This invention relates to a wheel suspension device of the rear part of a vehicle which in a conventional way has a rear axle connecting the two rear wheels with each other.

It is previously known to provide vehicles, having a rear part comprising leaf springs, with a wheel suspension device for the rear part of the vehicle comprising air spring suspension. In this connection the leaf springs of the vehicle, after having been cut off, are utilized as suspension support for the wheel suspension device or the leaf springs are exchanged for flat bars, suitable for the purpose. In this connection is referred to international patent publication WO 95/06571.

A drawback with this solution is that the wheel suspension device becomes relatively expensive to manufacture, since it comprises a special plate arrangement as a support for the lower part of the air bellows.

Furthermore, by American patent No. 5.346.247 is previously known a wheel suspension device, in which a leaf spring-like means functions as a support for the lower part of a bellows, which is possible to blow up. In this connection the leaf spring-like means is bent down at the rear axle ofthe vehicle, and the rear part ofthe means is twisted about 45° in relation to the front part. This design results in that the rubber bellows gets a position at a long distance, relatively spoken, from the rear axle, which leads to two drawbacks, namely a not completely good comfort and an insufficient ability ofthe vehicle to be lowered.

This invention intends to remove the drawbacks of the known technique and to provide a technical solution having the consequence that the rubber bellows can be placed close to the rear axle of the vehicle with the advantages this means. This has been made possible by the fact that the wheel suspension device has the features mentioned in the claims.

The invention also relates to the specially designed, leaf spring-like means. A preferred embodiment of the leaf spring-like means according to the invention shall be described more closely below with reference to the accompanying drawing, in which Fig. 1 shows a means, which is intended to be applied at the left side of the vehicle, seen in relation to its longitudinal centre line with the observer behind the vehicle. Fig. 2 shows the means according to Fig. 1, seen from below, and Fig. 3 shows a leaf spring-like means, which is intended to be applied at the right side of the vehicle. In the drawing figure 4 is a wheel suspension device according to the invention, seen from behind, depicted, the leaf spring-like means according to the invention being pans ofthe same.

The leaf spring-like means 1, according to the invention and Fig. 1. has a front portion 2. which has such a design that the means articulately can be fastened to the

underframe of the vehicle. The means 1 has such a position that its principal longitudinal direction LI is essentially parallel with the longitudinal direction of the vehicle. The rear portion 3 of the leaf spring-like means 1. according to the invention, is twisted in relation to the remaining part of the means, so that the longitudinal direction L2 of the rear portion 3 is essentially perpendicular to the longitudinal direction LI. The twisting is made in that way that the bottom portion 4 of the means 1 at the longitudinal part of the means becomes a top portion 5 at the transverse part of the means. Due to that fact a plane portion 5 is created, which is intended to constitute a lower supporting surface for an air bellows, intended for it. Furthermore, this twisting of the leaf spring-like means makes possible that its rear portion 3 simply can take a position where the portion 3 is directed obliquely forwards, which results in great advantages.

As a matter of fact the twisting angle α of the rear portion in relation to the front portion 2 is suitably the same as or greater that 90° but less than 180°.

In order that the supporting surface shall be greater, the plane portion 5, as is shown in the drawing, is provided with a plate 6 of suitable size, which is fastened on the portion 5 by means of a suitable bolt joint 7 or the like. This joint 7 is designed in that way that the plate 6 can take different side positions on the portion 5.

In Fig. 3 is shown a leaf spring-like means 8, which is intended to be fastened on the underframe of the vehicle at its right side, seen in the longitudinal direction of the vehicle when the observer stands behind the vehicle. This leaf spring-like means 8 is almost identical with the first described leaf spring-like means 1 and has accordingly in similarity with this one a front part 9. which is intended to be articulately fastened on the underframe of the vehicle.

The only difference between the two means 1 , 8 is that the later one has a sleeve-like projection 10 farthest out on its transverse portion 1 1, which projection is intended to make a flexible fastening of a stabilization rod to the portion 1 1 possible.

In Fig. 4 is shown the new wheel suspension device, which is provided with the leaf spring-like means 1. 8 according to the invention. Thus, each one ofthe transverse portions 5, 11 of these means constitutes a lower supporting surface for an air bellows 12. 13. Each one of the upper supporting surfaces for these bellows consists of a plate 14, 15, which plates are connected with a transverse, stabilizing girder 16. The plates 14, 15 on their top sides are provided with flanges 17, 18; 19. 20 or the like, projecting up, which facilitate the fastening of the wheel suspension device on longitudinal frame members ofthe underframe ofthe vehicle.

The wheel suspension device has further a lower, stabilizing rod 21, the one end of which is articulately fastened on the projection 10 at the transverse portion 1 1 of the means 8. The other end portion of the rod 21, according to this embodiment, is articulately fastened on means 22. which are arranged at and project down from the underside ofthe girder 16. As has been mentioned previously this invention makes a twisting of the rear portion in relation to the front portion possible, so that the twisting angle α becomes greater than 90°. This fact in its turn has the consequence that the air bellows comes more closely to the rear axle, which in the normal case is positioned just in front ofthe girder 16. The fact that the air bellows comes close to the rear axle leads to two essential advantages: Firstly, due to the fact that the comfort increases, and secondly the ability ofthe vehicle to be lowered down increases, which is of greatest importance during loading and unloading.

Furthermore, this invention makes possible for the air bellows to be positioned inside of the frame members of the vehicle, seen from the longitudinal centre line of the vehicle. This fact also leads to an improved ability ofthe vehicle to be lowered down. In the text has been mentioned "leaf spring-like means". This phrase partly comprises conventional leaf springs, partly bars of flat iron type.

The invention is of course not limited to the shown and described embodiment but can be modified within the scope ofthe following claims.