GB2353267A

GB2353267A - Hoists

Info

Publication number: GB2353267A
Application number: GB0015508A
Authority: GB
Inventors: Owen Peter Briggs
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-23
Filing date: 2000-06-23
Publication date: 2001-02-21
Anticipated expiration: 2020-06-23
Also published as: GB0015508D0; GB9914721D0; GB2353267B

Abstract

A hoist 1 comprising a base 5, an extendible support arm 12 mounted for longitudinal movement with respect to the base, and a hoist arm 18 mounted on the extendible support arm for pivotal movement about a horizontal axis 24 transverse to the direction of longitudinal movement. The hoist arm 18 has a horizontally extending arm 20 which extends transverse to the hoist arm and to which an item 2 to be lifted can be attached. In a preferred use of the hoist, the base is mounted inside an automobile and used for unloading and loading an short distance mobility vehicle for a disabled person from or into a car. Preferably, the extendable arm is moved by rack (15, Fig 3) and pinion 16 and the arm 19 via actuator 26 and links 30, 33. Alternatively, a motor (52, Fig 7) and first and second gears (50, 51) are used to move the arm 18. The hoist movements may be controlled by a plurality of sensors (Figs 8 and 9).

Description

2353267 Hoists The present invention relates to hoists. The invention is

particularly concerned with hoists for loading and unloading items into and out of automobiles. The invention is of particular utility in the field of lifting vehicles for disabled people into and out of larger vehicles such as cars, vans, coaches and so forth. However, features of the invention may be applicable to a number of situations where it may be necessary to lift heavy or bulky articles between one place and another, and especially between a vehicle and the ground. These include, for example, apparatus for lifting bicycles or other items onto the roof rack of a vehicle or into the back of a vehicle, and hoists for non- vehicle applications.

Many disabled people use small vehicles such as three or four wheel scooters or electric wheelchairs for short distance mobility. Examples include models produced by Sunrise Medical of Milton Keynes, England. In this specification such vehicles are referred to as IISDM vehicles". These SDM vehicles are often battery powered and may have limited range or otherwise be unsuitable for long distances. For such distances, disabled people need to use automobiles into which they can load these SDM vehicles, and these may be standard vehicles such as vans or multi purpose vehicles, or specially modified versions of these or of smaller vehicles such as hatchbacks or estate cars. SDM vehicles such as scooters or electric wheelchairs are too heavy to be lifted into and out of an automobile manually, typically weighing up to 100 kg or more, and it may be inconvenient or impractical, at the least, to use ramps. For this reason, it is known to use hoists to perform this task, such hoists for example being powered from the battery of the automobile.

In a known system an SM vehicle is suspended from a flexible cable or chain attached to the arm of a hoist which is provided in the rear part of a vehicles such as an estate car or hatchback. The hoist can be pivoted about a vertical axis. With the SDM vehicle inside the car, the user must firstly activate the hoist so as to lift the SM vehicle off the floor of the car. The hoist is then pivoted about a vertical axis to swing the SDM vehicle towards the rear opening of the car.

Simultaneously with the manual or automatic pivoting of the hoist, the user must manually guide the scooter through the opening. This may for example involve twisting the SM vehicle on the lifting cable so as to retain the SM vehicle in the correct orientation is relative to the opening despite the pivoting movement of the hoist. Once the hoist has been fully pivoted so that the SM vehicle is positioned totally outside the car, the cable is lowered until the SDM vehicle reaches the ground. Similar systems can be used to unload SDM vehicles from the sides of vans or any other vehicle openings.

There are a number drawbacks involved with such conventional hoist systems. Firstly, as the hoist pivots within the automobile body, it takes up a relatively large amount of space. Furthermore, as noted already the user may have to rotate the SDM vehicle manually to guide it in and out of the opening and this may be disadvantageous for the disabled. SM vehicles tend to have a number of awkward protrusions including wheels. Present arrangements tend to require the use of two movements simultaneously, and this can be a serious problem for disabled people who may have only one arm functional or may need to use one to steady themselves. one known arrangement requires users not only to steer the SM vehicle out of the automobile but also to turn it through ninety degrees.

