FR2755930A1 - AIR CABLE TRANSPORTATION SYSTEM, WITH RELEASABLE CLAMPS, INCLUDING MEANS FOR MEASURING THE TIGHTENING OF THE CABLE BY THE CLAMPS - Google Patents

Abstract

The mechanism comprises a jaw clamp (6,7) which locks a cabin or seat onto the cable (3) when the jaws and closed, a control lever (11) to open and close the clamp, one end of the lever forming the moving jaw (7), and a spring (19) to operate the control lever. The control lever is actuated by a ramp extending along the clamp line of travel, while a detector ensures that the clamp is fastened tightly to the cable when in the closed position.

Description

The invention relates to an overhead cable transport installation

  tractor carrier running continuously and in a loop between two stations, in particular a cable car or chairlift, comprising disengageable clamps for coupling loads to the cable, each clamp having: - a pair of jaws, clamping the cable when the clamp is in position closing; - A control lever for opening and closing the clamp, one of the end parts of this lever forming a movable jaw; an elastic device for actuating the gripper control lever from the open position to the

clamp closing position.

  Such installations are known in the prior art. We can refer, for example, to documents

  following: FR-2,724,357, FR-2,697,056, EP-582,528.

  An installation according to the invention furthermore comprises: a control ramp which extends along the path of travel of the clamp and cooperates with said control lever in the passage of the clamp to control the opening of the clamp, the elastic device then being kept under stress; the relaxation of this constraint, when the clamp has exceeded the control ramp, causing the clamp to return to the cable clamping position; - a means of measuring the cable tightness by the clamp.

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  The effective clamping of the cable by the clamps is one of the essential factors of safety and proper functioning of an overhead cable transport installation, in particular of a gondola and chairlift with detachable clamp, in which the clamps are open to

  each station entrance and closed at the exit.

  In a first known type of installation of the kind mentioned above, the elastic clamping force is controlled by exerting on the control lever an opposing force, just less than the normal force of opening of the clamp. A movement of the control lever, under the action of this lower force, translates

insufficient tightening of the clamp.

  This first type of installation has the drawback of operating all or nothing and of not ensuring a direct measurement of the clamping force exerted

by the jaw on the cable.

  A second type of installation known from the prior art comprises a standard for simulating a cable, on which the clamp is closed to measure the clamping force

  by sensors incorporated into the standard.

  This method allows a continuous measurement, representative of the state of wear of the clamp, but the setting

  implementing such a control device is complicated.

  Security is not absolute because the force subsequently exerted on the cable is not necessarily equal to that

measured on the standard.

  Another known type of installation comprises clamps incorporating a control spring which acts on the clamping spring and causes displacement during a

  excessive reduction in the force of this clamping spring.

  The set is incorporated in the clamp and the information

  must be transmitted to a landline.

  Another type of known installation includes optical, inductive or magnetic proximity detectors or even infrared or laser beam detectors making it possible to detect the position of one or more points of

  reference of the control lever of the disengageable pliers.

  The position of these reference points of the control lever of the disengageable clamp makes it possible to deduce the level of deformation of this lever, and therefore the value of the force, of the torque or of the tightening moment of the disengageable clamp

on the cable.

  This level of deformation is compared with threshold values, and the installation is eventually stopped

  when a crossing of one of said thresholds is detected.

  In such a device: - the signal delivered by the detector is a valid indication of the deformation of the control lever when the position of the clamp and the section of the cable are perfectly constant and that all the clamps are identical. As these conditions are rarely achieved in practice, it may prove necessary to carry out a second measurement to correct the first and to avoid parasites, in particular variations in the position of the clamp; - the presence of snow or grease can disturb the detection of the reference points on the control lever.

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  The object of the invention is to provide a simple, direct and reliable device for measuring the force of the torque.

  or when a clamp is clamped.

  Other objects and advantages of the invention

  will appear during the following description of a mode

  of embodiment given by way of nonlimiting example,

  description made with reference to the accompanying drawings in

  which: - Figure 1 is a view showing the means of controlling the cable clamping by the clamp, according to one embodiment of the invention; - Figure 2 is a detail view of part of the clamp shown in Figure 1, and - Figure 3 is a perspective view of a

  part of the clamp shown in Figures 1 and 2.

  In the figures, a disengageable clamp 1 has an elongated body 2 which extends in position coupled to the cable

3 at least transversely to it.

