DE202011001304U1 - Rope safety gear - Google Patents

Abstract

Rope catching device with a clamping mechanism (2) mounted in a housing (1) and a cable or rod (3) running through the housing and the clamping mechanism therein, characterized in that inside or outside of the housing (1) at least a relative to the housing movable mass (6) is mounted so that when a fall movement of the rope catching device, the movement of the mass relative to the housing, the clamping mechanism (2) directly or indirectly triggers.

Description

The invention relates to a rope catching device with a clamping mechanism mounted in a housing, a release mechanism mounted in the housing, a fastening and a cable or rod running through the housing and the clamping mechanism therein (FIG. 3 )

The preferred field of application of the invention are rope catching devices which serve as a safety device when lifting loads and in particular when lifting persons d. H. be used on hanging person receiving means (PAM). A typical field of application are z. As work platforms, work baskets, work seats or service lifts in wind turbines, which are powered by special winches approved for passenger transport.

To anchor the rope catching device on the PAM or on the suspension structure, the rope catching device is equipped with a mounting in which holes for inserting or screwing anchoring screws or load bolts are. The attachment is usually so flexible that the rope can run both horizontally (when pulling people and loads) and vertically (when lifting people and loads).

To crash the PAM z. B. to prevent failure of the support cable or the winch, a second, unloaded in normal operation support rope is used parallel to the support cable. This so-called safety cable can pass through the housing and the normally open clamping mechanism of the rope catching device during movements of the PAM unhindered.

• – eine zu große Schräglage des PAM;
• – eine zu hohe Geschwindigkeit des PAM;
• – eine zu geringe oder gar keine Last auf dem Lastseil;

If a crash of the PAM now threatens this is detected by a special sensor, which is usually a part of the rope catching device, which initiates the closing of the clamping mechanism. The sensor of the rope catching device responds inter alia to:

• - an excessive tilt of the PAM;
• Too high a speed of the PAM;
• - too little or no load on the load rope;

The generic rope catching device has been proven in the field and is used in almost all hanging people receiving means.

However, the known rope catching devices provided with a clamping mechanism have a serious disadvantage:
Since the clamping mechanism is triggered by the sensor only with a certain delay, but then occurs very abruptly occur when braking the PAM to a standstill very high impact loads. These are usually at values between 5 and 7, ie when braking, the occupant receiving device has a 5 to 7-fold load compared to the operating case.

The statutory provisions, however, only allow a maximum impact load of 5 times the weight.

To comply with this limit, various safety devices have already been proposed.

One of the known solution consists of a strong compression coil spring, which is mounted on the upper cable suspension. In the event of a fall, the spring gently brakes the person-receiving means because the spring lengthens the braking distance, which leads to a gentle braking.

The disadvantage of this solution is that it is an additional, large and heavy component, which can be forgotten during installation. It has also happened in practice that the spring was mounted on the wrong of the two ropes and therefore was completely ineffective when catching.

• – ein Sensor zum Erkennen einer zu große Schräglage des PAM; Üblicherweise wird dazu ein außen an der Seilfangvorrichtung befestigter Tastarm verwendet, der die Position des Lastseiles abfragt. Der Klemm-Mechanismus wird geschlossen, wenn das Seil aufgrund einer Schräglage des PAM einen zu großen Abstand von der Seilfangvorrichtung erreicht hat.
• – eine Sensor zum Erkennen einer zu hohen Geschwindigkeit (z. B. beim Fallen des PAM); Üblicherweise ist dazu hinter dem Klemm-Mechanismus eine sogenannte Seil-Abtastrolle eingebaut, die die axiale Bewegung des Seiles in eine Rotationsbewegung umwandelt. Ein sogenannter Fliehkraftregler wird durch die Rotation der Abtastrolle angetrieben. Der Klemm-Mechanismus wird geschlossen, wenn der Fliehkraftregler eine voreingestellte Drehzahl erreicht.
• – ein Sensor zum Erkennen einer zu geringen oder gar keiner Last auf dem Lastseil; Üblicherweise wird dazu ein außen an der Seilfangvorrichtung befestigter Tastarm verwendet, der die Spannung des Lastseiles permanet prüft. Der Klemm-Mechanismus wird geschlossen, wenn die Spannung im Seil zu gering ist.

Another disadvantage of the known rope catching devices is that different sensors are necessary for detecting all possible dangerous situations:

• A sensor for detecting an excessive tilt of the PAM; Usually, an outside of the rope catcher attached sensing arm is used to query the position of the load cable. The clamping mechanism is closed when the rope has reached too great a distance from the rope catching device due to an inclined position of the PAM.
• A sensor for detecting too high a speed (eg when the PAM falls); Usually, a so-called rope cam follower is installed behind the clamping mechanism, which converts the axial movement of the rope into a rotational movement. A so-called centrifugal governor is driven by the rotation of the cam follower. The clamp mechanism closes when the governor reaches a preset speed.
• A sensor for detecting too little or no load on the load rope; Usually this is a purpose outside of the rope catcher attached sensing arm used, which checks the tension of the load rope permanet. The clamping mechanism is closed when the tension in the rope is too low.

