US3771461A

US3771461A - Moving track for a transportation installation having independent vehicles

Info

Publication number: US3771461A
Application number: US00192432A
Authority: US
Inventors: F Giraud
Original assignee: LTV Aerospace Corp
Current assignee: LTV Aerospace Corp
Priority date: 1970-11-16
Filing date: 1971-10-26
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: FR2114087A1; DE2156865A1

Abstract

A moving track for a transportation installation for moving vehicles therealong, the track having a flexible support member which is movable vertically throughout substantially all its length and means for imparting, in the support member, a transverse vertical wave that moves in the desired direction of movement of the vehicle supported thereby. Each vehicle is supported on a forwardly and downwardly extending portion of the support member defining the front flank of a wave during acceleration or constant forward movement of the vehicle along the track and is supported by a portion of the support member defining the rear flank of a wave during the deceleration of movement of the vehicle along the track. Successive portions of the track are movable vertically and sequentially by pneumatic or electromagnetic means to produce the wave. In some forms of the track, the flexible track is supported by flexible tubes having cavities or chambers arranged longitudinally in the tubes and having means for successively and sequentially providing fluid under pressure to the chambers and for exhausting fluid therefrom to produce the waves in the track. In other forms, the track is in the form of a flexible cable or tube mounted on a plurality of longitudinally spaced, vertically movable arms having means for successively and sequentially moving the arms to produce the waves in the track.

Description

United States Patent [191 Giraud 1 Nov. 13, 1973 1 1 MOVING TRACK FOR A TRANSPORTATION INSTALLATION HAVING INDEPENDENT VEHICLES [75] Inventor: Francois L. Giraud, Plaisir, France [73] Assignee: LTV Aerospace Corporation, Dallas,

Tex.

221 Filed: Oct. 26, 1971 21 Appl. No.: 192,432

[30] Foreign Application Priority Data Nov. 16, 1970 France 7040974 [52] US. Cl 104/123, 104/154, 104/147 [51] Int. Cl E0lb 26/00 [58] Field of Search 104/1, 58, 89, 90, 104/91,l12,1l3,116,118,l20,123, 124, 125,147, 154, 155,162, 164

[56] References Cited UNITED STATES PATENTS 3,403,634 10/1968 Crowder 104/155 Primary Examiner-Gerald M. Forlenza Assistant ExaminerD. W. Keen Att0rneyWalter J. Jagmin et a1.

[57] ABSTRACT A moving track for a transportation installation for moving vehicles therealong, the track having a flexible support member which is movable vertically throughout substantially all its length and means for imparting, in the support member, 'a transverse vertical wave that moves in the desired direction of movement of the vehicle supported thereby. Each vehicle is supported on a forwardly and downwardly extending portion of the support member defining the front flank of a wave during acceleration or constant forward movement of the vehicle along the track and is supported by a portion of the support member defining the rear flank of a wave during the deceleration of movement of the vehicle along the track. Successive portions of the track are movable vertically and sequentially by pneumatic or electromagnetic means to produce the wave. In some forms of the track, the flexible track is supported by flexible tubes having cavities or chambers arranged longitudinally in the tubes and having means for successively and sequentially providing fluid under pressure to the chambers and for exhausting fluid therefrom to produce the waves in the track. In other forms, the track is in the form of a flexiblecable or tube mounted on a plurality of longitudinally spaced, vertically movable arms having means for successively and sequentially moving the arms to produce the waves in the track.

5 Claims, 11 Drawing Figures PAIENIEUNUV13 I975 3.771.461

SHEET 10F 6 Fig.1

3a 10a 4d 7/ 9a,

FRANCOIS L. GIRAUD ATTORNEY PATENTEDunv 1a 1975 SHEET 2 BF 6 HiH FRANCOIS L. GIRAUD ATTORNEY PATENIEununa I975 3.771.461 SHEET 3 0F 6 FRANCOIS L. GIRAUD INVEN M ATTbRNEY PATENTEUNUY131973 3.771.461 SHEET 5 n; 0

FRA OlS L. GIRAUD ENTO BYM

ATTORNEY PATENTEHImv 13 ms 377 1, 4s 1 SHEET 6 [IF 6 FRANCOIS L. GIRAUD INVE T R MW ATTOR EY MOVING TRACK FOR A TRANSPORTATION INSTALLATION HAVING INDEPENDENT VEHICLES The present invention relates to a moving track for a transportation installation, for example for carrying passengers using independent vehicles, particularly of the passive type.

