REAR END VEHICLE SPRING

Abstract: The present invention concerns a method of modifying the rear suspension assembly of a transport vehicle of a lighter type equipped with a body or similar, whereby the rear suspension assembly of the vehicle demonstrates a rigid, transverse rear axle that supports a wheel at each end, each of which is suspended relative to the body by means of a suspension means. The method according to the invention is characterised by the following steps: the rear axle (2) and the suspension means (11) and wheel (1) are removed from the vehicle; a specially designed pendulum arm (9) is attached to the undercarriage (3) of the vehicle on both sides of the longitudinal central line, whereby the forward section of the pendulum arm is mounted to pivot at a section of the undercarriage in front of the intended position of the rear wheel, while a rear section of the pendulum arm is intended to be able to receive a wheel (14); an inflatable and deflatable rubber bellows (15) is placed between the pendulum arm (9) and the undercarriage (3), in addition to which the rear section of the pendulum arm is jointed to pivot at one end of a shock abosorber (16), the second end of which is jointed to pivot with the undercarriage (3). The invention also concerns an arrangement that may be used for execution of the method.

Description: REAR END VEHICLE SPRING The present invention concerns a method of modifying the rear suspension assembly of a transport vehicle of a lighter type equipped with a body, whereby its rear suspension assembly demonstrates a rigid, transverse rear axle that is suspended relative to the body by means of a suspension device, which is arranged at each end of the rear axle. This type of rear suspension assembly is commonly found on transport vehicles of a lighter type, that is, up to a weight of 5 tonnes, that are used both for goods transport and for transport of persons. A proposal has recently been produced in the EU that TAXI vehicles should be designed such that they can provide different types of transport, such as stretcher transport, transport of school children, transport of handicapped persons in a wheelchair and normal transport of persons when operating as a taxi. Furthermore, the floor in the vehicle should be flat, and the entry height should be adjustable down to a value of approximately 250 mm. In order to satisfy these requirements, transport vehicles of lighter type have been modified in such a manner that the vehicle has been cut behind the driver's cabin, where after a new rear section has been attached to the front section of the vehicle. In this way, the new rear section has been designed such that the entry height becomes adjustable and such that it can be brought down to a value of approximately 250 mm. As the reader will rapidly realise, this is a particularly expensive modification of the vehicle, which will probably reduce the market for it. The present invention intends to offer another modification of the rear suspension assembly of the type of vehicle mentioned in the introduction that can be made both simply and cheaply, when considered in a relative manner. The new method demonstrates the steps that are specified in the subsequent claims. One preferred embodiment of an arrangement that can be used to make the method possible will be described in more detail below with reference to the attached drawings, in which Fig. 1 shows part of an existing rear suspension assembly of a lighter type of transport vehicle, seen from a region behind a left rear wheel, Fig. 2 shows the new arrangement arranged at a left rear wheel, and Fig. 3 shows schematically a part of the arrangement, arranged at a right rear wheel. Part of an existing rear suspension assembly is shown in Fig. 1, This part comprises a rear wheel 1, which is mounted in bearings such that it can rotate on a rigid, transverse rear axle 2. The rear wheel and the rear axle are suspended relative to the body 3 by means of a longitudinal leaf spring means 4, which is arranged at the two end sections of the rear axle, and the two ends of which are jointed to pivot in a forward 5 and a rear 6 attachment. The forward 5 attachment is preferably arranged at a transverse beam 7 that is arranged in the vehicle, while the rear 6 attachment is preferably arranged at a longitudinal beam 8 in the vehicle. The new air suspension means that is designed to replace the rear wheel suspension in a known transport vehicle is shown in Figs. 2 and 3. The new arrangement comprises a pendulum arm 9, which at its forward end demonstrates two parallel forwardly directed sections 10, 11 that are intended to be mounted to pivot each in one attachment 5, 12, which attachments are arranged at the previously named beam 7. The attachment 5 is thus appropriately comprised of the forward attachment for the leaf spring means 4, while the parallel attachment 12 is appropriately comprised of the rear attachment 6 of the leaf spring means 4, which attachment thus has been moved from its rear position to a forward position with the attachment 5 in a position that lies parallel with the beam 7. The pendulum arm 9 demonstrates at its rear end a section 13 that protrudes to the left (see Fig. 2), that is, the section 13 is directed at essentially 90° relative to a longitudinal line through the pendulum arm, to which the left rear wheel 14 is intended to be attached. Thus, it is appropriate if the pendulum arm 9 is designed in such a manner that it can be used both for the left and for the right rear wheel. Thus, when used for the right rear wheel (see Fig. 3) the pendulum arm is rotated by 180° around its own longitudinal axis and is mounted in this position on the right side of the rear suspension assembly. The arrangement further comprises an air bellows 15 of rubber, intended for inflation and deflation by air, which bellows is intended to be arranged between the pendulum arm and the lower surface of the body 3 of the vehicle. In this way, the upper end of the rubber bellows 15 is arranged against the lower surface of the longitudinal beam 8, while the lower end is attached to the upper surface of the pendulum arm 9. According to the invention, the rubber bellows 15 is preferably placed in front of the centre of the rear wheel, which means that the largest possible vertical motion of the body seen relative to the rear wheel is obtained, while at the same time, the comfort of the vehicle is greatest with this location of the air bellows 15. The new arrangement, in order to damp the suspension motions, also comprises a shock absorber 16, the lower end of which is jointed to pivot at the rear end section 17 of the pendulum arm 9, while its upper end is jointed to pivot in an appropriate manner on the lower surface of the body 3 at a point behind the attachment point o The new arrangement allows the rear section of the car to be lowered sufficiently for the distance between the inner surface of the floor of the vehicle and the plane of the road surface to become approximately 240 mm, that is, considerably lower than the standard that the EU has suggested. Furthermore, the vehicle with the new suspension system can be raised approximately 70 mm above the normal driving position, whereby accessibility is improved in the event of a poor road surface. Furthermore, the new arrangement provides greater comfort as a result of the fact that the rear suspension assembly is provided with individual wheel suspension. The new arrangement has a built-in safety system that makes it possible that: - the hand brake is applied when the vehicle is lowered; - the vehicle is prevented from being lowered when driving; it must be stationary; - the hand brake is only released once the intended driving mode has been recorded; - the speed is prevented from exceeding 30 km/h when the vehicle is driven in its raised driving position. The term "undercarriage" when used in the claims is intended to denote the lower surface of the body and the transverse and longitudinal beams that are arranged there. It is, of course, possible to modify the invention within the framework of the accompanying claims.

