EP0842837B1 - Transporting plant with aerial cable and releasable cable grippers including means for measuring the clamping force of the cable grippers. - 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

• une paire de mors, enserrant le câble lorsque la pince est en position de fermeture ;
• un levier de commande pour l'ouverture et la fermeture de la pince, l'une des parties extrêmes de ce levier formant un mors mobile ;
• un dispositif élastique pour actionner le levier de commande de la pince de la position d'ouverture à la position de fermeture de la pince.

The invention relates to a transport installation with an overhead cable carrying a tractor running continuously and in a loop between two stations, in particular a gondola or a chairlift, comprising disengageable clamps for coupling loads to the cable, each clamp having:

• a pair of jaws, enclosing the cable when the clamp is in the closed position;
• 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 closed position of the gripper.

Such installations are known in the art prior. We can refer, for example, to documents following: FR-2,724,357, FR-2,697,056, EP-582,528.

• une rampe de commande qui s'étend le long de la trajectoire de défilement de la pince et coopère avec ledit levier de commande au passage de la pince pour commander l'ouverture de la pince, le dispositif élastique étant alors maintenu en contrainte ; le relâchement de cette contrainte, lorsque la pince a dépassé la rampe de commande, provoquant le retour de la pince en position de serrage du câble ;
• un moyen de mesure du serrage du câble par la pince.

An installation according to the invention also comprises:

• a control ramp which extends along the travel path 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.

Efficient cable clamping is one of the essential factors of safety and good operation of a cable transport installation aerial, in particular a gondola and chairlift to disengageable pliers, in which the pliers are open to each station entrance and closed at the exit.

In a first known type of installation of its kind mentioned above, the elastic clamping force is controlled by exerting a force on the control lever antagonist, just below normal force opening of the clamp. A shift of the command, under the action of this lower force, translated insufficient tightening of the clamp.

This first type of installation presents the downside of operating all or nothing and not ensure direct measurement of the clamping force exerted by the jaw on the cable.

A second type of installation known in the art previous includes 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 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 exerted by the following on the cable is not necessarily equal to that measured on the standard.

Another known type of installation includes 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 known type of installation includes optical, inductive or magnetic proximity switches or even infrared or laser beam allowing 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 lever control of the disengageable pliers allows to deduce the level deformation of this lever, and therefore the value of the force, the torque or the moment of tightening of the disengageable pliers on the cable.

This level of deformation is compared to values thresholds, and the installation is eventually stopped when a crossing of one of said thresholds is detected.

• le signal délivré par le détecteur est une indication valable de la déformation du levier de commande lorsque la position de la pince et la section du câble sont parfaitement constantes et que toutes les pinces sont identiques. Ces conditions étant rarement réalisées en pratique, il peut s'avérer nécessaire d'effectuer une deuxième mesure pour corriger la première et s'affranchir des parasites, notamment des variations de position de la pince ;
• la présence de neige ou de graisse peut perturber la détection des points de référence sur le levier de commande.

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 cable section 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 eliminate 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.

The object of the invention is to produce a device simple, direct and reliable measurement of torque force or when a clamp is clamped.

• la figure 1 est une vue montrant les moyens de contrôle du serrage du câble par la pince, selon un mode de réalisation de l'invention ;
• la figure 2 est une vue de détail d'une partie de la pince représentée en figure 1, et
• la figure 3 est une vue en perspective d'une partie de la pince représentée en figures 1 et 2.

Other objects and advantages of the invention will appear during the following description of an 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;
• FIG. 2 is a detailed view of part of the clamp shown in FIG. 1, and
• FIG. 3 is a perspective view of part of the clamp shown in FIGS. 1 and 2.

In the figures, a disengageable clamp 1 has a elongated body 2 which extends in position coupled to the cable 3 at least transversely to it.

The body 2 carries a joint 4 of a hanger 5 directed downwards and supporting itself a cabin or a seat. Body 2 is extended on one side by a pair jaws 6, 7 together forming a clamping jaw 8 of the cable 3.

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

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 can have other structures than the one 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 extreme part 10 of a control lever 11.

The control lever 11 is rigid, in one piece, of a certain length. It spreads and can struggle 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, a steering pin 13 is fixed general transverse rotation of a control roller 14 lever 11 and therefore movable jaw 7, capable of cooperate with a control ramp that is part of the installation, not shown.

The body 2 of the clamp 1 carries rollers 16 of bearing and a cross member 17 friction drive with which additional means can cooperate of the installation.

The rollers 16 and the crosspiece 17 allow the displacement of the clamp 1, disengaged from the cable 3, on and the along transfer rails that are part of installation, not shown.