Transportation installations equipped with independent passive vehicles, that is to say vehicles with no self-contained sources of energy, for example for carrying passengers between the stations served by an installation of this nature, are already known. The vehicles, in such cases, are generally entrained at constant speed by conveyor devices of various types using, for example, belts, cables, chains, etc., which in certain cases form closed loops. Each vehicle which has to be stopped for unloading and/or loading at a station of the installation has to be switched in advance of this station off the main track, where its movement is controlled by the constant-speed conveyor device mentioned above, onto a side track which passes through the said station and which, when past the latter, permits switching the vehicle back onto the main track; the service of stations in transportation installations of this nature raises the problem of stopping, by braking, the passive vehicles switched onto the side tracks serving these stations, then of accelerating them from a standstill to the speed of the conveyor device at or constituting the main track.

The present invention relates to active and/or braking tracks which can be inserted, in particular, in side tracks serving the above mentioned stations of transportation installations, for example, ahead of and/or beyond the stations thereof, in order to solve the problems of the braking and the acceleration of the passive vehicles just mentioned. The active and/or braking tracks, according to the present invention, are likewise capable of other applications in transportation installations using independent vehicles of the passive type, which will be mentioned below in detail.

The active track for a transportation installation, for example for carrying passengers using independent vehicles, particularly of the passive type, according to the present invention, is characterized in that it comprises, for altering the speed of each vehicle and eventually entraining it at a uniform speed, at least one flexible bearing surface elongated in the direction of movement of the vehicle and supported elastically over at least a large part of its length, as well as means for creating, in this flexible bearing surface, a transverse wave (billow) progressing at an adjustable speed behind or in front of each vehicle, in the direction of movement thereof.

The working of the active track, according to the present invention, is based on the following principle: when transverse waves or billows are created, according to the present invention, in the flexible bearing surface on which, for example, a vehicle is moving at a uniform speed, the front of this vehicle can strike the rising flank of a wave which is preceding it, but is advancing at a rate lower than its speed, while its rear can be struck by the descending flank of a wave following it but progressing at a rate higher than its speed. In the first case the vehicle is braked and it can be stopped by decreasing the speed of the wave to a value close to zero. In the second case, on the contrary, the vehicle is accelerated, and it can even be launched from a standstill by increasing the speed of the wave from zero. The present invention makes it possible to embody active tracks for braking and accelerating passive vehicles in transportation installations of the type mentioned, in particular, for side tracks serving the stations thereof. An active track, according to the present invention, can also be used as a main track of a transportation installation of this nature, in which case it is then substituted for the conveyor device of conventional type. The latter application corresponds to a working condition intermediate between those corresponding,

respectively, to the braking and the acceleration of a vehicle, particularly in the case where each vehicle progresses on the flexible bearing surface preceded and followed, respectively, by two waves which progress at speeds equal to the speed thereof.

The active track, according to the present invention, offers the important advantage of being reversible, that is to say, that it can function either as a braking track when the wave is created ahead of the vehicle to be braked, or as an acceleration track when the wave is created behind the vehicle to be accelerated. the present invention also permits the embodiment of a simpler track which permits braking only; this simpler form of embodiment of the invention is characterized in that it comprises a flexible bearing surface elongated in the direction of movement of the vehicle and supported elastically over at least a large part of its length. It is the weight and kinetic energy of the vehicle to be braked which originate the formation of a wave in front of the said vehicle, the latter thus being gradually braked by gradual transformation of its kinetic energy into energy of deformation of the elastically supported flexible bearing surface.

By way of example, described below and illustrated schematically in the attached drawing, are several forms of embodiment of the track, according to the invention, for a passenger-carrying installation using passive, independent vehicles.

FIGS. 1 and 2 illustrate, schematically, a first form of embodiment.

