Switching system for a transportation system employing a guideway

Abstract

A switching system for a transportation system of the type employing a guideway and vehicles adapted to travel along the guideway. A guideway junction is provided having a first end communicating with a first portion of the guideway and having a bifurcated, second end communicating with second and third, mutually diverging portions of the guideway. A movable guide rail is positioned adjacent the first end of the junction and pivotable between first and second positions for initially guiding a vehicle in a respective one of two directions upon the vehicle entering the junction from the junction first end. A fixed, guiding means structure is positioned between the movable guide rail and the second guideway portion and is operable to guide a vehicle through the junction and onto the second guideway portion upon the vehicle being initially guided by the movable guide rail while the movable guide rail is in its first position; and another fixed, guiding means structure is operable to guide a vehicle through the junction and onto the third guideway portion upon the vehicle being initially guided by the movable guide rail positioned in its second position. In one embodiment of the switching system, the movable guide rail is positioned by an actuating means mechanism operable for moving the guide rail to a selected one of its two positions. In another embodiment adapted particularly to accommodate vehicles entering the junction from the second or third guideway portions, the movable guide rail is normally held in its first position by positioning means apparatus operable for resiliently urging the movable guide rail to its first position, and is deflected to its second position by vehicles which enter the junction from the third guideway portion.

Description

This invention relates to switching apparatus and, more particularly, to a switching system for a ground transportation system of the type employing a guideway and vehicles adapted to travel along the guideway.

Several ground transportation systems have been developed or proposed in which guideways, generally of approximately U-shaped cross-section, are provided for supporting and guiding various types of vehicles along predetermined routes. The guideway of such a system typically employs left and right, upright guide walls and a generally horizontal road surface, extending at least partially between the guide walls, for supporting the vehicles. Vehicles have been constructed which travel along such guideways upon resilient tires and which include following mechanisms adapted to engage the guide walls for guiding or steering the vehicles within the guideways. Alternatively, the following mechanisms may engage guide rail structures, in which case the guideway may consist only of a roadway and at least one guide rail structure extending along or alongside the roadway. Vehicles of the above type are similar to railway cars in many respects, but can provide advantages, such as improved riding qualities and quieter operation, over conventional railway vehicles. Guideway transportation systems are also suited for use with other types of vehicles, such as those employing ground-effect, air cushion, supporting means. Such ground-effect vehicles have great potential for high-speed ground transportation systems and, when adapted to travel within a guideway, can be safely and precisely maneuvered.

While the construction of guideway transportation systems is analogous to that of conventional railway systems in some respects, in other respects it differs radically therefrom, presenting a number of engineering problems to the designer. One such problem, to which the present invention is addressed, relates to the provision in such systems of practicable and reliable switching apparatus. The roadway, or the area normally extending between parallel guide walls, is required to be substantially clear of obstructions over at least large portions of its width in order that it may serve as a continuous, smooth-surfaced ramp upon which the tires or other supporting means of the vehicles may ride. This requirement varies according to the design of the system, e.g., according to the particular guidance system employed by the vehicles and the configuration of the tires of other supporting means, but in general there are necessarily relatively wide areas of the roadway which must remain substantially unobstructed if the vehicles are to achieve safe, smooth passage. This is in contrast to conventional railway systems, wherein the rails serve both to support and guide the cars, and wherein the area between the rails is not associated with the cars. Switching systems for conventional railways utilize the space between diverging, outer rails in switch junctions for the placement of duel, movable rails which divert the cars to one or the other of two, diverging, railway lines, it being required only that narrow gaps remain between the rails upon which the wheels ride and the other rails to permit passage of the flanges of the wheels. Because of the requirement, in guideway systems, that substantial portions of the roadway be clear of obstructions, such movable switching rails cannot be conveniently adapted for use in switches for guideway systems. It can thus be seen that the development of efficient switching apparatus for use in guideway transportation systems requires the solution of engineering problems unique to such guideway systems.