In order to overcome the problems outlined above, 3 - the inventors of the present invention have recognised that the problems are associated with the provision of a hoist which rotates about a fixed, vertical pivot axis within the automobile. The system of the present invention has therefore been designed so as to have a moving pivot point which provides significant advantages over the known hoist systems.

Viewed from one aspect the present invention provides a hoist comprising a base, an extendible support arm mounted for longitudinal movement with respect to the base, and a hoist arm mounted on the extendible support arm for pivotal movement about a horizontal axis.

In a typical use of such a hoist, the base will be is mounted inside an automobile and used for unloading and loading an SM vehicle. The extendible support arm will be in a retracted condition and the hoist arm connected by means of a cable, hook, cradle or other suitable means to an item such as a SW vehicle within the automobile. The hoist arm is initially pivoted upwardly about the horizontal axis by a small amount to lift the SDM vehicle from the floor of the vehicle. The support arm is then extended to move the hoist arm and SDM vehicle towards the automobile opening, such as the rear door of a car, and then the hoist arm is pivoted about the horizontal axis to move the SM vehicle out of the automobile and lower it onto the ground. Loading of the SM vehicle into the automobile will involve the reverse sequence of events, with the SM vehicle being lifted by the hoist arm to a position above the floor of the vehicle, the support arm being retracted to move the hoist arm and SM vehicle into the automobile, and then the hoist arm being pivoted to lower the SM vehicle onto the automobile floor.

Such an arrangement has considerable advantages over conventional hoist systems which are pivotal about a vertical axis.. The SM vehicle will better keep its 4 - orientation with respect to the automobile opening, and the arrangement can be more compact.

In a preferred arrangement, the horizontal pivot axis extends in a direction transverse to the direction of longitudinal movement. In this arrangement, the longitudinal distance between the base and the free end of the hoist arm when the support arm is fully extended and the hoist arm is pivoted out of the vehicle will be maximised.

In a preferred arrangement, the hoist arm can pivot either side of a vertical plane passing through the horizontal pivot axis. In such an arrangement, when the support arm is in the retracted condition the hoist arm may be pivoted beyond the above vertical plane so as to is lie on the same side as the support arm and provide a compact arrangement. Furthermore, by moving the hoist arm from one side of the plane to the other the steps of lifting and then lowering of the hoist arm can be carried out by pivoting the arm in a single direction.

In addition, it is not necessary to have a cable or the like which is winched up and down to raise and lower the SM vehicle, as this movement is provided by the pivotal arm.

It will be appreciated that terms such as horizontal and vertical used herein are not intended to be limited in a strict geometrical sense and as appropriate in the context include generally upright and generally transverse.

The extendible support arm could be retracted and extended relative to the base in a variety of ways. For example, it could be driven by a linear electric motor or by an electric motor acting on a rack and pinion mechanism, or by a hydraulic or pneumatic cylinder. Similarly, the hoist arm could be rotated about the vertical pivot axis by several different means such as electric, hydraulic or pneumatic actuators. Preferably, both the extendible support arm and the pivotal arm are actuated by electric motors so that they can be operated from an automobile's electric power supply. This provides a relatively simple and cost effective means of driving the apparatus.

In a preferred arrangement, there is provided a compact arrangement for actuating the hoist arm. This comprises an actuating member which is mounted on the extendible support arm and movable in the longitudinal direction with respect thereto. The free end of the actuating member is pivotally connected, by means of a first horizontal pivot, to one end of a first intermediate lever. The other end of the first intermediate lever is pivotally connected, by means of a second horizontal pivot, to the extendible arm at a position below the horizontal pivot axis of the hoist arm. A second intermediate lever has one end pivotally connected by means of a third horizontal pivot to the first intermediate lever at a position between the first and second horizontal pivots. The other end of the second intermediate lever is pivotally connected to the hoist arm by means of a fourth horizontal pivot which is spaced from the horizontal pivot axis of the hoist arm towards the free end of the hoist arm. In the preferred arrangement, the distance along the first intermediate lever between the first and third pivot points is less than the distance between the second and third pivot points.

