stationary alongside the falling person and free both hands and any other available mechanism in order to release the connector release member of the falling person. The manual speed control device that stops the flexible elongate member from unwinding may then be operated at the appropriate time to release the braking mechanism and continue unwinding the flexible elongate member from the reservoir.

However, in a complex embodiment, an electrical activation of the brake member may be provided, as is the case with the electrical activation of the connector release member. As with the electrical activation of the connector release member, the electrical activation of the manual speed control member may be controlled by wirelessly sending a signal from a controller located on the descending person and/or rescuer.

Drawings

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1 shows a person wearing a personal high-altitude rescue apparatus according to a first embodiment of the invention;

FIG. 2 shows a back side view of the embodiment of FIG. 1 rotated about a vertical axis;

figure 3 shows the embodiment of figure 1 worn by a suspended person after being arrested after a fall;

FIG. 4 shows the view of FIG. 3, but with the connector released and the person in an early stage of descent;

FIG. 5a shows a partial cross-sectional view of the embodiment of FIG. 1;

FIG. 5b shows a partial cross-sectional view of FIG. 5 a;

FIG. 5c shows the partial cross-sectional view of FIG. 5a in a first stage of operation;

FIG. 5d shows the partial cross-sectional view of FIG. 5a in a second stage of operation;

FIG. 6a shows the partial cross-sectional view of FIG. 5a with a first alternative connector release mechanism;

FIG. 6b shows FIG. 6a in a first stage of operation;

FIG. 6c shows FIG. 6a in a second stage of operation;

FIG. 7a shows the partial cross-sectional view of FIG. 5a with a second alternative connector release mechanism;

FIG. 7b shows FIG. 7a in a subsequent stage of operation;

FIG. 7c shows FIG. 7b in yet another stage of operation;

FIG. 8 shows a partial cross-sectional view of a third alternative connector release mechanism;

FIG. 9a shows a partial cross-sectional view of a fourth alternative connector release mechanism;

FIG. 9b shows a partial cross-sectional view of FIG. 9 a;

fig. 10 shows a personal height rescue apparatus according to a second embodiment of the invention being worn by a person;

FIG. 11a shows a partial cross-sectional view of the invention of FIG. 10;

FIG. 11b shows a partial cross-sectional view of FIG. 11 a;

FIG. 12a shows a partial cross-sectional view of the invention of FIG. 10 with an alternative method of deploying a flexible elongate member for release;

FIG. 12b shows a partial cross-sectional view of the invention of FIG. 12a in a second stage of operation;

FIG. 13a shows a partial cross-sectional view of the invention as applied to FIG. 1 or FIG. 10, showing a possible automatic release mechanism;

FIG. 13b shows a partial cross-sectional view of the invention in FIG. 13 a;

FIG. 13c shows a partial cross-sectional view of the invention of FIGS. 13a and 13b in a second stage of operation;

FIG. 13d shows a partial cross-sectional view of the invention of FIGS. 13a through 13c with a mechanical time delay arrangement;

FIG. 13e shows a partial cross-sectional view of the invention in FIG. 13d in a second stage of operation;

FIG. 14a shows a view of the present invention with an alternative arrangement for lanyard, harness and rescue rope connection in a first level of operation;

FIG. 14b shows the view of the invention in FIG. 14a in a second level of operation;

figure 14c shows a side view of the invention of figure 14a including the housing in a first mode of personnel fall;

figure 14d shows a side view of the invention of figure 14a including the housing in a second mode of personnel fall;

figure 14e shows a side view of the invention of figure 14a including the housing in a third mode of personnel fall;

FIG. 15a shows a partial cross-sectional view of the present invention with a centrifugal dynamic service brake arrangement;

FIG. 15b shows a partial view of the invention in FIG. 15 a;

FIG. 16a shows a partial cross-sectional view of the invention of FIGS. 14 a-15 b, included in a first stage of operation, with the brake also operated by the cable releasing the connector;

FIG. 16b shows a partial cross-sectional view of the invention of FIG. 16a in a second stage of operation;

FIG. 17a shows a side view of the invention as embodied in FIGS. 14 a-16 b;

FIG. 17b shows a front view of the invention in FIG. 17 a;

FIG. 18a shows a view of a portion of the invention with an extension of the cable for operating the release of the connector extending to the ground or other safety height when a person is arrested from a fall;

FIG. 18b shows a cross-sectional view of the invention in FIG. 18 a;

FIG. 18c shows a view of the first component of the present invention in FIG. 18 a;

figure 18d shows a view of the second component of the invention in figure 18 a.

Detailed Description

In fig. 1, a first embodiment of a personnel height rescue apparatus is shown worn on the back of a person 1 who is then performing ordinary work tasks at height. The person 1 wears a harness 2 which is firmly connected to the support 3 in fig. 2 by means of straps 4 and 5 of the harness 2 which pass through openings 6 in the support 3. The straps 4 and 5 also pass through guides 7 and 8 which are part of the personal height rescue device housing 9 or are connected to the personal height rescue device housing 9 in order to hold the personal height rescue device in place on the harness 2. In FIG. 1, a lanyard 10 is shown connected at one end to a loop 11 by means of a typical connection device, shown as a snap 12, while the other end of the lanyard 10 is connected to a secure anchorage provided by a fall arrest system or single point anchorage. The loop 11 and the bracket 3 are solid parts connected together so that any load applied to the lanyard 10 is transferred to the harness 2 through the connection between the loop 11 and the bracket 3. In the event that the person 1 is to fall, the severity of his fall and the resulting load exerted on his body depends to a large extent on his weight and the distance over which he falls before being arrested between the fall arrest anchor and his harness 2. However, regulatory authorities recognize the limit of loads that a person can withstand before suffering serious injury, and therefore require that personnel working at height should be equipped with an energy absorber between the harness and the fall arrest anchorage that limits the load on the harness in a manner that is independent of the severity of the fall. Such energy absorbers are typically incorporated into the lanyard 10 or another device commonly referred to as a fall arrestor that is connected between the harness and the fall arrest anchorage and relies on friction to absorb energy. The load limits required by regulatory authorities vary internationally. In europe, the load on the harness is limited to below 6kN, while in the us the load on the harness is limited to below 4 kN. Regulatory authorities also typically require that safety equipment components should be designed to perform maximum predicted loads with at least twice the factor of safety. The ring 11 and the bracket 3 and the connection between them need to withstand a load of at least 12kN in case a person is braked after falling.

Fig. 3 shows a person 1 provided with a first embodiment of a personal height rescue apparatus in a typical position after being braked after a fall. In particular during the aforementioned fall event the person's 1 body tends to fall towards the part of the harness 2 supporting his body and the harness 2 tends to experience some stretching, both of which result in the straps 4 and 5 becoming repositioned around the bracket 3 so that loads due to and following the fall event are borne by the bracket 3. The load on the bracket 3 is transferred through its connection to the loop 11 to the lanyard 10 and then to the safety fall arrest system or single point anchorage. The personal height rescue apparatus is able to withstand fall arrest loads between the harness 2 and the bracket 3, between the bracket 3 and the loop 11 and between the loop 11 and the lanyard 10.

When the person 1 is stopped after being arrested after a fall and suspended at height, the personal height rescue apparatus is now ready to be deployed to lower the person to the ground or other safe height, with a substantially static load applied through the bracket 3 and loop 11 corresponding to the weight of the person 1. Deployment is typically initiated by releasing a first connection between the loop 11 and the bracket 3, which is subject to the load during the fall arrest phase of the fall event, and replacing the connection between the loop 11 and the bracket 3 with a second connection comprising a flexible elongate member that can be deployed to lower the person. Fig. 4 shows that person 1 has initiated release of the connection between loop 11 and bracket 3, whereby the connection is transferred to flexible elongate member 21, thereby allowing loop 11 to move away from housing 9 and thus away from bracket 3 to which harness 2 is connected.

Figures 5a to 9a show in more detail the first embodiment with optional means for initiating the connection between the release ring 11 and the bracket 3.

