GB2154191A - Traffic system comprising steerable vehicles adapted for use as tracked vehicles and track-defining roads - Google Patents

Abstract

A system for transversely guidable vehicles comprises supporting arms 7, 8 and guide rollers 9, 10 which are mounted on these arms and which, when projecting sideways in the track lane 3, cooperate with guide surfaces 11, 14 bordering the road side. Since the transverse guidance arrangement on the driver's side is exposed to considerably less danger of being damaged than the arrangement on the right-hand side which is remote from the driver, only the right-hand guide roller needs to have a retractable design. A rigidly mounted left-hand guide roller 9 is advantageous when filtering into a track section. First, with the rigidly mounted guide roller 9 on the driver's side, the vehicle is driven up to the left-hand guide edge 11, which is extended forward on one side, and is guided on one side along this edge until the beginning of the right-hand guide edge 14 when the steering is turned, for example. By virtue of being guided on one side, the vehicle is in a specified transverse position before entering the track where it is guided on both sides, and therefore a road sensor 17 attached to the underside of the vehicle for extending the right-hand transverse guiding arrangement is operated reliably by a ramp-shaped control cam 13 on the road surface without special attention being required by the driver to adjust the guide rollers 9, 10. At the end of the track section 3 the transverse guiding arrangement is automatically retracted in an appropriate manner. <IMAGE>

Description

SPECIFICATION Traffic system comprising steerable vehicles adapted for use as tracked vehicles, and vehicles,, and track-defining roads The invention relates to a traffic system comprising steerable vehicles which are also adpated for use as tracked vehicles, and track-defining roads, as is known from, for example, German Offenlegungsschrift 30 09 857.

Vehicles, for example omnibuses, which are equipped with transverse guidance arrangements can run advantageously on particularly narrow driving routes designed specially for these vehicles.

Guide edges having lateral guide surfaces arranged along the roadside define the track required for this purpose, with guide rollers which are fixed to the vehicle and arranged in a horizontal plane rolling along these guide surfaces. The guide rollers project laterally from the vehicle contour and are attached to supporting arms which in turn are rigidly connected to the axle stubs, particularly of steerable wheels of an axle. The possibilities for the positioning of guide rollers in the vertical direction are severely limited.

On the one hand, they should have the maximum possible ground clearance. On the other hand, for the free movement of the vehicle body on bends the guide edges must not exceed a certain height. This results in the guide rollers having a relatively low ground clearance so that during untracked operation bottoming of and damage to the guide rollers can be caused particularly by kerbs or pavements if in addition there are also potholes or drain recesses in the road.

To enable a vehicle to be driven freely also on normal roads, it is known practice, for example from German Offenlegungsschrift 26 36 656, to design guide rollers on both sides of the vehicle to be retractable behind the vehicle contour, and thereby to obtain greater freedom of movement in the lateral and vertical directions, and to protect the transverse steering arrangements from damage. Operation of the retracting and extending mechanism is effected, for example, by the driver. However, the disadvantage in this case is that, when entering and leaving track routes, the driver's attention is required and failure to carry out the correct operating function can result in serious impairment of the transverse steering function.

An embodiment of a crossover point between a road and track section is known from German Offenlegungsschrift 30 35 519. The guide edge on the driver's side of the track begins in the entry area at an earlier stage than the guide edge on the side remote from the driver, which guide edge has a funnel-shaped widening. For entry the guide roller on the driver's side must be adjacent to the corres ponding guide edge. By applying a lateral or transverse force in the direction of the guide edge, for example by turning the steering mechanism, the vehicle is then steered on one side as far as the beginning of the other guide edge. At the end of the track section the two guides edges terminate simultaneously and are followed by a section of normal road.

According to German Patent Specification 10 87 471 there is a known transverse guidance arrangement which, upon entry of a vehicle into a track section, is automatically lowered into a guide groove in the ground and, vice versa, is raised if the vehicle leaves the track section. To lower the transverse guidance arrangement into the operating position a mechanical locking device is lifted for a short time by a deflecting cam or the like on the road surface and by a feeler or probe on the vehicle which cooperates with the deflecting cam so that by virtue of gravity a lever with the guide rollers attached thereto can drop. Lifting is effected for example by the track rollers rolling over an overriding element on the road. However, the overriding element can also be mounted in tunnels, for example on the arch.The lever bearing the guide rollers is then connected to a system of rods which is moved correspondingly in a vertical direction by cams. The disadvantage in this case is that the driver must steer the vehicle into a transverse position in which it is possible for the transverse guidance arrangement to be lowered in to the track groove. This calls for special driving skill or other means which are, however, not mentioned.