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

In the embodiment shown, a pair springs 19, 19 ', inclined relative to each other, symmetrically arranged on either side of the plane P ensure, that after the passage of the roller 14 against the ramp the control lever 11 returns to the position cable tightening 3.

When the roller 14 passes against the ramp lever, the lever 11 is positioned so that the clamp 1 is disengaged, the jaws 6, 7 being separated.

In the embodiment shown, a end of 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 ' 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 cable 3 is clamped between the jaws 7, 8 under the action of springs 19, 19 '.

Clamp 1 is guided by the transfer rails when passing the seats of a chairlift, a cabin from a gondola to boarding stations or landing.

The means of identification, measurement and control of the clamping force cable 3 by the disengageable clamp 1.

Subsequently, by deformation of the lever 11, an elastic deformation of this lever corresponding to a moderate strain amplitude at the location of its end portion 12 when tightening the cable 3, under the effect of springs 19, 19 'and / or others devices such as cylinders or the like.

The clamp 1 is provided with a rigid piece 22 fixed rigidly at its end 23, to the control lever 11, in zone 24.

In the embodiment shown, this area 24, for example by bolting, is located at neighborhood of jaws 6, 7, a 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 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.

The other extreme part 25 of the shaped part caliper 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 a screw adjustment 28, this screw 28 being mounted on the extreme part 25 of the stirrup-shaped part 22, a nut 29 allowing 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 arranged 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 moved away from the groove 31 into which 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 clamp disengageable 1 and when the cable 3 is tightened, the lever 11 movable relative to the fixed end portion 25 of the part 22 causes the rotation of the movable part 34 by in relation to axis 35.

In FIGS. 2, three different positions of the moving 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 clamp measurement device disengageable 1.

This calibration takes into account in particular the elastic deformation of the control lever 11 in position tightening, elastic deformation resulting from the action of compression springs 19, 19 ', and others devices such as cylinders, associated with the springs of compression.

Position B of the moving part 34 corresponds to tolerable deformation of the control lever 11.

Position C of moving part 34 corresponds to unacceptable deformation, because it is too small, of the lever 11, this deformation does not correspond 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.

This control is both positive and negative. In other words it can detect both a good that 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 moving part 34 is less than the position tolerable limit B.

The part 22 must have sufficient rigidity to that the displacement and deformation of the control lever 11 result only or essentially in 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 other types of pliers, in particular with fixed coupling to the cable or closing under the effect of the load and at bi-cable installations.

Claims (6)

1. A continuously moving transportation installation with carrying and hauling overhead cable (3), notably a cable car or chair lift, comprising disengageable clamps for coupling loads to the cable (3), each clamp (1) comprising:

   a jaw clamp (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 formed as a movable jaw (7);

   a resilient device (19, 19') for actuating the lever (11) controlling the clamp (1) from the open position to the closed position of the clamp (1);

   the installation also including:

   a control ramp which extends along the path of movement of the clamp (1) and cooperates with the lever (11) as the clamp (1) passes in order to control the opening of the clamp (1), the resilient device (19, 19') then being held under stress, the release of this stress, when the clamp (1) has passed beyond the ramp, causing the clamp (1) to return to the closed position;

   means of measuring the gripping of the cable (3) by the clamp (1),

   characterised in that the measuring means comprise a mechanical piece (34) set in movement when the lever (11) returns to the closed position of the clamp (1), the position reached by the said piece (34) when the lever (11) has reached the said closed position being associated with the degree of deformation of the said lever (11).
2. An installation according to Claim 1, characterised in that the movable piece (34) is able to move in rotation at its end (33) about a pin (35) carried by the lever (11).
3. An installation according to either one of Claims 1 or 2, characterised in that it also comprises means (37) for preventing passage of the clamp (1) when the position of the piece (34) is below a limit position corresponding to threshold values of deformation of the lever (11) and of clamping force on the cable (3), these threshold values being preset by calibration means (28, 29).
4. An installation according to Claim 3, characterised in that the calibration means (28, 29) are carried at a free end part (25) of a piece (22), fixed to the lever (11) at its other end part (23).
5. An installation according to any one of Claims 1 to 4, characterised in that the means of measuring the gripping are disposed in an area of high magnitude of deformation of the lever (11), close to its end part (12) opposite the movable jaw (7) .
6. An installation according to either one of Claims 4 or 5, characterised in that the piece (22) is fixed at its end part (23) to the lever (11) in an area (24) of low magnitude of deformation of the lever (11), close to the movable jaw (7).

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