A METHOD AND AN ARJANGEMENT TO STEER VEHICLES
This invention relates to a method to steer vehicles, especially vehicles for PRT (Personal Rapid Transit) or such kinds of vehicles or for PGRT (Personal and Goods Rapid Transit) , whereby the vehicles show steerable front wheels, which are intended for wheeling in a guideway supporting the vehicle and having power rails.
There is a need of a new method to steer such kinds of vehicles or vehicles in a trackbounded vehicle system with vehicles without a driver. Further, there is a need of being able to bring about an improved comfort in such vehicles and which in a satisfactory way fulfils demands upon noiseless and shock-free running and a system resulting in a noiseless, shock-free and smooth switching and at the same time is insensible to wind, snow or trash blowing round, for example plastic bags and leaves.
Vehicles, such as cars, are steered by a driver who, by turning the steer¬ ing-wheel of the vehicle, manually influences the front wheels to turn in desired direction. In PRT and similar vehicles the steering of a driver is replaced by some kind of mechanics. PRT and similar vehicles can be steered or shaped after many different basic principles and one is where steering is done by means of flanged wheels for rails, as in connection with rail¬ ways. It has also been tried other methods, for example to allow the vehicle to glide on air cushion or magnetic cushion and to be steered by guide wheels engaging a wall on both sides of the vehicle.
A method in accordance with the present invention has in view to fulfil the requirements made and at the same time to minimize or eliminate the incon¬ veniences of known methods and vehicles of the kind in question or which are steered by turnable front wheels.
One object of the method in accordance with the invention is to produce a possibility to locate power and signal cables and contact devices in such a sheltered way and in such a position that continuous and noiseless con- is effected. Another object of the method in accordance with the invention is that components included in the system, as power rails and the like, have the possibility to such a large room that they can be spread apart to reduce the risk of flash-over in connection with moisture. Further, that the room permits that the components can be given a durable dimensioning
and size, such as a wear-resisting dimensioning and size can be obtained on for example contact devices. The components should also be easy accessible for service, inspection and cleaning. In switching there exists an addi¬ tional object which is to effect a distinct and simultaneous contact of guide rail, power and signal conductivity. Still another object is to achieve a profile of the vehicles' guideway which is so low as possible so that the guideway will have a minimum of visual encroachment on the sur¬ roundings or the urban environment.
The method in accordance with the invention has the characteristic stated in the method claim 1.
The invention is also related to an arrangement to steer a vehicle of the kind in question for realization of the method, whereby the arrangement comprises a vehicle having steerable front wheels. The arrangement is characterized in that fact that ahead every front wheel is arranged a guide carriage, each of them is connected with a front wheel of the vehicle via an arm. Cto each guide carriage is arranged guide wheels, whereby at least one guide wheel is meant to bear on a guide rail for steering the vehicle, which guide rail is shown by a guideway.
The principle to steer a wheel of a vehicle with a follower being in front of the wheel and following a guide rail is previously known, for example by "dual-mode" buses. In this case the contact between guide rail and follower is done laterally or with a guide rail under the follower, which makes the system far greater liable to dirt, trash, snow and functional troubles than what is applicable in a working and fully automated system with transmission of power and with such demands in reliability in operat¬ ion as systems for PRT and similar.
Of said reason, one embodiment of the arrangement in accordance with the invention is that guide rails and power rails are arranged on a level above the wheels of the vehicle but at the same time arranged sheltered under portions of the guideway and/or under specially arranged protective sheets or similar.
Further characteristics of and advantages with the method and arrangement in accordance with the invention will in the following description be apparent by an embodiment example, whereby a simultaneous reference will
be made to the accompanying schematic drawings, of which Fig. 1 shows a cross section of a guideway for vehicles and a front view of a vehicle and an arrangement in accordance with the invention according to one embodi¬ ment, whereby the section is in front of the vehicle and in a part of the guideway where switching can be done and Fig. 2 shows from below the front part of the vehicle and a part of the guideway in Fig. 1.