Claims: Claims 1. A method of modifying the rear suspension assembly of a transport vehicle of a lighter type equipped with a body or similar, whereby the rear suspension assembly demonstrates a rigid, transverse rear axle that supports a wheel at each end, each of which is suspended relative to the body by means of a suspension means, c h a r a c t e r i s e d by the following steps: - the rear axle (2) and the suspension means (11) and wheel (1) are removed from the vehicle; - a specially designed pendulum arm (9) is attached to the undercarriage (3) of the vehicle on both sides of the longitudinal central line, whereby the forward section of the pendulum arm is mounted to pivot at a section of the undercarriage in front of the intended position of the rear wheel, while a rear section of the pendulum arm is intended to be able to receive a wheel (14); - an inflatable and deflatable rubber bellows (15) is placed between the pendulum arm (9) and the undercarriage (3), in addition to which the rear section of the pendulum arm is jointed to pivot at one end of a shock absorber (16), the second end of which is jointed to pivot with the undercarriage (3). 2. An arrangement that can be used to make the method according to claim 1 possible, c h a r a c t e r i s e d in that it comprises a pendulum arm (9), equipped with a forward section that is intended to be mounted to pivot to the undercarriage (3) of the vehicle at a region in front of the centre of the rear wheel (14), and a rear section to which it is intended that the rear wheel should be attached, and that an inflatable rubber bellows (15) exists, the lower section of which is intended to be placed on the upper surface of the pendulum arm, while its upper section is intended to be attached to the undercarriage of the vehicle. 3. The arrangement according to claim 2, c h a r a c t e r i s e d in that the front end of the pendulum arm (9) demonstrates two parallel forwardly directed sections (10, 11) that are intended to be pivotally arranged in an attachment (5, 12), while the rear end of the pendulum arm demonstrates a section (13), that is directed at essentially 90° relative to a longitudinal line through the pendulum arm (9), and that the rear wheel (14) is intended to be attached to this rear section (13). 4. The arrangement according to claim 3, c h a r a c t e r i s e d in that the pendulum arm (9) is designed in such a manner that, if it is turned 180° around its own longitudinal axis, when viewed from the position that it has at one side of the rear suspension assembly, the pendulum arm (9) can be mounted on the other side of the rear suspension assembly. 5. The arrangement according to any one of claims 2-4, characterised in that a rubber bellows (15) is intended to be placed in front of the centre of the rear wheel (14). 6. The arrangement according to any one of claims 2-5, characterised in that it comprises a shock absorber (16), the lower end of which is attached to pivot to the rearmost end section (17) of the pendulum arm (9), while its upper end is jointed to pivot in a suitable manner to the undercarriage of the vehicle at a point behind the attachment point of the lower end.

Inventors: SJOELUND ANDERS, SJOELUND, ANDERS
Applicants: SJOELUND ANDERS, SJOELUND, ANDERS
Application year: 2001
Main classification: B60G17
IPC codes: B60G3, B60G7, B60G17