FIGS. 3 to 5 illustrate the theoretical functioning of the form of embodiment of FIGS. 1 and 2.

FIGS. 6, 7, and 8 represent, schematically, respectively, three other forms of embodiment.

FIGS. 9 and 10 illustrate, schematically, two variants of the form of embodiment of FIG. 8.

FIG. 11 illustrates the use of the form of embodiment of FIG. 8 to constitute the main track of a transportation installation using passive vehicles.

FIGS. 1 and 2 represent, schematically, an active track for a passenger-carrying installation using passive, independent vehicles (not shown), which is constituted essentially by a belt 1 of a flexible material, for example, canvas, which rests by means of crosspieces 2, for example, of metal, on vertically

movable legs

3a and 3b. In the form of embodiment illustrated, there are disposed at equal intervals. below each cross-piece 2, a pair of

legs

3a and 3b supporting, respectively, the two edges of the bearing belt 1; lower ends of

legs

3a and 3b, in each of the two parallel rows of legs, are secured to the tops of two tubes of

deformable material

4a and 4b extending, respectively, below the sides of the bearing belt 1. The undersides of

tubes

4a and 4b are supported by a caisson 5, in the form of a flattened parallelepiped, extending below the bearing belt 1 and resting on the ground. Partitions 6a and 6b, parallel to the longitudinal direction of the bearing belt 1, define three, longitudinal channels in the caisson 5: two lateral channels 7a and 7b and a central channel 8. Known means, not shown, serve to feed these three channels with the same fluid under pressure, this fluid being kept at a high pressure in the lateral channels 7a and 7b and at a lower pressure in the central channel 8. In addition, transverse partitions 9a and 9b are disposed in each of the tubes of

deformable material

4a and 4b at regular intervals between the

successive legs

3a or 3b of a given row, as shown in section in FIG. 2, in such a way as to define, in the

corresponding tube

4a or 4b, a sealed

cavity

10a or 10b below the

corresponding leg

3a or 3b. Each of the transverse partitions 9a or 9b can be constituted by a deformable material, for example, by the

material constituting tubes

4a and 4b, and it can, for example, be glued on its perimeter to the inner wall of the corresponging tube. Finally, each of the

cavities

10a or 10b defined by transverse partitions 9a or 9b in

tubes

4a and 4b can communicate with the low-pressure, central channel 8 by means of a valve 11a or 11b as well as with lateral channel 7a and 7b by means of a

valve

12a or 12b; these

valves

11a, 11b, 12a, 12b can be of any known type, for example, electromagnetically operated valves.

In the diagrams in FIGS. 3 to 5, which are intended to explain the working of the active track, according to the present invention, which has just been described, a single, substantially horizontal line 1 represents the flexible bearing belt and the vertical zig-zag lines 10 represent the various elastic supports of the bearing belt 1, each constituted, in the form of embodiment in FIGS. 1 and 2, by a cross-piece 2, two

legs

3a and 3b, and two

cavities

10a and 10b. These diagrams show only one vehicle 13 of the installation, which has been given the diagrammatic profile of a boat simply in order to distinguish its front from its rear; but actually the present invention is not limited to a particular form of embodiment of the vehicles. These vehicles can, moreover, cooperate with the bearing surface provided by the flexible belt 1 by any known means, for example, a profiled hull, shoes, rollers, air cushions, etc.

Although the principal application envisaged for the present invention relates to transportation installations using passive, independent vehicles, it could also be applied without difficulty to vehicles provided individually with self-contained sources of energy whenever it would appear worthwhile to change the speed of these active vehicles, in particular, to stop them or accelerate them from standstill without drawing or their selfcontained sources of energy. FIG. 3 represents, schematically, a vehicle 13 at a standstill 'on the the flexible bearing surface 1. Its weight compresses the elastic supports 10 which are directly below its polygon of support (A designating the longest dimension in the direction of movement of vehicle 13), as well assome of the elastic supports 10 which are in front of and behind the vehicle, over a length B, known as the relaxation length," which depends on the various parameters of the installation. The importance of this will be specified below. In the case of the forms of embodiment in FIGS. 1 and 2, in the state of rest all valves 11a and 11b are open, and