With reference designation 1 in the figures is shown an arrangement accord¬ ing to one embodiment for steering of vehicles 11 of the kind in question in a guideway 2 for such vehicles. The arrangement 1 exists in this case both in the guideway 2 and in the vehicle 11.
The vehicles 11 are of such a kind that are part of a trackbounded vehicle system with vehicles without a driver for rapid personal transit, PRT (Personal Rapid Transit) or the like and/or rapid transit of cargo, goods or the like, PGRT (Personal and Goods Rapid Transit) or the like.
The guideway 2, which is meant for said kind of vehicles 11, forms a guide¬ way 2 for the vehicles and comprises a support 3- or a track for the wheels 14 of the vehicles 11 for the vehicles conveyance along the guideway. The said support 3 can itself rests upon a basis or a foundation, for example a foundation supported by columns, and shows a support track 4 or support surfaces for- the vehicle 11 or its wheels 14. Joining the said support 3 or support tracks 4 exist side walls 5 along the direction of the guideway 2, which side walls on a certain level above the support 3 are directed towards the middle of the guideway 2, as from the side walls 5 and in the direction of the opposite side wall 5 projecting flanges 6. In this respect, the support 3, both side walls 5 joining the support 3 and the said flanges 6 form two channels 25 or the like for the arrangement 1 or parts of the arrangement in accordance with the invention. As the support 3, side walls 5 with the said flanges 6 compose parts of the guideway 2, which are load- bearable, arranged to take up loadings and/or similar, these parts are shaped with an adapted strength. In accordance with one embodi-nent of the arrangement 1 according to the invention, the said support 3, side walls 5 with the said flanges 6 consist of two at a distance from each other exten¬ ding, load-bearing beams of steel, concrete or another material with struc¬ tural strength, which run between foundations supported by columns arranged at a distance from one another. According to an additional embodiment, the beams consist of substantially U-shaped beams, the open end of which are
directed towards each other, whereby the lower leg of the beams at this forms the said support 3 with support track 4 or support surfaces for the wheels 14 of the vehicle 11, the web the said side walls 5 and the upper leg the said flanges 6. The web of the beams can be shaped broader for an improved strength and bending strength of the beams if there are long span for the beams, whereby the said support 3, according to the embodiment example in the form of the lower leg, is arranged projecting from the web portion between the legs of the beam. Between the lower legs of the beams can be arranged stiffening stays or similar arranged at intervals. In orde to further cover the arrangement 1 the guideway 2 can comprise protective sheets 7 or similar, which can be shaped as an extension of the said flanges 6 of the side walls 5, see Fig. 1, or according to the said embodi¬ ment example, an extension of the upper leg of the beams. These protective sheets 7 or similar can be shaped of a simpler material or a material with lesser load-bearing capacity, as the protective sheets substantially have only a covering task for the arrangement 1 or parts of it against princip¬ ally different weather conditions, objects blowing around in the air or objects falling down, etc. The support 3, the side walls 5 and the said flanges 6 and in applicable cases the said protective sheets 7 indicate tw rocms 26, in which the arrangement 1 or parts of the arrangement and at least susceptible parts of the arrangement 1 are located and by this are well protected.
