GB2038733A - A wheel axle for a vehicle - Google Patents

Abstract

In a wheel axle for a vehicle, especially for a caravan trailer, the wheel axle has wheel rocker arms 5 coupled together by means of a "flexible" shaft 1 and a transverse stabilizer 4. The stabilizer is prismatic in cross- section and in the form of a linear strip of spring steel. It is attached between the rocker arms and apart from connections to the rocker arms it is unsupported throughout its length. The "flexible" shaft may comprise a straight length of tubing resiliently supporting an inner tube 2 by rubber packing strips 3, in which case the stabilizer passes through the tubing and is attached directly to the rocker arms of each of its ends. Alternatively the "flexible" shaft may be bent Figure 3 (not shown) in which case the stabilizer is attached between the rocker arms externally of the shaft. <IMAGE>

Description

SPECIFICATION A wheel axle for a vehicle Technical field of the invention The invention relates to a wheel axle for a vehicle, especially for a caravan trailer, wherein the wheel rocker arms have a flexible suspension and are connected by a transverse stabilizer.

Background art Wheel axles of vehicle trailers of known types have various constructions. That most generally used is the so-called rubber mounted flexible shaft, wherein a prismatic torque tube is rigidly connected to the frame or chassis of the trailer, the torque tube housing a torsion bar, which is also prismatic, and which is supported with respect to the torque tube by rubber packings. The wheel rocker arms are secured to the ends of the torsion bar.

In a known variant of this arrangement. the rubber mounted flexible shaft takes the form of an inclined trailer axle wherein the torque tube is bent so that the axes of the respective limbs of the tube are outwardly and downwardly angled with respect to the travel direction.

Both of the described rubber mounted flexible shafts have no transverse stabilizer.

In a practically known trailer axle, a transverse stabilizer is provided which is pivotally mounted to the chassis and has inclined limbs the ends of which are connected to the wheel rocker arms. The object of these transverse stabilizers is to provide a correcting force opposing the transverse bias of the trailer construction. Such a transverse bias can be caused either by external influence, e.g. wind forces, or by centrifugal forces when travelling round a bend.

When a transverse stabilizer is provided, the in and out springing movement of the wheels can be adversely affected by the described forces.

Disclosure of invention It is an object of the present invention to provide, in wheel axles of various kinds for vehicle trailers, especially for caravans, a transverse stabilizer arrangement, which is of particulary simple construction and therefore economical, and the adaption of which to axles of various types is possible without difficulty.

According to the invention there is provided a wheel axle for a vehicle comprising wheel rocker arms coupled together by means of a flexible shaft and a transverse stabilizer, characterised in that the transverse stabilizer is In the form of a linear strip of spring steel of prismatic cross-section arranged to interconnect the wheel rocker arms but otherwise to be unsunoorted, and to be rigidly and non-rotatably clampeo therein.

The cross section of the transverse stabilizer is preferably that of a regular hexagon, that is to say one having equal sides and equal internal angles. In the case where the transverse stabilizer is employed with a straight length rubber mounted flexible shaft, the stabilizer penetrates the internal hollow torsion bar of the flexible shaft. In the case where a bent shaft is used, the transverse stabilizer is clamped to an eccentric lug upon each wheel rocker arm.

In principle the particular construction of the wheel axle of the trailer is immaterial. The advantage of the transverse stabilizer in accordance with the invention lies in the fact that the latter can be produced by cutting off a length of spring steel strip corresponding to the spacing distance between the wheel rocker arms. It is necessary only to provide a receiving cavity in the wheel rocker arm corresponding to the cross-section of the transverse stabilizer to serve for introducing and clamping the stabilizer rigidly therein. Also it is not necessary to mount orto guide the transverse stabilizer upon the chassis or upon the framework of the trailer.

The principle of the invention transverse stabilizer is based on the action of a torsion bar. On the other hand in the above described state of the art the principle of the stabilizer is based upon the action of an eccentrically mounted flexible bar having bent limbs.

Brief description of the drawings Embodiments of the invention will now be described by way of example with reference to the accompanying drawing, in which: Figure 1 is a cross-section through a rubber mounted flexible shaft of a wheel axle having a transverse stabilizer; Figure 2 is part of a longitudinal section through the straight length rubber mounted flexible shaft of Figure 1; Figure 3 is a plan view of a bent flexible shaft with a transverse stabilizer; and Figure 4 is an end view of a wheel rocker arm of the bent flexible shaft according to Figure 3.

