DE69005295T2 - TERMINAL TEST DEVICE FOR CABLEWAYS. - Google Patents

Description

The present invention relates to a device for testing wire rope clamps of ski lifts. In a number of ski lifts, in particular chair lifts, problems arise in certain cases in that the wire rope clamps do not exert a sufficient correct clamping force on the traction wire rope. A number of near misses are described where the wire rope clamps slid or slid on the wire rope due to insufficient clamping forces.

The design of wire rope clamps can be divided into two main types, namely fixed wire rope clamps and releasable clamps. In fixed clamps, the clamping force is achieved by means of ring springs, which are tightened against a holding part or with a dynamometric bolt wrench. In releasable cable lifts, which are used especially in chair lifts and gondolas, the clamping force is normally achieved by means of ring springs, although other solutions are also known.

The change in the clamping force of wire rope clamps depends on a number of factors, among which the following are worth mentioning:

Reduction of the diameter of the wire rope due to lengthening of the cable and wear of the cable wires of the traction cable;

Wear on the cable-engaging surfaces of the clamp plates. It is expected that such Wear occurs, for example, as a result of movement of the wire rope clamps and when the clamps sag over roller areas and turntables. Bulges in the engaging surfaces can also occur when the outer wires of the wire rope are "pressed" into the clamp plates;

Elastic deformation of the wire rope due to the pressure exerted on the wire rope by the clamping or clamp plate. This deformation can be approximately 0.5-1.5 mm.

With a wire rope diameter reduction of 2 mm, which is a relevant value, a total wear of the clamping or clamp plates of 1.5-1.7 mm and simultaneous elastic deformation of the wire rope, there is a risk that there is no longer sufficient clamping force and that the wire rope clamps begin to slide or slip.

It is important that the wire rope clamps are monitored for wear. Lift suppliers give recommended values for wear that can be accepted. Even small deviations and wear and effects of the three factors mentioned above have led to wire rope clamps sliding or slipping on traction cables. For this reason, wire rope clamps should be checked regularly for safety against slipping or sliding in the longitudinal direction of the traction cable. The lift suppliers therefore provide information in their instructions for the respective lifts regarding the limits within which the traction force may vary. According to existing regulations, regular checks of the wire rope clamps must be carried out. by determining the traction force at which they begin to slide or slip on the traction cable. Existing devices for testing said traction force are complicated to install and use and there is therefore a high risk that such a device will be used infrequently compared to the intended amount.

The object of the present invention is to propose a device for testing wire rope clamps for ski lifts, which can be easily used and preferably firmly attached to a lift.

The problem was solved by the device according to the present invention:

- comprises a pulling tool intended to be mounted in a pulling position over a wire rope clamp so that it can exert a pulling force on the clamp in the direction of the cable,

- a fastening device for suspending the pulling tool in accordance with the cable,

- an actuating means for moving the pulling tool to or from the pulling position, and

- a traction device connected to the traction tool via a traction force sensor.

The fastening means is preferably designed for the fixed arrangement of the pulling tool, the actuating means, the pulling means and the pulling force sensor on a supporting structure which belongs to the lift.

According to a very advantageous embodiment, a frame supporting the pulling tool, actuated by means of the actuating means, also carries an opening means for opening a wire rope clamp to be tested in order to enable the movement of the same on the wire rope before the test.

Further preferred embodiments emerge from the wording of the dependent claims.

The invention will now be explained in more detail below with reference to an embodiment shown in the attached figures. In the figures:

Fig. 1 is a simplified perspective view of a device for testing wire rope clamps of ski lifts;

Fig. 2 is a top view of the device, corresponding to Fig. 1;

Fig. 3 shows a section in the direction of arrows III-III in Fig. 2;

Fig. 4 is a view in the direction of arrows IV-IV in Fig. 2 of the device according to the invention;

Fig. 5 is a view in the direction of arrows V-V in Fig. 3 of a further detail of the device according to the invention.