Thus, in the guideway 2 is comprised guide rails 8 and power rails 9. The guide rails 8 would also for example be able to be used as a power rail fo power conduction and/or signal transmission or earth, as well as the power rails 9, which form means for means for conducting power, signals and/or to earth or zero conductors. According to the erribodi ent example, the guid rails 8 are shaped with angled side portions or with a cross section as a truncated cone and are arranged in said rooms 26 and connected with or fixed to said flanges 6 of the side walls 5. The power rails 9 are likewis arranged in said rooms 26 and connected to or fixed to said flanges 6 of the side walls 5. The power rails 9 are arranged in the arrangement 1 or t the guideway 2 via insulated holders 10, as well as the guide rails 8 according to the erribodiment example shown. The guide rails 8 and the power rails 9 are carefully oriented with one another or arranged parallelly wit one another and oriented, for example at least partly by the said insulate holder 10. According to the embodiment example shown, the holder 10 is
shaped with a considerable width in order to lend the power rails 9 or the guide rails 8 and the power rails 9 to have an advantageous spreading and mutually distance, whereby the risk is eliminated for flash-over or simila It is further evident from the erribodiment example shown, that guide rails 8 and power rails 9 are arranged only on a level above the wheels 14 of th vehicle 11 but being at the same time sheltered in the guideway 2 under th flanges 6 and the protective sheets 7 and also that the holder 10 or the holders are arranged to the said flanges 6 and protruding from the flanges in the direction towards the middle of the guideway 2. The protective sheets 7 are arranged above and partly around the protruding parts of the holders 10 in order to protect them. The holders 10 can consist of relativ ely simple and mass-produced holders.
As the embodiment example, which is shown in the figures, shows a section of a guideway where switching can take place, the guide rails 8 and the power rails 9 are doubled, i.e. they exist in both of the guideway 2 shown rocms 26 or beams or underneath each flange 6 and in applicable cases each protective sheet 7 of the guideway 2. For the rest, besides in sections of the guideway which are shaped for switching, one guide rail 8 and one or more power rails 9 exist in one of these rooms 26 or beams or below one of these flanges 6 and in applicable cases below one of these protective sheets 7 of the guideway 2 and depending on in which direction switching can occur, in which direction or on which side a station-track is situated, etc.
The vehicles 11 show a cabin 12 for conveyance of passengers and/or cargo, goods and the like and according to the embodiment example are arranged above the guideway 2, which is arranged to support the vehicles 11 and a chassis or bogie, which is housed within the guideway 2. The cabin 12 and the chassis are connected by means of a frame member 13, which, according to the erribodiment example, extends through the upper side of the guideway 2 or an opening 23 in the guideway 2 or the guideway construction or bet¬ ween the beams or in applicable cases the protective sheets 7. The vehicles are equiped with wheels 14, as said, whereby each vehicle are steered by means of the front wheels as for example current vehicles, i.e. has turn- able and steerable front wheels, as cars. The wheels 14, for example a pair of front wheels and a pair of rear wheels, are driven by a motor 15 or an electric motor, which can be or are variable-speed motors, whereby also the wheels 14 can be speed controlled by the motors 15. The motors 15 are
electrically driven with electricity from the electric mains, why environ¬ mental influence is eleminated. With reference designation 24 in Fig. 1 is shown a driving shaft or coupling between motor 15 and wheel 14.
The vehicles 11 are without a driver, why the steering of the vehicles are realized automatically by guide wheels 18, which are arranged to the vehicle 11, its chassis or upon the upper side of the bogie, whereby the guide wheels are shaped to bear on the guide rail 8 of the guideway 2. According to the embodiment example, the guide wheels 18 are in pairs and in each pair arranged in a mutually angle or at an angle to be adapted to lie against the side edges or its tapered surfaces, see Fig. 1. As it is evident from the embodiment example shown, the in pairs arranged guide wheels are each carried by means of an axle 21 and each pair is carried by a guide carriage 16 or on its upper side and further that the guide carri- ages 16 are located below the vehicle 11 and at a distance ahead the wheel 14 or front wheels of the vehicle 11. With further reference to Fig. 2, it is evident that each of the guide carriages 16 with the in pairs arranged guide wheels 18 are connected with the front wheels 14 of the vehicle 11 b means of an arm 17 and when a guide carriage 16 follows a guide rail 8, th guide carriage steer, turn or angular displace the wheels of the vehicle via the arm 17. Thus, the front wheels 14 of the vehicle 11 are steered by the guide carriages 16 or one guide carriage 16, which lie against and are are steered by a guide rail 8, as it appears from the guide carriage 16 in the left part of Fig. 