In an alternative preferred arrangement, the arrangement for actuating the hoist arm comprises actuating means mounted on the hoist arm. A first gear wheel is pivotally mounted on the hoist arm such that it can be driven to rotate in a first or a second direction by the actuating means. A second gear wheel which meshes with the first gear wheel is then pivotally mounted on the horizontal pivot axis of the hoist arm and is attached to the hoist arm at a point removed from the horizontal pivot axis. Thus, when the first gear wheel is driven to rotate in a first direction, the pivot or hoist arm will pivot in that first direction and, when the direction of the first gear wheel is reversed, the hoist arm will pivot back to its original position.

The hoist of the invention could be operated in many different ways. Thus, a user could start and stop the movement of the extendible support arm and the hoist arm separately by means of separate controls such as switches. In another arrangement however, the apparatus includes control means for controlling the operation of the apparatus such that a loading or unloading operation may be initiated by a user and is then completed without any further input from the user, although the user may is be required to e.g. hold a button in whilst the operation is completed so that it can be stopped if there is a problem and the button is released. This is of course particularly advantageous for a disabled user as it would allow them, for example, to remain seated in their automobile until their scooter or electric wheel chair was on the ground ready for use. Of course, whilst the invention will be applicable in a number of contexts it is of particular significance for disabled persons where it may enable greater independence and in any event be more convenient.

Preferably the control means include a plurality of sensors such as magnetically actuated reed switches which produce a positive signal when the support arm and/or the hoist arm is in a desired position.

Still more preferably, the control means include means for adding fixed time delays to the signals obtained from the sensors so that each of the hoist arm and the support arm will be fully in position before the control means activate a subsequent stage in a loading or unloading operation of the hoist. Thus, the motion of the support arm and the hoist arm in each stage of the loading and unloading operations will overrun slightly to avoid any misfunction of the hoist caused by a positive signal being produced by the reed switches before they are fully activated Viewed from another aspect there is provided a method of unloading an item through an opening of a vehicle, there being provided in the vehicle and adjacent the opening a hoist comprising a base secured to the vehicle, an extendible and retractable support arm mounted for longitudinal movement with respect to the base towards and away from the opening, and a hoist arm mounted on the extendible support arm for pivotal movement about a horizontal axis, wherein the hoist arm is pivoted upwardly to lift the item, the support arm is extended to move the hoist arm and item towards the opening, and the hoist arm is pivoted to lower the item from the vehicle.

Viewed from another aspect there is provided a method of loading an item into the interior of a vehicle through an opening thereof, there being provided in the vehicle and adjacent the opening a hoist comprising a base secured to the vehicle, an extendible and retractable support arm mounted for longitudinal movement with respect to the base towards and away from the opening, and a hoist arm mounted on the extendible support arm for pivotal movement about a horizontal axis, wherein the hoist arm is pivoted upwardly to lift the item, the support arm is retracted to move the hoist arm away from the opening, and the hoist arm is pivoted to lower the item into the vehicle.

Preferably the item to be unloaded from or loaded into the vehicle is a short distance mobility vehicle for a disabled person. The terms "disabled person,' used herein encompasses those with long term or permanent disabilities and those with short term disabilities caused by injuries for example. Whilst the primary use of the hoist is intended for a personal vehicle in which there will be a single SDM vehicle, it could be 8 incorporated in for example ambulances or coaches and be for use with multiple SM vehicles which are loaded or unloaded one after the other.

Preferably, the hoist arm has at its free end a horizontally extending arm, extending transversely of the hoist, to which the item to be lifted is attached at a plurality of spaced positions. This will restrict the tendency of the item to swing about a vertical axis, a problem with existing systems.

Still more preferably, the item to be lifted is attached to the horizontally extending arm by straps, the ends of which are attached to the horizontally extending arm such that, as the hoist arm is pivoted about the horizontal axis when lifting an item, the is straps are wrapped around the horizontally extending arm to lift the item relative to the horizontal arm by an amount corresponding to the reduction in the free length of the straps.