In fig. 5a and 5b, the pins 13 and 14 are cylindrical shafts whose axes are perpendicular to the parallel plates that are part of the housing 9, and the two pins are supported between the parallel plates. Two pins 13 and 14 are also located in the bracket 3 so that the bracket 3 is firmly connected to the pins 13 and 14. The holder 3 may also be firmly connected to the housing 9. However, pin 14 differs from pin 13 in that pin 14 has a flat portion 18 and is also rotatable relative to housing 9, so that flat portion 18 is also rotatable relative to housing 9 about the axis of pin 14. The ring 11 has abutments 15 and 16 which each bear against the pins 13 and 14 respectively, so that the ring 11 cannot move in the direction of arrow 17 when the planar portion 18 is in the radial orientation shown in figure 5 a.

The lever 30 is rigidly connected to the pin 14 such that rotation of the lever 30 also results in rotation of the pin 14. The lever 32 is in the same plane as the lever 30 and is rotatable about an axis 33 and has a torsion spring 34 which tends to urge rotation in a clockwise direction relative to figure 5a so that the lever 32 normally abuts a stop pin 35 in its rest position. The levers 30 and 32 are connected by a pin 31, the pin 31 being rigidly connected to the lever 32 and also constrained within a slot 36 on the lever 30, such that radial movement of the pin 31 about the axis 33 will cause radial movement of the lever 30 and pin 14 relative to the housing 9. The cable 37 is a length of flexible elongate member which is connected at one end to the lever 32 and at its other end is located at a convenient location on the harness of the person 1. The cable 37 is shown enclosed by a sleeve 38. Typically, the sleeve 38 is a tubular sleeve that protects the cable 37 and is under significant tension to prevent the cable 37 from being pulled accidentally, for example, during a fall arrest event. A clip 39 securely connects the sleeve 38 to the housing 9. In fig. 5c, the cable 37 is shown as having been pulled substantially in the direction of arrow 40, whereby rotating the lever 32 about the shaft 33 in a counter-clockwise direction causes the lever 30 to rotate with the pin 14 in a clockwise direction about the pin 14 relative to the housing 9, such that the planar portion 18 also rotates in a clockwise direction. When the flat portion 18 reaches the degree of rotation indicated in fig. 5c, the abutment 16 of the ring 11 can rotate about the abutment 15 supported on the pin 13 independently of the pin 14. In fig. 5d, the ring 11 is shown separated from the two pins 13 and 14.

To avoid the possibility of accidental release other than subsequent suspension after being arrested from a fall, two different actions are typically required in order to complete activation of the release mechanism. In its simplest form, this may be achieved by requiring the person 1 to enter a lanyard pouch which may be secured with a temporary securing means such as Velcro (Velcro) before pulling the lanyard 37 to initiate release.

When the loop 11 is released for lowering the person 1 after the fall has been arrested and suspended, the weight of the person 1 is then transferred to the flexible elongate member 21. In fig. 5a, the flexible elongate member 21 is a length of flexible elongate member which is fixedly connected at one end to the loop 11 and at its other end to the end stop 22. From its connection to the ring 11, the flexible elongate member 21 passes through the two guide members 19 and 20 and is then wound helically around the cylinder 23 in a counter-clockwise direction with respect to fig. 5a, the cylinder 23 being rigidly connected to the housing 9. The cylinder 23 reduces the tensile load on the flexible elongate member 21 between the position where the flexible elongate member is wound from the loop 11 onto the cylinder 23 and the position where the flexible elongate member leaves the cylinder 23. This is essentially a result of the radial friction between the surface of the flexible elongate member 21 and the radial surface of the cylinder 23. Figure 5a shows a flexible elongate member that has been wound around the cylinder 23 for approximately two turns. However, the number of windings will depend on the coefficient of friction between the flexible elongate member 21 and the surface of the cylinder 23. Once leaving the cylinder 23, the flexible elongate member 21 is wound helically around the drum 24 in a clockwise direction with respect to fig. 5a, the drum 24 being able to rotate about the shaft 25, the shaft 25 being fixed to the housing 9. On one axial end of the drum 24 there are six pins shown including a pin 26a and a pin 26g protruding from the surface of the drum 24, whereby all six pins are equally spaced radially around the shaft 25. In fig. 5c, the speed control lever 41 is a weighted lever pivotable about an axis 42 and having shaped holes 43 through which six pins, including pins 26a and 26g, protrude from the surface of the drum 24. When the loop 11 is released and the weight of the person 1 is transferred to the flexible elongate member 21, the flexible elongate member slides around the cylinder 23 and rotates with the drum 24 around the shaft 25. As the flexible elongate member leaves the cylinder 23 and passes around the drum 24, the tension in the flexible elongate member 21, which is substantially equivalent to the weight of the person 1, is reduced as previously described. As the drum 24 rotates with the flexible elongate member 21, the speed control lever 41 is forced to move with the six pins comprising 26a and 26g in opposite radial directions along the arc defined by the juxtaposed apertures 43. Since rotation of the drum 24 produces movement of the speed control lever 41 about the shaft 42, there will be a limit such that inertial resistance caused by movement of the speed control lever 41 will be resisted and thus reduce or limit the rotational speed of the drum 24, thereby limiting the speed at which the flexible elongate member is unwound from the drum 24. The use of the cylinder 23 to reduce the tensile load on the flexible elongate member 21 enables the speed control lever 41 to be relatively compact. Although the speed control lever 41 is shown as one means for limiting the speed at which the flexible elongate member 21 is unwound from the drum 24, any other suitable means for controlling speed may be used.

The flexible elongate member 21 moving away from the loop 11 from the drum 24 passes between the guides 44 and 45 before being packaged in the storage area as shown in figure 5 a. Typically, the guides 44 and 45 are arranged so that they bear slightly on the flexible elongate member 21 to provide some tension between leaving the storage area and the flexible elongate member 21 wound onto the drum 24. At the storage end of the flexible elongate member 21 there is an end stop 22 which is firmly connected to the end of the flexible elongate member 21 so that in the event of depletion of the stored flexible elongate member when the person 1 is lowered, the end stop 22 will become jammed between the guides 44 and 45, thereby preventing the flexible elongate member 21 from leaving the housing 9.

The flexible elongate member 21 may be a new high strength polymer rope. In practice it needs to withstand a substantially static tension load corresponding to the weight of the person 1, which is typically about 1 kN. However, when an increased safety factor of about 4 times is employed, the tension load may be increased to at least 4 kN. Various high strength fiber ropes are widely used, and the ropes typically have a cross-sectional diameter as small as 4mm to have a breaking load of up to 18 kN. The flexible elongate member 21 may therefore be a high strength rope such that the rope can be stored compactly, the rope being of sufficient length and light weight to safely descend a suspended person. Compactness and light weight are important factors in view of the fact that personal height rescue apparatus are worn by personnel working at height. However, the flexible elongate member 21 may be any other suitable material including steel or steel wire or a polymeric or fabric tape.

In fig. 5d, the lever 32 has a protruding pin 46 such that when the lever 32 is rotated about the shaft 33 in a counterclockwise direction relative to fig. 5d, the pin 46 bears on a surface 47 of the speed control lever 41, thereby limiting the radial range of motion of the speed control lever 41 about the shaft 42 and resisting rotation of the drum 24. Therefore, although the cable 37 releases the loop 11 when pulled to the first stage substantially in the direction of arrow 40, thereby allowing the loop 11 to move away from the housing 9 when the flexible elongate member 21 is deployed, the cable 37 may be pulled to a second stage that resists or stops the radial movement of the speed control lever 41, thereby slowing and if necessary stopping the descent of the person 1. In some embodiments, both the aforementioned first and second stages of operating the cable 37 may be the same, such that the brakes are applied while the connector is released.