Switching systems of several types have been proposed for guideway systems, but they suffer from a number of disadvantages. One approach has been to provide a relatively massive, movable, blade structure in a junction of two, mutually diverging, guideway and on an enlarged scale(FIG. 1)the co-pending application for11.2

While the guide wheel assemblies 24, 25, 26, 27 of FIGS. 2-6 constitute examples of a preferred embodiment, other, modified constructions are possible. For example, it may be desirable, for safety, to employ redundant guide wheels and guide rollers, as shown in FIG. 8. In this modification, the frame 82A is enlarged and extended so that it can also support a second redundant guide wheel 29A and a redundant guide roller 83A positioned to the rear and in register with the guide wheel 29 and the guide roller 83, respectively. The redundant guide wheel 29A and guide roller 83A are each of slightly lesser diameter than the corresponding, primary guide wheel 29 and guide roller 83, respectively, so that only the primary guide wheel 29 and guide roller 83 are normally used. Should the guide roller 83, for example, fail during operation of the vehicle 12, the redundant guide roller rais rails 104 aligned end-to-end along the guideway 19 but electrically insulated from each other to define a plurality of discrete, positional blocks, or lengths of guideway 19, each spaced a known distance ahead of the switch 10. A vehicle, represented by the block 12, is provided with route control logic circuitry 105 including an on-board register unit 106 comprising computer memory devices which are operable to store information both identifying and a vehicle and denoting its programmed route through the system. A vehicle 12 which approaches the switch 10 on the portion of the primary guideway 19 adjacent the first of the signal rails 104 is sensed by a wayside, vehicle detection circuit 109 connected across the ground rail 103 and the respective signal rail 104, the detection circuit 109 then serving to activate an automatic wayside/vehicle communication circuit 110. It will be apparent to those skilled in the art, for example, that a relay could suitably be incorporated in the detection circuit 109 for providing a positive signal to the wayside communication circuit 110. The wayside communication circuit 110 then interrogates the vehicle as to its identification and programmed route. A vehicle-to-wayside communication circuit 107 aboard the vehicle is operative to transmit, at periodic intervals, a signal indicative of the information stored in the on-board register 106 as to the vehicle identity and programmed route. Transmittal of information between the vehicular communication circuit 107 and the wayside/vehicle communication circuit is accomplished by conduction through contact brushes 111 slidably associated with the rails 103, 104 or, alternatively, by the induction of electrical signals to the rails. The wayside/vehicle communication circuit 110, upon its being activated by the vehicle detection circuit 109, reads the next emission of the vehicle-to-wayside communication circuit 107 as to the information stored in the on-board register 106. Having received this information concerning route and vehicle identity, the automatic wayside/vehicle communication circuit 110 transmits the information to the automatic switch control logic circuit 112 which then translates the information into a control signal for positioning correctly the switch 10 as well as subsequent, adjacent switches (not shown) in accordance with the preselected route; the control signal actuates the switch 10 if the switch is not in the appropriate position. Various other control circuits, outside the scope of this disclosure, are also connected to the vehicle 12 through the wayside/vehicle communications circuit 110 for performing other functions such as the automatic control of velocity and braking. The passive switch 10' then serves to conduct the vehicle back to the primary guideway 19, the resiliently biased rail structure 63E serving to permit passage through junction 32E of vehicles entering from either the secondary guideway 20 or the primary guideway 19. No control signal is necessary for positioning of the rail structure 63E but sensing devices (not shown) may be installed therein for monitoring its operation.