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

Figure 1 shows a hoist according to one embodiment of the invention, in a loaded condition; Figure 2 shows the hoist of Figure 1 in a partially unloaded condition; Figure 3 shows the hoist in a more advanced unloaded condition; Figure 4 shows the hoist in a fully unloaded condition; Figure 5 shows part of the hoist arm according to one embodiment of the invention in a fully unloaded condition; Figure 6 shows the part of the hoist arm of Figure in a loaded condition; Figure 7 shows an alternative arrangement for driving the pivotal hoist arm of the invention; Figure 8 shows a logic arrangement for controlling a sliding assembly in a hoist according to the invention; and Figure 9 shows a logic arrangement for controlling a hoist arm in a hoist according to the invention.

The figures show a hoist 1 for loading and unloading an item indicated generally at 2 into and out of an automobile whose floor is indicated generally at 3, through an opening of the automobile such as a door or hatchback indicated generally at 4. The item 2 may be an SM vehicle for a disabled person such as a scooter or electric wheelchair. The item 2 is indicated simply to illustrate the position of the load and is not to scale; in practice an SDM vehicle would be much larger.

is As can be seen the hoist 1 comprises a base in the form of a housing 5 which, in this example, is mounted to the automobile in a horizontal orientation by bolting mounting plates 6 at 7 to a side wall inside the automobile. The housing 5 includes two laterally spaced side members 8, only one of which can be seen in the drawings. Extending along each side member 8 is a longitudinal slot 9. The free end 10 of the housing is provided with a bearing 11 which extends between the two plates 8 at their lower edge. A sliding assembly 12 is mounted in the housing for sliding extension and retraction with respect to the housing. The forward end of the sliding assembly 12 rests on the bearing 11. At the rear end of the sliding assembly, on each side, there is a support plate 13 which is slidably located in the slot 9 by means of pins 14. The sliding assembly is also provided with a longitudinally extending rack 15 (Figures 3 and 4) which is engaged with a pinion 16 located between the side members 8 near their free ends and driven by an electric motor 17. The sliding assembly can thus be extended and retracted in a horizontal direction by operating the electric motor. The extent of travel of the sliding assembly relative to - the housing 5 may be limited physically by the pins 14 in the slots 9 which run parallel to the direction of travel of the slidable member. However, micro switches or other position sensors are preferably used to determine the extent of travel of the assembly, and adjustments can be made according to the particular installation requirements as will be described further below.

At the forward end of the sliding assembly is mounted a hoist arm 18 which in this particular embodiment has an upwardly extending arm 19 terminating in a horizontal, transversely extending arm 20 to which the item 2 is attached by suitable means indicated diagrammatically at 21. In practice, the item 2 would be considerably larger and the attaching means would not be a long cable or the like but e.g. straps to hold the item 2 securely to the horizontal arm 20. By providing two spaced mountings along the arm, the item will be prevented from swinging about a vertical axis, a problem with existing designs. At its lower end the hoist arm is provided with a yoke consisting of a pair of laterally spaced plates 22, and this is mounted to flanges 23 of the sliding assembly by means of a horizontal pivot 24 passing laterally across the sliding assembly. The hoist arm can pivot from the positions shown in Figures 1 and 2 where it is to the left of the vertical plane 25 passing through the pivot axis 24, through to the positions shown in Figures 3 and 4 on the other side of plane 25.

Pivotal movement of the hoist arm is effected by a linear actuator 26 operated by an electric motor 27.

The rear end of the linear actuator is mounted by means of a pivot pin 28 between the support plates 13. At its forward end the linear actuator 26 is mounted by means of a transverse pivot pin 29 to one end of a pair of first intermediate levers 30 (only one shown) which are positioned on either side of the sliding assembly. The other ends of the levers 30 are connected by means of transverse pivot 31 to the sliding assembly at a position below the pivot axis 24 of the hoist arm and slightly forward of the plane 25. Between the first intermediate levers 30, at a position which is about one quarter of the distance from pivot 29 to pivot 31, extends a transverse pivot pin 32. To this is pivotally connected a second intermediate lever 33, whose other end is pivotally connected at 34 to a transverse pivot pin extending between the plates 22 of the yoke of the hoist arm 18. Operating the electric motor causes an operating member 35 of the linear actuator, to which the pivot pin 29 is connected. to extend or retract, causing the hoist arm to pivot about the axis 24. Extension of the operating member causes the hoist arm to pivot in the clockwise direction, and retraction causes anticlockwise rotation. The linkage arrangement between the actuator and the hoist arm is such that a relatively small amount of longitudinal translation results in a significant are of movement of the hoist arm 18. Micro switches or other motion detectors are preferably used to limit the arc of movement as will be described further below.