However, this does not ensure that the vehicle is in a transverse position in which the transverse guidance arrangement is also activated by the cams on the road. It is possible that the correct triggering can also be achieved only at particularly low driving speeds.

In addition, the transverse guidance arrangement concerned is of a completely different type from that to which the subject of the invention is to be applied.

German Offenlgungsschrift 30 09 857, which was mentioned in the introduction, describeds a transverse guidance arrangement having guide rollers which are mounted on rigid supporting arms and roll along lateral guide edges. However, in the area of road intersection, for example points of crossings, there may be provided types of roadway from which the lateral vertical guide edges must be omitted. In this case an auxiliary transverse guidance arrangement or system is provided, comprising a central guideway and track groove of the type as described in German Patent Specification 10 87 471. When crossing over from the outer guideway to the central guideway the transverse guidance element must be lowered or raised.Atouch-contact roller bar, connected to the track guide lever to which the central guide rollers are attached, bears at one end a touch-contact roller which cooperates with extending and retracting cams on the roadway. The cams are formed by a shaped slot in which the touchcontact roller engages laterally. In this connection reference is made merely to the automatic lifting and lowering of a central guideway, that is for crossing overfrom a track section having lateral guide edges to a track section having a grooved guide, and vice versa.

The problem underlying the invention is to reduce the risk during normal road use, of damage to transverse guidance arrangements having guide rollers projecting from the vehicle on both sides and, yet to enable crossover from untracked operation on normal roads to tracked operation on special track sections having lateral guide surfaces, and vice versa,withoutthe driver's attention being required for adjusting the guide rollers.

According to the present invention there is provided a traffic system comprising steerable vehicles which are also adapted for use as tracked or guided vehicles, and track-defining roads, the vehicles each having transverse guidance arrangements which are associated with the steerable wheels of the vehicle and include guide rollers which are supported by supporting arms and which, projecting laterally cooperate with opposed guide edges on the road, and which assist in the execution of the turning movement of the steerable wheels, and having road sensing elements located on the vehicle and which road sensing elements cooperate with control means on the road surface which are located in the area before entry to and after exit from respective track sections, wherein the guide roller of the transverse guiding arrangement which is located on one side of the vehicle is mounted on its support arm so as to be retractable and extendable by means of an associated control element, the control element being adapted to be activated by means of the road sensing elements and, in a filtering-in area leading to the track section, the guide edge on the other side to said one side extends further forward than the oppositely lying guide edge, and in the direction of travel, the control means on the road surface of the filtering-in section is located after the beginning of the guide edge on said other side, but before the beginning of the oppositely lying guide edge.

The transverse guidance arrangement on the driver's side is, even in the event of a low ground clearance, considerably less exposed to the risk of damage than the arrangement on the side remote from the driver, and therefore only this latter guide roller is designed to be retractable. To filter into a track section the vehicle is driven firstly, with the rigidly mounted guide roller on the driver's side, up to left-hand guide edge (when driving on the right) which is extended forward on one side, and is guided on one side along this edge until the beginning of the right-hand guide edge when the steering mechanism of the vehicle is turned, for example.By virtue of being guided on one side, the vehicle is in a specified transverse position before entering the track section where it is guided on both sides, and therefore a road sensor attached to the underside of the vehicle for extending the right-hand transverse steering arrangement is operated reliably by a ramp-shaped control cam on the road surface without special attention being required bythe driver to adjust the guide rollers. Before leaving the track section, the vehicle is activated by the, or an additional, laterally offset road sensor and by a control cam which is arranged appropriately on the roadway and which causes the transverse guidance arrangement to be retracted.For the sake of safety the control cam in the filtering area is lower than the control cam before the exit from the track section so that the road sensor for retracting the transverse guidance arrangement cannot under any circumstances be inadvertently operated.

It is advantageous that the risk of damage to the guide rollers exposed to danger has been reduced, without the driver having to intervene in each steering operation, and without also the high costs which would be involved in the case of transverse guidance arrangements which are retractable on both sides, and yet having almost the same safeguard against damage. It is also advantageous that, in the event of the control system of the transverse guidance arrangements being damaged, a vehicle with a guide roller which is rigidly mounted on one side i.e., cannot be retracted, can still pass through a tracked section while guided cn one side.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a plan view of filtering and exit sections of, as well as a diagrammatically represented vehicle entering a track section; Figure 2 shows a front view of the steerable front axle of the vehicle with transverse guidance arrangements in the position for road travel, corresponding to the vehicle in the filtering section shown in Figure 1, and Figure 3 shows a side view of a road sensing element attached to the underside of the axle, in front of the ramp-shaped profile of a control cam on the road surface.

