AU621821B2 - Vehicle anti-roll device - Google Patents

Description

Davies Collison, Melbourne and Canberra.

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1 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION (Original) FOR OFFICE USE Cli 621821 Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: o ae* SRelated Art: 0 0.

*0 0 00 00 000 0 Name of Applicant: .*Address of Applicant: 0 0 0 Actual Inventor(s): o "*Ad ress for Service: a 0 PACCAR AUSTRALIA PTY. LTD.

64 Canterbury Road, Bayswater, 3153, in the State of Victoria, Commonwealth of Australia.

GRAEME BURGE BOUCHER DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Complete specification for the invention entitled: "VEHICLE ANTI-ROLL DEVICE" The following statement is a full description of this invention, including the best method of performing it known to us 1

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I i -r t.'1 -i I- V .Jcal- w a-mo tno alttitation required) Note, Initial all alterations.

DAVIES OLLISON MELBOURNE and CANBERRA.

DAV1FS COLLISON, MELBOURNE and CANBERRA.

Sl I-1 I.1 f la VEHICLE ANTI-ROLL DEVICE This invention relates to a vehicle anti-roll device.

o oo ol o o a a p ooe a. a p a a a a a a a saa a cco a o I* a 4 r a In one aspect, the invention provides a vehicle anti-roll device comprising a plurality of torsion rods coupled at respective first ends to an axle of a vehicle at fixed locations relative to the axle for pivotal movement of the first ends of the torsion rods about respective first axes, said first axes being substantially parallel to said axle, said locations being in spaced apart relation in the direction of extent of said axle, the torsion rods being coupled at respective second ends thereof to links connected to the vehicle chassis, the rods and respective links being arranged so as to permit the rods to move in the forward to rearward direction relative to the vehicle pursuant to corresponding movement of the axle whilst restraining axial rotation of the ends of the rods relative to the axle and the vehicle chassis, whereby rotation of the axle about a forward to rearward axis of the vehicle is resiliently restrained by torsional forces within the torsion rods.

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tc *f The invention is further described by way of example only with reference to the accompanying drawings in which; Figure 1 is a diagrammatic perspective view of a conventional vehicle anti-roll device; Figure 2 is a perspective diagram of anti-roll device constructed in accordance with the invention; and Figure 3 is a fragmentauy side-view of the anti-roll device in Figure 2.

In Figure 1, a vehicle axle 10 is shown as having wheels 12, 14 at opposite ends thereof and a conventional anti-roll bar 18. Bar 13 is of U-shaped form having a portion 18a which extends parallel to and, for example, immediately forward of the vehicle axle, and which is secured to the vehicle axle by couplings 20, 22 at spaced locations along the length of the axle 10 so as to constrain the bar 18 against movement in the forward to rear direction relative to the vehicle to which the roll bar is attached but permitting rotation of the roll bar 18 about the axis of the portion 18a.

At opposite ends of the portion 18a, the bar 18 presents portions 18b, 18c which extend in the lengthwise direction of the vehicle, such as forwardly from the axle 10. At free ends thereof, the portions 18b, 18c are coupled to respective links 26, 28, these extending upwardly from pivotal connections to the portions 18b, 18c to pivotal connections (not shown) to the vehicle chassis. The pivotal connections of the links 26, 28 to the vehicle chassis and to the portions 18b, 18c of bar 18 are arranged to permit pivotal movement about transverse axes relative to the vehicle but to 1<_ L:i i

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t o Ir o o cocc *oo substantially preclude other relative movement between the links 26, 28, the vehicle chassis and portions 18b, 18c.

In use of the bar 18, rotation of the wheel azle 10 about the lengthwise front to rear axis 32 of the vehicle is resisted by resilient deformation of the bar. In particular, in the case of rotation about the axis 32 in the direction which is clockwise as viewed in Figure 1, illustrated by arrow 32a, the wheel 14 as shown will tend to rise and the wheel 12 will tend to drop. In this case, one may consider the forward ends of the portions 18b, 18c as fixed so that the tendency is for the end of bar portion 18c adjacent axle 10 to be moved upwardly out of the normal horizontal plane containing the portions 18a, 18b, 18c and for the end of the portion 18b adjacent axle 10 to be moved downwardly relative to such plane. The resultant deformation of the bar 18 is resisted by torsional forces generated in portion 18a due to the natural resilience of the bar, which forces tend to restore the bar 18 to its condition under which the arm portions 18a, 18b, 18c are coplanar.

Whilst arrangements of the above kind are well known and in common use, they do have a disadvantage that under some circumstances, particularly with heavy vehicles such as trucks, the bar 18 may need to be formed of very substantial and heavy guage material, so tending to excessively increase the cost of fitment to the vehicle and adversly affecting the performance of the vehicle.