It can thus be appreciated that the switching system is adapted to provide highly reliable service over long periods of time. Because it employs only one , movable , track portion, it eliminates the need for complex actuating mechanisms operable for simultaneously aligning multiple , movable, track elements as in the prior art system initially described. Further, the movable rail structure is of relatively simple, one-piece construction and is mounted by means only of a relatively simple bearing structure. In the preferred embodiment in which L-shaped rail structure having downwardly projecting guide rails are used, the danger of the switch becoming jammed as a result of foreign objects falling alongside the movable rail elements is greatly reduced. This is because the movable rail structure does not sweep across the surface of the roadway, but is rather suspended above the roadway surface; moreover, because the space between the movable third guide rail and the adjacent, first guide wall portion is covered by the horizontal portion of the movable rail structure, accidental or even intentional placement of foreign objects in that space is made quite difficult. Such failsafe construction is of particular advantage when the switch system is to be installed in a public area, such as an airport, through which large numbers of people pass and in which the danger of vandalism and the possibility of foreign objects being accidentally thrown onto the guideway are always present.

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.

Claims

1. In a transportation system of the type employing vehicles adapted to travel along a guideway comprising a roadway and structure providing at least one guide surface, having vertical extension, extending along the guideway for guiding the vehicle, the system including a plurality of guideway junctions, each junction having a first end communicating with a first portion of the guideway and a widened, bifurcated, second end communicating with second and third, mutually diverging portions of the guideway, the transportation system including at least one primary guideway and at least one secondary guideway, having inlet and outlet ends, connected to the primary guideway by respective, oppositely directioned switching systems, the transportation system further including programmable control means for sensing the positions of the respective vehicles and for automatically actuating respective ones of the switching systems at appropriate times in response to the movement of the respective vehicles and according to respective, preselected routes programmed in the control system with respect to each vehicle, an improved switching system adapted for use in such a transportation system, the switching system comprising:

a single movable guide rail positioned adjacent the first end of the junction and pivotable about an approximately vertical axis between first and second positions;

first guiding means, comprising a first guide surface on the movable guide rail, for guiding a vehicle toward the second guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its first position; and

second guiding means, comprising a second guide surface on the movable guide rail, for guiding a vehicle toward the third guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its second position,

third guiding means , immovably positioned between the movable guide rail and the second guideway portion, for guiding a vehicle through the junction and onto the second guideway portion upon the vehicle being initially guided by the first guiding means and comprising a guide surface defined by a structure immovably positioned between the movable guide rail and the second guideway portion; and

fourth guiding means , immovably positioned between the first end of the junction and the third guideway portion, for guiding a vehicle through the junction and onto the third guideway portion upon the vehicle being initially guided by the second guiding means , the fourth guiding means comprising a guide surface defined by a structure immovably positioned between the first end of the junction and the third guideway portion, the movable guide rail being spaced laterally, relative to the junction, from the guide surface of the fourth guiding means, the movable guide rail having a first end adjacent the junction first end and a second end adjacent the guide surface of the third guiding means and between the structure of the third guiding means and the junction first end, the first and second guide surfaces extending along the movable guide rail to a location thereon adjacent the movable guide rail second end, the portions of the first and second guide surfaces adjacent the movable guide rail second end being intermediate the respective guide surfaces of the third and fourth guiding means upon the movable guide rail being in its second position.

2. The switching system of claim 1, wherein the fourth guiding means comprises a means for guiding a vehicle toward the first guideway portion upon the vehicle entering the junction from the third guideway portion, wherein the third guiding means comprises a means for guiding a vehicle toward the first guideway portion upon the vehicle entering the junction from the second guideway portion, wherein the second guiding means comprises a means for guiding a vehicle through the junction and onto the first guideway portion upon the vehicle being initially guided by the fourth guiding means, and wherein the first guiding means comprises a means for guiding a vehicle through the junction and onto the first guideway portion upon the vehicle being initially guided by the third guiding means.

