IMPROVED DEVICE FOR THE CLAMPING AND THE AUTOMATIC CATCHING OF VEHICLES TO THE DRIVING CABLE OF AERIAL TRANSPORT PLANTS

Abstract: The invention relates to a device for the clamping and the automatic catching of vehicles onto a driving cable of plants for the aerial transport of people and/or of freight, of the type comprising a vise, constituted by a stationary jaw and a movable jaw, pivoted to each other, and suitable to be clamped onto said cable by means of the action of at least one elastic means, wherein said stationary jaw is prolonged into a supporting pin for said vehicles, and said movable jaw is prolonged into a lever controlling its opening or closure onto said driving cable in cooperation with said stationary jaw, said elastic means acting between said supporting pin and said control lever to the purpose of keeping them open wide apart relatively to the hinging axis of said jaws.

Description: The present invention relates to a device for the clamping and automatic catching of vehicles onto a driving cable of plants for the aerial transport of people and/or of freight, as defined in the preamble of claim 1. A device of this type is known from US-A-4 441 630. Purpose of the present invention is to improve the known devices increasing their operating reliability. Further purposes are to provide a device having particular structural simpleness and consequently lower costs of actuation, of course always in compliance with the safety rules in force, even in case of neglected maintenance and/or use conditions in particularly hostile environments. Further but not least purpose, the device must allow a very simple, reliable and cheap check of the efficiency of the clamping, at each departure of the vehicle from the station. These and further purposes, according to the present invention, are achieved by the features of the characterizing portion of claim 1. The structural and functional characteristics and the advantages of a device according to the present invention shall be better understood from the following exemplifying and not limitative disclosure, relating to the attached schematic drawings, wherein: Fig.1 is an elevation view of a device according to the present invention clamped onto a driving cable, Fig.2 is a view equivalent to that of Fig.1 with the vise open, and Fig.3 is a top plan view of the device of Fig.1. Referring to the drawings, a device according to the present invention comprises essentially a vise 11 composed by a fixed jaw 12 and a movable jaw 13, pivoted to each other by means of a pin 14, and suitable to clamp a driving cable 15. The fixed jaw is extended horizontally into a pin 16 for supporting the arm 17 of a vehicle (not shown) such as a multi-seat chair. The end of the supporting pin 16, between the fixed jaw 12 and the arm 17 of the vehicle, bears laterally protruding on opposite sides two projections 18 bearing sliding wheels 19 on guide rails 20, provided in the nearby of the stations, and a dragging block 22, positioned in an upper position relatively to the jaws 12, 13. The other free end of the supporting pin 16 is provided too with at least a sliding wheel 21 sliding on guide rail 20. The movable jaw 13 is extended into a control lever 23 ending at its free end with an angled support 24 having a rounded outer profile and supporting a plastic rotary element 25 suitable to operatively act on shaped guide surfaces 26 provided above and in correspondence with the guide rails 20 in the stations. The radius of the rounded outer profile of the angled support 24 is slightly lower than the radius of said rotary element 25. Between said supporting pin 16 and said control lever 23 two parallel, spaced apart helical springs 27 are provided, guided by respective coaxial rods 28, hinged on one side in 29 to the control lever 23, and on the other side passing through a shaped plate 30, hinged in 31 to the supporting pin 16. The free end of said rods 28 bears unilateral stopping means 32 such as nuts and related washers. The hinging 29 is constituted in the example by an enlarged and bored portion 33 of the control lever 23 suitable to receive a small pin or peg 34 for fastening the eyes 35 of the rods 28 and of washers 36 for the containment of the springs 27. Said two parallel helical springs 27 have a long stroke, and are positioned at such a mutual distance, that no interference exists of the same with the angled support 24 and the rotary element 25. The operating way of a device for clamping and automatic catching of the vehicle onto a driving cable in the nearby of stations is quite understandable. The individual vehicles (not shown) are clamped by means of the vise 11 in its closed position to the driving cable 15 (Fig.1), which, in the case of the monocable type plant acts also as the track cable. When the wheels 19 and 21 come in correspondence of the station, they engage the guide rails 20, the dragging block 22 interacts e.g. with a set of wheels 37 for gradually braking the vehicle. Almost at the same time the rotary element 25 interacts with a shaped guide 26 positioned above it, which obliges it to shift downwards. This action causes the opening of the vise 11 (Fig.2), caused by the rotation of the movable jaw 13 around the pin 14, and the compression of the springs 27 made possible by the sliding of the rods 28 and by the presence of the articulations 29 and 31. In a known way the vehicle is then dragged into its departure position, wherein a second set of wheels 37 with increasing speed is present. The operation of the closure of the vise 11 thus takes place, determined by a second shaped guide 26 which acts on the vise control lever 23 opening and then closing again the vise onto the cable 15, in cooperation with the springs 27. A device according to the present invention is hence provided with a kinematic mechanism displaying a plurality of well defined characteristics, which can be summarized as follows: great structural simpleness, with a limited number of components, and hence a limited number of couplings in relative motion; structure of the "open" type, so as to allow an immediate access and avoid the collection of snow or of ice within cavities from which their withdrawal is difficult; accurate design of the couplings, selected in such a way that the movement of the kinematic mechanism facilitates the removal of any accumulated mass of snow, avoiding its compacting; elastic system constituted by two "long stroke" parallel helical springs, so as to easily break any possible ice layer by twisting deformation; the two springs are completely separated and not coaxial, so as to easily allow the passage of the snow through their turns; the assemblage is carried out in such a way that the lack of a spring does not impair the efficiency of the other one; the "long stroke" of the springs guarantees also a relative insensitiveness to the small unevennesses in the mechanism due to the machining tolerances; the kinematic mechanism is of direct type, in the sense that the thrust of the springs acts directly between the fixed jaw and the movable jaw, without the interposition of connecting rods, cams or levers, and also the opening of the vise takes place directly through a rotary element solid with the control lever of the movable jaw; the kinematic mechanism is free from a dead point, and hence the vise has only one resting configuration, in its closure position; in such a way, the sharp sign variations of the opening and closure stresses are avoided, with a decrease in the dynamic stresses, and a greater comfort for the vehicle's passengers. The thrust of the springs is directly transmitted between the fixed jaw and the movable jaw, and the actual clamping stress is simply the product of the springs thrust times the ratio of the arms relatively to the pivoting of the jaws. The helical compression springs are positioned with respect to the control lever so as to form an angle substantially different from 90°, whereby to a springs' length variation such a variation of the arm with respect to the pivot pin of the jaws corresponds, as to keep sensibly constant their product for a wide range of the actual diameter of the cable. In such a way, a sufficient clamping is always secured, but without that overdimensionings of the springs and of the elements connected to them are necessary. The vise, relatively to the position of normal closure, allows a further safety stroke allowed by the length still available in the guide rods, before the stopping against the plate. This further stroke is hence securing a sufficient clamping also with a lower diameter of the cable, or even in the presence of ovalized cable portions. A device according to the present invention includes structural provisions to avoid the possibility of a missed releasing from the cable on entering the station: the opening force is applied directly to the movable jaw through the plastic rotary element; the movement of the jaw is hence obliged by the geometrical shape of the guide surface installed in the station; in case of breaking or of lack of the plastic rotary element, the opening takes anyway place due to the sliding of the surface against the angled support of the control lever, having a suitably radiused outer profile; also in case of breaking of the jaw in its portion between the wheels and the articulation of the springs, an emergency opening of the vise is still possible by acting on the free length of the control lever, comprised between the dragging block and the hinging of the guide rods, thus allowing the disengagement of the cable. So, as at least three opening possibilities exist, it is not necessary to envisage any rapid breaking for possible missed unclamping. An automatic device according to the present invention is hence recommended for chairs of from two to four seats, it being particularly light, simple and reliable. Moreover, by coupling two or more devices according to the present invention, it is possible to use vehicles for six, eight or more people.

