Technical field

The present invention relates, in general, to continuously moving cable transport systems. More particularly, the invention concerns a clamping device for the automatic connection of a vehicle to the cable of a continuously moving cableway. The present invention is intended to be applied with particular advantage, even if not exclusively, to continuously moving cable transport systems having a pair of carrying-hauling cables. This choice, however preferable for the reasons that will be explained in the following, is not to be considered as limiting, since the clamping devices described herein may also be used in systems with a single carrying-hauling cable, as well as in multi-cable systems with multiple carrying-hauling cables.

Prior art

For a better understanding of the prior art and of the problems inherent to it, a known type of clamping device for the automatic connection of a vehicle to the cable of a continuous motion cableway will first be described. Reference is made to FIGS. 10 and 11 of the accompanying drawings, taken from patent publication WO 2014/097204 Al, in the name of the same Applicant. A clamping device comprises a movable jaw 11 and a fixed jaw 12. The fixed jaw 12 is formed of a support element 13 to which is secured the suspension arm S of a suspended vehicle. The movable jaw 11 is formed by one end of an operating rocker lever 15 hinged to the support element 13 around an axis parallel to the cable F. Following the oscillations of the lever 15 in the vertical plane, the movable jaw rotates between a closed or cable-clamping position (FIG. 10) and an open position (FIG. 11).

When a vehicle arrives at a station of the system and must be disconnected from its carrying-hauling cable, the cable must be moved laterally and downward away from the clamping device, once it has been opened. In mono-cable installations, the clamping device with the whole vehicle can be deviated laterally by a minimum angle to facilitate the release from the cable. US patent No. 4 760 798 describes a clamping device having two movable jaws which cooperate to clamp a cable.

An object of the present invention is to facilitate the stages of releasing from the cable and coupling to the cable of a continuous motion cableway. In particular, one should avoid interference between the jaws of the clamping device and the cable when the clamping device is open.

It is complicated to deviate the cable laterally within a station to move it away from the clamping device of the vehicle just released from the cable. In fact, for this purpose it is necessary to provide a set of inclined axis rollers, which make this an unattractive choice.

The problem with releasing clamping devices from cables is particularly felt in continuous motion cable transport systems with a pair of carrying-hauling cables. In the stations, one must effectively simultaneously release two clamping devices from two respective parallel cables. In these cableway systems, it is not possible to deviate the vehicles laterally, because this would facilitate the release of the vehicle from only one of the two cables, without allowing the release from the other cable.

Therefore, the need is felt to improve the release of the cable from the clamping device in the vertical direction, that is, deviating the cable or cables downward and eliminating the risk that the tips of the jaws interfere with the cables. In a similar way, it is desired to facilitate the reverse operation by safely clamping the clamping device onto the cable when the vehicle is coupled to the carrying-hauling cable.

Summary of the invention

The aforementioned and other purposes and advantages are achieved, according to an aspect of the invention,, by a clamping device having the features defined in claim 1. Preferential embodiments of the clamping device are defined in the dependent claims.

In summary, a clamping device for the automatic connection of a vehicle to the cable of a continuously moving cableway comprises a support element that can be secured to the suspension arm of a vehicle. A first operating rocker lever is hinged to the support element for oscillating in a substantially vertical plane around a fulcrum carried by the support element; on the first control lever are mounted a slider and one or more sets of springs which push the slider towards the fulcrum. A first movable jaw is formed at one end of the first control lever, while a second movable jaw is formed by a second lever hinged to the support element to oscillate around the fulcrum. One or two connecting rods are hinged to the slider and to the second lever. The connecting rods convert the force exerted by the springs toward the fulcrum into a force having two components:

a first component, perpendicular to the first control lever, for rotating the first lever upwards, bringing the first movable jaw to clamp the cable against the second movable jaw, and

a second component, perpendicular to the second lever, for rotating the second lever downwards, bringing the second movable jaw to clamp the cable against the first movable jaw.