  The body 2 carries an articulation 4 of a hanger directed downwards and itself supporting a cabin or a seat. The body 2 is extended on one side by a pair of jaws 6, 7 together forming a clamping jaw 8 of the

cable 3.

  In the embodiment shown, one of the jaws 6 is fixed and the other mobile, the fixed jaw 6 being situated inside, the other jaw being turned towards the outside of the clamp, the jaws 6, 7 taking cable 3

Above.

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  The jaw 6 is fixed and the other jaw 7 is articulated

  on a longitudinal axis 9 carried by the body 2.

  The clamp 1 may have other structures than that shown. Several cable clamping jaws can be arranged on the same clamp body, on the same side of the

  body or on opposite sides of the body.

  In the cable clamping position 3 by the jaws 6,

  7, the axis 9 extends parallel above the cable 3.

  The movable jaw 7 is rigidly secured to a

  end part 10 of a control lever 11.

  The control lever 11 is rigid, monobloc, of a certain length. It extends and can be struggled during a pivoting on the axis 9 parallel to a plane P substantially perpendicular to the cable 3 corresponding to the

plan of Figures 1 and 2.

  At the end portion 12 of the control lever 11, opposite the movable jaw 7, is fixed an axis 13 of generally transverse direction of rotation of a control roller 14 of the lever 11 and therefore of the movable jaw 7, capable of cooperating with a control ramp forming part of

the installation, not shown.

  The body 2 of the clamp 1 carries rollers 16 for rolling and a cross member 17 for friction drive with which complementary means can cooperate

of the installation.

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  The rollers 16 and the crosspiece 17 allow the movement of the clamp 1, disengaged from the cable 3, on and along transfer rails forming part of

installation, not shown.

  The control lever 11 is permanently biased in the cable clamping position 3 by at least one compression spring, or more generally a member

elastic loading.

  In the embodiment shown, a pair of springs 19, 19 ', inclined with respect to each other, arranged symmetrically on either side of the plane P ensure that, after the passage of the roller 14 against the control ramp, the control lever 11 returns to position

cable tightening 3.

  When the roller 14 passes against the control ramp, the lever 11 is positioned so that the

  clamp 1 is disengaged, the jaws 6, 7 being separated.

  In the embodiment shown, one end of the springs 19, 19 'or adjoining supports

  is articulated to the gripper body 1 on the side of the jaws 7, 8.

  In this embodiment, the other end 21, 21 'of the spring supports 19, 19' or adjoining supports is articulated on the control lever 11 near the

control roller 14.

  In the figures, the control roller 14 has left the control rail and the cable 3 is clamped between the

  jaws 7, 8 under the action of springs 19, 19 '.

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  The clamp 1 is guided by the transfer rails when passing the seats of a chairlift, from a cabin of a gondola to the embarkation or disembarkation stations. The means of locating, measuring and checking the clamping force will now be described.

  cable 3 by the disengageable clamp 1.

  Subsequently, by deformation of the lever 11 will be understood an elastic deformation of this lever corresponding to a moderate deformation amplitude at the location of its end portion 12 when the cable 3 is tightened, under the effect of the springs 19 , 19 'and / or others

  devices such as cylinders or the like.

  The clamp 1 is provided with a rigid piece 22 rigidly fixed at its end 23, to the control lever

11, in zone 24.

  In the embodiment shown, this fixing zone 24, for example by bolting, is located in the vicinity of the jaws 6, 7, at one third of the total length of the lever 11 and below this lever 11 when the clamp 1

is in normal position.

  In this zone 24, the amplitude of deformation of the lever 11 when the clamp 1 is closed and

cable tightening 3 is weak.

  In the embodiment shown, this part

  22 has a shape similar to that of a stirrup.

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  The other end part 25 of the stirrup-shaped part 22 is located above the control lever 11

  and supports an adjustment device 26.

  This adjustment device 26 first comprises

place an O-ring 27.

  This O-ring washer 27 is associated with an adjusting screw 28, this screw 28 being mounted on the extreme part 25 of the stirrup-shaped part 22, a nut 29 making it possible to fix the position of the screw 28 and, consequently, of the O-ring 27 relative to the shaped part

caliper 22.

  Part 30 of the O-ring 27 penetrates

  in a groove 31 at the base 33 of a moving part 34.