In Figure 1, the item 2 is in the fully stored position, resting on the floor 3 inside the automobile. The sliding assembly is fully retracted, with the support plates 13 at the rear of the slots 9, and the control member 35 of the linear actuator 26 is also fully retracted so that the hoist arm is at its maximum extent of rotation to the left of the plane 25, pointing back into the automobile away from the door 4. In order to unload the item from the automobile, the user will open the door 4 of the automobile and operate a suitable control switch to activate the unloading process. From this stage onwards the process can be fully automated by means of various position sensors provided on both the hoist and the automobile together with programmable control means, although manual or partially manual operation would be possible. The control means by which fully automated operation is achieved are described below.

The first stage of the process is for the sliding assembly to remain in its fully retracted condition, but for the linear actuator 26 to be activated by a certain amount to extend the control member 35 and rotate the hoist arm by a small amount in the clockwise direction, to the position shown in Figure 2. This will lift the item 2 off the floor of the automobile, as shown. The next phase, is to hold the linear actuator in the same position, but to rotate the pinion 16 to extend the rack and thus extend the sliding assembly 12 to the is position shown in Figure 3, with the support plates at their maximum extent along the slots 9. Depending upon the nature of the installation and the configuration of the automobile it may or may not be necessary for this extension of the sliding assembly to take the hoist arm 18 through the open doorway of the automobile. It may be sufficient for the item 2 to remain at least partly within the confines of the automobile.

In the final stage of the unloading process, the sliding assembly 12 remains fully extended and the linear actuator 26 is activated again to extend the control member 35 further to its fully extended position as shown in Figure 4. During this movement of the control member 35, the hoist arm 18 pivots clockwise through the plane 25 and then down to a fully lowered position as shown in Figure 4. At this point the item 2 will be in contact with the ground outside of the automobile, and this could be determined by a sensor which would then pass a signal to the motor 27 of the linear actuator to switch it off. At this point, if not done automatically, the user would switch off the hoist, and detach the item from the hoist arm. The hoist could be left in this condition, ready for subsequent reloading of the item back into the automobile, or could be retracted so that the vehicle door can be shut. With the hoist in the fully extended position as shown in Figure 4, reloading of the item 2 is a matter of attaching the item to the hoist arm 18 and then reversing the procedure. Thus the hoist arm will be lifted to the position shown in Figure 3, the sliding assembly will be retracted to the position shown in Figure 2, and then the hoist arm will be lowered to the position shown in Figure 1 to place the item on the floor of the automobile.

An alternative actuating mechanism for the pivotal hoist arm 18 is shown in Figure 7. only a part of the housing 5 for the sliding assembly 12 is shown and the rack 15 and pinion 16 driving mechanism for the sliding assembly which is the same as that used in the embodiment of Figures 1 to 4 has not been shown f or the sake of clarity.

As shown in Figure 7, a first gear wheel 50 is pivotally mounted about the horizontal pivot axis of the hoist arm 18. This first gear wheel 50 is attached to the hoist arm 18 at a point removed f rom the pivot axis by, for example, welding such that rotation of the first gear wheel will cause the hoist arm 18 to pivot about its horizontal pivot axis. A second gear wheel 51 is rotationally driven by an electric motor 52 which is actuated by the control system described below to rotate in a first direction to unload the item and to rotate in the reverse direction to reload the item. The motor 52 and second gear wheel 51 could be mounted on the hoist arm 18 as shown so that the second gear wheel 52 engages with the first gear wheel 51. Alternatively, they could be mounted on the sliding assembly 12. Consequently, actuation of the motor will cause the pivot arm 18 to pivot in the direction of rotation of the motor.