1. As it appears from the guide carriage 16 in th right part of Fig. 1, the guide carriage and its guide wheels 18 are not arranged in contact with a guide rail 8 but are situated in a lowered position or similar. Thus, one of the two guide carriages 16 are arranged to lie against the guide rail 8 arranged in the guideway 2. In switching sections along the guideway, where it exists two guide rails 8, and at the switching, each guide carriages 16 can be arranged to lie against a guide rail, however it is only during a short time or a moment, as one tenth of a second and before that one of the guide carriages 16 falls off and is lowered to a resting position. According to the embodiment example, the guide carriages 16 are thus arranged to be able to be raised or be lifted from a resting position to a contact condition, working position or a steering situation with the guide rail 8. The arrangement and the lifting movement to connect the guide carriages can be shaped in different ways, for exaπ le by the fact that the arms 17 are hinged on a horizontal shaft in front of the wheels 14 of the vehicle 11 or that the arms 17 are stiff
between the wheels 14 and the guide carriages 16, whereby only the guide carriages 16 are arranged to be able to be lifted. One of the two guide carriages 16 or the in pairs arranged guide wheels 18 are always raised in order to follow the guide rail 8, whereby the guide wheels 18 fence about the guide rail 8. Thus, each vehicle 11 can switch through the varying branchings of a network and up to its destination and into the correct station-track, etc. by the fact that one of the two guide carriages 16 or the in pairs arranged guide wheels 18 are raised and in contact with a guide rail 8.
The turnable front wheels 14 of the vehicle 11 can be or are meant for being interconnected by controls 27, track rods or other kinds of wheel rods in known manner from for example cars.
A fender wheel 29 is indicated in Fig. 1. The task for these wheels are as rotating fenders prevent that the wheels 14 of the vehicle 11 on one hand get into touch with the side walls 5 of the guideway 2, on the other will lift or raise, for example severe wind or a hurricane blow in connection with in other respects unfavourable circumstances, when such a lifting or raising would be able to occur.
The vehicle 11 is equipped with power contact devices 19 and signal contact devices, which are arranged on or to be carried by the guide carriages 16 according to the erribodiment example and according to an advantageous embo- diment of the arrangement and the method in accordance with the invention and moreover, according to one embodiment, are arranged or are located along one and the same partition line 22, for example by being arranged on holders 20 for the contact devices, which holders extends in or form a con¬ tinuation of that axle 21, which carries the guide wheels 18.
The arrangement and the method in accordance with the invention involve an optimum advantageous location of contact devices 19 to guide wheels 18 with one another by the fact that they partly are seated on the same component or on the guide carriage 16, partly can be located along or close to the same partition line 22. By that contact devices 19 of an guide carriage 16 get always a well localized and distinct contact with their respective power rails 9 in the guideway 2 for power, signal and/or earth and are ensured a continuous contact or lying and with uniform force against respective power rails 9 or 8, 9 in the guideway 2. Furthermore, it is
attained an optimum of lateral location even when the steered vehicle 11 partly deviate laterally from the line of the guide rail 8. The guide car¬ riage 16 follows in the partition line 22 only the guide rail 8 and not th movements of the vehicle 11.
The said frame member 13 of the vehicle 11 between cabin 12 and chassis is shaped as a thin member, whereby the opening 23 or the slot into the upper part 6 or parts 6, 7 of the guideway construction 3 - 6 or 3 - 7 or betwee the side walls 5, their flanges 6 or in applicable cases protective sheets 7 or beams get narrow. Owing to this the possibility for spreading of rail 8, 9 or electric energy conducting or signal conducting rails 9 or 8, 9 or the like is not unnecessarily restricted. Thus, the upper part 6 or parts 6, 7 of the guideway construction 3 - 6 or 3 - 7 are possible to give a wide shaping to cover the arrangement 1 and/or the rails 8, 9 in order to permit the advantageous spreading of power rails 9 or 8, 9 and by that also contact devices 19 and protection for rails and contact devices. Powe rails 9 or 8, 9 and contact devices 19 have also a sheltered placing in th arrangement 1 by the arrangement of them into the room 26 and the arrange¬ ment of the power rails 8, 9 under the upper part 6 or 6, 7 of the guidewa 2. The guideway construction 3 - 6 or 3 - 7 covers practically the chassis of the vehicle 11 completely and the more susceptible parts of the arrange ment 1. Guide rails 8, power rails 9, etc. of the guideway 2 and guide car riages 16, arms 17, etc. of the vehicle 11 can by this contruction also be shaped simpler and are easier to assemble and kindly to service. The power rails 9, or 8, 9 are arranged a little above the wheels 14 of the vehicle 11 so that the wheels can pass freely below the rails 8, 9 at switching.