3. In a transportation system employing at least one vehicle adapted to travel along a guideway having two mutually spaced guide walls having vertical extension, the system including a first guideway portion and second and third, mutually diverging guideway portions each having a pair of mutually spaced guidewalls having vertical extension, a switching system comprising:

a junction of the first, second, and third portions of the guideway, the junction having a first end which communicates with the first guideway portion and a widened, second end having a first outlet communicating with the second guideway portion and a second outlet communicating with the third guideway portion, the junction having a first guide wall portion contiguous, at the first end of the junction, with one of the guide walls of the first guideway portion and contiguous, at the second end of the junction, with the guide wall of the second guideway portion spaced farthest from the third guideway portion, and a second guide wall portion extending between the other guide wall of the first guideway portion and the guide wall of the third guideway portion spaced farthest from the second guideway portion, the second guide wall portion diverging from the first guide wall portion in the direction, along the second guide wall, from the junction first end to the second outlet;

a single movable guide rail positioned adjacent the first guide wall portion and extending from the first end of the junction to a location between the junction first and second ends, the movable guide rail being pivotable about a substantially vertical axis between a first position, in which the movable guide rail is equidistant, along its length, from the first guide wall portion, and a second position in which the movable guide rail diverges from the first guide wall portion and toward the second guide wall portion in the direction, along the movable guide rail, from the first end and toward the second end of the junction;

first guiding means, on the movable guide rail, for constraining the vehicle to travel alongside the first guide wall portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its first position;

second guiding means, on the movable guide rail, for diverting the vehicle from the first guide wall portion and toward the second guide wall portion upon the vehicle entering the junction through the junction first end when the movable guide rail is in its second position;

third guiding means for constraining the vehicle to travel through the junction alongside the first guide wall portion and through the first outlet upon the vehicle being initially constrained to travel alongside the first guide wall portion by the first guiding means; and

fourth guiding means for constraining the vehicle to travel through the junction alongside the second guide wall portion and through the second outlet upon the vehicle being initially diverted toward the second guide wall portion by the second guiding means.

4. The switching system of claim 3, the third and fourth guiding means each comprising a respective following means mounted on the vehicle and a respective, elongated surface distinct from the guide wall portions, having vertical extension, and fixedly located relative to a respective one of the first and second guide wall portions of the junction.

5. The switching means of claim 4,

the following means of the third guiding means being operative for engaging the elongated surface of the third guiding means upon the vehicle having entered the junction first end when the movable guide rail is in its first position, and

the following means of the fourth guiding means being operative for engaging the elongated surface of the fourth guiding means upon the vehicle having entered the junction first end when the movable guide rail is in its second position.

6. The switching system of claim 3, further comprising positioning means for moving the movable guide rail from its second to its first position.

7. The switching system of claim 3 6, the positioning means comprising means resiliently urging the movable guide rail to its first position.

8. The switching system of claim 3 6, the positioning means comprising an actuator operable for selectively moving the movable guide rail between its first and second positions.

9. The system of claim 3, the guideway having an approximately horizontal roadway extending at least partially between the first and second guide wall portions of the junction and the movable guide rail being positioned over the roadway and between the first and second guide wall portions.

10. The system of claim 3, wherein the first guiding means comprises a guide surface extending along the length of the movable guide rail, facing the first guide wall portion, and equidistantly spaced along its length from the first guide wall portion when the movable guide rail is in its first position, and wherein the second guiding means comprises a guide surface extending along the length of the movable rail and facing toward the second guide wall portion.

11. The system of claim 3, wherein there is provided a first, fixed guide rail immovably supported adjacent the second guide wall portion, the fourth guiding means comprising a guide surface extending along the first fixed guide rail and confronting the second guide wall portion, and wherein there is further provided a second fixed guide rail immovably supported adjacent the first guide wall portion, the third guiding means comprising a guide surface extending along the second fixed guide rail and confronting the first guide wall portion.