valves

12a, 12b are closed so that the lowest pressure prevails in the

various cavities

10a and 10b and consequently, the various elastic supports 10 (FIGS. 3 to 5) constituted thereby have a same minimal height (at least at distances equal to B ahead of and behind the vehicle 13). To accelerate vehicle 13 from a standstill, in the direction of arrow F in FIG. 4 valves Illa and 11b of

cavities

10a and 10b, situated just behind the standing vehicle 13, are abruptly closed and at the same time their

valves

12a and 12b are opened to fill the said cavities with the fluid, under high pressure, contained in lateral channels 7a and 7b. As a result, the elastic supports 10 increase in height behind the standing vehicle 13, as seen in FIG. 4, and the flexible bearing belt 1 which, in the example of embodiment considered, is attached to a fixed member 14. (FIG. 4) at its downstream end only, assumes the profile represented in the said FIG. 4. Then the

valves

12a and 12b of the cavities situated just behind the standing vehicle 13 are closed and valves 11a and 11b are opened while the reverse operations are performed for the valves of

cavities

10a and 10b situated somewhat downstream of the preceding ones, i.e. substantially below vehicle 13. The result is a displacementin the direction of arrow F of the descending flank of the wave previously formed behind vehicle 13, which is therefore entrained in the direction of arrow F, at a horizontal speed substantially equal to the rate at which the said wave advances. This advancement of the wave and of the vehicle pushed by it is continued by suitably operating the valves of the

various cavities

10a and 10b in succession, in the direction of arrow F. The proper operation of the said valves is particulary easy in the event they are operated electromagnetically. If the valves of the successive cavities are operated, respectively, at equal intervals in succession and if the time of filling with fluid under high pressure is the same for all cavities, it is clear that the wave created at the rear of standing vehicles 13 will advance at a uniform speed. It is, however, possible to vary the speed from zero, or a very low level to a level equal to the speed which it is desired to impart to the vehicle, by gradually decreasing, in the direction of arrow F, the intervals of time separating the operations of the valves of two successive cavities and/or the filling times of these successive cavities with the high pressure fluid. The latter result can, in particular, be achieved by imparting, to the valves of the successive cavities, full opening whose cross-sections are graduated and, in particular, increasing in the direction of the acceleration to be produced. In an advantageous form of embodiment of the invention, the valves, preferably with electromagnetic operation, which are provided to fill or empty each of the

cavities

10a and 10b, are operated by means of known means, such as electrical contacts controlled manometrically or mechanically by the filling or emptying of the cavities situated upstream, or by the transverse displacements of the bearing surface 1 or of its

supports

2, 3a, 3b which were produced by these upstream cavities.

The active track described above can also be used to slow down or brake, eventually to the stopping point, a vehicle 13 arriving at one end thereof at a uniform speed V, provided that the end of the bearing belt 1 which is connected to fixed member 14 is the end which is upstream of the vehicle 13. In ther words, a given active track, according to the present invention, can be used to accelerate and brake vehicles, always in the same direction, only if it is fixed at both ends. On a vehicle already in movement, it can, therefore, be made to perform desired actions of acceleration and of braking. The same advantage of reversibility is obtained in the case in which, according to a variant, the

bearing belt 1 isnot merely placed on crosspieces 2, but is attached to at least some of them. In this case, the bearing belt 1 must be elastically deformable in the direction of its length, and/or the upper ends of the

supports

2, 3a, 3b must be elastically displaceable in the same direction, which is allowed by the deformability of the tubes 4a 4b. As seen in FIG. 5, the braking is produced by creating a transverse wave or billow ahead of the vehicle 13 to be braked by filling the corresponding cavities a and 10b at high pressure, producing an increase in the height of the elastic supports, of which they form a part, and by having this wave advance in the direction of movement of the vehicle 13 to be braked, by the means described above in the case of the acceleration of a vehicle, first a speed just equal to, or even a little higher than the speed V of the vehicle 13 to be braked, then at a speed decreasing, eventually, down to a zero value.