In the figures, a fixed part is shown, for example as a beam of a supporting structure in a ski lift, which is not shown, designated 2. This supporting structure can, for example, be arranged in connection with a station. The pull cable of the lift is designated 4. A wire rope clamp, which is partially cut away in Fig. 1 for reasons of clarity, is designated 6. The chair support of the same has been omitted from the figures. In the embodiment shown and described, it is assumed that the clamp is a clamp of a previously known type which is detachably connected to the wire rope. In particular, the type shown here has a pressure point 8 (Fig. 5) at its end, directed away from the clamp end, at which the clamp spring (not shown) is actuated when pressed, so that the clamp is temporarily released from the wire rope 4.

The beam 2 supports a frame 1, generally designated 10. The frame 10 comprises two upper parallel side beams 12 and 14, which are supported at one end thereof by the beam 2 for rotation about horizontal axes of rotation 16 and 18. Between a cross beam 20, rigidly connecting the beams 12 and 14, and the beam 2, two actuating cylinders 22 and 24 are rotatably connected for moving the frame 10 about the axes of rotation 16 and 18. The axis of rotation 15 of the beam 14 extends in fact through a further beam 26, which is fixed to the underside of the beam 2 in line with the beam 14.

In cross-section, the beams 14 and 26 are largely square, and inside them a running gear 28 and 30 respectively serves as a guide for both. The running gears 28 and 30 hold a pulling tool through a longitudinal through hole in the floor of the respective beams 14 and 26, generally designated by the reference numeral 32, and a traction sensor 34. The traction tool 32 comprises a traction rod portion 36 which extends parallel to the beam 14 and beneath it and which is rotatably connected to one end of the traction sensor 34 about a horizontal axis of rotation 38. A traction piston 40 from a traction cylinder 42 is connected to the other end of the traction sensor 34 for rotation about a horizontal axis of rotation 44. The cylinder 42 is attached to another fixed structure 46 of the cableway, which will not be described. In particular, the cylinder 42 is rotatably suspended via mounting brackets 48 in the structure 46 for rotation about an axis of rotation 50 parallel to the axes of rotation 38 and 44.

The tie rod portion 36, which extends vertically above the wire rope 4 for part of its length, is bent in the region of the end portion of the beam 14, opposite the pivot point 18, at the reference number 52, so as to form a portion 50 (Fig. 3) which extends parallel with respect to the beam 20 and leads via an arc 56 (Fig. 2) into a portion 58 (Fig. 2) parallel to the beam 14. The portion 58, which is parallel with respect to the portion 36, is thus laterally displaced with respect to the portion 36. In particular, this displacement is such that the portion 58 extends in a vertical plane directly adjacent to the clamp portion, designated 60, of the wire rope clamp 6, this clamp portion 60 merging straight into a flat and wide portion of the control housing 62 of the clamp. The section 58 leads via a further arch 64 into a section 66 which extends vertically in said vertical plane and essentially in an elongated vertical plane of symmetry the clamp 6 to just above the upper side of the housing 62. Finally, from the section 66 there extends a pulling hook formed by three further arches 60, 70 and 72. This pulling hook extends in said vertical plane for direct engagement above the housing 62, as shown in the figures.

At each end of the beam 12 a vertically extending flat strut 74 and 76 is attached. Between the lower ends of the struts 74 and 76 is arranged a beveled guide beam 78 with a square cross section, which extends parallel to the beam 12. On the guide beam 78 a bracket 80 is arranged movable along the length thereof. The bracket or the carriage 80 surrounds the beam 78 by means of a curved wall, on the inside of which 4 pairs of rollers 82 are arranged for engagement on each side of the beam 78. In particular, the bracket or the carriage 80 can be of the type WV3-25F from Vahle and for this reason need not be described in more detail.

