WO1993017885A1

WO1993017885A1 - Variable geometry joint system designed mainly for trailer trucks

Info

Publication number: WO1993017885A1
Application number: PCT/PL1992/000008
Authority: WO
Inventors: Wojciech Pilarczyk
Original assignee: Wojciech Pilarczyk
Priority date: 1992-03-05
Filing date: 1992-06-17
Publication date: 1993-09-16
Also published as: PL293749A1

Abstract

The purpose of the invention as it is presented herein is designing the trailer-truck joint system able to provide variable turning axis of vehicle being hauled in relation to the truck (or tractor) depending on cornering direction and based on mechanical parts. The invention idea consists in the variable - geometry joint system designed mainly for trail-truck road trains, characterized in that it combines at least two pairs of structural nodes (4) fixed in such way that one pair is located at the hauling vehicle rear part (1) and the other at the hauled vehicle, i.e. trailer (2) or semi-trailer (9) front part, with two structural nodes (4) connected one to another by means of at least pull rods (5) and (6) in such way that the pull rods (5), (6) form diagonals of the quadrangle circumscribed over the nodes (4). The other important feature of this invention is that the structural node pair (4), mounted in the vehicle, has got its elements spaced for the distance equal to the vehicle breadth. It is also important in a specific case the pull rods (5, 6) could be equal with their length to the spacing of node (4) in the vehicle (1) and trailer (2). The joint system according to this invention does offer reduction of distance between the two vehicles to the necessary minimum and additionnally it provides improvement in force distribution exerted to the hauling vehicle in time of making cornering or when the unit is going down a hill.

Description

VARIABLE GEOMETRY JOINT SYSTEM DESIGIED MAINLY FOR TRAILER TRUCKS

The subject for this invention is a variable geometry joint system designed mainly for trailer trucks.

The commonly used joining method for trailer trucksis that in which a trailer is connected with a truck by means of a pinned yoke with a triangular draught bar fixed with its base against the trailer fore axle and fitted with an eye at its free end, through which a yoke fixing pin is inserted.

If a hauled vehicle is the trailer, it is fixed on a swivel fifth wheel being situated over a truck rear axle or axle system. Such simple and commonsystems are, from the transport economics point of view, ineffective due to a significant distance between the truck and trailer or between the truck driver's cab and semi trailer. That distance results from the curved movement geometry of the multi members trailer trucks unit. International regulations on road traffic do determine the maximum volume of such unit.

In the result the tendency towards minimalization of a void space and driver's cab lenght as well as a distance between particular members of such units is observed. There are many methods by which these distances are reduced to a necessary minimum.

It is known from The German Patent Specification lo. PE 3050869 the solution where a distance between the truck and trailer is

significantly reduced. Its basic idea Is to shift the yoke fixing the truck and trailer far behind under the truck load carrying body and applying a special trailer construction with a stiff draught bar being the trailer carrying frame extension and with the trailer axles located close one to another in the trailer middle lenght. The disadventage of such solution consists in fact that special trailers have to be used with hardly accessible yoke installed under the truck carrying body.

Another solution according to the German Specification No. DE 3720035 is free of above mentioned disadventages. A yoke at which the trailer draught bar is attached had been settled on a mechanical hydraulic structure. The construction described in that specificaton included a turntable installed under the truck cargo carrying body and an assembly of cantilever jibs of hydraulically controlled lenghts. Due to the turntable any horizontal swings of the trailer fixing is possible whilst the hydraulic system offers that the unit lenght is self controlled when cornerings are made. The solution like this does ensure possibility to keep the trailer close to the truck when travelling straight ahead and to have a safe a collision free distance between the truck and trailer when cornering is made. The solution disadventage is rather highly complicated joint system and the fact it can be applied only to hauling regular trailers.

The Patent specifications issued by The European Patent Office under Nos 0290363 and 0297009 show the joint system solutions usable both for trailers and semi trailers. Those two solutions do employ variable geometry jointsystems with telescopic, draught bars of

hydraulically controled lenghts and structural nodes which allow the trailer or semitrailer to turn in relation to the tractor or truck round the axis that depends on turning direction, i.e. to the left or right of the truck rear outline edge. All above presented examples assume draught bars of changeable lengths as essential hauling trailer and/or

semitrailer haulings elements. However they differ with their mechanical systems which make the hauled vehicle axle turnable in relation to the truck depending on covering direction.