The form of embodiment of the invention described above, which has the advantage of being able to produce accelerations or deceleration s independently of the mass of the vehicle, is capable of numerous variations. The various cavities, 10a and 10b in particular, can be independent of one another. All that is required is that each one have a deformable upper wall on which a mobile leg, such as 3a or 3b, can be supported. A track, according to the invention, can be embodied to allow only the braking of vehicles by having the two rows of

cavities

10a and 10b respectively communicate with a single duct, paralleling the track and containing a fluid kept at a constant pressure, through orifices with sections decreasing in the direction of movement of the vehicle to be braked, whereby there are created in the two parallel rows of cavities, waves of depression that are propagated at a decreasing speed. Since, in a braking track, according to the invention, at least a part of the kinetic energy of the vehicle is dissipated as heat, cooling means must be provided, in particular for the ducts of fluid under pressure.

However, in all forms of embodiment of the invention, the flexible bearing surface 1 and the moving parts of its elastic supports (the crosspieces 2, legs 3a 3b and the deformable parts of the

tubes

4a, 4b in FIGS. 1 and 2) must have a weight per unit of surface area on the same order of size as the quotient of the total weight of each vehicle 13 divided by the surface area of its polygon of support. Under this condition of approximate equality of interacting masses, the transfer of energy between the passive vehicle and its active track takes place, according to the invention, with the greatest possible efficiency. To meet this condition, it may be necessary to ballast the crosspieces with lateral weights 17 (FIG. 1). If this condition is met, it also favors the following method of operation of the active track, according to the present invention, which experience has shown to be the most advantageous; the progressing transverse wave is created in the bearing surface 1 in such a way that vehicle 13 will be constantly borne by its descending flank 15, in the case of acceleration (FIG. 4), or by its rising flank 16, in the case of braking (FIG. 5), and so that this

flank

15 or 16 of the transverse wave will have a different slope in front of and behind vehicle 13, in particular, a steeper slope to the rear of the vehicle, in the case of acceleration (FIG. 4),

and ahead of the vehicle 13, in the case of braking (FIG. 5). The latter conditions insure the stability of the processes of acceleration or braking of the vehicle.

As a matter of fact, in the case of acceleration, for example, if for any reason the vehicle 13, at some moment, is running at a speed somewhat lower than the wave following it, and if, therefore, its position with respect to the descending flank 15 of this wave shifts slightly toward the peak of the said wave, the inclination of the vehicle 13 to the horizontal (clearly seen in FIG. 4) increases slightly because of the indicated increase in the slope of the descending flank 15 toward the rear of vehicle 13 and thus produces an increase in the resultant of the weight of the vehicle 13 and the re action applied to it by the part of bearing surface 1 on which it rests, and hence, a corresponding increase in the thrust applied to the said vehicle which tends to send it back down along the descending flank 15 of the wave. It would be easy to see that if the momentary speed of vehicle 13 for a short while exceeds the speed of the following wave, a process which is the reverse of the one described above would tend to return the said vehicle to its position on the descending flank 15 represented in FIG. 4. It is a matter, therefore, of a stable position, as is the position of the braked vehicle 13 on the rising flank 16 of the wave preceding it (FIG. 5).

According to another characteristic of the invention, the relaxation length B, along which the flexible bearing surface 1 is deformed ahead of and behind the standing vehicle 13 (FIG. 3), must be on the same order of size as the longest longitudinal dimension A of the support polygon of vehicle 13 in its direction of movement; this condition can be met only by a suitable choice of the longitudinal elasticity and/or the tension of the flexible bearing surface 1, as well as of the degrees of freedom of movement of the elastic supports 10 (the

mobile legs

3a, 3b in FIGS 1 and 2 can, for example, be guided vertically). All these conditions fix, in particular, the speed at which the deformation wave, created by the weight and kinetic energy of the vehicle to be braked (FIG. 5), can be propagated along the elastically supported flexible belt. It is also thanks to these conditions that the length of this progressive wave of deformation is greater than the longest (longitudinal) dimension A of the support polygon of the vehicle in the direction of its movement.

