Cable transport installation with cars driven by friction

In the by-pass zone of a car transfer track, in a terminal station of a detachable gondola lift or chairlift, the cars are driven by tired wheels. Transmission between two successive wheels comprises two toothed bevel pinions, wedged onto the wheel spindles, which engage with an inverter bevel pinion inserted between adjacent toothed benel pinions.

BACKGROUND OF THE INVENTION 
The invention relates to a gondola lift or chairlift with cars detachable 
from the cable in the stations comprising a transfer track on which the 
cars run being driven by friction by tired wheel trains, spaced along the 
track, each wheel being rotatably mounted on a horizontal spindle or axis 
perpendicular to the track and being driven in rotation. 
In stations of the detachable gondola lifts or chairlifts, hereafter called 
chairlifts, the cars, in this instance chairs, are driven by chains with 
push fingers or tired friction wheels, spaced along the track. The 
friction wheels are very flexible and enable driving at variable speeds 
for braking or acceleration of the cars. The movement, derived from the 
cable or from a motor, is generally transmitted from one wheel to the 
other by belts and pulleys, wedged onto the wheel spindles. In the curves 
of the transfer track, notably in the by-pass zone, the wheel spindles are 
arranged perpendicularly to the curved track and are therefore no longer 
perfectly parallel. This results in wear of the belts and notable losses 
of power. By lengthening the belts and providing return pulleys, alignment 
defaults of these pulleys can be at least partially compensated, but 
transmission is more complicated. 
The object of the present invention is to achieve an efficient transmission 
from one wheel to the other in the by-pass zone by simple means. 
SUMMARY OF THE INVENTION 
The chairlift according to the invention is characterized in that in the 
by-pass zone of the track, the driving force is transmitted from one wheel 
to an adjacent wheel by a cog-wheel transmission which tolerates the angle 
formed between the spindles of the two wheels. 
Cog-wheel transmission between non-parallel spindles is state-of-the-art, 
in particular toothed bevel pinion gear and, according to the invention, 
an inverter pinion is fitted between the two pinions wedged onto the 
spindles of the friction wheels to keep the rotation direction of the 
successive wheels. The three pinions of a cog-wheel transmission from one 
friction wheel to the other are preferably identical and their spindles 
extend in the same plane. The same toothed pinion, wedged onto the 
friction wheel spindle, receives the movement of the previous wheel and 
transmits it to the next wheel. The use of pinions made of plastic 
material reduces noise and lubrication problems. 
It is important to standardize the drive systems and according to a 
development of the invention, the friction wheel spindles, which support 
the drive toothed pinions and the inverter pinion spindles are each 
mounted in a standard bearing box and these bearing boxes are fixed to a 
girder which follows the trajectory of the by-pass track. By providing 
adjustable fixing, precise positioning of the bearing boxes can be 
obtained by inserting between the toothed pinions a film, whose thickness 
corresponds to the clearance necessary for correct operation. The bearing 
box of a friction wheel supports on one side the friction wheel and on the 
other side the toothed wheel, whereas an inverter pinion box only supports 
the inverter pinion. The cog-wheel transmission is located on the inside 
of the curve. The size of the pinions obviously depends on the distance 
between the spindles and should the need arise, an inverter pinion smaller 
or larger than the drive pinions can be used. 
Cog-wheel transmission is also suitable for the straight sections, but it 
is unsuitable for speed variations, in particular in the acceleration or 
braking zones of the chairs. Cog-wheel drive systems can easily be 
combined with belt systems by fitting, for example, on the spindle of the 
first by-pass zone wheel, in addition to the toothed pinion, a pulley 
receiving the movement of the previous wheel of the straight zone by means 
of a belt. Switching from one transmission mode to the other is therefore 
simple and easy to achieve. 
Driving by cog-wheels is naturally well-suited to friction wheels of a 
rhythm device, whose second drive mode may be of any kind, notably a chain 
with push fingers.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the figures, transfer track 9 of a chairlift, for example, includes a 
curved section 10 and tired wheels 11, located at regular intervals along 
the track to cooperate by friction with a friction plate 30, supported by 
the support carriage of the chair or car 29 (FIG. 4). The curved section 
10 succeeds a straight section 12, only the last two tired wheels of which 
are represented, which straight section 12 can comprise the braking zone 
of the chairs detached from the cable at the entrance to the station. In a 
symmetrical manner the semicircular curved section 10 of the by-pass track 
can be connected to a straight section, aligned with the exit strand of 
the cable and comprising the acceleration wheels. Detachable chairlifts of 
this kind are well-known and for example described in the French Patent 
application No. 9,005,309 of Apr. 24, 1990 filed by the applicant which 
corresponds to the copending U.S. patent application Ser. No. 07/631,963. 