Fig. 6a to 6c show a first alternative arrangement for releasing the loop 11, thereby requiring the cables 50 and 51 to be pulled in a particular sequence with cable 50 preceding cable 51. This will further reduce the likelihood of accidental release of the mechanism prematurely. In fig. 6a, the lever 48 is connected to the lever 32 such that the lever 32 can rotate about an axis 54 relative to the lever 48. The lever 49 is rotatable about an axis 53 and has a projecting pin 52, which projecting pin 52 is rigidly fixed to its surface and bears on a surface 56 of the lever 49. Furthermore, the lever 49 has an abutment 55 supported on the lever 48. Therefore, if the cable 51 is pulled substantially in the direction of the arrow 51a, the lever 48 is prevented from moving because the protruding pin 52 bears on the surface 56 of the lever 48. This is also applicable if both cables 50 and 51 are pulled simultaneously, substantially in the direction of arrow 51 a. However, if the cable 50 is first pulled substantially in the direction of arrow 50a as shown in fig. 6b, the lever 49 is rotated about the shaft 53, allowing the protruding pin 52 to move away from the surface 56 on the lever 48, so that the lever 48 can then be moved by pulling the cable 51 substantially in the direction of arrow 51a as shown in fig. 6c, thereby rotating the lever 30 and releasing the loop 11. The addition of a torsion spring 105 at the shaft 53 which tends to rotate the lever 49 in a clockwise direction relative to fig. 6b will only allow the cable 51 to be pulled after and at the same time as the cable 50 is pulled to its extent.

Fig. 7a to 7c show a second alternative arrangement for releasing the loop 11, thereby requiring pulling of the cable 58 substantially in the direction of arrow 58a and then releasing of the cable 58, but requiring the pulling and releasing sequence to be performed more than once in succession. The illustrated embodiment includes a release mechanism that requires 3 consecutive pulls of the cable 58 to release the loop 11. In fig. 7a, the lever 62 is rigidly connected to the pin 14 and has a stop 64 bearing on a stop 65, the stop 65 being connected to a part of the housing 9. A torsion spring 66 is between the lever 62 and the housing 9 such that the lever 62 tends to move in a counter-clockwise direction relative to fig. 7a towards the stop 65. The lever 62 also has radial teeth that engage with a pawl 61, the pawl 61 being mounted on the lever 59 such that the pawl 61 can rotate relative to the lever 59 about an axis 63. The lever 59 is rotatable about an axis 60 and has a cable 58 connected thereto. The shaft 60 is connected to the housing 9. The torsion spring 67 between the pawl 61 and the lever 59 tends to urge the cam 61 in a clockwise direction relative to figure 7a towards the lever 62. The torsion spring 68 between the lever 59 and the housing 9 tends to urge the lever 59 in a clockwise direction relative to fig. 7a towards the stop 65. When the cable 58 is pulled for the first time, substantially in the direction of arrow 58a, the pawl 61 engages the first tooth of the lever 62 and rotates the lever 62 and pin 14 through a limited arc in a clockwise direction. Due to insufficient load on the ring 11 bearing on the pin 14, the friction generated between the ring 11 and the pin 14 will be overcome by the strength of the torsion spring 66, and thus the lever 62 will return to its original position when the cable 58 is released. However, in the event that the loop 11 carries the weight of the person 1 relative to the pin 14, the friction generated between the loop 11 and the pin 14 will be sufficient to overcome the strength of the torsion spring 66, so that after the first pull of the cable 58, the lever 62 and the pin 14 will rotate relative to the loop 11 and remain rotated. Pulling the cable 58 further in the direction substantially of arrow 58a will cause the cam 61 to engage in a subsequent tooth in the lever 62, thereby rotating the lever 62 through a further arc of rotation. Fig. 7b shows the beginning of a third pull of the cable 58, substantially in the direction of arrow 58a, and fig. 7c shows that the third pull has been completed, whereby the flat portion 18 in the pin 14 is rotated sufficiently to enable disengagement of the loop 11. This is a particularly safe release method because it requires a different continuous pull on the cable 58 and the lever 62 returns to its starting position against the stop 65 if the load on the loop 11 is insufficient to resist the torsion spring 66. Although fig. 7 a-7 c illustrate embodiments that require three pulls of the cable 58 in succession, other types of embodiments may require two or more pulls.

Figures 8, 9a and 9b show a third and fourth alternative method of initiating the release of the ring 11, so that the release can only be initiated between a minimum and a maximum range of loads on the ring 11, whereby the load range specifically includes loads equal to the weight of a person, but excludes light loads such as may be encountered during high altitude normal activities and heavy loads such as occur when the brakes fall. The embodiment in fig. 8 shows a simple mechanism that will resist the ring 11 being released below a predetermined threshold of load on the ring 11. The lever 71 is rotatable about a shaft 70, the shaft 70 being fixed in the housing 9. The lever 71 also has a protruding surface 74 that interfaces with a mating surface on the ring 11. The spring 73 is a compression spring between an abutment 73a connected to the housing 9 or a part thereof and the lever 71, and the spring 73 is of sufficient strength to urge the lever 74 against the ring 11 such that if the surface 18 on the pin 14 were to be rotated to a position where the ring 11 could otherwise be disengaged there, the engagement of the projecting surface 74 on the lever 71 would secure the ring 11 in place up to a minimum threshold of the magnitude of the load between the ring 11 and the pin 14.

The embodiment of fig. 9a and 9b shows a mechanism that will resist the release of the ring 11 above a predetermined threshold of the load on the ring 11. The lever 30 is rigidly connected to the pin 14 with the flat surface 18 and there is a torsion spring 81 tending to urge the lever 30 and the pin 14 to rotate in a counterclockwise direction with respect to the ring 11. Both levers 75 and 82 rotate about the same axis 76, and a torsion spring 80 is arranged between the levers 75 and 82, tending to urge the lever 82 to rotate in a clockwise direction relative to fig. 9a towards the lever 75. The cable 79 is connected to the lever 82. A pin 78 projects from a surface of the lever 75 and is in form engagement with a slot in the lever 30 such that rotation of the lever 75 about the shaft 76 also causes the lever 30 to rotate about the pin 14. If the load on the ring 11 bearing on the two pins 13 and 14 is above a predetermined maximum threshold limit, the friction generated between the pin 14 and the ring 11 if the cable 79 is pulled substantially in the direction of arrow 79a will be greater than the strength of the torsion spring 80. In such a case, cable 79 will cause lever 82 to rotate, but lever 75 will be held by lever 30, and lever 30 in turn is held by friction between pin 14 and ring 11. However, if the friction between the pin 14 and the ring 11 is not sufficient to overcome the strength of the torsion spring 80 (as would be the case if the load on the ring 11 is below a predetermined upper threshold), then the rotational movement of the lever 82 initiated by the cable 79 will rotate the lever 75, and the lever 75 will then rotate the lever 30 and pin 14, allowing the ring 11 to disengage. The two embodiments shown in fig. 8 and in fig. 9a and 9b may be combined to provide a mechanism that will only allow the release of the loop 11 between predetermined maximum and minimum thresholds of the load on the loop 11.

A second embodiment of a personal high altitude rescue apparatus is shown in figures 10, 11a and 11 b. In fig. 10, the second embodiment is shown worn on the back of a person 1 who is then performing a normal work task at height. The second embodiment of the invention is the same as the first embodiment in terms of the release mechanism for releasing the loop 11 and in terms of the method of connecting the personal height rescue apparatus to the harness 2 using the bracket 3. The main difference is the means for storing and deploying the flexible elongate member when lowering a person after being suspended after a fall arrest and the means for controlling the speed of deployment of the flexible elongate member and thereby the rate of lowering of the person.