According to another advantageous characteristic of the braking tracks, according to the present invention, the flexible and elastically supported bearing surface must have a low natural frequency of transverse vibra' tion, on the order of several Hz. Under these conditions, the vehicle 13, when at rest, will cause, by its own weight, a depression of depth H (FIG. 3) in the bearing surface 1 sufficient so that in the case of braking, for example, the said vehicle will create ahead of itself, in the said bearing surface 1, a wave high enough to rapidly brake its movement. Thus, if the natural frequency of transverse vibration of the elastically supported flexible belt 1 is close to l Hz, the standing vehicle will create, in the said flexible belt, a depression about 25 cm. deep, sufficient to permit, in case needed, an effective braking of the said vehicle.

The variant of the form of embodiment of the invention described above, which is illustrated schematically in section in FIG. 6, differs from the above only in that the caisson 5 contains a single, longitudinal channel 18 in which there circulates a rapid current of fluid under constant pressure, and that each of the

cavities

10a, 10b can communicate with this single channel 18 by means of a curved tube 19, which is mounted for pivotal movement about an axle 20 perpendicular to that of channel 18, hence perpendicular to the bearing belt I. In the form of embodiment illustrated in FIG. 6, the axle 20 passes through the lowermost wall of the caisson by means ofa sealed journal 21, and means, not shown, are provided outside the caisson for pivoting the curved tube 19 by means of its axle 20 between the position shown in solid lines, wherein the inlet of the curved tube 19 opens upstream (arrow f indicating the direction of circulation of fluid under pressure), and the opposite position, represented in broken lines in FIG. 6. The working principle of this variant differs from that described above only in that each of the cavities a, 10b is filled with fluid under pressure when the corresponding curved tube 19 is turned in such a way that the current of fluid enters it without hindrance (position in solid lines in FIG. 6), while a depression is created therein when curved tube 19 occupies the opposite position (position in dotted lines). The variant of the embodiment of the invention illustrated in FIGS. 1 and 2, which is represented schematically in elevation in FIG. 7, differs therefrom only in that the

mobile legs

3a, 3b (only the legs 3b being visible) are supported, respectively, on wide-surfaced floats 22 immersed in a liquid 35 contained, for example, in a channel cut below the track. This form of embodiment of the invention constitutes a braking track exclusively, whose working principle corresponds to the one illustrated diagrammatically in FIG. 5.

Another variant (not shown) of a braking track, according to the present invention, can be obtained by using, as a bearing surface, the upper face of an elongated body of elastic material containing a large number of cells filled with a gas, and communicating or not with one another and with the atmosphere; the working of such a braking track likewise corresponds to the principle illustrated in FIG. 5. In the form of embodiment of the invention illustrated in perspective in FIG. 8, the' bearing surface is embodied by a flexible cable or tube 23 resting on arms 24 which are mounted pivotally on substantially vertical pylons 25 in such a way as to be subject to an elastic force of return toward their horizontal position. In the form of embodiment illustrated in FIG. 8, the elastic return force applied to each pivoting arm 24 is generated by a bellows 26 mounted in such a way as to be supported by the corresponding pylon 25 and to act on the pivoting arm 24. Two

ducts

27 and 28 containing, respectively, a fluid at high and low pressures are disposed in such a way as to parallel the track, for example, being supported by the pylons 25. Means, not shown, for example, electromagnetically operated valves, make it possible to have each of the bellows 26 communicate,-as desired, with one or the other of the two

ducts

27 and 28. This active track, according to the present invention, can be used both to brake and to accelerate a vehicle 13, which is intended, for example to carry two passengers, and is suspended from a carriage whose wheels 30 can roll on the cable or tube 23. In any case, the principles involved are the same as the ones described above and illustrated schematically in FIGS. 4 and 5.

In the variant illustrated in FIG. 9, which represents, in elevation only, an arm 24 mounted pivotally on a pylon 25, the latter supports two

identical bellows

26a and 26b aligned along a vertical axis in such a way as to exert antagonistic actions on the pivoting arm 24. When a valve 29 is closed, the same low pressure prevails in the two

bellows

26a and 26b as in duct 28, and the arm 24 is held in the horizontal position represented, the two

bellows

26a and 26b exerting forces of return toward the horizontal thereon. The opening of valve 29, however, permits the establishment in the lower bellows 26a of the high pressure prevailing in duct 27, which causes the lifting of arm 24 and bearing cable 23.