12. In a transportation system employing at least one vehicle adapted to travel along a guideway, the guideway comprising a roadway bordered by left and right, mutually parallel, approximately upright guide walls, each vehicle having apparatus including left and right guide walls following structures adapted to ride against the left and right guide walls, respectively, for guiding the vehicle along the roadway between the guide walls, a switching system comprising:

a junction of a first portion of the guideway and of second and third, mutually diverging portions of the guideway, the junction having a first end communicating with the first guideway portion and at which the mutually diverging, second and third guideway portions are merged, and a bifurcated, widened, second end communicating with the second and third guideway portions, the junction having a first guide wall portion extending between respective ones of the guide walls of the first and second guideway portions and a second guide wall portion having a first end contiguous with the other guidewall of the first guideway portion and a second end located adjacent the second end of the junction and contiguous with the guide wall of the third guideway portion spaced farthest from the second guideway portion, the second guide wall portion diverging, from its first to its second end, from the first guide wall portion;

a first guide rail immovably positioned over the roadway adjacent the second guide wall portion and extending alongside the second guide wall portion at a constant height above the roadway, the first guide rail having a guide surface substantially perpendicular to the roadway, continuous along the length of the first guide rail, facing the second guide wall portion, and spaced from the second guide wall portion by a constant, predetermined distance, the first guide rail extending from the second end toward the first end of the second guide wall portion, the first guide rail being spaced from the junction first end and spaced from the first guide wall portion by a distance at least as great as the spacing between the left and right guide walls of the guideway;

a second guide rail immovably positioned over the roadway adjacent the first guide wall portion and extending alongside the first guide wall portion at a constant height above the roadway, the second guide rail having a guide surface substantially perpendicular to the roadway, continuous along the length of the second guide rail, facing the first guide wall portion, and spaced from the first guide wall portion by a constant, predetermined distance, the second guide rail extending from the bifurcated, second end of the junction toward the junction first end and being spaced from the junction first end by a distance greater than the distance between the junction first end and the first guide rail;

a third guide rail constituting a single, movable guide rail; having first and second ends and pivotally supported over the roadway adjacent the first guide wall portion and between the second guide rail and the first end of the junction, the third guide rail having first and second, oppositely facing guide surfaces each substantially perpendicular to the roadway, the first guide surface of the third guide rail facing the first guide wall portion, the third guide rail being pivotable, about a rotational axis substantially perpendicular to the roadway and spaced between the first and second ends of the third guide rail, between a first position in which the second end of the third guide rail is contiguous with the second guide rail and in which the first guide surface of the third guide rail is equidistant, along its length, from the first guide wall portion, and a second position in which the first end of the third guide rail is positioned immediately adjacent the first guide wall portion and in which the third guide rail second end is spaced, from the first guide wall portion, beyond the second guide rail and in which the distance between the second guide wall portion and the second guide surface of the third guide rail, along a line perpendicular to the second guide wall portion and intersecting the second end of the third guide rail, is substantially equal to the distance between the left and right guide walls of the guideway;

first guide rail following means, mounted on the at least one vehicle, for movably engaging the first guide surface of the third guide rail, and subsequently, the guide surface of the second guide rail, upon the vehicle passing through the junction from the junction first end when the third guide rail is in its first position and, upon the third guide rail alternatively being in its second position, for movably engaging the second guide surface of the third guide rail and diverting the vehicle toward the second guide wall portion; and

second guide rail following means, mounted on the vehicle, for movably engaging the guide surface of the first guide rail and guiding the vehicle along the second guide wall portion and into the second portion of the guideway upon the vehicle being diverted toward the second guide wall portion by the first guide rail following means.

13. The switching system of claim 12, wherein the first guide rail following means comprises a first guide roller rotatable about an axis perpendicular to the roadway and having a diameter less than the spacing between the first guide wall portion and the guide surface of the second guide rail and less than the spacing between the first guide wall portion and the first guide surface of the third guide rail upon the third guide rail being in its first position, and wherein the second guide rail following means comprises a second guide roller rotatable about an axis perpendicular to the roadway and having a diameter less than the spacing between the first guide rail and the second guide wall portion, the second guide roller being positioned between the first guide rail and the second guideway portion upon the first guide roller being adjacent the second end of the third guide rail and in contact with the second guide surface of the third guide rail when the third guide rail is in its second position.