It is envisaged that a greater degree of rotation of the hoist arm 18 will be achievable with the gear mechanism described above than with the linear actuator and linkages of the embodiment of Figures 1 to 4. This would allow a greater degree of flexibility in the height from which items could be lowered to the ground using a hoist according to the invention.

As shown in Figures 5 and 6, in a preferred embodiment, the item to be lifted is attached to the hoist arm by two flexible straps 40, 41 which are connected to the transversely extending arm 20 by rivets 42. The position of the rivets is chosen so that when the transversely extending arm is in the fully lowered position shown in Figure 5, the rivets will be located on the outer side of the arm such that the full length of the flexible straps 40, 41 will extend downwardly from the rivets. Then, when the arm 20 has been pivoted back to its fully raised position, the arm has rotated so that the rivets are located on the inner edge of the arm and the straps 40, 41 are wrapped around the arm. Consequently, an extra amount of lift of the item over and above the lift achievable by the hoist arm can be obtained.

Although in the preferred embodiments described above, the pivotal motion of the hoist arm and the retraction and extension of the sliding assembly are carried out separately, they could be combined if appropriate. Thus, for example, during unloading the pivoting motion of the hoist arm to lower the item to the ground could commence before the extension of the sliding assembly is complete, if the configuration of the automobile in question permits this. In some cases the item might contact the interior roof of the car if this was done.

A lift outside the rear of the automobile could be used in combination with the hoist described above. In this arrangement, the hoist would unload the item from inside the automobile and deposit it on the lift, which would then lower the item to the ground. There could be a single control which opens the door of the vehicle, such as a tailgate, and commences the unloading sequence.

The loading and unloading sequences can be controlled by suitable position sensors and programming or sequencing means to achieve the desired sequence, if desired by means of a single control for loading and unloading. If not incorporated with automatic opening o e.g. a door or hatchback for the vehicle, interlock means could be provided to ensure that the hoist cannot operate whilst the door or hatchback is closed and thus damage the automobile.

In the embodiment of the hoist as shown in Figures 1 to 4, the operation of the hoist is fully automatic once a user has initiated the process.

The operator handset has two buttons, one for LOAD and the other for UNLOAD. For safety reasons one or other of the buttons must be kept depressed to maintain motion of the hoist. These provide signals L and UL which are positive when the respective buttons are depressed. A system of interlocks ensures that the switches providing power to both motors must be ON and the control system will only respond to one button at a time.

Micro switches and magnetically operated reed switches (not shown) are provided on the hoist at various key positions to provide signals indicating when each of the stages of movement of the hoist is complete.

The positions of the switches and corresponding magnets are chosen depending on the maximum extent of movement required for the hoist in any particular application.

Thus, a first set of switches is provided on the sliding assembly 12 and corresponding magnets are provided on the housing 5 to produce a positive signal 0 when the sliding assembly 12 has been extended to its final desired position. When the sliding assembly 12 is in its fully retracted position, the switches will produce a second positive signal I. The notation used for these signals when negative (i.e. when the sliding assembly is not in the required position) is 0 and I. Three further sets of micro switches, reed switches and magnets (also not

shown) are provided on the linkage mechanism and pivot arm to produce positive signals P, U and D when the position of the pivot arm corresponds to the item being in the fully stored position, the item being lifted from the floor of the vehicle (i.e. the arm is fully raised) and the item being in the fully unloaded position respectively. Again, when the arm is not in the required position, negative signals P, U and D are obtained.

The logic circuit which controls the relay S for feeding the electric motor 17 which drives the sliding assembly 12 is shown in Figure 8. It will be appreciated that this figure is only a schematic representation of the logic used. As shown, a f irst AND gate 60 is located on the left of relay S and a second AND gate 62 is provided to the right of relay S. A signal from AND gate 60 will actuate the motor to extend the sliding assembly 12 and a signal from AND gate 62 will actuate the motor in the opposite direction to retract the sliding assembly 12.

