GB2079416A - Rope clamp - Google Patents

Abstract

A rope clamp comprises a body (10, 20) having a seat (12) towards which a clamping element (17) can be urged by the wedging action of a driven element (21), the latter being driven in a direction transverse to that of the clamping element (17) by means of a screw (24). The clamping element (17) can, after a closure plate (19) has been withdrawn, be replaced by a further clamping element adapted to clamp a rope (13) of different size. The screw (24) is provided with a transmission element (26) trapped in a recess in the driven element (21) and has a bore (29) extending lengthwise and serving to deliver lubricant to the interface between the screw (24) and the transmission element (26) and, via a transverse passage, to the screw thread. The clamping and driven elements (17, 21) co-operate via projections (36) on limbs of the former engaging in channels (37 to 39) in the latter such that the former is drawn away from the seat (12) on reversal of the latter. <IMAGE>

Description

SPECIFICATION Clamping device This invention relates to a device suitable for clamping a rope. Devices for clamping ropes are provided on certain rail vehicles, primarily rail vehicles used in mine workings, which are towed by a rope.

According to the invention, there is provided a device comprising a body having a seat for a rope, a clamping element which is guided for movement along a first path towards and away from the seat for engaging the rope and urging same onto the seat, a driven element guided for movement relative to the body along a second path transverse to the first path and a driving element arranged for cooperation with both the body and the driven element to drive the driven element along said second path, the driven element and clamping element being adapted to co-operate with each other with a wedging action which forces the clamping element towards the seat when the driven element is moved in a first direction along said second path.

A device according to the invention can be so arranged that the pressure with which the clamping element engages the rope exceeds the pressure with which the driving element engages the body and the driven element. The frictional forces opposing movement of the driving element relative to the body are then smaller than would be the case if the driving element was engaged directly with the clamping element to cause the latter to engage the rope with the same pressure. Furthermore, a device according to the invention can be arranged on a vehicle so that the seat for the rope is situated near to the ground and the driving element is spaced further from the ground, without the driving element projecting upwardly from the remainder of the device.

It will be appreciated that, when the device is fitted to a rail vehicle used in a mine working, a body of the vehicle or a load carried on the vehicle may extend over the device. This would make access to a driving element in the form of a vertical screw inconvenient.

In a device according to the invention, the driving element may be screw which is rotatable about an axis which is at least approximately horizontal with the screw extending from the driven element towards a lateral boundary of the vehicle.

The driven element and clamping element are preferably also adapted for cooperation in a manner such that the clamping element is drawn away from the seat when the driven element is moved along the second path in a second direction, opposite to the first direction. This facilitates release of a rope from the device and enables the clamping element to be moved away from the seat to provide a relatively large gap into which a further rope can be introduced.

One example of a clamping device embodying the invention will now be described, with reference to the accompanying drawings, wherein: Figure 1 shows a side elevation of the device, a cover being omitted; and Figure 2 shows the device in cross-section on the line ll-ll of Figure 1,togetherwith a rope clamped by the device The clamping device illustrated includes a body 10 which, in use, is bolted to a rail vehicle, holes 11 being provided in a top plate of the body for this purpose. As viewed in Figure 2, the body has approximately the shape of a J with the lower part of the body providing a seat 12 for a rope 13 to be clamped by the device. The seat extends along substantially the entire length of the body.

At a level spaced upwardly from the seat 12, the body 10 includes three walls, 14, 15 and 16, which are spaced apart along the body and receive between them two clamping elements, 17 and 18 having respective seats for the rope. A closure plate 19 which extends along substantially the entire length of the body is detachably mounted on the walls 14, 15 and 16 by means of screws and defines in conjunction with the body a pair of guideways which extend vertically in alignment with the seat 12.

The clamping elements 17 and 18 are disposed in these guideways and constrained against movement relative to the body other than towards and away from the seat. When the closure plate is removed from the body, the clamping elements can be withdrawn from between the walls 14, 15 and 16 and separated from the body. The clamping elements may then be replaced by further clamping elements adapted to clamp a rope having a diameter different from that of the rope 13.

At a level above that of the clamping elements, when engaged with the rope 13, there is formed in the stem 20 of the body and in the closure plate 19 respective aligned openings in which there is received a driven element 21. The driven element is guided for movement relative to the body along a second path which extends through these openings and is transverse to the path along which the clamping element 17 moves. In the example illustrated, the second path is perpendicular to the path of the clamping element.

Cooperating formations are provided on the body 10 and driven element 21 for guiding the driven element along the second path. These formations comprise an undercut groove 22 formed in an uppermost face of the driven element 21 and a pair of headed studs 23 secured in the body. The heads of the studs 23 engage in the groove 22 and restrain movement of the driven element 21 in all directions except directions along the second path. The part of the body in which the studs 23 are engaged and against which the uppermost face of the driven element bears may be separable from the remainder of the body so that it can be replaced if it becomes worn.

There is also supported by the body 10 for movement along the second path a driving element in the form of a screw 24 which is engaged with a female screw thread formed in a boss 25 of the body.

At its end adjacent to the driven element 21, the screw is provided with a transmission element 26 which is trapped in a recess formed in the driven element and is adapted to transmit from the screw to the driven element force acting in either direction along the second path. The screw is rotatable relative to the transmission element.

An end portion of the screw 24 remote from the transmission element 26 projects at one side of the device and is readily accessible, even when the device is secured beneath a body of a rail vehicle.

This end portion of the screw is formed with flats 27 with which there can be engaged a tool for rotating the screw. A lock nut 28 which is engageable with the boss 25 is provided for locking the screw against rotation. A bore 29 extends through the screw 24 along its axis of rotation and communicates with the interface between the screw and the transmission element 26 and also communicates, via a transverse passage, with the screw thread in the boss 25.