14. The switching system of claim 12, further comprising a first guide wheel mounted on the vehicle adjacent the first guide roller, the first guide wheel being spaced vertically from the third guide rail along the first guide roller being in contact with the third guide rail and spaced vertically from the second guide rail upon the first guide roller being in contact with the second guide ral, and a second guide wheel mounted on the vehicle adjacent the second guide roller, the second guide wheel being spaced vertically from the first guide rail upon the second guide roller wheel being in contact with the first guide rail.

15. The switching system of claim 14, wherein the first guide wheel is adapted to contact and roll along the first guide wall portion upon the vehicle being adjacent the first guide wall portion, the first guide roller being spaced from the first guide wall portion, upon the first guide wheel contacting the first guide wall portion, by a distance approximately equal to the thickness, between the first and second guide surfaces, of the third guide rail.

16. The switching system of claim 14, wherein the first and second guide wheels respectively confront and are each adapted to roll along a respective one of the guide walls, external of the junction, and each constituting a respective portion of a respective one of the left and right guide wall following structures.

17. The switching system of claim 12, wherein the first and second guide rails constitute portions of first and second, fixed, L-shaped rail structures, respectively, and the third guide rail constitutes a portion of a movable, L-shaped rail structure, each rail structure having, in cross-section, a horizontal portion extending between the respective guide rail and the respective, adjacent, guide wall portion.

18. The switching system of claim 17, wherein the first and second guide wall portions respectively constitute mutually consfronting sidewalls of first and second upright curbs extending along respective sides of the junction, and wherein the horizontal portions of the first and second L-shaped rail structures extend over and are rigidly affixed to the second and first curbs, respectively, and wherein the horizontal portion of the third L-shaped rail structure extends over and is pivotally mounted on the first curb.

19. The switching system of claim 17, wherein the first, second, and third guide rails project downwardly from the horizontal portions of the respective L-shaped rail structures.

20. In a transportation system employing at least one vehicle adapted to travel along a guideway comprising a roadway and structure providing at least one guide surface, having vertical extension, extending along the guideway for guiding the vehicle, the system having a junction having a first end communicating with a first portion of the guideway and a widened, bifurcated, second end communicating with second and third, mutually diverging portions of the guideway, a switching system comprising;

a single movable guide rail positioned adjacent the first end of the junction and pivotable about an approximately vertical axis between first and second positions;

first guiding means, comprising a first guide surface on the movable guide rail, for guiding a vehicle toward the second guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its first position; and

second guiding means, comprising a second guide surface on the movable guide rail, for guiding a vehicle toward the third guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its second position,

third guiding means , immovably positioned between the movable guide rail and the second guideway portion, for guiding a vehicle through the junction and onto the second guideway portion upon the vehicle being initially guided by the first guiding means and comprising a guide surface defined by a structure immovably positioned between the movable guide rail and the second guideway portion; and

fourth guiding means , immovably positioned between the first end of the junction and the third guideway portion, for guiding a vehicle through the junction and onto the third guideway portion upon the vehicle being initially guided by the second guiding means and comprising a guide surface defined by a structure immovably positioned between the first end of the junction and the third guideway portion, the movable guide rail being spaced laterally, relative to the junction, from the guide surface of the fourth guiding means, the movable guide rail having a first end adjacent the junction first end and a second end adjacent the guide surface of the third guiding means and between the guide surface of the third guiding means and the junction first end, the first and second guide surfaces extending along the movable guide rail to a location adjacent the movable guide rail second end, the portions of the first and second guide surfaces adjacent the movable guide rail second end being intermediate the respective guide surfaces of the third and fourth guiding means upon the movable guide rail being in its second position.