The inputs to AND gate 60 are the signal from the unload button (UL), the signal indicating whether or not the arm is fully raised (U) and a signal (0d), which is the signal indicating whether or not the arm is fully extended with a fixed time delay added to it.

Similarly, the inputs to the AND gate 62 are the signal from the load button (L), the signal indicating whether or not the arm is fully raised (U) and a signal (Id) which is the signal indicating whether or not the arm is fully retracted with a fixed time delay added to it.

The logic circuit for controlling the relay A which drives the motor 27 or 52 for driving the pivotal arm 18 is then shown in Figure 9. Again, a signal from the left hand side of the relay causes the arm to rotate out of the vehicle while a signal from the right hand side causes the arm to rotate into the vehicle. First and second AND gates 64, 66 on the left hand side of the relay A provide an input to an OR gate 67. The input to the first AND gate 64 consists of the unload signal (UL), the signal indicating whether or not the pivot arm 18 is fully raised, with a time delay added to it (Ud) and the signal indicating whether or not the sliding assembly 12 is fully retracted with a fixed time delay added to it (Id).

The input to the second AND gate 66 consists of the unload signal (UL), the signal indicating whether or not the sliding assembly is fully extended (0) and the signal for indicating when the item is in the fully unloaded position (D). If the output from either of these two AND gates is positive, then a positive signal will be passed to the relay via the OR gate 67.

on the right hand side of the relay A, third and fourth AND gates 69, 70 are provided. The output from these AND gates is passed through an OR gate 68. The input to the third AND gate 69 consists of the load signal (L), the signal to indicate whether or not the pivot arm 18 is in the fully raised position, with a fixed time delay added to it (Ud) and the signal to indicate whether or not the sliding assembly 12 is fully extended, with a f ixed time delay added to it (0d).

The input to the fourth AND gate 70 consists of the load signal (L), the signal indicating whether or not the sliding assembly is fully retracted (I), and the signal indicating whether or not the item is fully loaded in the vehicle (P).

The operation of the logic circuits of Figures 8 and 9 during the unloading of an item from a vehicle is now described. Firstly, UL is energised (i.e. a user presses the unload button). Lid and Id are present and so power is provided to the relay A through AND gate 64 and the OR gate 67. The arm 18 stops when the arm is up and Ud is removed, i.e. it becomes U. Signal U also starts the slide and removes signal I.

The delayed signal Id ensures that gate 64 remains open until Ud ceases. The delay on Ud is adjusted so that motion of the arm ceases when it is mid way between two series connected reed switches that signal the arm up position.

Next, with the arm in the up position gate 60 opens and the slide assembly 12 travels out of the vehicle.

The slide motion ceases when the slide is fully extended and Od ceases, i.e. it becomes positive (0).

0 is now present and gate 66 opens. The arm is rotates until D ceases (it becomes D). The load is now down.

Loading is the reverse of this sequence. Thus, during loading, L is energised. Gate 69 is open and powers the arm in the reverse direction until the delayed signal Ud ceases. The delay on Od is longer than Ud so that Ud determines the stopping point.

U is now active and gate 62 opens and the slide assembly 12 travels in. Motion ceases when Id ceases (or becomes positive (I)).

The presence of I opens gate 70 and the arm drives down until P ceases. The load is now parked in the vehicle.

The delayed signals Id and Od ensure that the micro switches detecting the motion of the slide are fully depressed before motion ceases.

Using the control system described above, the hoist of the invention can be operated by a person merely holding down a button. Thus, the system makes the hoist easier for disabled people to use by minimising the input required while ensuring that the item is lowered to the ground safely.

one advantage of the present invention is that when the hoist is in the fully retracted condition it does not take up an excessive length in the automobile.

However, when the sliding assembly and the pivotal hoist arm are fully extended there is a considerable deployment length.

It will be appreciated that the embodiment described above is one possible embodiment only of the apparatus of the invention. Modifications may be made both to the specific apparatus and to the broad aspects of the invention currently defined herein. The invention is not restricted to the loading and unloading of items into and out of automobiles, whether they be vehicles for the disabled or other items, and is applicable to a number of situations.