In fig. 11a and 11b, the flexible elongate member 85 is a length of flexible elongate member connected at one end to the ring 11 and passing through the guides 87 and 88 before being helically wound onto the drum 90 in a clockwise direction relative to fig. 11 a. The other end of the flexible elongate member 85 is fixedly connected to the drum 90. The drum 90 is rigidly connected to the pin 91. At one end of the pin 91 there is a head portion which is rotatable within an axial bearing 92, the axial bearing 92 being fixed to the housing 86 so that both the drum 90 and the pin 91 can rotate together within the axial bearing 92. The pin 91 also passes through an axial bearing 96 fixed within an arrangement 95, the arrangement 95 being rigidly connected to or part of the housing 86. Beyond the arrangement 95, the pin 91 has a threaded portion shown as a typical right-handed thread 93. The nut 94 is a specially shaped nut having a central threaded bore that screws onto the threads 93 of the pin 91. Thus, the drum 90, the pin 91 and the nut 94 may rotate together relative to the housing 86. A coil spring 98 is connected between the nut 94 and the pin 91 and tends to urge the nut 94 to rotate in a counterclockwise direction relative to the pin 91 such that the coil spring 98 tends to urge the threads on the nut 94 to unscrew relative to the threads 93 on the pin 91. Speed control disk 99 is a disk that is attached to structure 95 and holds a viscous material 100 such that the viscous material is disposed between speed control disk 99 and nut 94. The adhesive material is used to create a predetermined resistance between the nut 94 and the arrangement 95 such that when the drum 90 is rotated in a counter-clockwise direction relative to fig. 11a, the threaded portion of the nut 94 tends to tighten onto the threads 93 of the pin 91 towards the drum 90. When the cable 37 is pulled to release the ring 11, substantially in the direction of arrow 40, the drum 90 is rotated in a counter-clockwise direction relative to the housing 86 and relative to figure 11a, thereby unwinding the flexible elongate member 85 from the drum 90. The extension of coil spring 98 tends to unscrew nut 94 from pin 91, thereby allowing drum 90 to rotate. However, when the rotational speed of the drum 90 exceeds a predetermined limit, the viscous resistance exerted by the viscous material 100 between the nut 94 and the arrangement 95 tends to overcome the strength of the coil spring 98 and cause the threaded portion of the nut 94 to tighten onto the thread 93 of the pin 91, causing both the pin 91 and the drum 90 to move toward the nut 94. Friction disc 101 is a disc made of a friction material having a substantially predetermined coefficient of friction between itself and the mating surfaces of arrangement 95 and drum 90, such that when pin 91 and drum 90 are moved towards friction disc 101, and arrangement 95 and drum 90 interact with friction disc 101, the rotational speed of drum 90 is reduced until the strength of spring 98 exceeds the viscous resistance exerted by viscous material 100, thereby tending to unscrew the threaded portion of nut 94 relative to threads 93 of pin 91, such that drum 90 tends to move away from friction disc 101, thereby reducing the resistance to rotational movement of drum 90. Ball bearing 97 separates nut 94 and arrangement 95 such that nut 94 is prevented from becoming locked to arrangement 95. Without the ball bearings 97, the nut 94 could become locked to the arrangement 95 due to friction developed between their mating surfaces, so that when the rotational speed of the drum 90 is reduced below a predetermined limit, the helical spring 98 would not be able to overcome the friction and therefore not unscrew the nut 94 relative to the pin 91.

Therefore, in the above embodiment, the rotational speed of the drum 90 is effectively controlled, and the descending speed of the person 1 is effectively limited. A manually controlled brake with a mechanism that simply applies a resistance to the nut 94 in addition to the viscous resistance applied by the viscous material 100 can be easily added. Such a mechanism may then be coupled to a cable or other suitable operating member to operate the brake by pulling the cable.

Although the automatic speed control applied to the drum 90 is shown as being applied by the viscous material 100 creating a resistive force on the nut 94, the application of the resistive force may be any other suitable component that provides a dynamic resistive force that is related to the rotational speed of the drum 90, thereby limiting the rate of descent of the person 1 after the ring 11 is released. In case the length of the flexible elongate member 85 is not sufficient to lower the person 1 to a safe height, the flexible elongate member 85 is prevented from leaving the drum 90, since the ends of the flexible elongate member are firmly connected to the drum 90. Furthermore, the flexible elongate member 85 may be of any suitable material and cross-section. In practice, however, it has been found that the steel cord is both strong and compact when wound around the drum. In particular, high strength polymer ropes can be used because they are strong, compact and lighter than steel ropes. Polymeric tapes such as fabric tapes may also be used.

Fig. 12a and 12b show an arrangement similar to that of fig. 11a and 11b, except that the releasable connector acting on the ring 11 is replaced by a releasable stop which prevents the drum 90 from rotating, thereby preventing the drum 90 from deploying a flexible elongate member and applying a dynamic fall arrest load to a speed control mechanism which controls the speed at which the flexible elongate member is deployed from the drum, until the releasable stop is released. In fig. 12a first end of the flexible elongate member 85 is fixed to the drum 90 and then a substantial length of the flexible elongate member is helically wound onto the drum 90, the second end of the flexible elongate member 85 being securely connected to the loop 101. The ring 101 is significant in that it does not have the essential feature of preventing it from moving away from the drum 90. As in the case of fig. 11a and 11b, the drum 90 can be rotated about the shaft 91, whereby the shaft 91 is fixed between the parallel sides of the housing 86. There is also a mechanism for controlling the rotational speed of the drum 90 similar to that in figures 11a and 11b, although this is not clearly shown. The claw stop 104 is connected to or integral with a lever 102, the lever 102 being able to rotate relative to the casing 86 about its axis 103 fixed to and arranged between two parallel sides of the casing 86. The tension spring 105 forces the lever 102 to tend to rotate in a clockwise direction relative to fig. 12a and 12 b. In a dynamic fall arrest situation, a dynamic fall load will be applied to the ring 101 in a direction away from the drum 90 such that a dynamic fall load will be applied to the flexible elongate member 85, thus tending to cause the drum 90 to rotate. However, to prevent the drum 90 from rotating in a counterclockwise direction relative to fig. 12a and 12b, and thereby apply a relatively high dynamic fall load to the speed control mechanism, a dog stop 104 as shown in fig. 12a engages in a cut-out portion 106 in the edge of the drum 90, stopping its rotation. The line drawn between the shaft 103 and the engagement surface between the claw stop 104 and the cut-out portion 106 is ideally substantially parallel to the length portion 85a of the flexible elongate member 85 such that the tensile load applied to the length portion 85a is substantially cancelled by the claw stop 104 at its shaft 103, thereby minimising the load between the drum 90 and its shaft 91. After the dynamic fall arrest situation is concluded, the cable 37 can be pulled in the direction of arrow 40, thereby also pulling its connection 107 to the lever 102 against the drive load applied by the tension spring 105, causing the lever 102 to rotate in a counterclockwise direction relative to fig. 12a and 12b until the degree of rotation is sufficient to release the pawl 104 from its engagement with the drum 90 at the cut out portion 106 of the drum 90. The drum 90 is then free to rotate, thereby unwinding the flexible elongate member 85 at an unwinding speed controlled by the speed control mechanism. It is clear that any of the aforementioned methods for operating the release member and releasing the releasable connector in fig. 5a to 11b may equally be applied to the release pawl stop 104. Also, there are many different arrangements that can be used to stop the flexible elongate member 85 and/or its deployment component (e.g., drum 90) from moving during a fall arrest event, thereby preventing dynamic fall arrest loads from being applied to the speed control mechanism. A disadvantage of acting on the flexible elongate member or the flexible elongate member deployment means to stop movement of the flexible elongate member rather than using a releasable connector acting on the releasable loop as shown in figures 5a to 11b is that dynamic fall arrest loads are applied to at least a portion of the length of the flexible elongate member 85, particularly between the loop 101 and the initial helical winding wound onto the drum 90. To minimise the size and weight of the flexible elongate member, the relatively highly loaded portion of its length may have greater strength than the remainder. This greater strength may be provided in a variety of ways including simply increasing the cross-sectional area of the flexible elongate member along that portion of its length which has a relatively higher load or by specifying a stronger material for that portion of its length. Alternatively, more than one length of flexible elongate members may be arranged in parallel and secured together along a portion of the length of the flexible elongate member having a relatively high load or the flexible elongate members may be wrapped around the connection with the ring 101 such that the wrapped length is also helically wound onto the drum 90 until the load is reduced by radial friction to effectively double the strength properties of the relatively high load portion of its length.

Figures 13a to 13c show means for automatically releasing the ring 11 so that release is initiated when the load applied to the ring 11 is within predetermined upper and lower limits. When a person is equipped with a personal high-altitude rescue device in normal use, which does not include a fall event, the person may use his connection to a safe anchorage as a means for restraining his position or for recovering from tripping and slipping, and it is therefore desirable in such a case that the loop 11 is not released. Therefore, the predetermined lower limit below which the loop 11 cannot be activated will typically be determined by the weight of the lightest personnel equipped with personal height rescue apparatus. A typical lower limit may be about 400N. To ensure that the flexible elongate member cannot be deployed until substantially the end of the fall arrest procedure, the predetermined upper limit for the load will typically be determined by the weight of the heaviest person provided with the personal height rescue apparatus. A typical upper limit may be about 2000N.