Figure 1 shows, in a diagrammatic plan view, a left hand drive vehicle 1 which has come from a normal road and is in a filter zone 2 before a track section 3.

The front axle 4 and rear axle 5, and the position of supporting arms 7, 8 with associated guide rollers 9, 10 of a transverse guidance arrangement and extending around the front wheels 6 can also be seen.

The guide roller 10 on the side remote from the driver is retracted within the outer profile of the vehicle 1, which is advantageous in normal untracked operation. The guide roller 9 which is arranged on the left as seen by the driver, i.e., on the driver's side, is adjacent to the left-hand vertical guide edge 11.

The steering linkage which consists of track levers, track rod and axle body can also be seen. An arrow indicates the direction of travel 12. In the direction 12 ahead of the vehicle 1 a control cam 13, which is on the entry side in the right half of the roadway or at least off the centre of the roadway, is arranged before the track section 3, the said cam having, for example, a ramp-shaped profile in side view. The right-hand guide edge 14 begins to funnel inwards in direction 12 after the control cam 13. A break in the track section 3 is indicated by dot-dash lines running vertically to the lane of the track section 3. This is followed by the beginning of the exit zone. The vertical guide edges terminates simultaneously with a funnel-shaped widening. A control cam 15 on the exit side in the left half of the roadway is situated before the end of the track section 3.

Figure 2 shows a front view of the front axle region of the vehicle 1 according to Figure 1 which is in the filter zone 2, before the control cam 13 on the entry side. The guide roller 9 is adjacent to the left guide edge 11. The right-hand supporting arm 8 and guide roller 10 are in a position retracted within the vehicle contour. Road sensing elements 16, 17 are provided on the axle body, to the left and right of the centre.

The control cams 15, 13, which project above the road surface 18, can be seen in the form of dot-dash lines after the sensing elements and each in the appropriate transverse position. The control cam 13 on the entry side is lower than the control cam 15 on the exit side. This has the advantage that, with road sensing elements 16, 17 arranged at staggered heights in an appropriate manner, and because of the low gear shifting gate on the entry side, the road sensing element 16 cannot under any circumstances be actuated inadvertently by a control cam on the entry side.

Figure 3 is a side view of the road sensing element 16 or 17 attached to the underside of the axle body, in a position shortly before running over the control cam 13 or 15. The road sensing element comprises a pivotable bar 19 which is pivotally mounted on an articulated element fixed to the axle and biassed by a spring to a contacting position. When the vehicle runs over a control cam, the end of tilting bar 19 is lifted by being pivotted in a clockwise direction as shown in Figure 3, and a pilot valve 20, which is connected thereto, is operated, which valve is connected to a control element (not shown), for example a hydraulic or pneumatic working cylinder or even an electromechanically operable spindle drive.

During untracked operation, i.e., on normal roads, the right-hand guide roller on its support arm is retracted on the vehicle 1, as already mentioned, and the left-hand guide roller is in a position projecting laterally from the vehicle. The right-hand transverse guiding arrangement is designed to be automatically retractable and extendable because the right-hand supporting arm 8 and guide roller 10 are particularly exposed to the risk of damage in normal road traffic.

This is due to the fact that the vehicles, for example omnibusses, have to drive close to pavements, particularly at stopping points, and, moreover, the ground clearance of relatively low mounted support arms and guide rollers is very soon taken up by high pavements and, in addition, potholes or drain recesses therein. On the other hand, the transverse guiding arrangement on the left side points towards the centre of the roadway. Past experience has shown that damage to low mounted guide rollers and support arms occurs considerably less often in this position.Therefore, the guide rollers on the left-hand side can be kept in a constantly extended position with almost the same safeguard against damage and without the expense of complicated retractable transverse guidance arrangements, to enter a track section 3 it is necessary for the guide roller 9 on the left hand side to be constantly extended, as it is in this case. Only then is it possible for the guide edge - which extends forward on the driver's side - of a track section 3 to be used as a guide ridge on one side for the left-hand guide roller without the driver having, for example, to operate swithes for extending transverse guiding arrangements. Without reducing speed before the track section, the driver can steer the vehicle in the direction of the left-hand guide edge until the guide roller is adjacent thereto.A transverse or lateral force can be applied to the vehicle by turning the steering mechanisms or other means, which force ensures guiding on one side. Whilst the vehicle 1 is being guided or steered on one side before the filter zone 2, it is also particularly in a specific transverse location. This ensures that the control cam 13 on the road surface in the filter zone 2 and the road sensing element 17 on the vehicle are aligned in the same transverse position relative to one another so that the road sensing element 17 is definitely operated.