Said curved wall of the support 80 holds, via a short connecting web 84, projecting parallel with respect to the beam 20, a mounting plate 86 for a pressure cylinder 88. In particular, the mounting plate 86 is fixedly arranged with respect to the hook end 68, 70 and 72 of the pulling tool 32 by means of two cross braces 90 and 92 which extend between the plate 86 and the pulling tool. The cross brace 90 extends from the peripheral region of the plate 86 to the inside of the arch 64 of the pulling tool, where it is secured by welding. The cross brace 92 extends parallel with respect to the brace 90 from the peripheral region of the plate 86 in direct contact with the bend 68 of the pulling tool, where it is also fastened by welding, and from where the cross brace 92 is bent downwards to a section 94 intended to engage against the outside of the clamp section 60 of the clamp 6.

The pressure cylinder 88 is attached to the plate 86 so that its pointed pressure piston 96 is directed against the pressure point 8 at the end of the clamp 6, away from the clamp section 60, and so that the pressure point 8 lies within the longitudinal extension of the impact direction of the piston 96.

The tensile force sensor 34, which can be, for example, an Öhrnell tension meter type LOD-G, is connected in a manner not shown to a central instrument with a digital display of the peak value and the average value of the applied tensile force.

The functionality of the device will now be described in more detail.

In a non-working position of the device, the frame 10 and the parts supported by it are pivoted upwards about the pivot axes 16 and 18 by means of the cylinders 22 and 24, so that the clamps attached to the wire rope 4 are not affected by the pulling hooks 68, 70 and 72.

A first step in using the device consists in lowering the frame 10 so that the pull rod 36 clamps the clamp 6 by means of the pull hook 68, 70 and 72 in the manner described above.

In a second step, the spring of the wire rope clamp 6 is actuated by means of the pressure piston 96 of the pressure cylinder 88 via the pressure point 8 so that the wire rope clamp is released from the wire rope. In this state of the clamp 6, released from the wire rope 4, the cylinder 42 is actuated to pull the clamp 6 via the pulling tool 32 along the cable into the intended test position. The last-mentioned step should not be carried out too often so as not to damage the wire rope during testing.

With the clamp 6 arranged above the selected test point, the pressure piston is retracted so that the spring of the clamp 6 is released and the wire rope clamp is tensioned onto the wire rope.

In a further step, the tensile force for testing the wire rope clamp is now applied by means of the hydraulic cylinder 42. In particular, the hydraulic cylinder 42 is operated until the clamp 6 is released from the wire rope 4. During the pulling cut, the tensile force applied is continuously measured by means of the tensile force sensor 34, the signal of which is received by the central instrument mentioned above, which stops at the highest tensile value. This provides information as to whether the wire rope clamp is holding with the correct clamping force, in accordance with the manufacturer's recommendations. Depending on the type of wire rope clamp, the tensile forces used vary between 600 and 1000 kg.

When the clamp test is finished, the frame 10 is pivoted upwards so that the wire rope clamp can be moved further and a new test cycle can be started with the next clamp.

The operation and recording of the measured value is recommended to be carried out from a cabin by an operator located in connection with the cable car. The measured values can be stored in a computer if desired, which enables continuous checking of the clamps. The condition of the clamps can thus be continuously monitored, which leads to safe operation of the cable car and to the clamps being replaced at the right time.

As an alternative to the hydraulic cylinder 42, a mechanical screw spindle or a manually operated reel can also be used as a traction device. Although it is intended to arrange the device on the lift, movable variants of the same are also conceivable. For a fixed device, a hydraulic cylinder or a mechanical reel or winch is the most suitable traction device.

The advantage of a fixed device is that the pulling force can be tested more regularly and in a safe and comfortable manner.

In summary, considering the accidents and near-accidents that have occurred, wire rope clamps have been the cause and it is therefore important that they are checked. With the test device according to the present invention, it is possible to to easily check the clamping force of the wire rope clamps on the traction rope.