Best modes of carrying out the invention In the practical examples of Figures 1 and 2 there is shown a rubber mounted flexible shaft of the rectilinear axis type. In this arrangement a stationary torque tube 1 is connected to the chassis or the framework of the trailer. In this torque tube 1 there is located a prismatic inner tube 2, which may also be crimpted in cross-section, and which is resiliently supported with respect to the torque tube 1 by means of strips 3 of rubber packing. The wheel rocker arms 5 are connected to the ends of the internal tube 2 (see Figure 2). The forces developed by the loading and the travelling motion of the trailer act through the wheels and the wheel rocker arm 5 upon the inner tube 2, which consequently tends to rotate about its longitudinal axis and is thereby supported resiliently in a shock absorbing manner by the rubber packings 3.

In the interior of the inner tube 2 there is arranged a transverse stabilizer 4, which penetrates the inner tube 2 and is connected to the wheel rocker arms 5 but is otherwise unsupported. The wheel rocker arms 5 have a cavity 6 of prismatic section corresponding to that of the stabilizer, in which the transverse stabilizer 4 is non-rotatably located and clamped. It is advantageous to design the transverse stabilizer 4 with a cross-section corresponding to that of a regular hexagon, although other cross sectional shapes are not excluded,.

The transverse stabilizer 4 has the effect that the bias of the trailer structure resulting from external forces (wind pressure) or centrifugal forces when travelling around a curve is taken up by the stabilizer and a correcting force is applied in opposition to this bias. The bias of the trailer structure causes an accentuated deflecting movement of the loaded wheel rocker arm at the loaded side of the trailer.

This increased deflection movement results in a torsional stress upon the transverse stabilizer 4, which supports itself against the other wheel rocker arm, so that from this torsion there are derived the restoring forces for the correction of the trailer structure.

In the practical example of Figure 3 there is shown a bent flexible shaft 7, wherein the ends of the individual limbs of the torque tube 1 are inclined from the centre downwardly and inclined towards the direction of travel. In such a practical construction it is not possuble to arrange the transverse stabilizer 4 within the internal tube 2. For this reason the wheel rocker arms 5 are provided with lugs 9, in which the rectilinear transverse stabilizer 4 is nonrotatably fitted and clamped. The wheel drums are shown at 8, and 11 indicates the forward travel direction of the trailer.

As shown in Figure 4 the wheel rocker arm 5 is provided with a cavity the shape of which corresponds to the cross-section of the stabilizer 4, and which determines the non-rotatable character of the connection. In order that the transverse stabilizer 4 can also be clamped in the direction of the longitudinal axis, a clamping screw 10 is provided for each wheel rocker arm 5, which penetrates the lug 9 and clamps the transverse stabilizer 4 with respect to the lub.

It will be obvious that the arrangement of the transverse stabilizer 4 can also be applied to trailer axles designed otherwise than shown in the example. Such trailer axles may, for example, include torsion bars with impact shock absorbers. The invention is therefore not restricted to the practical examples here shown.

Claims (5)

1. A wheel axle for a vehicle comprising wheel rocker arms (5) coupled together by means of a flexible shaft (7) and a transverse stabilizer (4), characterised in that the transverse stabilizer (4) is in tne form of a linear strip of spring steel of prismatic cross-section arranged to interconnect the wheel rocker srmS (5 > but otherwise to be unsupported, and to be rigidly and non-rotatably clamped therein.

2. A wheel axle as claimed in Claim 1, characte rised in t 1at the flexible shaft (7) is a straight length of hollov rubber tube, the transverse stabilizer (4) passing through the hollow tube (2) of said flexible shaft.

3. A wheel axle as claimed in Claim 1, characterised in that the flexible shaft (7) is bent and the transverse stabilizer (4) is clamped to an eccentric lug (9) on each of the wheel rocker arms (5).

4. A wheel axle as claimed in any preceding claim, characterised in that the cross section of the transverse stabilizer (4) is a regular hexagon.

5. A wheel axle for a vehicle substantially as hereinbefore described with reference to the drawings.