Lubricant can be delivered to this screw thread and to the interface between the screw and transmission element through the bore 29.

The driven element 21 and clamping element 17 are adapted to co-operate with each other with a wedging action which forces the clamping element towards the seat 12. Thus, the end face of the clamping element which is presented towards the driven element is inclined at an angle nearto 90" to the direction of movement of the clamping element.

The face of the driven element 21 presented towards the clamping element 17 has two portions, a leading portion inclined at approimately 30" to the second path and a further portion 31 which is parallel to the adjacent surface of the clamping element. The leading portion 30 extends from an end of the driven element remote from the screw 24 in a direction generally along the second path to the face portion 31.

The clamping element 17 and driven element 21 are further adapted to co-operate in a manner such that the clamping element is drawn away from the seat 12 when the driven element is moved along the second path in a direction towards the boss 25. The clamping element includes a pair of limbs, 32 and 33, which project in a direction away from the seat 12 and between which that part of the driven element which bears the face portions 30 and 31 is received.

In this part of the driven element, there are formed two channels, 34 and 35, the open mouths of which face away from each other and towards the limbs 32 and 33 respectively. On the limb 32, there is a projection 36 which engages with a sliding fit in channel 34 and a similar projection is provided on the limb 33 to engage in the channel 35.

Each ofthe channels 34 and 35 has an open end at that end of the driven element 21 which is remote from the screw 24 and, adjacent to its open end, a rectilinear portion 37 which is parallel to the length of the undercut groove 22. This portion of the groove merges smoothly with an intermediate portion 38 which is parallel to the leading surface portion 30 and merges soothly with a further end portion 39.

The end portion 39 is parallel to the surface portion 31 and emerges at a face of the driven element adjacent to the screw.

As shown in Figure 2, a leading end portion 40 of the driven element protrudes through the opening in the closure plate 19 when the rope 13 is clamped by the device. To protect this end against mechanical damage, the body 10 includes a cover 41 which is separable from the remainder of the body.

When the rope 13 is to be released, the screw 24 is rotated in a direction to draw the driven element 21 towards the boss 25. The projections 36 slide over surfaces of the channels 34 and 35 and draw the clamping element 17 away from the rope. The rope can then be withdrawn along the seat 12. If it is required to substitute a different clamping element for the element 17, the cover 41 and closure plate 19 are released and removed and the clamping element can then be withdrawn from the body, the projections 36 emerging from the end portions 37 of the channels. A further clamping element is inserted by reversing this procedure.

After a rope has been introduced between the seat 12 and clamping element, the element 21 is driven by the screw 24 away from the boss 25 so that the clamping element is urged downwardly into engagement with the rope by the leading surface portion 30 of the driven element. The surface portion 31 of the driven element then engages the corresponding surface of the clamping element and there occurs a wedging action which drives the clamping element towards the seat 12 with a force considerably exceeding the force exerted on the driven element 21 from the screw 24. Thus, excessive stressing of the screw threads and the establishment of large frictional forces between the screw and body and between the screw and transmission element are avoided. Deformation of the screw threads and of the transmission element also are avoided whilst the rope is subjected to a high clamping force.

There are associated with the clamping element 18 a driven element, screw and transmission element all arranged in the same manner as the driven element 21, screw 24 and transmission element 26.

The clamping elements 17 and 18 are normally used to clamp a single rope.

Claims (13)

1. A device comprising a body having a seat for a rope, a clamping element which is guided for movement along a first path towards and away from the seat for engaging the rope and urging same onto the seat, a driven element guided for movement relative to the body along a second path transverse to the first path and a driving element arranged for cooperation with both the body and the driven element to drive the driven element along said second path, the driven element and clamping element being adapted to co-operate with each other with a wedging action which forces the clamping element towards the seat when the driven element is moved in a first direction along said second path.

2. A device according to claim 1 wherein the driven element and the clamping element are also adapted to cooperate in a manner such that the clamping element is drawn away from the seat when the driven element is moved along said second path in a second direction.

3. A device according to claim 1 or claim 2 wherein the body defines a guideway along which the clamping element moves and one side of the guideway is normally closed by a closure element detachably mounted on the body.

4. A device according to claim 3 wherein the closure element has an opening through which the driven element protrudes when the device is in use.

5. A device according to claim 4 wherein the body has a demountable cover which covers a protruding part of the driven element.

6. A device according to any preceding claim wherein the driven element and the body have respective cooperating formations which restrain the driven element against movement towards the seat.

7. A device according to claim 6 wherein said cooperating formations are disposed at a face of the driven element remote from the clamping element.

8. A device according to claim 7 wherein said cooperating formations include an undercut groove in one ofthe driven element and the body and wherein the formation of the other of the driven element and the body has a head engaged in the groove.

9. A device according to claim 8 wherein the undercut groove is in the driven element and the headed formation is on the body.

10. A device according to claim 2 or according to any one of claims 3 to 9 as appendant to claim 2 wherein the clamping element includes a pair of limbs which project in a direction away from the seat, a part of the driven element is received between the limbs, said part of the driven element is formed with channels facing towards the limbs, projections on the limbs engage in the channels and the respective lengths of the channels are inclined to the second path.

11. A device according to claim 10 as appendant to claim 4 wherein the channels have open ends in a portion of the driven element which protrudes through the opening of the closure element.

12. A device substantially as herein described with reference to and as shown in the accompanying drawings.

13. Any novel feature or novel combination of features disclosed herein or in the accompanying drawings.