In further figures show:

Fig. 6 shows in a sketch the principle of a further design as a replacement for the entire arrangement, shown in Fig. 1;

Fig. 7 is a top view showing three operational steps in using the device of Fig. 6;

Fig. 8 is a view in the direction of arrows VIII-VIII in Fig. 7;

Fig. 9 is an end view in the direction of arrows IX-IX in Fig. 8, and

Fig. 10 is a simplified side view of yet another embodiment of the device according to the invention.

The embodiment according to Figures 6-9 comprises two pointed wedges 100 connected to a beam 102, for example made of aluminum. The beam 102 carries a pulling piston 104 connected via a pulling force sensor 106 to a pulling hook 108. In terms of their function, the elements 104, 106 and 108 correspond to the elements 42, 34 and 68-72 of the previously described embodiment, the pulling piston 104 also being used for moving the pulling hook to and from its operating position and to replace the cylinders 22 and 24 of the previous embodiment.

The pull hook 108 is rotatable at 110 so that it can be pivoted upwards in the direction of arrow 112 when the pull hook contacts a stop 114 on the side of the beam 102 when the pull hook is ejected by the pull piston 104. This "frees" the hook 108 from the wire rope clamps. From what has been described and from a comparison with the previous design variant, it can be seen that the pull piston also takes over the function of the cylinders 22 and 24 to pivot the pull hook away from the wire rope clamps.

In the embodiment according to Figures 6-9, the control housing 115 carries a fastening, generally designated 116, for each wire rope clamp, designated 117 in Fig. 7. The clamp housing 115 includes a clamp actuating spring, not shown.

Specifically, the mount 116 includes a rod 118 for operating the clamp (the spring). The outer end of the rod 118 carries a pair of rollers 120. The mount 116 is held at one end of the housing 115 at 122 and has a clamp end 124 directed against the pair of rollers 120.

When the draw hook is in the position shown in Fig. 6, it can engage a clamp in a similar manner as described in connection with the previous embodiment.

During the pulling of the clamp 117 by means of the cylinder 104, the clamp takes the following positions A, B and C, shown in Fig. 7. In position A, the wedges 100 are moved between the clamp end 124 and the rollers 120. In the second position B, the wedges 100 have pushed the rollers 120 outward so that the spring releases the clamp 117 which can then be moved to the intended test location in the same manner and for the same purpose as described in the previous embodiment. At the test location, position C, the wedges 100 allow the rollers 120 to move back so that the clamp is fixed and can be subjected to tensile tests with the arrangement shown in Fig. 6. From the above it should be apparent that the distance between positions A and B is the distance for the clamp to be released and the distance between positions B and C is the distance of movement for the clamp 117.

In the embodiment according to Fig. 10, the draw hook, here designated 130, is moved as required to or from its operating position by means of the draw cylinder, here designated 132. In particular, the draw cylinder 132 is connected at 134 to a holder 136 which is rotatably held at 138 by a slide 140. The slide 140 is guided linearly in a guide 142 which is enclosed in a frame, generally designated 144. Furthermore, the slide 140 has a support roller or sliding rib 146 which engages in the guide. A stop 148 is arranged at the front end of the guide 142. In connection with the stop 148, a cam profile 150 for the support roller 146 is also arranged on the end side of the frame 144. A stop point 152 is provided for the stop of one end of the tension sensor 144, the other end of which is connected to the end 156 of the cylinder 132, remote from the bracket 136. The tensile force sensor 154 has the same function as the tensile force sensor 34 in the first embodiment.

As indicated, the bracket 136 in Fig. 10, in addition to the tensile test position shown in solid lines, also has a position shown in dashed lines in which position it is pivoted upwards, away from the path of movement of the wire rope clamps, analogous to the case in the previously described embodiments. This position is reached after the bracket, operated by the piston 132, has been stopped by the stop 148 and, with the continued action of the piston 132, rotates about the pivot axis 135, moving the support roller 146 upwards along the cam profile 150 to the position shown.

