GB1566066A

GB1566066A - Road track vehicle

Info

Publication number: GB1566066A
Application number: GB3695477A
Authority: GB
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1976-09-16
Filing date: 1977-09-05
Publication date: 1980-04-30
Also published as: DE2641637A1; DE2641637C2; IT1089881B

Description

(54) A ROAD TRACK VEHICLE (71) We, DAIMLER-BENZ AKTIEGESELL- SCHAFT, of Stuttgart - Unterttirkheim, Federal Republic of Germany, a Company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to a vehicle adap ted for use, selectively so as to be guided in a track and to run on roads, particularly, but not exclusively, for a traffic system for local short-distance passenger traffic, such as suburban commuters.

A traffic system of this kind combines the advantages of purely track-bound traffic having a separate permanent way namely high transport capacity and great punctuality, little space required, and the facility of being run at least partially auto matically - with the advantages of road traffic not dependent on tracks - good service over a wide area, and flexibility provided that the vehicles are without difficulty convertible from track running to road running. Good service for an area can be supplied in outer districts in a flexible and inexpensive manner, and in addition in a crowded centre transport can be provided in a safe and punctual manner on particularly narrow running tracks.

A particular problem in a traffic system of the kind referred to consists of the requirement of the lowest possible entrance height into the vehicle on the one hand the entrance is typically disposed near the axle, usually at the front - and a whole catalogue of requirements in respect of the means for guiding the vehicle transversely on the track, by means of transverse guide rollers and transverse guide webs or surfaces on the track on the other hand. These requirements are as follows: In the vertical direction the clearance between a transverse guide roller and the carriageway must be sufficiently great to avoid not only contact with the ground, but above all, contact with curbstones when running on roads, taking into account all conceivable suspension and pitching movements of the vehicle.

The transverse guide webs on the track channels must be sufficiently high to leave above the top edge of the transverse guide rollers a reserve of height for vertical movements of the transverse guide roller on the transverse guide webs.

The relative position of the lower edge of the vehicle body - this position determines the entry height - in relation to the top edge of the transverse guide webs must be such that contact with the web is avoided if the vehicle body deflects on its suspension, pitches, and/or rolls; in this connection it must be borne in mind that when travelling on bends any overhanging parts extending beyond the axles of the vehicle must project over the webs.

Finally, it is desirable that all the equipment for the track guidance to be installed in existing models which have been proved successful, without any great modification of existing vehicle constructions, or at least without major modifications to the supporting parts.

According to the present invention there is provided a vehicle adapted for use selectively on a road and a trackway having channels with laterally opposed transverse guide surfaces for guiding the vehicle, the vehicle having transverse guide rollers disposed on both sides of the vehicle in the region of the vehicle axles the guide rollers being adapted to co-operate with the transverse guide surfaces to guide the vehicle, wherein each of the transverse guide rollers is guided for movement along an upwardly directed path on the vehicle, this path ex tending in use at least approximately parallel to the transverse guide surfaces and being urged by a force storage means in the direction of a lower position determined by stop means. This makes it possible for the transverse guide rollers to be disposed in a particularly low position without danger, because contact with the ground can now safely be tolerated as the rollers can yield elastically in the upward direction.

The rollers may be guided on a long lever arm along a slighly curved portion of a circular arc or rectilinearly in a column guide. For road running the rollers may also for example be raised by means of a working piston adapted to be operated by compressed air. The deflection or lifting path preferably amounts approximately to at least maximum axial overall dimension of the transverse guide roller itself. As protection against chafing and to facilitate repulsion and slipping-off, the lower side of the transverse guide roller is provided with a protective plate, which may be in the form of an emergency running wheel of this kind the transverse guide roller can be provided with a relatively soft tread surface, thus contributing towards the transverse comfort of the vehicle. The leading peripheral side of the transverse guide-roller may be protected by a deflector skid.

An embodiment of the invention will now be described by way of example, with reference to the drawings, in which: Figure 1 shows a side elevation, Figure 2 a plan view, Figure 3 a front elevation view of the front axle construction of an omnibus, with the supporting arms carrying the yieldable transverse guide rollers, and Figure 4 shows in detail the axial vertical yielding guide of a transverse guide roller.

The road-running omnibus indicated in dot-dash lines in Figure 1 is capable of being guided by means of transverse guide rollers on a running channel 2 consisting of a carriageway 3 and laterally opposed transverse guide web or surfaces 4. The transverse guiderollers which project laterally slighly beyond the body profile of the vehicle and are situated at a particularly low level co-operate with the transverse guide webs, the distance between which is greater than the width of the body profile.