The object of the invention is to provide a rope catching device that satisfies the legal safety regulations with regard to the impact load on the PAM, reliably responding to all dangerous situations (inclination, overspeed, slack rope) by triggering the clamping mechanism and can be easily mounted.

This object is achieved according to the invention specified in claim 1, characterized in that within the housing a movable mass is mounted so that the movement of the mass triggers the clamping mechanism during a falling movement of the rope catching device.

By appropriate storage, the movable mass can additionally trigger the clamping mechanism even with a tilt of the rope catching device or the PAM and a slack suspension cable.

Due to the integration in the housing of the rope catcher can be dispensed with additional attachments. At the same time, this provides protection against incorrect assembly, as the installation of additional parts is not required.

One of the preferred embodiments is shown in the two appended drawings:

1 Side view of the rope catching device according to the invention with removed housing cover and movable mass, unloaded state

2 Side view of the rope catching device according to the invention with removed housing cover and movable mass, condition catching case with mass moved upwards

In the drawings, 100 designates the rope catching device with the passing rope or rod ( 3 ).

In the preferred embodiment, the movable mass ( 6 ) via cylindrical helical compression springs ( 5 ) as resilient elements in the housing ( 1 ) stored. At the same time, the resilient elements also take over the guidance of the mass in the housing and thus ensure the lowest possible friction.

The helical compression springs ( 5 ) have a preferably as low as possible spring rate and are at rest only by the weight of the movable mass ( 6 ) and preferably biased as strong as possible.

As long as the rope catching device is at rest or moving up or down at a constant speed, no additional forces act on the moving mass and the mass remains in the resting state.

However, if acceleration forces act on the rope catching device, the mass moves as a result of the mass inertia:
When approaching in the upward direction and braking from the downward movement, the mass moves down. When braking from the upward movement and when starting in the downward direction, the mass moves upward. However, since the acceleration only acts for a short time, no large movement of the mass occurs. However, in case of failure of the winch or the support rope fall the rope catching device in free fall down, the mass of this embodiment moves over a long time upwards.

1 shows the preferred embodiment of the rope catching device ( 100 ) at rest:
The clamping mechanism ( 2 ) is open, ie the wire rope ( 3 ) can pass unhindered through the rope catching device. The moving mass ( 6 ) is in the rest position, ie the helical compression springs ( 5 ) are due to the weight of the mass ( 6 ) strongly biased.

2 shows the preferred embodiment of the rope catching device ( 100 ) in case of catch:
The clamping mechanism ( 2 ) is due to the movement of the moving mass ( 6 ) and is closed, ie the wire rope ( 3 ) is released from the clamping mechanism ( 2 ). The cable force is now transmitted to the housing via the clamping mechanism ( 1 ) and on the attachment ( 4 ) transfer. This slows the PAM to a standstill and prevents a crash.

The moving mass ( 6 ) is located in 2 in the working position, ie the two compression springs ( 5 ) are relaxed and in addition to the inertia for an acceleration of the mass ( 6 ), so strengthen the closing movement of the clamping mechanism ( 2 ).

Since in this system not only a preset release speed must be achieved, but the moving mass ( 6 ) the clamping mechanism ( 2 ) can trigger directly and without time delay, the energy absorbed by the system when braking to a standstill fall energy is lower than in the conventional devices. As a result, the impact load occurring in the event of a fall greatly reduces and the limit value of the standard for the brake shock can be easily met.

Claims (8)

Rope catching device with one in a housing ( 1 ) mounted clamping mechanism ( 2 ) and with a running through the housing and the clamping mechanism therein rope or rod ( 3 ), characterized in that within or outside the case ( 1 ) at least one relative to the housing movable mass ( 6 ) is mounted so that when a fall movement of the rope catching device, the movement of the mass relative to the housing the clamping mechanism ( 2 ) directly or indirectly triggers. Rope catching device according to claim 1, characterized in that the mass movable relative to the housing ( 6 ) is mounted so that in an inclined position of the rope catching device or the PAM, the movement of the mass relative to the housing, the clamping mechanism ( 2 ) directly or indirectly triggers. Rope catching device according to claim 1, characterized in that the mass movable relative to the housing ( 6 ) is mounted so that in a floppy suspension rope, the movement of the mass relative to the housing the clamping mechanism ( 2 ) directly or indirectly triggers. Rope catching device according to claim 1, characterized in that in order to support or enhance the movement of the mass ( 6 ) relative to the housing ( 1 ) at least one resilient element ( 5 ) is available. Rope catching device according to claim 1, characterized in that for guiding the mass at least one element ( 5 ) is available. Rope catching device according to claim 1, characterized in that the resilient element ( 5 ) in the resting state compensates in whole or in part for the gravitational force acting on the mass. Rope catching device according to claim 1, characterized in that the resilient element ( 5 ) preferably has the lowest possible spring rate. Rope catching device according to claim 1, characterized in that the resilient element ( 5 ) is preferably a helical compression spring made of steel or other suitable material.

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