WHEEL SUSPENSION SYSTEM

Abstract

It is disclosed a system for leveling of load between front and rear wheels on a trailer, consisting of a rubber-torsion axle FIG. D with longitudinal members 4 which center is pivotally mounted to the torsion axles pivot arms 7. With a wheel in each end of the longitudinal members, the system is working as a complete bogie unit which has vertical spring motion effect, as shown in FIG. B. For trailers with no need of such spring motion effect, the longitudinal members can be mounted direct to the inner tube 9 in the rubber-torsion element.

Claims

1. A wheel suspension system for a trailer with four wheels, wherein the system is adapted to equalize the trailer's weight between front and rear wheels, comprising: a transverse torsion axle including a pivot arm at each end, each pivot arm having a first end rigidly fastened to the torsion axle's rotatable inner member, and wherein the other end of the pivot arm is pivotably connected to a central point of a longitudinal member, each longitudinal member having a wheel mounted on each of its ends.

2. A wheel suspension system according to claim 1, wherein the torsion axle either includes torsion elements mounted in one transverse axle body of full width or as two separate torsion elements mounted one on each side of the trailer.

3. A wheel suspension system according to claim 1, wherein the torsion axle includes rubber torsion elements with three or more solid rubber bar.

4. A wheel suspension system according to claim 1, wherein the torsion elements include a bar of spring steel.

5. A wheel suspension system according to claim 1, wherein the longitudinal members are connected directly to the torsion axle's rotatable inner members, without pivot arms.

Description

DESCRIPTION OF THE DRAWINGS

[0018] The attached drawing is meant to schematically show the principal function of the basic and well-known rubber-torsion axle and how driving characteristics for both car and trailer are improved by implementing the invention's bogie suspension system.

[0019] FIG. A shows a schematic drawing of how a conventional trailer with two separate rubber torsion axles reacts when a front wheel hits a bump in the road. The trailer's drawbar 2 and ball joint goes up and gives the rear end of the pulling vehicle a lift:

[0020] The trailer includes two separate rubber-torsion axles 1, and a draw bar 2 with ball joint. When passing a road bump 3, the front end of the draw bar 2 will go up. However, the car will partly prevent this, and instead the trailer's rear wheels will be lifted with the result that both the car's and the trailer's rear wheels will have less ground pressure.

[0021] FIG. B shows how a trailer with one rubber torsion axle and the invention's bogie-member system acts in the same situation. The system includes a rubber torsion axle with a pivot arm at each end thereof, each pivot arm having a first end connected to the axle and a second end projecting therefrom. On each side of the trailer there is a longitudinal bogie member 4 connecting the front and rear wheels 1. The second end of each pivot arm is hinged to the middle of the corresponding bogie member 4. When passing the road bump 3 the drawbar 2 with ball joint are kept in an almost level position. The rubber torsion axle may be replaced with a steel-rod torsion axle.

[0022] FIG. C shows how a longitudinal bogie-member 4 can be mounted directly to the inner tube of a rubber-torsion axle without pivot arms. Mounted this way, the rubber bars in the rubber-torsion axle keeps the inner tube and longitudinal members in a firm but elastic and vibration damping grip, but it gives no vertical spring motion effect. Also here the rubber torsion axle may be replaced with a steel torsion axle.

[0023] FIG. D shows the well-known principle of a basic rubber-torsion axle, where the upper part shows the axle in cross section and the lower part is a view along the axle.

[0024] Solid rubber bars 5 are squeezed between inner 9 and outer 6 square tubes when the pivot arm 7 is moved. The square tube 6 forms the torsion axle's main body. The longitudinal member is pivotally mounted on the pivot arm 7. The torsion axle may be a continuous unit spanning the width of the trailer chassis, or it may consist of two parts, i.e. two separate torsion elements mounted one on each side of the chassis.