  This part 34 is articulated around an axis of rotation 35 disposed on a boss 36 of the control lever

11.

  The boss 36 of the control lever 11 is located on the upper face of this lever, it supports the axis of rotation 35 of the moving part 34 but is spaced from the groove 31 into which the part 30 of the washer penetrates.

toric 27.

  At its extreme part 25, the part 22 is therefore not

  rigidly fixed to the control lever 11.

  When the control lever 11 returns to the position corresponding to the closing of the disengageable clamp 1 and to the tightening of the cable 3, the movement of the movable lever 11 towards the fixed end portion 25 of

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  the part 22 causes the moving part 34 to rotate by

in relation to axis 35.

  In Figures 2, three different positions of the movable part 34 are shown. Position A corresponds to a normal position of the

  control lever 11 when the cable is tightened 3.

  The nut 29 placed on the screw 28 allows a calibration of the clamp tightness measurement device

disengageable 1.

  This calibration takes account in particular of the elastic deformation of the control lever 11 in the clamping position, elastic deformation resulting from the action of the compression springs 19, 19 ′, as well as other devices such as jacks, associated with the compression springs . Position B of the moving part 34 corresponds to

  tolerable deformation of the control lever 11.

  Position C of the moving part 34 corresponds to an inadmissible deformation, because it is too small, of the control lever 11, this deformation not corresponding to

  sufficient cable clamping force 3.

  The control of the position of the part 34 can be

provided by various devices.

  This control can be, among other things, visual.

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  This control is both positive and negative. In other words, it makes it possible to detect both a good and a bad clamping force of the cable 3 by the jaws 6,

7 of clamp 1.

  In the embodiment shown, a template 37 prohibits the passage of the disengageable clamp 1 when the position of the movable part 34 is less than the tolerable limit position B. The part 22 must have sufficient rigidity for the displacement and the deformation of the control lever 11 translate only or essentially by a

  rotation of the moving part 34 relative to the axis 35.

  The invention is advantageously applied to a

  detachable chairlift or cable car clamp.

  However, the invention is of course applicable to other types of clamp, in particular with fixed coupling to the cable or closing under the effect of the load and to

bi-cable installations.

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Claims (6)

  1. Transport installation using a tractor-carrying aerial cable (3) running continuously, in particular a cable car or chairlift, comprising disengageable clamps for coupling loads to the cable (3), each clamp (1) comprising: - a clamp jaw (6, 7), gripping the cable (3) when the clamp (1) is in the closed position; - A control lever (11) for opening and closing the clamp (1), one of the ends (10) of this lever (11) being shaped as a movable jaw (7); - an elastic device (19, 19 ') for actuating the control lever (11) of the clamp (1) from the open position to the closed position of the clamp (1); the installation also comprising: - a control ramp which extends along the path of travel of the clamp (1) and cooperates with the lever (11) in the passage of the clamp (1) to control the opening of the clamp (1), the elastic device (19, 19 ') then being held under stress, the relaxation of this stress, when the clamp (1) has exceeded the ramp causing the clamp (1) to return to the position of closing; - means for measuring the cable tightness (3) by the clamp (1), characterized in that the measuring means comprising a mechanical part (34) set in motion when the lever (11) returns to the closed position of the clamp (1), the position reached by said part (34) when the lever (11) has reached said closed position being associated with the degree of deformation of said lever (11). 12 2755930   2. Installation according to claim 4, characterized in that the moving part (34) is rotatable at its end (33) around an axis (35) carried by the lever (11).   3.Installation according to any one of   claims 1 or 2, characterized in that it comprises,   in addition, means (37) making it possible to prohibit the passage of the clamp (1) when the position of the workpiece (34) is less than a limit position corresponding to threshold values of deformation of the lever (11) and of force cable tightening (3), these threshold values being preset   by calibration means (28, 29).   4. Installation according to claim 3, characterized in that the calibration means (28, 29) are carried at an extremely free part (25) of a part (22), integral with the lever (11) to its other part extreme (23). 5.Installation according to any one of   Claims 1 to 4, characterized in that the means for   tightening measurement are arranged in a zone of high amplitude of deformation of the lever (11), close to its   end part (12) opposite the movable jaw (7).   6.Installation according to any one of   claims 4 or 5, characterized in that the part (22)   is secured at its end (23) to the lever (11) in an area (24) of small amplitude of deformation of the   lever (11), close to the movable jaw (7).