In fig. 13a, pins 13 and 14 bound ring 11. The pin 13 is secured between the parallel sides of the housing 86. The pin 14 is cylindrical with a flat portion 18 along its length and is secured to or an integral part of a larger diameter pin 110. The pin 110 is fixed between the parallel sides of the housing 86 so that it can rotate about its central axis relative to the housing 86. When a load is applied to the ring 11, typically in the direction of arrow 111, the ring 11 bears on the pin 14, tending to rotate the larger pin 110 in a clockwise direction relative to fig. 13a and the housing 86, as a result of the position of the pin 14 being offset from the center of the pin 110. Fig. 13c shows how this rotation of the pin 110 eventually results in the ring 11 being able to disengage the constraint provided by the two pins 13 and 14. However, in FIG. 13a, if the load on the ring 11, typically in the direction of arrow 111, is greater than a predetermined upper limit of about 2000N, the friction between the pin 110 and the interconnecting surfaces of the housing 86 is sufficient to prevent rotation of the stop pin 110. Fig. 13b shows the view of fig. 13a with the outer side of the parallel sides of the housing 86. A first end of the link 112 is fixed to the pin 113 so that the link 112 rotates about the pin 113, and a second end of the link 112 is connected to the tension spring 114. An extension spring 114 is also connected to the housing 86 at a connection location 115 such that the extension spring 114 forces the link 112 to move toward the location 115. The pin 113 is typically fixed to or an integral part of the pin 110 and the central axes of the two pins are aligned. When the ring 11 is lightly loaded in the direction of arrow 111, the tension spring 114 forces the pin 110 against the housing 86 such that if the load on the ring 11, typically in the direction of arrow 111, is less than a predetermined lower limit of about 400N, friction between the pin 110 and the interconnecting surfaces of the housing 86 prevents the rotation of the catch pin 110. However, if the load on the ring 11 is within the predetermined upper and lower limits, the load between the pin 110 and the housing 86 will tend to be relieved by the reaction of the ring 11 and the tension spring 114, such that the friction between the pin 110 and the housing 86 is relatively small, and therefore the pin 110 can rotate within the housing 86. Also, the pin 113 can be relatively easily rotated in a relatively small diameter hole in the link 112.

Fig. 13d and 13e show means for delaying the release of the ring 11 in fig. 13a to 13c for a predetermined period of time. The embodiment in figures 13a to 13c will allow the ring 11 to release when the load on the ring 11 is between the upper and lower limits. However, this may occur during the brake fall process rather than at the substantial end of the process. Therefore, it is desirable to include a time delay to ensure that the load between the upper and lower limits has been maintained for a period of time, typically about 30 seconds, allowing sufficient time for any dynamic fall arrest event to end before the ring 11 is released. In fig. 13d, lever arm 118 is fixed to or integral with pin 110 and pin 14. When a load is applied to ring 11, typically in the direction of arrow 111 and within predetermined upper and lower limits, lever arm 118 is forced to rotate with pin 110 in a clockwise direction relative to fig. 13d and 13 e. At its end remote from its connection to the pin 110, the lever arm 118 is supported on a roller 121 which can be rolled about an axis 122. Shaft 122 is connected to receptacle 123, receptacle 123 is rotatable about pin 120, and pin 120 is connected to or disposed between parallel sides of housing 86 such that lever arm 118 forces receptacle 123 to rotate in a counterclockwise direction relative to fig. 13 d. The suction cup 124 is secured to the housing 86 and has a flexible diaphragm. In fig. 13d the receptacle 123 is pressed against the suction cup 119 creating a vacuum or partial vacuum in the suction cup 119 such that the receptacle is forced to adhere to the suction cup 119. The action of lever arm 118 bearing on roller 121 tends to separate receptacle 123 from suction cup 119. Suction cup 119 has a small hole through which air can leak until after a predetermined period of time has elapsed, the vacuum in suction cup 119 is sufficiently full that suction cup 119 is no longer forced to adhere to receptacle 123. Typically, the receptacle 123 is urged towards the diaphragm 124 by a spring (not shown) to ensure that a vacuum or partial vacuum is maintained within the suction cup 119 during normal use of the personal height rescue apparatus, more particularly to ensure that it can be reset if the load on the loop 11 varies between and beyond the upper and lower limits. This reset mechanism is needed, for example, if the falling person will oscillate or bounce due to any resilience of the fall arrest device or system after being arrested from the first fall. The effect of the rebound can apply a wide range of loads to the ring 11, which may be within and outside the upper and lower limits.

In the foregoing embodiment, the loop 11 to which the lanyard is connected and the bracket 3 to which the harness is connected are rigidly connected to the housing 9 so that when a load is applied between the loop 11 and the bracket 3 in the event that the person falls, the housing 9 can be forced to rotate about the bracket 3 as the loop 11 and bracket 3 tend to align with the applied load. This is generally not a problem if the falling person first falls with his feet (in a substantially upright position with the head above the body and the body above the feet) because any rotation of the housing 9 about the bracket 3 towards the body of the falling person is unlikely and therefore little load is applied to the housing 9. However, if the fall is falling in a prone position with the head, feet and body substantially in the same plane and the rescue device is mounted on the back of the fall, the housing 9 will tend to rotate to the back of the fall as the ring 11 and bracket 3 are forced into line with the load applied to arrest the fall. When the lower edge of the housing 9 contacts the back of a falling person, the ring 11 and bracket 3 will be constrained to such an extent that they can be aligned with the applied load, resulting in all three components being difficult to load, particularly the housing 9. The rotation of the housing 9 and its contact load on the back of a falling person may be sufficient to cause injury. The same applies if the falling person falls with the head down and the body and feet above the head.

In practice, it is difficult to determine how a person will fall, so all possible eventualities must be prevented. Figures 14a to 14e show a preferred embodiment which provides different fall modes by allowing articulation between the housing 9 and both the lanyard connection member and the harness connection member. The ring 11 in the previous embodiment is replaced by a ring 130 and an anchor 131.

In fig. 14a and 14b, ring 130 and anchor 131 are each shown folded from a laminar material to form a ring in each, and ring 130 has an elongated mouth 130a through which anchor 131 passes, so that when elongated mouth 130a bears on ring 131a in anchor 131, ring 130 and anchor 131 are effectively securely connected to each other. Also, the ring 130 is rotatable about the radial axis of the folded ring 131a in the anchor 131. A folding loop 130b in the loop 130 is provided to enable a removable fastener such as a snap hook (typically at the end of a lanyard or other safety cord) to be passed through the loop 130b to achieve a secure connection with the loop 130. The strap bracket 133 has two parallel arms 133a and 133b spaced apart by a connecting bar 133c that is perpendicular to each arm and is fixedly secured to or is a part of one end of each arm. A shaft 134 is connected to the other end of each arm and is securely located in the arrangement 135 such that the strap bracket 133 can be rotated relative to the arrangement 135 about the axis of the shaft 134. Anchor 131 is also effectively secured to arrangement 135 whereby notches 131b and 131c in anchor 131 shown in fig. 14b engage cylindrical stop 136 and camming stop 137, respectively. The arrangement 135 is shown formed from a flat sheet of material with a back face 135a and two parallel side faces 135b and 135c, the two parallel side faces 135b and 135c being perpendicular to the back face 135a and formed for convenience by folding two opposite edges of the sheet material. One end of the cylindrical stop 136 is fixed to the plane of the back face 135a of the arrangement 135, and the cylindrical axis of the cylindrical stop 136 is perpendicular to the plane of the back face 135a of the arrangement 135. A front plate, not shown in fig. 14a and 14b, is positioned with its plane parallel to and spaced from the back face 135a of the arrangement 135 and in the ports 135d and 135 e. The other end of the cylindrical stop 136 is then firmly fixed to the front plate, so that the arrangement 135 and the front plate are also effectively rigidly connected to each other. A cam stop 137 is fixed between the arrangement 135 and the front plate and is rotatable about an axis parallel to and spaced from the axis of the cylindrical stop 136. Thus, in fig. 14a, both the ring 130 and the strap support 133 are fixed to the arrangement 135 and are rotatable on axes that are substantially parallel with respect to each other and the arrangement 135.