In one of the examples the trailer or semitrailer position control mechanism includes a transverse beam that is attached to the truck and trailer position control hydraulic cylinders. In the other version the mechanical system consists of a romboid articulated joint fixed in the way that its two oposite corners consitute connections between the train (trailer - truck) separate parts, members and its other corners, located on the seckond diagonal, form the trailer turning axes in relation to the truck.

One more version shows the trailer turning axis change system as restricted to the special truck and trailer side-mounted corner elements which, if coupled together with their sides form a kind of a loose articulated joint. All above mentioned solutions are disadvantageous in the same way, namely they require a hydraulic system in order to control a draught bar length.

The purpose of this invention is to introduce a trailer-truck joint system that allows to change the hauled vehicle turning axis in relation to the truck and cornering direction and it is based only on mechanical elements.

The invention idea consists in a variable geometry trailer-truck joint characterized by the fact that it combines at least two pairs of structural nodes being fixed in such way that one pair is at the hauling vehicle (truck) rear and the other at the hauled vehicle (trailer or semitrailer front, with the said nodes connected one to another by means of at least two pull rods in the way that the pull rods do form diagonals of quadrangle circumscribed over the said nodes.

Further characteristic feature of the invention is that apart to a vehicle maximum width the vehicle mounted structural node pair is spaced accordingly. It is also important that in specific case the said connecting rods may be of a length that is equal to the truck and trailer node spacings.

The joint system according to this invention does enable to reduce a truck/trailer distance to the necessary minimum and, in addition, it improves distribution of forces acting on the truck in time of making cornerings or when a unit is going down a hill.

The subject of this invention is illustrated in two execution examples, Fig. 1 shows a schematic trailer-truck joint when travelling stright ahead from the top view, and Fig. 2 - a similar situation view with a difference that it also shows such a joint system top view when cornering is made to the left, the latter is marked with the dotted line. Fig. 3 is made to 11lustate the system view with the other side elements ommited for better clarity. In the first execution example for the invention application illustrated on Fig. 1 and Fig. 3 the hauling vehicle rear part (1) and the hauled vehicle front part (2) are have got fitted articulated joints that constitute the structural nodes (4). The stuctural nodes (4) are connected one to another by means of pull rods (5) and (6) in such way that the pull rods (5) and (6) form diagonals of the quadrangle circumscribed over the structural nodes (4). At the same level as the structural nodes (4) there are attached thrust elements (3) on which the structural nodes (4) will rest while cornering is made. In the execution example showed on Fig. 2 one pair of articulated joints that form the structural nodes (4) is fixed to the beam (7) situated just behind the hauling vehicle driver's cab (1) whilst the other articulated joint pair is attached at the trailer front part (6).

Similary to the previous example, the structural nodes (4) are connected with pull rods (5) and (6). The dotted line is made to show the trailer position (8) related to the truck (1) and the structural nodes (4) and (4') as well as the pull rods (5) and (5') in time of making cornering.

Claims

P A T E N T C L A I M S

1. The variable - geometry joint system designed mainly for trail-truck road trains, characterized with that it consists of at least two pairs os structural nodes (4) fixed in such way that one pair is located at the hauling vehicle rear part (1) and the other at the hauled vehicle, i.e. trailer (2) or semi-trailer (9) front part, with two strustural nodes (4) connected one to another by means of at least pull rods (5) and (6) in such way that the pull rods (5), (6) form diagonals of the quadrangle circumscribed over the nodes (4).

2. The system as per above claim 1, characterized with that the structural node pair (4), mounted in the vehicle, has got its separate points spaced for the maximum breadth of the vehicle.

3. The system as per above claim 1, characterized with that in the specific case the pull rods (5), (6) could be equal with their lenght to the spacing of node (4) in the vehicle (1) and trailer (2).