The tired friction wheels 11 are supported by spindles 13, each of which 
are rotatably mounted in a bearing box 14, fixed on a curved girder 21 
which extends along the by-pass zone 10. The spindle or rotation axis 13 
bears on the opposite end to the wheel 11 a toothed bevel pinion 15, which 
rotates with the wheel 11. All the bearing boxes 14 with the friction 
wheel 11 and toothed pinion 15 are identical and are spaced regularly 
along the track, so that the chair carriage is always in contact with at 
least one tired wheel 11 which provides its drive. Between two successive 
bearing boxes 14 of tired wheels 11 there is fitted a bearing box 16, 
which may be identical to the other bearing boxes 14, but does not support 
a tired wheel 11. The toothed pinion of the bearing box 16 is an inverter 
bevel pinion 17, which engages with the two adjacent drive pinions 15 to 
transmit the movement of a wheel 11 to the next wheel. The diameter of the 
toothed pinions 15, 17 is naturally chosen to suit the spacing of the 
wheels 11 and their conicity corresponds to the angle formed by the two 
successive rotation axes 13. The diameter of all the toothed pinions 15, 
17 is preferably the same, but it is possible to use smaller or larger 
inverter pinions 17 and drive pinions 15 of different diameters, all 
combinations being possible. In the example represented in the figures, 
all the tired wheels 11 rotate at the same speed and in the same direction 
to move the chairs at constant speed in the by-pass zone 10. 
In the straight section 12, transmission is preferably by means of pulleys 
18 and belt 19, each spindle supporting two pulleys 18, one receiving and 
the other driving. The spindle of the transition tired wheel 20 from the 
straight section 12 to the curved section 10 supports a pulley 18, 
connected by a belt 19 to the adjacent pulley of the straight section 12 
and a toothed pinion 15 engaging with the adjacent inverter pinion 17 of 
the curved section 10. Transmission of movement between the tired wheels 
is thus kept over the whole track in a particularly simple manner. Other 
transmission systems can naturally be used. The toothed pinions 15, 17 are 
made of suitable plastic material. 
Fixing the bearing boxes 14, 16 to the girder 21 requires a certain 
precision and according to the invention a possibility of adjustment when 
fitting is provided. Referring to FIG. 3, it can be seen that the girder 
21 is formed by a U-shaped iron section 22, extended by two side flanges 
23, between which a protrusion 24 of the bearing box 14, 16 engages. A 
vertical fixing screw 25 passes through an elongated orifice 26, arranged 
in the U-shaped iron section 22 and is screwed into a threaded orifice 27 
of the bearing box 14, 16 to maintain the latter between the flanges 23. 
It can be understood that before the screw 25 is tightened, the bearing 
box 14, 16 can slide between the flanges 23 in the longitudinal direction 
of the girder 21 and within the limits of the fore and aft position of the 
toothed pinion 15 and thus the orifice 26 to adjust the clearance between 
the toothed pinions 15, 17. Adjustment is facilitated by inserting between 
the teeth of these pinions 15, 17 a thin film of a thickness corresponding 
to the clearance necessary for correct operation. After the fixing screw 
25 has been adjusted and tightened, the assembly merely has to be secured 
by means of a bolt 28 connecting the flanges 23 in proximity to the box 
14, 16. Other correct positioning modes are obviously conceivable. 
Operation of the transmission by toothed gear is apparent from the above 
description and it is clear that it can also be used on the straight 
sections. The friction wheels can drive the chair carriages on their own 
or belong to a rhythm device, equipped with a second drive means, notably 
by chain with push fingers. The speed of the friction wheels can be 
variable and controled by a programer to make up for rhythm deviations and 
form a rhythm device according to the French Patent application No. 
9,007,598 of Jun. 13, 1990 filed by the applicant. The drive can be 
derived from the movement of the cable or of the cable return pulley, the 
use of an independent motor naturally being possible. This French Patent 
application corresponds to the copending U.S. Pat. Ser. No. 07/631,466. 
The invention also extends to cog-wheel transmissions using non-bevel 
pinions.