21. The switching system of claim 20, wherein the first and second guide surfaces constitute guide surfaces extending along opposite sides of the movable guide rail.

22. The switching system of claim 21, including following means mounted on the vehicle and operative for engaging the first guide surface of the movable guide rail upon the vehicle entering the junction from the junction first end when the movable guide rail is in its first position and for engaging the second guide surface of the movable guide rail upon the vehicle entering the junction from the junction first end when the movable guide rail is in its second position.

23. The switching system of claim 20, wherein the fourth guiding means also comprises a means for guiding a vehicle toward the first guideway portion upon the vehicle entering the junction from the third guideway portion, wherein the third guiding means comprises a means for guiding a vehicle toward the first guideway portion upon the vehicle entering the junction from the second guideway portion, wherein the second guiding means comprises a means for guiding a vehicle through the junction and onto the first guideway portion upon the vehicle being initially guided by the fourth guiding means, and wherein the first guiding means comprises a means for guiding a vehicle through the junction and onto the first guideway portion upon the vehicle being initially guided by the third guiding means.

24. The switching system of claim 23 and further comprising positioning means for moving the movable guide rail from its second to its first position.

25. The switching system of claim 24, the positioning means comprising means resiliently urging the movable guide rail to its first position.

26. The switching system of claim 24, the positioning means comprising an actuator operable for selectively moving the movable guide rail between its first and second positions.

27. In a transportation system employing at least one vehicle adapted to travel along a guideway having an approximately horizontal roadway extending between left and right, approximately upright guidewalls, the system including a first guideway portion and second and third, mutually diverging guideway portions, a switching system comprising:

a junction of the first, second, and third portions of the guideway, the junction having a first end which communicates with the first guideway portion and at which the second and third guideway portions are merged and a widened, bifurcated, second end having a first outlet communicating with the second guideway portion and a second outlet communicating with the third guideway portion, the junction, having a first guide wall contiguous, at the first end of the junction, with one of the guide walls of the first guideway portion and contiguous, at the second end of the junction, with the guide wall of the second guideway portion spaced farthest from the third guideway portion, and a second guide wall portion extending between the other guide wall of the first guideway portion and the guide wall of the third guideway portion spaced farthest from the second guideway portion, the second guide wall portion diverging from the first guide wall portion in the direction, along the second guide wall, from the junction first end to the second outlet, the roadway extending between the first and second guide wall portions;

a first fixed rail structure, of L-shaped cross-sectional configuration, extending along the second guide wall portion from the second end of the junction to a location spaced from the first end of the junction, the first, fixed rail structure having a horizontal portion and a vertical portion comprising a first guide rail portion projecting downwardly toward the roadway and extending alongside the second guide wall portion at a constant height above the roadway, the first guide rail portion having a guide surface substantially perpendicular to the roadway, continuous along the length of the first guide rail portion, facing the second guide wall portion, and spaced from the second guide wall portion by a constant predetermined distance, the first guide rail portion being spaced from the first guide wall portion by a distance at least as great as the spacing between the guide walls of the guideway portions;

a second, fixed rail structure, of L-shaped cross-sectional configuration, extending along the first guide wall portion from the second end of the junction to a location spaced from the first end of the junction by a distance greater than the distance between the junction first end and the first rail structure, the second, fixed rail structure having a horizontal portion and a vertical portion, comprising a second guide rail portion, projecting downwardly toward the roadway and extending alongside the first guide wall portion at a constant height above the roadway, the second guide rail portion having a guide surface substantially perpendicular to the roadway, continuous along the length of the second guide rail portion, facing the first guide wall portion, and spaced from the first guide wall portion by a constant distance equal to that between the first guide rail portion and the second guide wall portion,