Fig. 14c to 14e show the ring 130 and strap bracket 133 hinged relative to the housing 9 for different fall postures, the ring 130 being loaded in the direction of arrow 146 and the bracket 133 being loaded in the direction of arrow 147. In all fig. 14c to 14e, the arrangement 135 is connected to and housed within the housing 9. Figure 14c shows the loop 130 and strap cradle 133 in line with the enclosure 9, thus assuming a typical position in which a person would fall with their feet first, with no significant load on the enclosure 9, as the enclosure 9 has no tendency to rotate about the strap cradle 133 towards the strap 2 and the body of the falling person. Fig. 14d shows the loop 130 and strap cradle 133 in line, as would be typical if a person were to fall head down. Although in fig. 14d the housing 9 has some tendency to rotate around the strap bracket 133 towards the strap 2, the load on the back of the falling person is less likely to be traumatic and can be relieved by the circular area 9a on the housing 9 to distribute the load on the back of the falling person. Fig. 14e shows the loop 130 in line with the strap support 133, which is typical if a person falls in a prone position with the head, body and feet substantially at the same vertical level, where there is no significant load on the housing 9, as in fig. 14c, due to any tendency for the housing 9 to rotate about the strap support 133 towards the strap 2 and hence towards the body of the falling person. In fig. 14a, ring 130 rests on projecting abutments 135f and 135g on arrangement 135, as shown in fig. 14b, in order to avoid anchor 131 being excessively loaded in a direction other than the direction in which anchor 131 is eventually released as shown in fig. 14 b.

In fig. 14b, the cam stop 137 shares some similarities with the lever 62 in fig. 7 a. In its normal radial position when the fall is arrested, the cam stop 137 has a substantially cylindrical surface to engage into the cut-out 131c in the anchor 131. However, when the camming stop 137 is rotated in a counterclockwise direction relative to fig. 14a to the extent shown in fig. 14b, the cylindrical surface is rotated away from the cut-out 131c and replaced by a planar cut-out region that allows the anchor 131, and thus the ring 130, to disengage the arrangement 135. The pin 138 is securely located in the anchor 131 and one end of the flexible elongate member 85 typically terminates in an elongate member formed in a closed loop defined by means such as a ferrule, and the loop is then securely connected around the pin 138.

In practice, the two methods shown in fig. 11a and 11b for housing flexible elongate members 21 and controlling their speed of deployment have been found to be advantageous because friction discs 101 are the primary means for reducing the speed of rotation of drum 90, while viscous material 100 acts merely as a servo for controlling the force causing drum 90 to bear on friction discs 101. This means that the viscous material 100 requires relatively little viscous drag to control the drum 90, so that the servomechanism can be relatively light in weight and economical to manufacture. However, a viscous material can be problematic because its viscosity tends to vary according to its temperature, such that when the rescue device is used to descend persons, some of the dissipated heat within the device can be transferred to the viscous material 100 and affect its viscous drag characteristics. An alternative is to use a centrifugal braking mechanism, an embodiment of which is shown in fig. 15a and 15 b.

As in fig. 11a and 11b, the embodiment of fig. 15a has a flexible elongate member 85 helically wound onto a drum 90. One end of the flexible elongate member 85 is connected to a component such as the anchor 131 in figures 14a and 14b and the other end is securely connected to the drum 90 which is not shown in figure 15 a. The drum 90 is rigidly connected to the pin 91 and both are rotatable within a bearing surface 150 which is part of the housing 9 c. The pin 91 has a threaded region 93a which engages in a mating threaded region in a specially shaped nut 94. The nut 94 passes through the center of the spur gear (drive gear 151) and is frictionally secured to the drive gear 151 by means of a brake bushing 152 and a spring washer 153 such that relative rotational movement between the nut 94 and the drive gear 151 is prevented until the reverse torque between the nut 94 and the drive gear 151 exceeds a predetermined limit. The thrust bearing 154 minimizes friction between the nut 94 and the housing 9 c. When the drum 90 and the pin 91 are rotated together in the direction of tightening the mating thread faces between the pin 91 and the nut 94, the nut 94 will tend to unscrew relative to the pin 91 because the thrust bearing 154 has no significant friction between the nut 94 and the housing 9 c. Thus, when the drum 90 rotates relative to the housing 9c, the drive gear 51 will also tend to rotate in the same direction.

The drive gear 151 intermeshes with a spur gear (idler gear 155) and the idler gear 155 freely rotates about a spindle 161. The idler gear 155 meshes with a spur gear (pinion gear 156). The pinion gear 156 is rigidly connected to a spindle 157, and the spindle 157 is connected to a tile (shoe) drive arm 158, such that the spindle 157 and tile drive arm 158 are constrained to rotate together. As also shown in fig. 15b, the pad drive arm 158 is located between pads 159a and 159b, and both pads 159a and 159b may rotate about their cylindrical axes within a cylindrical friction lining 160 housed in a housing 9e, housing 9e being located between housings 9c and 9d, such that rotation of the drive gear 151 will cause rotation of the pads 159a and 159 b. As the pads 159a and 159b rotate, the mass and rotational speed of each pad will determine the magnitude of the radial force between each pad and the cylindrical friction lining 160, which is converted into a tangential braking force that is then transmitted back to the drive gear 151 through the spur gear train. The resultant resistance on gear 151 will also exert a resistance on nut 94 such that ongoing rotation of drum 90 will tend to screw pin 91 into mating threads in nut 94. As pin 91 is drawn toward nut 94, drum 90 is also drawn toward friction discs 101, friction discs 101 are restricted from rotating relative to housing 9c, thereby reducing the rotational speed of drum 90. As the rotational speed of the drum 90 is further reduced, the rotational speed of the drive gear 151 and ultimately the shoes 159a and 159b is reduced, thereby also reducing the centrifugal resistance tending to tighten the nut 94 onto the pin 91. Eventually, the centrifugal resistance will be reduced to such an extent that the threads of nut 94 tend to unscrew relative to pin 91, thereby allowing drum 90 to move away from friction discs 101 and freeing drum 90 so that its rotational speed may increase again. In this way, the centrifugal brake acts as a dynamic servo to adjust the braking force between drum 90 and friction discs 101 in accordance with the rotational speed of drum 90, thereby controlling the speed at which flexible elongate members 85 are deployed from drum 90. A significant advantage of this arrangement is that the centrifugal brake mechanism may be of relatively low strength and light weight, since the friction between drum 90 and friction discs 101 performs the primary task of reducing the speed of drum 90. Since such servos are required for relatively small mechanical loads, it has been found that both the drive gear 151 and the idler gear 155 can typically be made of plastic.

In a preferred embodiment, it has been found advantageous that the mating thread faces between the pin 91 and the nut 94 are coated with a low friction material and that the threads have a non-standard extended pitch to increase the tendency of the nut 94 to unscrew relative to the pin 91.

During the process of lowering the person to ground or a safe height with the rescue device, the person may temporarily land on an abutment in the rescue path and then make a second fall. In the worst case, the second fall may involve some free fall, wherein a person falls through a vertical distance without the flexible elongate member unwinding from the drum 90. In this case, at the end of the free fall distance, the rotation of drum 90 will accelerate sharply and quickly to a speed which will activate the centrifugal servo brake and support drum 90 on friction disc 101 with a relatively high force which can be transmitted to the person descending and to the rescue device itself. To mitigate this effect, as shown in fig. 15a, as the spring washer 153 forces the nut 94 and the driving gear 151 to bear against the brake collar 152, the predetermined frictional attachment between the nut 94 and the driving gear 151 will be overcome and the drum 90 and the nut 94 will rotate independently of the driving gear 151, thereby ensuring that the load on the flexible elongate member 85 never exceeds a predetermined limit which effectively limits the load on personnel and the flexible elongate member 85 to a safe level typically of about 2.5kN or 3 kN. The fall energy from a free fall is multiply absorbed at least in part by the rotational movement of the drum 90 against the load and the degree to which the drum 90 rotates.

