GB2225986A

GB2225986A - Vehicle suspension

Info

Publication number: GB2225986A
Application number: GB8926325A
Authority: GB
Inventors: Symister Raymond Moore; Graham Mills
Original assignee: MILLMOOR COMMERCIAL SERVICES L
Current assignee: MILLMOOR COMMERCIAL SERVICES L
Priority date: 1988-11-30
Filing date: 1989-11-21
Publication date: 1990-06-20
Also published as: GB8827974D0; GB8926325D0

Abstract

A vehicle, especially a trailer of monocoque construction, has a suspension arrangement having first and second transversely spaced longitudinal members each comprising a forward portion 10 and a rear portion 12 the facing ends of which are spaced apart, a bridging portion 38 connected to the top of the front and rear portions adjacent their facing ends 14, 16, and mounting means for suspension assemblies for carrying at least one wheel axle 18, 20 are connected to said forward and rear portions adjacent said facing ends. <IMAGE>

Description

IMPROVED VEHICLE SUSPENSION The present invention concerns improvements in or relating to vehicle suspensions, especially but not exclusively suspensions for trailers for commercial vehicles of the type having a load carrying floor which lies below the level of the top of the trailer wheels.

Trailers of this design are particularly advantageous in that the load to be carried by the trailer need not be raised by the same extent as normal when being loaded and unloaded as the vehicle floor is lower than normal. The floor height in normal trailers is governed by the height of the wheels as the floor is normally above the wheels.

It has been proposed in the past to reduce the floor height by accommodating the wheels in a wheel box which encroach onto the floor space at each side of the trailer.

In the past certain arrangements of this nature have been disadvantageous as the reduction in floor width at the wheel boxes has given rise to load carrying problems. In other proposals problems have been encountered in accommodating the transverse axles for the trailer wheel assembly, which axles extend from one side of the vehicle to the other and consequently any longitudinally extending chassis members must be sufficiently high to clear the axles when at their maximum deflection on the suspension system and this has resulted in increased floor heights.

It is an object of the present invention to obviate or mitigate these disadvantages.

According to the present invention there is provided a suspension arrangement for a vehicle, having first and second spaced longitudinal members each comprising a forward portion and a rear portion the facing ends of which are spaced apart, a bridging portion connectioned to the top of the forward and rear portions adjacent their facing ends, mounting means for suspension assemblies for carrying at least one wheel axle being connected to said forward and rear portions adjacent said facing ends.

Preferably the arrangement includes a pair of axles and a further mounting means for the suspension assembly is mounted to the underside of said bridging portions.

Preferably the bridging portion comprises two vertically spaced plate members fixed relative to each other with the upper member being transversley outwardly displaced relative to the lower member.

Preferably tie means may extend between said bridging portions of the pair of longitudinal members.

Further according to the present invention a vehicle having a body of monocoque construction and a suspension arrangement having first and second spaced longitudinal members each comprising a forward portion and a rear portion the facing ends of which are spaced apart, a bridging portion connected to the top of the forward and rear portions adjacent their facing ends, mounting means for suspension assemblies for carrying at least one wheel axle being connected to said forward and rear portions adjacent said facing ends.

Preferably said longitudinal members extend over only part of the length of the body.

Alternatively the longitudinal members may extend over the full length of the body.

An embodiment to the present invention will now be described by way of example only with reference to the accompanying drawings in which: Fig.1 shows a side elevation of a vehicle suspension arrangement.

Fig.2 shows a plan thereof.

A vehicle suspension arrangement comprises a pair of longitudinal members A and B each comprising of a first forward longitudinal portion 10 in the form of a beam and, spaced therefrom and at the same level, a rear longitudinally extending portion 12.

The facing ends 14, 16 of the portions are inclined to the vertical and spaced apart by a distance which is sufficient to enable the transverse axles 18, 20 of the vehicle running gear to be accommodated therebetween. The axles are mounted by elliptical springs 22, 24 in the normal manner, consequently the suspension assembly will not be described in any detail in this specification. The forward end of the front leaf spring 22 is mounted to the underside of the forward beam portion 10 in mounting means generally shown by the reference number 26. A similar mounting means 28 is provided at the forward end of the rear portion 12 and mounts the rear end of the elliptical spring 24.The rear end of the forward elliptical spring 22 and the forward end of the rear elliptical spring 24 are mounted on a standard spring mounting means 30 which, in turn, is mounted on a bottom plate 32 of a longitudinally extending bridging beam portion shown generally by the reference number 34. The upper member of the bridging beam portion 36 is connected to the lower portion by a vertical web, end pieces 38 and, if necessary, by vertical centre pieces 40. A transverse tie member 42 in the form of a box beam extends from the centre of one bridging beam to the other bridging beam.