As the case is in the present invention and by collecting and placing both guide rails and power rails only at the top in the room 26 in the guideway 2 one also pave the way for an optimum of utilization of the width of the guideway construction concerning to give the vehicles 11 a large wheel bas and by that a well or improved lateral stability than what is usual for vehicles of this kind.
In that case the guide rail 8 is utilized as a power rail, signal rail or the like, a contact device 19 can be arranged on the guide carriage 16 bet ween the guide wheels 18 for conducting power and/or signals or similar, see reference designation 28 in Fig. 1.
In known arrangements of this kind, the vehicles are not steered for example by wheels but power rails and contact devices participate in the steering, whereby besides considerable wearings and insecure operation an unsatisfactory travel comfort is obtained, i.a. by a shaking conveyance of the vehicle and in the course of loud and troublesome sounds, as screechin and the like. In the method and the arrangement according to the invention the steering operation for the vehicle is separated from that contact, which shall exist between rails and contact devices for conducting for example power and signals. Both said functions exist in two different sys- terns. In this case, the great forces existing from the vehicle and the con veyance of the vehicle will be supplied on the wheels of the vehicle and o the guide wheels respectively. The steering control and its forces are sep separated from that contact, which is needed between contact devices and rails for the support of power and signals, etc. through the guide carri- ages and their guide wheels and the steering engagement with guide rail or guide rails. The conctact devices shall only bear on the power rails for the contact with these and not for any steering function for the steering of the vehicle. Thus, in the method and the arrangement in accordance with the invention it is secured a durable arrangement with a safe contact bet- ween contact devices and power rails, signal rails and the like eliminating interruptions of the service and results in a safe contact to earth. Said contacts are free from noise and result in a noiseless running, i.e. the contacts does not produce any noise or noise worth mentioning. In utiliz¬ ation of the invention in vehicles of the kind in question it is attained a travel comfort and conveyance qualities for the vehicle existing in modern vehicles meant for roads and the speed applicable for road bounded vehicle traffic can be kept up, which thus in addition give capacity and economy for vehicles of the kind referred to in this connection.
Without exceeding the scope of the concept of the invention, modifications of the method and the arrangement in accordance with the invention should be possible. Thus, it would be completely thinkable to carry out the arrangement according to the invention as an elevated track. In that case the protective sheets would be replace by a fully covering sheet and the cabin frame member and the cabin be attached underneath instead of above the track. However, there exists inconveniences with elevated tracks, as that the track must be located substantially higher and the support posts for the track must be cantilevered to allow room for the vehicles or the carriages to be able to pass the posts. At switching the bogie must pass
over the rail, in which the vehicle is hung. Moreover, elevated tracks hav a specific factor of risks in that objects as for example lorries, trucks or contract machines by mistake can be parked under the elevated tracks where the vehicles or carriages are conveyed. Another important disadvant- age with elevated tracks is that the passengers feel themselves floating, as they cannot get a feeling of a stationary basis. Furthermore, it must be once again emphasized that in the method and the arrangement in accord¬ ance with the invention the steering forces from guide rails and contact devices for conducting of electricity, signals and to earth are unloaded and the contacts are neither arranged as sliding elements or the like whic steer or take part in steering of the vehicle, as the steering of the vehicle is done by guide wheels or devices separated from electrically contact elements. The method and the arrangement are thus not restricted to that which has been shown and described in the erribodiment example but soley by the following claims.