Claims: A device for the clamping and automatic catching of vehicles onto a driving cable (15) of plants for the aerial transport of people and/or freight, comprising a vise (11) constituted by a fixed jaw (12) and a movable jaw (13) pivoted to each other by means of a pin (14), said fixed jaw (12) being extended into a supporting pin (16) for said vehicle and said movable jaw (13) being extended into a lever (23) provided with a rotary element (25) for controlling its opening or closure onto said driving cable (15) in cooperation with said fixed jaw (12), and an elastic means constituted by two helical compression springs (27) acting between said supporting pin (16) and said control lever (23) for keeping them open apart relatively to the axis of the pivot pin (14) of said jaws (12, 13), characterized in that said springs (27) are parallel and spaced apart from each other, each one of said springs being coaxial to a related guide rod (28), said guide rods (28) being on one side constrained in an articulated fashion to said control lever (23) and on the other side being articulated to said supporting pin (16), said guide rods (28) being axially slidable relatively to the axis of said springs (27), stopping and stroke limiting means (32) being provided to prevent the outcoming of said springs (27) and to keep them loaded, said helical compression springs (27) being positioned with respect to said control lever (23) so as to form an angle substantially different from 90°, whereby to a variation of length of the springs, which involves a variation of their action forces, corresponds a variation of the lever arms by which that forces act on the control lever (23) with respect to the pivot pin (14) of the jaws (12,13), the variations of that forces and arms being such that the product of spring forces to the length of that arms is kept sensibly constant for a wide range of angular positions of said control lever (23). A device according to claim 1, characterized in that said two parallel springs (27) are spaced apart from each other by such a distance that said control lever (23) can be inserted between them. A device according to claim 1, characterized in that said control lever (23) is provided with an angled support (24) having a rounded outer profile, onto which a rotary element (25) is positioned, which rotary element (25) has a radius slightly greater than that of the rounded outer profile of said support (24).

Inventors: LEVI, FERRUCCIO
Applicants: LEITNER S.P.A.
Application year: 1985
Main classification: B61B12
IPC codes: B61B12