As a person descends through a distance at a controlled rate, the large amount of energy absorbed as a result of controlling the descent rate will be converted into heat. Although this is not usually a problem, it is sensible to manage the heat distribution within the rescue device, in particular in the vicinity of the plastic parts. In practice, it has been found that heat can be effectively stored in drum 90 if drum 90 is made of aluminum and friction disc 101 is restrained by housing 9c from rotating with drum 90. In addition, if the flexible elongate member 85 is made of galvanized steel wire, the steel wire itself can store heat and dissipate heat, albeit slowly, as it is deployed from the rescue device. Alternatively, if flexible elongate member 85 is made of a fiber rope susceptible to heat, housing 9c may be made of aluminum, and drum 90 may restrict friction disc 101 from rotating with drum 90.

Referring to fig. 14a, 14b, 15a and 15b, fig. 16a and 16b show an embodiment with a lowering brake operated by a cable 37, and the cable 37 has the function of initiating the release of the anchor 131. Fig. 16a shows the lowering brake being applied when the cable 37 is released, and fig. 16b shows the lowering brake being released when the cable 37 is pulled.

In fig. 16a, the cable 37 is connected to one end of a lever 166, the other end of the lever 166 is connected to a pin 165 and can rotate about the pin 165, such that when the cable 37 is pulled, the lever 166 rotates about the pin 165. The position of the pin 165 is fixed relative to the housing 9 d. Lever arm 169 is also connected to pin 165 and can rotate about pin 165. The pin 170 is connected to one end of the lever arm 169 and the brake lever 171 so that both the lever arm 169 and the brake lever 171 can rotate about the pin 170. Towards the other end of the brake lever 171, the brake lever 171 is first constrained between the brake ring 173 and an abutment 172 closer to the end of the brake lever 171. The position of the central axis of the abutment 172 and the brake ring 173 is fixed relative to the housing 9d, and the brake ring 173 is rotatable within a cylindrical housing 9f, which is typically an integral part of the housing 9 d. The axis of rotation of the brake ring 173 is the same as the axis of rotation of the pads 159a and 159b in fig. 15a and 15b, and the brake ring 173 has lugs 173a and 173b located between the ends of the pads 159a and 159b so that the brake ring 173 and the pads 159a and 159b are effectively constrained to rotate together on a common axis. The torsion spring 174 forces the pin 170 to rotate about the pin 165 in a counter-clockwise direction relative to fig. 16a, so that the brake lever 171 is forced to bear on the brake ring 173 as its movement is limited by the abutment 172, thereby exerting a load on the pads 159a and 159b to arrest and stop their rotation, so that the rotational speed of the drum 90 is reduced or stopped, slowing or stopping the deployment of the flexible elongate member 85.

In fig. 16b, the cable 37 is shown in a position after being pulled in the direction of arrow 37a, such that the lever 166 is rotated in a clockwise direction relative to fig. 16 b. The pin 168 is connected to the lever 166 and is raised at one end above the surface of the lever 166 so that it forms an abutment against the lever arm 169 at a contact surface 169a, whereby the lever arm 169 tends to rotate around the pin 165 in a clockwise direction with respect to fig. 16b, whereby the pin 170 and the end of the brake lever 171 connected to the pin 170 also rotate around the pin 165, thereby allowing the brake lever 171 to move between the brake ring 173 and the abutment 172. The torsion spring 174 forces the brake lever 171 to rotate towards the abutment 172 and away from the brake ring 173. The brake shoes 159a and 159b are free to rotate so that the drum 90 is also able to continue unwinding the flexible elongate member 85. A spring, not shown in either fig. 15a or 15b, forces the lever 166 to rotate about the pin 165 in a counterclockwise direction relative to fig. 15a and 15b, so that when the cable 37 is released after being pulled in the direction of arrow 37a, the lever 166 returns to its position as shown in fig. 15a, and the brake is then applied.

Referring to fig. 14a and 14b, fig. 16a and 16b also show a preferred embodiment for releasing the anchor 131 by pulling the cable 37. The lever 167 is connected at one end to the pin 168 and is rotatable about the pin 168. The pin 168 is also connected to the lever 166 such that when the cable 37 is pulled in the direction of arrow 37a, the lever 166, the pin 168 and the one end of the lever 167 rotate together about the pin 165 in a clockwise direction relative to fig. 16 a. A spring, not shown in either fig. 15a or 15b, tends to force the lever 167 to rotate in a clockwise direction about the pin 168 relative to fig. 16 a. A pin 167a is fixed to the other end of the lever 167 and engages in a first tooth of the cam stop 137. The cam type stopper 137 rotates about the axis 137a, and the position of the cam type stopper 137 is fixed with respect to the housing 9 d. When arresting a fall, the cam stop engages in the cut-out 131c in the anchor 131 in fig. 14b, preventing the anchor 131 from disengaging the arrangement 135. When the cable 37 is pulled in the direction of arrow 37a, the lever 167 and pin 167a exert a load on the first tooth of the cam stop 137, tending to rotate the cam stop 137 in the counterclockwise direction relative to fig. 16 a. After the first pulling action of the cable 37, the cam stop 137 remains engaged in the cutout 131c in the anchor 131. A spring, not shown in either fig. 16a or 16b, tends to force the camming stop 137 to rotate about its axis 137a in a clockwise direction relative to the figure so that the camming stop 137 will tend to return to the first position as shown in fig. 16a when the cable 37 is released. However, when there is a predetermined level of load between one's sling and the ring 130 (as would occur when the fall is arrested), the cam stop 137 will bear against the cut-out 131c in the anchor 131, and after the cable 37 is released, the frictional resistance between the contact surfaces of the cam stop 137 and the cut-out 131c will be sufficient to prevent the cam 137 from returning to its first position. In such a fall arrest situation, when the cable 37 is released, the pin 167a engages in the second tooth of the cam stop 137, so that another pull of the cable 37 will rotate the cam stop 137 through another angle of rotation to an extent where the cam stop 137 is not engaged with the cut-out 131c, and then the anchor 131 can be disengaged as shown in fig. 16 b. This method of releasing the anchor 131 avoids accidental release of the anchor 131, for example, in the event that the cable 37 is accidentally caught.

It will be appreciated that the brake operated by the cable 37 will typically be applied after the anchor 131 is released and while the person is descending. This braking function is particularly useful if the person is to descend from one height in the sky to another height than the ground. For example, if a fall of a person on a high-rise building is arrested, it would be advantageous if the person could descend and stop alongside the lower height to be rescued. However, in the case of relatively simple lowering operations at high altitudes, a cable brake mechanism may not be required, in which case it would be more economical to provide the rescue apparatus without it. Fig. 17a and 17b show external views of a rescue apparatus incorporating the embodiment described in fig. 14a, 14b, 15a and 15b and in fig. 16a and 16b, which may or may not include a brake operated by a cable 37.

In fig. 17a the harness of harness 2 passes through restraint 185 and around harness bracket 133. A limiter 185 is typically used with the harness to prevent the rescue device from sliding relative to the harness. The ring 130 is generally angled as shown at rest, and the snap is then secured by the open ring. The bracket 133 will normally rotate relative to the housing 9d due to the weight of the rescue apparatus. However, for convenience when carrying the rescue apparatus under normal operating conditions, the bracket 133 is typically held in the position shown in fig. 17a, typically by one or more straps connecting the lower portion of the housing 9c or 9d to the harness bracket 133.

In fig. 17b, the dashed circles indicate how the drum 90, the drive gear 151, the idler gear 155 and the pinion gear 156 will typically be positioned inside the device receiving parts 9b, 9c and 9 d. The mounts 186 and 187 are used to position the arrangement 135 of fig. 14a and 14b within the housings 9c and 9 d. The cable 37 is shown without any sleeve because in many embodiments making multiple pulls initiate release of the anchor 131 will be sufficient to avoid accidental release before the fall is arrested.

Reference has been made to the possibility that the degree of loss of ability of a person when a fall is arrested is such that the person cannot manually operate the release cable 37, and further reference is made to the proposed solution whereby an extension of the cable 37 may fall to the ground or other safe height during the process of arresting the fall, allowing another person to initiate the release mechanism instead of from the height to which the fall person is going to fall. Fig. 18a, 18b, 18c and 18d show examples of embodiments providing such an extension of the cable 37.

