Belt conveyor for the end terminal of a ski lift

The invention concerns a movable platform for ski lifts, more particularly a belt conveyor for an arrival platform.

Belt conveyors have been used for a long time for conveying persons, e.g. in airports, underground railways or stores, but only in recent times they are being applied to ski runs, in particular to ski lifts.

In some ski lifts, belt conveyors are actually used for assisting skiers in taking the chairs. Indeed, if the skier is on a walkway moving at about one third the chair lift speed, taking the chairs is made easier, especially for less expert skiers.

Moreover, in case of a fall, the relative speeds between the skier and the chair are lower, with consequent advantages from the safety standpoint. In fact, for technical reasons intrinsically related with the chair lift structure, it is impossible to immediately stop the chair lift.

Further, last generation chair lifts are characterised by a higher and higher flow per hour, obtained also by increasing the chair speed. Indeed, speeds of about 2.5 to 2.8 m/s are attained.

Use of belt conveyors however is generally limited to the start platforms of ski lifts, especially because of the difficulty to maintain a proper safety level, in any conditions, at the moment the skiers leave the chairs.

High speed however implies considerable safety problems at the moment of leaving the chairs, in particular in multi-place (two-, three- and four-place) chair lifts.

Indeed, often and often, problems due to the speed difference between the chair and the underlying and slightly descending snowy ground add to the difficulties due to the limited side spacing between skiers.

This results in an increased number of falls while skiers are leaving the chairs, with consequent risk for the personal safety of the users (one should think for instance of the risk that a chair hits a skier fallen before the area where the pulley rotates).

In those situations the attention degree of the staff at the arrival moment is a decisive factor: the staff can act onto the control systems by stopping the installation thereby avoiding accidents, but also reducing the flow per hour of the installation with consequent economic damage.

The aim of the present invention is to provide a movable platform for a ski lift, to be used in the terminal portion of the same, thereby allowing skiers quickly to leave the area of rotation of the chair, so that the drawbacks of the conventional systems are eliminated.

This aim is attained by a movable arrival platform with a variable set up, so that different operating positions can be taken.

Another aim of the present invention is to provide a movable platform that can be readily converted to a stationary platform, without stopping the operation of the installation for long periods.

The above and other aims of the invention are attained by the movable arrival platform made in accordance with the invention, as claimed in the appended claims.

Advantageously, the movable arrival platform made in accordance with the invention can be applied to any ski lift, such as a chair lift, a ski tow etc.

The above and other aims of the invention will become more apparent from the description of a preferred embodiment, with reference to the accompanying drawings, in which:

• Fig. 1 is a side view of a movable landing platform made in accordance with the invention;
• Fig. 2 is a top view of a movable landing platform made in accordance with the invention;
• Fig. 3 is a front view of a lifting system for the movable landing platform made in accordance with the invention, and
• Fig. 4 is a side view of the lifting system shown in Fig. 3.

With reference to Figs. 1 and 2, a movable arrival (or landing) platform 2 for ski lifts, located at the terminal portion of a chair lift, essentially comprises an endless belt conveyor 4, 6 and an evacuation platform 8. The whole system rests on ground 10 through a supporting basement made of concrete, also denoted in the drawing by reference numeral 10.

Fig. 1 shows the end portion of a chair lift, in particular a pulley 22 bearing a cable 24 to which the chairs (not shown in the drawing) are suspended. After the skiers have left the chairs, the chairs rotate about pulley 22 to travel back to the lower station. The end portion of the chair travel therefore corresponds with the portion of movable platform 2 comprising endless belt conveyor 4, 6.

The endless belt conveyor is divided into two sections hinged to each other by a hinge 12, namely a first horizontal stationary section 4, rigidly fastened to basement 10, and a second section 6, with variable set up, which is supported, at its end remote from hinge 12, by a lifting mechanism 20 that will be described in detail later on.