Claims

Claims

A hoist comprising a base, an extendible support arm mounted for longitudinal movement with respect to the base, and a hoist arm mounted on the extendible support arm for pivotal movement about a horizontal axis.
2. A hoist as claimed in claim 1, wherein the horizontal pivot axis extends in a direction transverse to the direction of longitudinal movement.
3. A hoist as claimed in claim 1 or 2, wherein the hoist arm can pivot either side of a vertical plane is passing through the horizontal pivot axis.
4. A hoist as claimed in claim 1, 2 or 3, wherein the hoist arm has a horizontally extending arm, extending in a direction transverse to the hoist arm.
5. A hoist as claimed in claim 4, wherein a plurality of spaced attachment means for attaching an item to be lifted to the hoist are provided on the horizontally extending arm.
6. A hoist as claimed in claim 5, wherein the attachment means comprise straps, the ends of which are attached to the horizontally extending arm such that, as the hoist arm is pivoted about the horizontal axis when lifting an item, the straps will be wrapped around the horizontally extending arm to lift the item relative to the horizontally extending arm by an amount corresponding to the reduction in the free length of the straps.
7. A hoist arm as claimed in any preceding claim, further comprising means for actuating the hoist arm which comprise:

an ac tuating member mounted on the extendible support arm and movable in the longitudinal direction with respect thereto; a first intermediate lever, a first end of which is pivotally connected by means of a first horizontal pivot to the free end of the actuating member, the other end of the first intermediate lever being pivotally connected, by means of a second horizontal pivot, to the extendible arm at a position below the horizontal pivot axis of the hoist arm; a second intermediate lever having one end pivotally connected by means of a third horizontal pivot to the first intermediate lever at a position between is the first and second horizontal pivots, and the other end of the second intermediate lever being pivotally connected to the hoist arm by means of a fourth horizontal pivot which is spaced from the horizontal pivot axis of the hoist arm towards the free end of the hoist arm.
8. A hoist as claimed in claim 7, wherein the distance along the first intermediate lever between the first and third pivot points is less than the distance between the second and third pivot points.
9. A hoist as claimed in any of claims 1 to 6, further comprising means for actuating the hoist arm which comprise:

a first gear wheel pivotally mounted on the hoist arm such that it can be driven to rotate in a f irst or a second direction; actuating means for driving the first gear wheel in a first or second direction of rotation; a second gear wheel which meshes with the first gear wheel and is pivotally mounted on the horizontal pivot axis of the hoist arm and is attached to the hoist - 22 arm at a point removed from the horizontal pivot axis.
10. A hoist as claimed in any preceding claim, further comprising control means for controlling the operation of the apparatus, wherein the control means comprise:

a plurality of sensors which produce signals when the hoist arm and/or support arm are in predetermined positions; and means for adding fixed time delays to the signals obtained from the sensors so that each of the hoist arm and the support arm will be fully in position before the control means activate a subsequent stage in a loading or unloading operation of the hoist.
11. A method of unloading an item through an opening of a vehicle, there being provided in the vehicle and adjacent the opening a hoist as claimed in any preceding claim, whose base is secured to the vehicle, wherein the hoist arm is pivoted upwardly to lift the item, the support arm is extended to move the hoist arm and item towards the opening, and the hoist arm is pivoted to lower the item from the vehicle.
12. A method of loading an item into the interior of a vehicle through an opening thereof, there being provided in the vehicle and adjacent the opening a hoist as claimed in any of claims 1 to 10, whose base is secured to the vehicle, wherein the hoist arm is pivoted upwardly to lift the item, the support arm is retracted to move the hoist arm away f rom the opening, and the hoist arm is pivoted to lower the item into the vehicle.
13. A method as claimed in claim 11 or 12, wherein the item to be unloaded from or loaded into the vehicle is a short distance mobility vehicle for a disabled person.
14. A hoist substantially as herein described and with - 23 reference to the accompanying drawings.
15. A method of loading an item into a vehicle or unloading it from the vehicle substantially as herein described and with reference to the accompanying drawings.
16. A vehicle having therein a hoist as claimed in any of claims 1 to 10 and 14.