Transverse guide rollers are disposed in the regibn of each axle in front of and behind each vehicle wheel 5 on each side of the vehicle, that is to say a total of four rollers for each vehicle axle. Because of the extremely low position of the transverse guide rollers-their clearance f amounts to about half the width of the rollers (Figure 19 the transverse guide webs 4 can be made particularly low (web height h) whilst still having adequate safety space in the upward and downward directions, so that they can without difficulty be lower by an adequate safety margin s than the ground clearance H of the vehicle, which in this respect is of conventional type. Ground clearance should be kept particularly low, especially in the region of the entrances 6, because it directly dictates the entrance step height. On tight bends the ends of the vehicle project beyond the transverse guide webs on the outer side of the bend, while the region between the axles projects beyond the webs on the inner side of the bend. Because of pitching movements the ends of the vehicle are particularly liable to bottom and can easily be raised in order to prevent this.

The low arrangement of the transverse guide rollers with the slight clearance f is made possible by the fact that firstly they are disposed on unsprung parts of the vehicle axle and accordingly undergo only relative small movements or displacements, particularly in the downward direction, namely through wear of the tyres and flattening of the tyres due to shocks, load and/ or loss of air pressure. Secondly, the low operating position of the transverse guide rollers is permitted by their elastic resiliency in the upward direction and by their optional additional retractability when running on the roads, so that contact with curbstones can be taken without damage or even avoided.

The illustration of the front axle 7 in Figures 1 to 3 shows an axle body 9 which carries the vehicle body 8 and which is connected to the latter by way of longitudinal and transverse links 10 and 12 respectively. In the case of the front axle carrying the steerable wheels, axle joints 12 are provided. A brake flange 14 and a wheel journal 15 are disposed on the articulated steerable part 13. The supporting arms 16 carrying the transverse guide rollers are provided on the brake flange. These supporting arms thus participate in the steering movement of the steerable wheels, and when the vehicle is running on a track the steering of these wheels is determined by the rollers and the supporting arms.

On the ends of the supporting arms are mounted vertical guide bushes 17 in which round hollow guide columns 1'8 are held in such a manner as to be readily slidable but secured against tilting. The guide columns are secured against rotation in the guide bush 17, although this is not shown in the drawling. The columns may alternatively be of square or triangular cross section The top end of the guide column is secured in the guide bush against falling out by means of a flange 21 adapted to be screwed on and bearing against the upper end face of the guide bush. The flange 21 acts as a stop to determine the bottom position of the transverse guide roller in which the latter is ready for operation, as shown in the drawing. A pneumatic working cylinder may, for example, also be provided in the interior of the hollow guide column for the purpose of raising the transverse guide rollers when running on roads. On the bottom end of the guide column are fas tened the journal 19 for the transverse guide roller 1 and a small flange 22 for a loading spring 23. The loading spring 23 is disposed between the bush 17 and the spring support flange 22 and urges the roller 1 into the operating position shown.

The spring need not be particularly strong, since it simply has to secure the roller only against upwardly directed axle shocks originating from irregularity of the carriageway, with an acceleration greater than that due to gravity. In order to permit the easiest possible yielding of the roller when contact is made with the ground or an obstacle, the spring should be as soft as possible.

On the tub 20 which rotates together with the roller 1 is screwed a round shock-andwear-resistant protective shield 24 which is in the form of a flat cone, which is provided on its outer periphery with an emergency running rim 25 of solid rubber. The emergency running rim is smaller than the tread surface of the roller 1 to the extent of the flattening a - including tyre wear which is formed on a pneumatic tyre under load. Only during extreme transverse accelerations of the vehicle will the emergency running rim 25 reach the transverse guide web and support the relatively soft transverse guide roller.

The exposed front side of the tranverse guide roller is protected by a stationary, downwardly sloping deflector skid 26 which is fastened on the guide column (holding arm 27) and can yield together with the roller. The deflecting skid 26 extends the effective deflecting surface to the height of the top edge of the transverse guide roller.

In order to prevent the transverse guide roller from being pushed upwards by rolling on the transverse guide web, the transverse guide webs may be provided with a negative slope which biases the transverse guide rollers downwards. Instead or additionally thereto the transverse guide rol ler may also be given a corresponding track by suitable forward inclination of the axis of rotation in relation to the vertical direc tion.

In an alternative form, each of the transverse guide rollers is disposed on a swivell ably mounted lever with an axis extending substantially in the horizontal plane of the vehicle at the height of the transverse guide roller in its position of operation so that pivotable movement of the lever moves the guide roller along said upwardly directed path.

WHAT WE CLAIM IS: 1. A vehicle adapted for use selectively on a road and a trackway having channels with laterally opposed transverse guide surfaces for guiding the vehicle, the vehicle having transverse guide rollers disposed on both sides of the vehicle in the region of the vehicle axles, the guide rollers being adapted to co-operate with the transverse guide surfaces to guide the vehicle, wherein each of the transverse guide rollers is guided for movement along an upwardly directed path on the vehicle, this path extending in use at least approximately parallel to the tranverse guide surfaces, and being urged by a force storage means in the direction of a lower position determined by stop means.

2. A vehicle according to claim 1, wherein each of the transverse guide rollers is disposed on a swivellably mounted lever with an axis extending substantially in the horizontal plane of the vehicle at the height of the transverse guide roller in its position of operation so that pivotable movement of the lever moves the guide roller along said upwardly directed path.