The carriage 140 may carry means (not shown) for monitoring the clamping force of a clamp.

Claims (14)

1. Device for testing wire rope clamps (6) in ski lifts, characterized by - a pulling tool (32) intended to be mounted in a pulling position above a wire rope clamp (6) so that it can exert a pulling force on the clamp in the direction of the cable (4), - a fastening means (10) for suspending the pulling tool (32) in accordance with the cable, - an actuating means (22,24) for moving the pulling tool (32) to or from the pulling position, and - a traction means (42) connected via a traction force sensor (34) to the traction tool (32). 2. Device according to claim 1, characterized in that the pulling tool (32) comprises a pulling rod (36), one end of which is connected to the pulling force sensor (34) and the other end of which has a pulling hook (68, 70, 72) intended to be attached above the wire rope clamp (6), close to the wire rope. 3. Device according to one of claims 1 or 2, characterized in that the fastening means comprises means (28, 30) for the displaceable hanging arrangement of the pulling tool (32) and the pulling force sensor (34) along the wire rope. 4. Device according to one of the preceding claims, characterized in that the pulling tool (32) is rotatably connected to the tensile force sensor (34) in order to enable the tool to be pivoted upwards from the wire rope clamp (6) by means of the actuating means (22, 24). 5. Device according to claim 4, characterized in that the tensile force sensor (34) and the pulling tool (32) are movably arranged in a corresponding guide (26 or 14) intended to be placed parallel to the wire rope (4), said guides being connected to one another so as to be rotatable, and in that the actuating means includes a lifting means (22, 24) which acts on the guide (14) of the pulling tool (32). 6. Device according to one of the preceding claims, characterized in that the traction means (42) is arranged in a rotatable hanging manner and is rotatably connected to the traction force sensor (34) by means of a traction end (44). 7. Device according to one of the preceding claims, characterized in that the fastening means (10) is arranged for the fixed arrangement of the pulling tool (32), the actuating means (22,24), the pulling means (42) and the pulling force sensor (34) on a fastening arrangement (2,46) in accordance with the lift. 8. Device according to claim 7, characterized in that a frame (12,14,20) movable by means of the actuating means (22,24) and carrying the pulling tool (32) also carries a means (88,96) for opening a wire rope clamp (6) to be tested, so that it can be moved along the wire rope before carrying out the test. 9. Device according to claim 8, characterized in that the opening means (88, 96) is arranged to open the wire rope clamp (6) when the pulling tool (32) engages it, and that subsequently the pulling means (42) is arranged to pull the wire rope clamp (6) to a desired test point on the wire rope, where the wire rope clamp is closed again for testing. 10. Device according to claims 5 and 9, characterized in that the clamp (6) is of the type known per se which can be opened by engaging with an operating tool at a pressure point (8) on the clamp, that the frame (12,14,20) comprises a beam (12) arranged laterally to the pulling tool (32) and which extends in parallel with and rigidly connected to the guide (14) of the pulling tool, and which is rotatable about an axis of rotation (16) coaxial with the axis of rotation (18) of the guide of the pulling tool, said beam (12) serving to support a holding means (80,86) movable along the beam for the opening means (88,96) constituting said operating tool, and said holding means (80,86) being connected to the pulling tool (32) and supporting the operating tool (88,96) so as to be directed to the pressure point (8) for engaging in a wire rope clamp (6) to be movable, on which the pulling tool (32) is in a pulling position. 11. Device according to one of the preceding claims, characterized in that the tensile force sensor (34) is connected to an indicator for the highest tensile value to which it is exposed during the test. 12. Device according to one of the preceding claims, characterized in that the traction means comprises a hydraulic cylinder, a mechanical screw spindle or a manually operable reel or winch. 13. Device according to one of the preceding claims, characterized in that the traction means (104) is used as said actuating means. 14. Device according to one of the preceding claims, characterized in that a means for opening the wire rope clamp is carried by the structure of the pulling tool.