The suspension arrangement is mounted to the underside of a trailer body manufactured from folded sheet aluminium such that the body is of monocoque construction.

Such construction requires no longitudinal chassis members extending along its entire length. The floor of the trailer is mounted on the upper faces of the front and rear beam portions 10 and 12 and if the body portion has transversely extending box members, as shown for example at 44, these extend through the front and rear beam portions 10 and 12.

Conveniently, the trailer body portion can be formed in the manner described in our U.K. Patent No. 2071022 It will be realised that the bridging beams 34 are located above the floor level of the trailer body and consequently they will encroach into the load space.

Conveniently, they are enclosed in boxed-off mudguard areas, enclosing not only the bridging beams but also the vehicle wheels. As these mudguards do not carry load, apart from the load of any goods placed thereon, they need not be of substantial construction. To reduce the encroachment of the bridging beams into the trailer body, the upper plate 36 is, as described above, laterally outwardly displaced relative to the lower plate 32.

It will be realised that any load in the vehicle, either its self-load or its pay-load is transmitted to the road by way of the wheels W, the axles 18, 20 the spring assembly 22 24; 26 and 28 and the longitudinal beam portions which transmit load to the monocoque trailer body floor.

Various modifications can be made without departing fjrom the scope of the invention. For example alternative suspension assemblies can be accommodated provided that the suspension mounting means are carried on the longitudinal members. One axle rather than a pair of axles can be utilised. Alternative means may be provided between the longitudinal members to tie them together, for example the transversely extending beam 42 may be replaced by diagonally extending ties or may even be dispensed with if the vehicle floor is of sufficient strength to tie the longitudinal members together against transverse separation. Other body structures can be accommodated, for example, curtain sided bodies, and/or bodies fabricated from glass reinforced plastics. The bridging beams can be deeper than those illustrated. The longitudinal members may extend along the entire length of the trailer. The bridging beams need not be formed from plate material but could comprise a pre-formed I-beam section. It is convenient that the bridging beams are formed from plate material in order that their top plates can be transversely outwardly displaced relative to their bottom plates to reduce encroachment into the load area.

Claims

1. A suspension arrangement for a vehicle, having first

and second spaced longitudinal members each comprising a forward portion and a rear portion the facing ends of which are spaced apart, a bridging portion connected to the top of the forward and rear portions adjacent their facing ends, mounting means for suspension assemblies for carrying at least one wheel axle being connected to said forward and rear portions adjacent said facing ends.

2. An arrangement as claimed in Claim 1, including a pair of axles and a further mounting means for the suspension assembly mounted to the underside of said bridging portion.

3. An arrangement as claimed in Claim 1 or Claim 2, in which the bridging portion includes two vertically spaced plate members fixed relative to each other with the upper member being transversely outwardly displaced relative to the lower member.

4. An arrangement as claimed in any of Claims 1 to 3, in which tie means extend between said bridging portions of the pair of longitudinal members.

5. A vehicle having a body of monocoque construction and a suspension arrangement having first and second spaced longitudinal members each comprising a forward portion and a rear portion the facing ends of which are spaced apart, a bridging portion connected to the top of the forward and rear portions adjacent their facing ends, mounting means for suspension assemblies for carrying at least one wheel axle being connected to said forward and rear portions adjacent said facing ends.

6. A vehicle as claimed in Claim 5, in which said longitudinal members extend over only part of the length of the body.

7. A vehicle as claimed in Claim 5, in which the longitudinal members may extend over the full length of the body.

8. A suspension arrangement for a vehicle, substantially as hereinbefore described with reference to the accompanying drawings.

9. A vehicle substantially as hereinbefore described with reference to the accompanying drawings.

10. Any novel subject matter or combination including novel subject matter disclosed in the foregoing specification or claims and/or shown in the drawings, whether or not within the scope of or relating to the same invention as any of the preceding claims.