3. A vehicle according to claim 1, wherein each of the transverse guide rollers is disposed on a telescopically guided column movable relative to and at least approximately vertically disposed guide.

4. A vehicle according to any one of claims 1 to 3, wherein the clear operating height of the transverse guide rollers above road elevl is less than the vertical spacing of the lateral surfaces of the transverse guide rollers abutting the channels.

5. A vehicle according to claim 4 wherein said clear operating height is half the vertical spacing of said lateral surfaces.

6. A vehicle according to any one of claims 1 to S wherein each of the transverse guide rollers is provided with an operating means for moving the transverse guide rollers into a raised position for road travel.

7. A vehicle according to any one of Claims 1 to 6 wherein the side of the transverse guide rollers which faces the carriageway is provided with a conical or curved shock-and-wear-resistant protective shield.

8. A vehicle according to Claim 7 wherein a protective shield is fastened to the rotating part of each of the appertaining transverse guide rollers.

9. A vehicle according to Claim 8 wherein the protective shield is circular in its outer contour.

10. A vehicle according to Claim 9 wherein on its outer periphery the protec

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the transverse guide roller in which the latter is ready for operation, as shown in the drawing. A pneumatic working cylinder may, for example, also be provided in the interior of the hollow guide column for the purpose of raising the transverse guide rollers when running on roads. On the bottom end of the guide column are fas tened the journal 19 for the transverse guide roller 1 and a small flange 22 for a loading spring 23. The loading spring 23 is disposed between the bush 17 and the spring support flange 22 and urges the roller 1 into the operating position shown. The spring need not be particularly strong, since it simply has to secure the roller only against upwardly directed axle shocks originating from irregularity of the carriageway, with an acceleration greater than that due to gravity. In order to permit the easiest possible yielding of the roller when contact is made with the ground or an obstacle, the spring should be as soft as possible. On the tub 20 which rotates together with the roller 1 is screwed a round shock-andwear-resistant protective shield 24 which is in the form of a flat cone, which is provided on its outer periphery with an emergency running rim 25 of solid rubber. The emergency running rim is smaller than the tread surface of the roller 1 to the extent of the flattening a - including tyre wear which is formed on a pneumatic tyre under load. Only during extreme transverse accelerations of the vehicle will the emergency running rim 25 reach the transverse guide web and support the relatively soft transverse guide roller. The exposed front side of the tranverse guide roller is protected by a stationary, downwardly sloping deflector skid 26 which is fastened on the guide column (holding arm 27) and can yield together with the roller. The deflecting skid 26 extends the effective deflecting surface to the height of the top edge of the transverse guide roller. In order to prevent the transverse guide roller from being pushed upwards by rolling on the transverse guide web, the transverse guide webs may be provided with a negative slope which biases the transverse guide rollers downwards. Instead or additionally thereto the transverse guide rol ler may also be given a corresponding track by suitable forward inclination of the axis of rotation in relation to the vertical direc tion. In an alternative form, each of the transverse guide rollers is disposed on a swivell ably mounted lever with an axis extending substantially in the horizontal plane of the vehicle at the height of the transverse guide roller in its position of operation so that pivotable movement of the lever moves the guide roller along said upwardly directed path. WHAT WE CLAIM IS:

1. A vehicle adapted for use selectively on a road and a trackway having channels with laterally opposed transverse guide surfaces for guiding the vehicle, the vehicle having transverse guide rollers disposed on both sides of the vehicle in the region of the vehicle axles, the guide rollers being adapted to co-operate with the transverse guide surfaces to guide the vehicle, wherein each of the transverse guide rollers is guided for movement along an upwardly directed path on the vehicle, this path extending in use at least approximately parallel to the tranverse guide surfaces, and being urged by a force storage means in the direction of a lower position determined by stop means.

10. A vehicle according to Claim 9 wherein on its outer periphery the protec

tive shield is provided with an emergency running rim facing the transverse guide web.

11. A vehicle according to Claims 9 or 10, wherein the diameter of the running rim of the protective shield is smaller than that of the transverse guide roller by the amount of the flattening of a pneumatic tyre of the transverse guide roller under normal operating load.

12. A vehicle according to Claim 10 or 11 wherein said running rim is of solid rubber.

13. A vehicle according to any one of Claims 1 to 12 wherein at least in the region of that part of the transverse guide roller lies in the direction of travel there is provided a shock-and-wear-resistant deflecting skid surrounding the transverse guide roller, this skid being peripherally stationary but adapted to move up and down together with the transverse guide roller and being sloping on its lower side.

14. A vehicle according to any one of Claims 1 to 13 wherein the range of vertical movement of the transverse guide roller is made sufficiently long to enable the bottom edge of the transverse guide roller to move upwardly to a position approximately at the height of the transverse guide web.

15. A vehicle according to any one of Claims 1 to 14 wherein said force storage means comprises a spring.

16. A vehicle adapted for use on both a road and a trackway substantially as described herein with reference to and as illustrated in the accompanying drawings.