The fabric band 202 is a length of woven fabric band that is typically part of a person's harness. A loop, shown as loop 202a in figure 18b, is formed in the fabric strip 202 with the loop axis parallel to the width of the fabric strip 202, and then the loop 202a passes through a substantially rectangular opening in one side of the cylindrical drum 201. The length of the port is at least as long as the width of the fabric strip 202 and the width of the port is limited on each side by two opposing slanted walls 201c and 201d which are connected to and typically part of the drum 201. The pins 204 are cylindrical pins, typically having a length that is the same as the width of the fabric strip 202 and less than the length of the port in the drum 201. The pin 24 is placed in the loop 202a with its cylindrical axis parallel to the folding axis of the loop 202 a. The width of the port in the drum 201 is less than the effective diameter of the pin 204 and the loop 202a, so that neither the pin 204 nor the loop 202a can normally be returned through the port in the drum 201 without first removing the pin 204. The flexible elongate member 200 is a length of flexible elongate member which is helically wound around the drum 201 and fills the drum 201 at least in the region of the loop 202a, such that both the loop 202a and the pin 204 are effectively located between the flexible elongate member 200 and the port in the drum 201. 201e and 201f in fig. 18c are stops that retain the pin 204 and prevent the catch pin 204 from moving along its cylindrical axis. The cover 203 is assembled on the fabric strip 202 by its slot 203c, and then it is positioned on the drum 201 as a means to prevent the flexible elongate member 200 from disengaging from the edge of the drum 201. Abutments 203a and 203b in fig. 18b and 18d assist in positioning the cover 203 in position relative to the drum 201. For convenience, the cover 203 may be attached to the webbing 202 at attachment members 205 to prevent it from becoming easily detached from the webbing 202. In practice, Velcro (Velcro) has been found to be suitable as the attachment means 205.

A flexible elongate member 200, preferably made of strong, relatively small diameter (compact) and lightweight rope, is securely connected to or part of the stay 37 in fig. 17 b. In practice, it has been found that some modern fibre ropes having a small diameter as small as 2.5mm provide sufficient strength. The length of the flexible elongate member 200 is typically at least as long as the flexible elongate member 85 wound onto the drum 90 in fig. 15a, so that there is sufficient length to reach the ground or some other safe height after a person has been arrested from a fall.

When a person is braked from a fall, the fabric strap of the person harness is loaded significantly with a tensile load due to the restraint and arrest of the fall. When the fabric strip 202 is loaded beyond a predetermined height, typically in the opposite direction of arrows 206 and 207 in figure 18b, the sloped walls 201c and 201d deflect under load as the loop 202a tends to straighten until the deflection of the sloped walls 201c and 201d is sufficient to enable disengagement of both the pin 204 and the loop 202a through the port in the drum 201. When the pin 204 and loop 202a are disengaged, the drum 201 is free to fall away from the fabric strip 202 and down to the ground or other safe height. As the drum 201 falls, the drum 201 also rotates as the flexible elongate member is unwound from the drum. It has been found that rotation of the drum 201 during its descent is advantageous because the drum tends to roll away from any obstacles in its path. When the drum 201 reaches the ground or some other safe height, a person other than the falling person can pick up the rope and operate the falling person's rescue device. If flexible elongate member 200 is a relatively strong small diameter rope, it may be difficult for a person to grasp the rope tightly enough to operate the rescue device release mechanism. The slots 201a and 201b in the drum 201 enable the cord to be mechanically gripped on the drum 201 by the drum itself so that a person can grasp the drum 201 instead of the flexible elongate member 200 to achieve the necessary gripping and pulling tension.

In any of the methods of releasing the ring 11 in any of the embodiments from fig. 1 to 13e, including any or all of the methods for releasing the drum 90 in fig. 12a and 12b and for releasing the ring 130 and anchor 131 in fig. 14a to 17b, a timer may be added so that if the release has not been performed manually for a predetermined period of time, the release mechanism may be automatically activated. This would be useful in the event that a person is injured when falling and/or being braked and therefore cannot operate the manual release control to release the ring 11 or the pawl stop 104. Alternatively, an additional extended manual release control may be used, which is provided in fig. 18a, 18b, 18c and 18 d. Furthermore, in any of the above embodiments, the personal height rescue apparatus may be connected to any suitable harness or harness and in any position relative to the person wearing the harness or harness. For example, a personnel high altitude rescue apparatus may be attached in front of a person, particularly if the person is performing a task that requires him or her to face a secure anchorage provided by a fall arrest system or a single point anchorage.

Any of the above references to manual control may also refer to control by any other part of a person's body, limb or head. The cord in any of the pull cords referred to in the description of any of the preceding embodiments is typically a flexible elongate member, and all of the preceding references to flexible elongate members refer to flexible elongate members which may be made of any suitable material and with any suitable cross-section.

The embodiments described differ in their details, but they are linked together by a common operating principle. Thus, those skilled in the art will appreciate that features described with reference to one embodiment will generally be applicable to other embodiments.

The invention has been described in detail above with reference to these specific embodiments, and it will be understood by those skilled in the art that these are only exemplary and that the following modifications are possible within the scope of the claims.

Claims

1. A high altitude rescue apparatus having a fall arrest function and a descent function, comprising: a load element releasably retained in a first position relative to a bracket, the bracket being connected to a harness in use; a safety line having one end connected to the load element and the other end connected, in use, to a safety anchorage; a flexible elongate member secured at one end to the load element and at the other end to at least one speed control component; release means for releasing the load element from the first position such that when the load element is released, the load element and the flexible elongate element are moveable at a controlled speed relative to the stent to provide a controlled rate of descent, wherein the elongate element is coiled on a rotatable drum and the portion of the elongate element proximal to the load element is stronger than the remainder of the elongate element.

2. Height rescue apparatus as claimed in claim 1 wherein the stronger portion of the elongate element extends around the drum a plurality of turns.

3. Height rescue apparatus as claimed in claim 1 wherein the stronger portion of the elongate element is fixed relative to the drum and is releasable therefrom after a fall.

4. Height rescue apparatus as claimed in claim 1 wherein the release means acts directly or indirectly on the drum.

5. Height rescue apparatus as claimed in claim 4 wherein the release means comprises a cable acting against a spring on a lever which engages in one or more grooves formed in the drum.

6. Height rescue apparatus as claimed in claim 5 wherein the cable has an additional length accommodated on a drum, the length being adapted to fall to the ground in the event of a fall, whereby the cable can be actuated by a person other than the user.

7. Height rescue apparatus as claimed in claim 1 wherein the release means is electrically actuated.

8. Height rescue apparatus as claimed in claim 7 wherein the electrical actuation is controlled remotely.

9. Height rescue apparatus as claimed in claim 1 wherein the speed control means comprises a hand brake.

10. Height rescue apparatus as claimed in claim 1 wherein the speed control means comprises a servo dynamic speed control mechanism.

11. Height rescue apparatus as claimed in claim 1 wherein the speed control means comprises a centrifugal braking mechanism.

12. Height rescue apparatus as claimed in claim 1 wherein a load limiting member is provided for limiting the load on the elongate member after the load element has been released.

13. Height rescue apparatus as claimed in claim 12 wherein the speed control means comprises a centrifugal brake mechanism comprising the drum in threaded connection with a nut which frictionally engages a drive gear which is resiliently urged towards the nut, the drive gear driving rotation of a pad driver having pads mounted thereon for engagement with a cylindrical friction lining, and a friction element provided between the drum and the housing.

14. Height rescue apparatus as claimed in claim 1 wherein the flexible elongate element is arranged within a housing which is fixed relative to the bracket.

15. Height rescue apparatus as claimed in claim 1 wherein the cross-sectional area of the stronger part of the flexible elongate element is greater than the cross-sectional area of the remainder of the flexible elongate element.

16. Height rescue apparatus as claimed in claim 1 wherein the stronger part of the flexible elongate element comprises two or more lengths of elongate element arranged in parallel and secured together.