With the operation of the road sensing element 17, the pilot valve 20 for example is also actuated and a hydraulic or pneumatic control element is activated to pivot the right-hand support arm 8 and guide roller 10 out into the sensing position. With the beginning of the right-hand guide edge 14, the transverse guiding arrangements on both sides of the vehicle 1 are therefore in the sensing position. In order that the guide roller 10 may enter engagement against the right-hand guide edge 14 without shock, the beginning of the right-hand guide edge extends outwards in a funnel shape.

Before departure from a tracked section as shown in Figure 1, a further control cam 15 is arranged in the left half of the roadway in order to actuate the road sensing element 16 arranged on the left side in a corresponding transverse position. This actuation causes the control element for retracting the righthand transverse guidance arrangement to be activated. In order that the guide roller 10 may not be retracted while still in the track section 3, but only shortly after leaving it, a control connected to the road sensing element 16 can actuate the control element with a time delay. This has the advantage that the the location of the control cam 15 on the road does not have to be effected with extreme precision.

As can also be seen in Figure 2, the control cam 13 on the entry side is lower and broader than the control cam 15 on the exit side. The width is advantageous if, for any reason whatever, for example because of side swaying, the vehicle 1 is not correctly steered in the transverse direction. In this case, because of the width of the control cam, the road sensing element is still operated with great reliability by this cam even whenever the vehicle deviates from the correct transverse position. Instead of a wide control cam, the road sensing element could also have a corresponding width.In order that the switch responsible for retracting the transverse guiding arrangement may not under any circumstances be actuated whenever the vehicle is in an incorrect transverse position, the road sensing element on the entry side for extending the transverse steering arrangement is arranged at a correspondingly lower lever than the road sensing element 16 on the exit side. Accordingly, this level is naturally also the height of the preferably ramp-shaped control cams. The control cam 15 on the exit side can be high and narrow because the vehicle 1, which is track-guided, then drives over the control cam 15.

This eliminates the possibility that the road sensing element 17 might be damaged, for example inadvertently, by the high extending control cam 15.

Even a single road sensing switch, which is operated alternately by control cams of equal height in the entry to and exit from track sections, would be sufficient in principle. By an appropriate control the transverse steering arrangement is then alternately retracted and extended. However, less reliability as to the position of each of the guide rollers is to be assumed in this case.

The described embodiment is of a left hand drive vehicle driving on the right hand side of the road but it will be understood that, for vehicles designed for driving on the left-hand side, reference to the left and right are reversed as appropriate, so that the side of the vehicle nearest the kerb has the retractable guide arrangement.

Claims (8)

1. A traffic system comprising steerable vehicles which are also adapted for use as tracked or guided vehicles, and track-defining roads, the vehicles each having transverse guidance arrangements which are associated with the steerable wheels of the vehicle and include guide rollers which are supported by supporting arms and which, projecting laterally cooperate with opposed guide edges on the road and which assist in the execution of the turning movement of the steerable wheels, and having road sensing elements located on the vehicle and which road sensing elements cooperate with control means on the road surface which are located in the area before entry to and afterexitfrom respective track sections, wherein the guide roller of the transverse guiding arrangement which is located on one side of the vehicle is mounted on its support arm so as to be retractable and extendable by means of an associated control element, the control element being adapted to be activated by means of the road sensing elements and, in a filtering-in area leading to the track section, the guide edge on the other side to said one side extends further forward than the oppositely lying guide edge, and in the direction of travel, the control means on the road surface of the filtering-in section is located after the beginning of the guide edge on said other side, but before the beginning of the oppositely lying guide edges.

2. A system according to claim 1, wherein entry and exit control means are located successively in the filtering-in section and in the exit section and are in a laterally offset arrangement relative to one another.

3. A system according to claim 1 to 2, wherein the exit control means for retracting the transverse steering arrangement (is designed to be higher than the entry control means).

4. A system according to any one of claims 1 to 3, wherein the entry control means is several times wider than the associated road sensing element.

5. A system according to any one of claims 1 to 4, wherein the control element, which is in the form of a working cylinder, is adapted to be actuated by a pilot valve connected to the road sensing elements.

6. A system according to any one of claims 1 to 5, wherein the road sensing element are in the form of pivotable bars which are pivotally mounted on the underside of the vehicle and are resiliently biassed to a contacting position.

7. A system according to any one of claims 1 to 6, wherein the output of the road sensing element for retracting the transverse steering arrangement is connected to a control element through a time-delay arrangement.

8. A traffic system substantially as described herein with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.