The connecting rod may have a convex surface protruding toward a rolling surface provided by the support element in such a way that when the connecting rod oscillates due to the oscillation of the first control lever, the convex surface rests against the rolling surface and can roll along it.

The support element preferably has a resting surface facing upwards and constituting a lower abutment for the second lever.

According to another aspect, the invention provides a continuous motion cable transport system, in particular a gondola lift comprising a pair of carrying-hauling cables and a plurality of suspended vehicles, wherein each vehicle is provided with a pair of clamping devices of the type claimed herein for automatic coupling to one of the two cables.

Brief description of drawings

A few preferential embodiments of the invention are described below referring to the accompanying drawings, in which:

FIG. 1 is a partial vertically sectioned view of a clamping device according to one embodiment of the invention, in a closed clamped condition;

FIG. 2 is a partial vertically sectioned view of the device of FIG. 1 in a partially open condition;

FIG. 3 is a partial vertically sectioned view of the device of FIG. 1 in a fully open condition;

FIG. 4 is a schematic perspective view of a vehicle suspended from a pair of carrying-hauling cables in a continuously moving cable transport system;

FIG. 5 is a perspective view of the device of FIG. 1 ;

FIG. 6 is a partial sectioned top view of the device of FIG. 1 ;

FIGS. 7, 8 and 9 are partial sectioned views of a clamping device according to three further respective embodiments; and

FIGS. 10 and 11 are two partial vertically sectioned views of a known clamping device in a closed and open condition respectively.

Detailed description

Referring initially to FIGS. 1 to 3, indicated collectively at 10 is a clamping device for the automatic connection of a vehicle to a cable C of a continuously moving cableway or gondola lift or chair lift.

The clamping device 10 comprises two movable jaws, a first outer movable jaw 1 1 and a second inner movable jaw 12, cooperating to tighten and release the cable C. As intended herein, the terms "inner" and "outer" are to indicate positions respectively closer and further away from the body of the clamping device.

Reference numeral 13 indicates a support element to which a suspension arm S of a vehicle V is attached (shown in FIG. 4). The type of suspended vehicle, for example a gondola or seat, is not relevant for the purposes of the applicability of the present invention. In FIG. 4, a gondola vehicle V is illustrated suspended by a pair of clamping devices 10 to a pair of parallel carrying-hauling cables C, D in a continuously moving cable transport system. The support element 13 supports rotatably a fulcrum 16, which extends along an axis of oscillation substantially parallel to the cable C.

The first outer movable jaw 11 is defined by a first end of a first operating rocker lever 15 hinged to the support element 13 around the fulcrum 16 so as. to be able to oscillate or rotate in a substantially vertical plane between a closed or clamped position of the cable (FIG. 1), a partially open position (FIG. 2) and a fully open position (FIG. 3).

The first operating rocker lever 15 has a second end 18 on which an end roller R is rotatably mounted (known per se). The end roller R cooperates with ramps located in the stations of the system to control the oscillation of the lever 15 around the fulcrum 16, causing the displacement of the outer jaw 1 1 away from the cable C.

The inner movable jaw 12 is formed by a second lever 17 having a first end hinged to the fulcrum 16 to be able to oscillate in a substantially vertical plane. The second lever 17 has a second end hinged in 25 to a connecting rod 23 or to a pair of parallel connecting rods 23, described later.

On the first rocker lever 15, a slider 20 is slidably mounted, preferably made as a sliding plate, with a central tubular portion 21 inserted over the first lever 15 and a plate portion 22 which extends transversely to the first lever 15. The slider 20 is connected in an articulated manner to the second lever 17 via the pair of connecting rods 23, parallel and side-by-side in a direction perpendicular to the cable C. One of the connecting rods is visible in FIGS. 1, 2 and 3. The connecting rods 23 are hinged to the slider 20 and the second lever 17 around the two respective pins 24 and 25 parallel to the fulcrum 16 and therefore to the axis of oscillation of the first control lever 15.