a single movable rail structure of L-shaped cross-sectional configuration pivotally supported adjacent the second guide wall portion and between the second fixed rail structure and the first end of the juncture, the movable rail structure having a horizontal portion and a vertical portion, comprising a third guide rail portion, projecting downwardly toward the roadway, the third guide rail portion having first and second ends and first and second, oppositely facing guide surfaces each substantially perpendicular to the roadway, the first guide surface of the third guide rail portion facing the first guide wall portion, the movable rail structure being pivotable, about a rotational axis substantially perpendicular to the roadway and spaced between the first and second ends of the movable rail structure, between a first position, in which the second end of the third guide rail portion is contiguous with the second guide rail portion and in which the first guide surface of the third guide rail portion is equidistant, along its length, from the first guide wall portion, and a second position in which the first end of the third guide rail portion is positioned immediately adjacent the first guide wall portion and in which the third guide rail portion second end is spaced, from the first guide wall portion, beyond the second guide rail portion and in which the distance between the second guide wall portion and the second guide surface of the third guide rail portion, along a line perpendicular to the second guide wall portion and intersecting the second end of the third guide rail portion, is substantially equal to the distance between the left and right guide walls of the guideway portions;

first guide rail following means, mounted on vehicle, for movably engaging the first guide surface of the third guide rail portion, and subsequently, the guide surface of the second guide rail portion, upon the vehicle passing through the junction from the junction first end when the movable rail structure is in its first position and, upon the movable rail structure alternatively being in its second position, for movably engaging the second guide surface of the third guide rail portion and diverting the vehicle toward the second guide wall portion; and

second guide rail following means, mounted on the vehicle for movement engaging the guide surface of the first guide rail portion and guiding the vehicle alongside the second guide wall portion and onto the third portion of the guideway upon the vehicle being diverted toward the second guide wall portion.

28. The switching system of claim 27, the vehicle having means for movably engaging the guide walls for guiding the vehicle along the guideway, the means for movably engaging the guide walls including left and right follower structures adapted to ride against respective ones of the guide walls, the first and second guide rail following means being mounted on respective ones of the left and right follower structures.

29. The switching system of claim 28, wherein the first and second guide rail following means respectively comprise first and second guide rollers rotatable about respective axes substantially perpendicular to the roadway, each guide roller projecting upwardly from the respective follower structure upon which it is mounted, the first guide roller being positioned in horizontal register with the second and third guide rails, and the second guide wheel being positioned in horizontal register with the first guide rail.

30. In a transportation system employing at least one vehicle adapted to travel along a guideway, the system having a guideway junction having a first end communicating with a first portion of the guideway and a widened, bifurcated, second end communicating with second and third, mutually diverging portions of the guideway, a switching system comprising:

guiding means, comprising a single movable guide rail positioned adjacent the first end of the junction and pivotable about an approximately vertical axis between first and second positions, having a first guide surface operative for constraining a vehicle from turning toward the third guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its first position, the guiding means further having a second guide surface operable for guiding a vehicle toward the third guideway portion upon the vehicle entering the junction from the junction first end when the movable guide rail is in its second position;

another guiding means comprising structure immovably positioned between the movable guide rail and the second guideway portion and operative for guiding a vehicle through the junction and onto the second guideway portion upon the vehicle being constrained by the first-mentioned means from turning toward the third guideway portion; and

yet another guiding means comprising structure immovably positioned between the first end of the junction and the third guideway portion and operative for guiding the vehicle through the junction and onto the third guideway portion upon the vehicle being initially guided toward the third guideway portion by the first-mentioned guiding means, the movable guide rail being spaced laterally, relative to the junction, from the structure of the third mentioned guiding means, the movable guide rail having a first end adjacent the junction first end and a second end adjacent the structure of the second-mentioned guiding means and between the structure of the second mentioned guiding means and the junction first end, the first and second guide surfaces extending along the movable guide rail to a location thereon adjacent the movable guide rail second end, the portions of the first and second guide surfaces adjacent the movable guide rail second end being intermediate the respective structures of the second and third mentioned guiding means upon the movable guide rail being in its second position.