While in the forms of embodiment illustrated in FIGS. 8 and 9, the means provided for pivoting the arms 24, i.e., bellows 26, 26a, 26b, exert forces of return to their horizontal position on the said arms; in the case of the form of embodiment illustrated in FIG. 10, this return force is exerted by a spring 30 which is mounted in such a way as to be supported by the corresponding pylon 25 and to act on the pivoting arm 24. Moreover, the means for pivoting the arm 24 are provided by an electromagnet 31 which is mounted in such a way as to be supported by pylon 25 and to act on a mobile armature 32, solid with pivoting arm 24. In the form of embodiment illustrated in FIG. 10, the electromagnet is mounted to pivot at the end of a rod 33 extending from a brake device, in particular, a dash-pot 34 itself mounted rigidly on pylon 25. This arrangement has the effect of slowing down the movement of approach of electromagnet 31, when it is energized, and its mobile armature 32 in such a way as to avoid too sudden an upward pivoting movement of arm 24.

The forms of embodiment of an active track, according to the present invention, which are illustrated schematically in the FIGS. 8 to 10 can be simplified for the provision of simple braking tracks. In the case of a braking track, as a matter of fact, it is sufficient if each of the pivoting arms 24 is subjected to at least an elastic force of return to the horizontal position, this elastic return force being producible by a simple spring (as in FIG. 10), or by one or more bellows communicating with a single duct extending along the track and containing a fluid kept at constant pressure, respectively, through orifices with cross-sections decreasing in the direction of movement of the vehicle to be braked, in such a way as to produce, in the successive bellows, a wave of compression which is propagated at a decreasing speed in the direction of movement of the vehicle to be braked.

FIG. 11 represents, schematically in elevation, an active track, according to the present invention, of the type illustrated in FIG. 8, in the case where it is used to entrain

several vehicles

13a, 13b, 13c c, at uniform speed. Each of the pivoting arms 24 is then animated, by the drive means provided (which can be one of the types illustrated in FIG. 8 to 10), with an oscillation that lies in a vertical plane that passes through the corresponding pylon 25, with the same amplitude and frequency for all the pivoting arms, the relative phases of these oscillations of the pivoting arms 24 being chosen in such a way that the flexible bearing cable 23 will assume the sinusoidal profile seen in FIG. 11, which profile is propagated in the direction of arrow F at a rate equal to the speed at which the

various vehicles

13a, 13b, etc., are to be entrained. As seen in FIG. 11, in the course of this process of entrainment, the

carriages

29a, 2%, etc. of the

various vehicles

13a, 13b, etc. position themselves on the descending flanks of the successive waves formed by the profile of the flexible cable 23, and the successive vehicles, for example, 13a, 13b

maintain a constant interval that is equal to the wavelength of this sinusoidal profile. An active track of this nature can be used both to move the vehicles of a passenger-carrying installation atslow speed through one of the stations of this installation and to constitute the main track of such an installation, thus replacing the conventional conveyor device which is ordinarily used for this purpose.

While only one embodiment of the invention, together with modifications thereof, has been described in detail herein and shown in the accompanying drawing, it will be evident that various further modifications are possible in the arrangement and construction of its components without departing from the scope of the invention.

What is claimed is:

l. A track for a transportation installation, for example for passengers, using independent vehicles, particularly of the passive type, characterized in that it comprises, to modify the speed of each vehicle, and eventually to entrain it at a uniform speed, at least one flexible bearing surface extending in the direction of movement of the vehicles, and supported elastically on at least a large part of its length, in combination with means to create, in this flexible bearing surface, a transverse wave progressing at an adjustable speed behind or in front of each vehicle in the direction of its movement, the track being further characterized in that the flexible bearing surface and the mobile parts of its elastic supports have a weight per unit of surface on the same order of size as the quotient of the total weight of each vehicle divided by the surface of its polygon of support.