Each connecting rod 23 has a convex surface 29 protruding towards a rolling surface 27 integral with the support 13. The convex surface 29 is adapted to allow the connecting rod 23 to roll, preferably without sliding, over the rolling surface 27 in the clamping device's opening and closing movements. The relative position of the elements constituting the clamp defines the radius of curvature and the center of the arc of circumference for the convex surface 29, so that the convex surface 29 can roll without sliding on the surface 27.

In the embodiment illustrated in FIGS. 1-3, the convex surface 29 of each connecting rod

23 is provided by a rigid element 26 mounted on the respective connecting rod in a removable manner, for example by means of screws or other fastening elements, so as to be replaceable.

The support element 13 can form a catch 28, adjacent to the rolling surface 27, an end-of- travel agent to stop the oscillation of the first lever 15 downwards.

The convex surface 29 is appropriately located in an intermediate position between the pin

24 that rotatably connects the connecting rod 23 to the slider 20, and the pin 25 that rotatably joins the connecting rod 23 to the second lever 17.

The support element 13 has a resting surface 14 facing upward and toward the second lever 17 to serve as an abutment surface which stops the downward movement of the second lever 17, as explained herein after. Preferably, the resting surface 14 is formed by a projection protruding from the support element 13 in a laterally inward direction.

Between the slider 20 and the second free end 18 of the first lever 15, elastic thrust elements are interposed, preferably a plurality of helical springs 30, 31, 32, 33, intended to push the slider 20 toward the fulcrum 16.

The connecting rods 23 convert the axial thrust exerted by the elastic elements 30-33, compressed along the longitudinal axis of the first lever 15, into a reaction force having two components:

a first component Fl, perpendicular to the longitudinal axis of the first lever 15, for rotating the first lever 15 upwards, bringing the first movable jaw 11 to clamp the cable C against the second movable jaw 12, and

a second component F2, perpendicular to the longitudinal axis of the second lever, for rotating the second lever 17 downward, bringing the second movable jaw 12 to clamp the cable against the first movable jaw 11.

The elastic elements 30-33 act against a fixed reaction plate 19, blocked on the free end 18 of the first lever 15, adjacent to the end roller R. The end roller R is intended to cooperate, in a manner known per se, with inclined fixed guides (not shown) installed in the vehicle arrival and departure stations.

Before the vehicle enters a station, the clamping device 10 is in the closed condition FIG.l, in which the jaws 11, 12 are clamped on the cable C. At this stage, the convex surfaces 29 of the connecting rods 23 are not in contact with the rolling surface 27 of the support element 13.

The springs 30-33 are compressed between the slider 20 and the end plate 19. The connecting rods 23 and the second lever 17 push towards the resting surface 14. The thrust exerted by the springs has a first component Fl, which holds the first lever 15 raised in the clamped jaw position, and a second component of force F2, which holds the second lever 17 lowered. More particularly, the second component of force F2 exerted by the connecting rods 23, acts via the pin 25 perpendicular to the second lever 17, so as to rotate the second lever 17 downward in abutment against the resting surface 14. The second inner movable jaw 12 is clamped against the cable C. The first component of force Fl pushes the first lever 15 via the pin 24, making it oscillate or rotate upwards, bringing the first outer movable jaw 11 to clamp the cable C against the second inner movable jaw 12. The rotation imparted on the first lever 15 from the first component of force Fl is in the direction opposite to the rotation imparted on the second lever 17 by the second component of force F2.

The resting surface 14 constitutes a fixed angular reference which determines the angular position of both jaws, and therefore the whole clamping device, with respect to the cable.

When the vehicle enters the station, the end roller R engages a ramp or inclined upper guide (not shown) which lowers the first control lever 15. The consequent reduction in the angle between the first lever 15 and the connecting rods 23 (FIG. 2) causes a further compression of the springs 30-33, with progressive opening of the jaws 11, 12. The first lever 15 lowers to cause the displacement of the first outer movable jaw 1 1 in a laterally or transversely outward direction. The connecting rods 23 lower, bringing the convex surfaces 29 into contact with the rolling surface 27. A further lowering of the first lever 15 causes the convex surfaces 29 to roll along the rolling surface 27. It will be observed that, by proceeding with the lowering of the first lever 15, the support point of the convex surfaces 29 on the rolling surface 27 moves progressively in the transverse direction toward the inside. The pin 25 raises causing the second lever 17 to rotate upward in the direction opposite to the direction of rotation followed by the first lever 15, causing the displacement of the second inner movable jaw 12 in a laterally or transversely inward direction.