From the structural standpoint, the belt conveyor comprises a self-supporting external structure of steel or zinc plated iron, bearing and endless belt 26 through a plurality of pinions. A driving station 18 and a return station 16, arranged at opposite ends of the conveyor, transmit the motion to belt 26 and keep it at the proper operating tension.

Endless belt 26 is made of a plurality of articulated elements, preferably of plastic material. Preferably the linear speed of the belt is slightly higher than the chair speed, for instance 0.4 - 0.5 m/s higher.

The right end of the second section 6 is connected, at hinge point 14, with one end 8a of the evacuation platform 8, the opposite end 8b resting, preferably in slidable manner, onto basement 10.

The shape of basement 10 is such as to allow inclining the second section 6 by a slope of about 15% and, at the same time, lowering the evacuation platform 8 by arranging it horizontally.

In normal operating conditions, i. e. when the endless belt conveyor is operating, both sections 4 and 6 lie in a same horizontal plane, lifting mechanism 20 is in lifted condition and evacuation platform 8 is inclined to the right, to allow skiers to leave the arrival area.

If on the contrary the operation of belt conveyor is stopped, e. g. for a technical failure, it is possible to create again in short time the conventional arrival conditions, in which an inclined platform covered with a thin snow layer is provided.

Indeed, by lowering lifting mechanism 20, the second section 6 of the movable platform takes inclined position 6', shown in broken line in the drawing, whereas evacuation platform 8 takes horizontal position 8'.

In those conditions, by merely covering conveyor belt 4, 6' with a snow layer, the ski lift can be immediately restarted and the repair or maintenance of the belt conveyor can be postponed until the ski lift closure time.

Figs. 3 and 4 show in detail the structure of lifting mechanism 20. In the exemplary embodiment shown, two lifting mechanisms 20 and 20', located at opposite sides of the belt conveyor, are provided, as shown in Fig. 3. Yet, for sake of simplicity, the operation of a single mechanism 20 will now be described, since both mechanisms have the same structure. Moreover, both mechanisms are always simultaneously operated.

Fig. 4 therefore shows in detail a lifting mechanism 20, of electromechanical type. The mechanism comprises a pantograph structure with four articulated rods 36, 38, 40, 42. A first rod 36 and a second rod 38, X-crossing each other, are pivotally connected with basement 10 at two fixed points 32, 34, whereas a third rod 40 and a fourth rod 42 are pivotally connected, at one end, with the second rod 38 and the first rod 36, respectively, and at the other end, with an upper horizontal member 44 coupled with the end portion of second section 6 of the belt conveyor.

A motor-driven system consisting of an electric motor 28 and a threaded rod 30 is applied in correspondence with pivot points 46, 48 of rods 38, 36 with rods 40, 42. Threaded rod 30 engages a corresponding threaded bush provided in pivot 46, whereas electric motor 48 is fastened to pivot 48. Rotation of threaded rod 30 connected with motor 28 causes pivot points 46, 48 to move towards or away from each other, thereby lifting or lowering, respectively, the end portion of the second section 6 of the conveyor.

When lifting mechanism 20 is in a wholly lifted position, as shown in Fig. 4, upper rods 40 e 42 are not parallel with each other but converge to form a V, since the spacing between intermediate pivot points 46, 48 is lower than the spacing between the points of connection with upper horizontal element 44.

The above arrangement results in a particularly safe lifting mechanism 20: indeed, when the mechanism is in lifted position, the load resting on the platform tends to close rods 40, 42 towards the inside, so that the mechanism becomes a self-supporting structure. Therefore any failure, of either mechanical or electrical nature, in motor-driven system 28, 30 cannot affect the installation safety.

Upper horizontal member 44 is in turn hinged below the second section of the conveyor 6, so as to make the movements of the two elements independent.

Lifting mechanism 20 may be replaced by any conventional mechanism, e. g. an oil-pressure operated system: in this case however it is preferred that the mechanism is equipped with a safety stay, to be removed when the structure is to be lowered.