2. A track installation for the braking of a car supported thereon and movable longitudinally thereof in a given direction, the installation comprising a plurality of vertically extending pylons; a plurality of arms each pivotally mounted at one end thereof on a respective one of the pylons and having a free end spaced from the pylon; a cable extending between the arms and receiving support from each arm at a location spaced, along the respective arm, from the associated pylon, whereby downwardly directed forces imposed on the cable tend to pivot the free ends of the arms downwardly; at each pylon, a bellows having first and second ends; means at each pylon connecting the first end of the associated bellows to the associated arm; means at each pylon mounting the second end of the associated bellows on the respective pylon in a position in which downward movement of the arm imposes a compressing force on the bellows; a duct extending along the cable and filled with a fluid; means for maintaining the fluid in the duct at a substantially constant pressure; a plurality of conduits, each of which provides communication between a respective one of the bellows and the duct; and an orifice in each of the conduits at a location between the duct and an associated bellows, the cross-sectional areas of successive ones of the orifices decreasing in the direction of movement of the vehicle.

3. A track on which at least one vehicle is supported for movement along the track, said track including:

an elongated, flexible member;

supporting means disposed below the flexible member and supporting the flexible member at a plurality of longitudinally spaced locations therealong, the supporting means being independently and vertically movable at said locations to impart vertical movements to the flexible member at said locations; and

means for individually moving the supporting means vertically and in sequence for producing in the flexible member a transverse, vertically extending wave that moves longitudinally of the member and in a desired direction of movement of a vehicle having bearing surfaces supported on the flexible member, the supporting means comprising:

an elongate, flexible, tubular member having a plurality of longitudinally spaced chambers;

a plurality of bearing members disposed between said flexible member and said tubular member at the locations of said chambers;

means for selectively connecting each of said chambers to a source of fluid under pressure, whereby expansion of a chamber as the fluid under pressure is introduced thereinto causes upward movement of the portion of the flexible member above such chamber; and

means for venting fluid from each chamber, whereby contraction of a chamber as the fluid is exhausted therefrom permits downward movement of the portion of the flexible member above such chamber.

4. The track of claim 3, wherein said supporting means include:

an elongate member containing a first passage connectable to a source of fluid under pressure and a second, exhaust passage extending longitudinally below said tubular member; and

first and second valving means for selectively connecting each of said chambers of said tubular member to said first and second passages, respectively.

5. The track of claim 4, said tubular member being supported by said elongate, passage-containing member.

Claims

1. A track for a transportation installation, for example for passengers, using independent vehicles, particularly of the passive type, characterized in that it comprises, to modify the speed of each vehicle, and eventually to entrain it at a uniform speed, at least one flexible bearing surface extending in the direction of movement of the vehicles, and supported elastically on at least a large part of its length, in combination with means to create, in this flexible bearing surface, a transverse wave progressing at an adjustable speed behind or in front of each vehicle in the direction of its movement, the track being further characterized in that the flexible bearing surface and the mobile parts of its elastic supports have a weight per unit of surface on the same order of size as the quotient of the total weight of each vehicle divided by the surface of its polygon of support.

3. A track on which at least one vehicle is supported for movement along the track, said track including: an elongated, flexible member; supporting means disposed below the flexible member and supporting the flexible member at a plurality of longitudinally spaced locations therealong, the supporting means being independently and vertically movable at said locations to impart vertical movements to the flexible member at said locations; and means for individually moving the supporting means vertically and in sequence for producing in the flexible member a transverse, vertically extending wave that moves longitudinally of the member and in a desired direction of movement of a vehicle having bearing surfaces supported on the flexible member, the supporting means comprising: an elongate, flexible, tubular member having a plurality of longitudinally spaced chambers; a plurality of bearing members disposed between said flexible member and said tubular member at the locations of said chambers; means for selectively connecting each of said chambers to a source of fluid under pressure, whereby expansion of a chamber as the fluid under pressure is introduced thereinto causes upward movement of the portion of the flexible member above such chamber; and means for venting fluid from each chamber, whereby contraction of a chamber as the fluid is exhausted therefrom permits downward movement of the portion of the flexible member above such chamber.

4. The track of claim 3, wherein said supporting means include: an elongate member containIng a first passage connectable to a source of fluid under pressure and a second, exhaust passage extending longitudinally below said tubular member; and first and second valving means for selectively connecting each of said chambers of said tubular member to said first and second passages, respectively.