In the fully lowered position of the first lever 15 and the fully raised position of the second lever 17, the jaws 1 1, 12 are open and spaced laterally or horizontally from the cable C (FIG. 3).

The fully lowered position of the first lever 15 may advantageously be determined by the abutment of the slider 20 against the stop element 28. Alternatively, the abutment against the stop component 28 or against another stop surface integral to the support element 13 may be determined by another element rotationally integral with the first lever 15 around the fulcrum 16.

When the vehicle exits the station, a guide inclined upwards (not shown) allows the progressive lifting of the roller R and the consequent tightening of the jaws as a result of the springs. In the closing stage, the second inner movable jaw 12 will approach first the cable C (FIG. 2) while the first outer movable jaw is still displaced from the cable. Then, with the progressive distension of the springs, the second lever 17 abuts against the resting surface 14, the connecting rods 23 rotate counterclockwise around the pin 25, and the first lever 15 brings the first outer movable jaw 1 1 to clamp the cable against the second inner movable jaw 12. Those skilled in the art will understand that the number and arrangement of the springs, as well as the geometric shape of components such as, for example, the slider 20 may be different with respect to the examples illustrated herein.

According to an embodiment (FIG. 7), the convex surface 29 is integral with the support element 13. The connecting rods 23 each have a flat rolling surface 27 in this example. A rigid element 26, which has a convex surface 29 projecting towards the rolling surface 27 of the connecting rod, is fixed on the support element 13.

Also in this case, the relative position of the elements constituting the clamp defines the radius of curvature and the center of the arc of circumference for the convex surface 29, so that the convex surface 29 can roll without sliding on the surface 27.

According to another embodiment (FIG. 8), the convex surface 29 is provided by an element rotatably mounted on the connecting rod 23, such as a roller 26 or another rotatable convex body of a non-circular or not completely circular shape, for example in the shape of a half moon. The convex surface of the rotatable element protrudes toward a rolling surface 27 integral with the support element 13 in a way such that when the connecting rod 23 oscillates due to the oscillation of the first control lever 15, the convex surface 29 rests against the rolling surface 27 and the rotatable element 26 can roll along the rolling surface 27.

The diameter or curvature of the convex surface of such a rotatable element can advantageously be chosen as desired or be variable, without causing friction against the rolling surface ¹ 27.

According to a variant (not shown), the rotatable element 26 may be mounted on the support element 13 to roll against a rolling surface 27 provided by the connecting rod 23.

The clamping device described herein allows a significantly wider opening of the jaws compared to traditional clamps with only one movable jaw. By way of illustration, for a 40 mm diameter cable, the space between the ends of the open jaws is approximately 54 mm compared to 48 mm obtainable with a known type of clamp. The clamping device can also be effectively used in mono-cable installations.

According to the embodiment illustrated in FIG 9, an additional elastic element 36 may be mounted to exert a stabilizing elastic traction which pulls the second lever 17 towards the resting surface 14. To this end, the second lever 17 may form an arm 37 at one end of the lever 17 opposite the end which has the jaw 12. Once the cable is clamped, the elastic element 36 prevents the assembly consisting of the two levers 15, 17 and the connecting rods 23 from oscillating upward (counterclockwise observing FIG. 9) and thus risking that the first jaw 11 could accidentally bump against the line of rollers mounted on the pylons along the cable's path.

Several aspects and embodiments of the clamping device have been described. It is intended that each embodiment may be combined with any other embodiment. The invention, moreover, is not limited to the described embodiments, but may be varied within the scope defined by the appended claims.