In Figures 2 and 3, an anti-roll device is shown coupled to the axle 10 which carries wheels 12, 14 in the same fashion as described in relation 1 i o 4* or c o cc 0(

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1 0 4f ftc' a f It' ft.f tt r 4 to Figure i. Here, however, the bar 18 is replaced by two torsion rods 42, 44. These are arranged in a generally horizontal plane containing the axis of axle 10 and extend, in this case, forwardly from the axle 10 parallel to the front-to-rear axis 32 of the vehicle, one to either side thereof. At the rear enis, the rods 42, 44 are coupled to the axle 10 by couplings 48, 50. These permit pivoting of the rear ends of the rods 42, 44 about a common axis parallel to the axis of axle 10 and somewhat forwardly thereof, whilst otherwise constraining these ends of the rods against movement relative to the axle 10 and, in particular, preventing lengthwise axial rotation of the rods 42, 44 at the location where these join the couplings.

At forward ends, links 56, 58 are provided which pivotally couple, at respective one ends thereof, to ends of the respective rods 42, 44 distant from couplings 48, 50 and thence extend generally upwardly and somewhat forwardly to pivotally interconnect with the vehicle chassis.

These links 56, 58 are arranged to be pivotally coupled to the chassis or components which are fixed relative to the chassis to allow the links to rotate relative to the chassis about a common transverse axis 59 and to allow the rods 42, 44 to rotate relative to the links about transverse axes 61, 63 which, in the rest state of the device 40, are coaxial. The links 56, 58 also prevent substantial movement of the rods relative to the vehicle chassis in a side-to-side direction of the vehicle, and constrain the forward ends of the rods 42, 44 against rotation, axially of the rods, relative to the couplings 56, 58 and relative to the vehicle chassis.

As better shown in Figure 3, the axle 10 may 4.

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-4 be mounted, as is customary, on leaf springs 62 disposed one to either side of the vehicle chassis.

Figure 3 also shows the pivotal connection of link 58 to the chassis, by means of a pin 60 to a lug 62 on the chassis. Link 56 may be connected to the chassis in a similar way.

In use, rotation of the axle 10 about the axis 32, such as in the direction of the arrow 32a again shown in Figure 2, is resisted by forces generated as torsional forces in the rods 42, 44. In particular, as shown, if the wheel 14 should rise relative to the normal horizontal rest plane containing the axle 10 and rods 42, 44 whilst the wheel 12 should drop relative thereto, there is a 0. 4 tendency for the ends of the rods 42, 44 adjacent the axle 10 to be rotated in the directions indicated by arrows 42a, 44a relative to the fixed forward ends thereof, that is to say, in the anti-clockwise direction as shown in Figure 2. This rotation gives rise to development of torsional forces within the rods which resiliently resist the up and down movement of the wheels 12, 14 and which tend to restore the axle 10 its rest horizontal position.

The links 56, 58 permit a degree of forward to rearward movement of the rods 42, 44 relative to the chassis such as may be needed to accommodate slight forward to rearward motions and up and down movements which occur during use. Again, the pivotal interconnections provided between the rods 42, 44 and the bar 10 are provided in order to not interfere with the up and down movement of the axle 10 as a whole.

The described arrangement has been advanced merely by way of explanation and many modifications i L It tr I 4 4't EtCi t I iC I CC fE 6 may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

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Claims (9)

1. A vehicle anti-roll device comprising a plurality of torsion rods coupled at respective first ends to an axle of a vehicle at fixed locations relative to the axle for pivotal movement of the first ends of the torsion rods about respective first axes, said first axes being substantially parallel to said axle, said locations being in spaced apart relation in the direction of extent of said axle, the torsion rods being coupled at respective second ends thereof to links connected to the vehicle chassis, the rods and respective links being arranged so as to permit the rods to move in the forward to rearward direction relative to the vehicle pursuant to corresponding movement of the axle whilst restraining axial rotation of the ends of the rods relative to the axle and the vehicle chassis, whereby rotation of the axle about a forward to rearward axis of the vehicle is resiliently restrained by torsional forces within the torsion rods.

2. A vehicle anti-roll device as claimed in claim 1 wherein there are two said rods spaced apart laterally of the vehicle, and said first axes lie on a first substantially common axis adjacent to the axis of the axle.

3. A vehicle anti-roll device as claimed in claim 2, wherein said first 20 substantially common axis is forward of the axis of said axle.

4. A vehicle anti-roll device as claimed in any one of claims 1 to 3 wherein said links are pivotally connected to the vehicle chassis at locations laterally spaced relative to said chassis, for pivotal movement about a substantially common second axis 25 extending in the side-to-side direction relative to said chassis. A vehicle anti-roll device as claimed in claim 4 wherein said links are shorter than said rods and extend rearwardly and downwardly from said substantially common second axis.

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6. A vehicle anti-roll device as claimed in any one of claims 1 to 5 wherein the rods are coupled at respective second ends thereof to the links for pivotal movement about respective axes which are aligned in the side-to-side direction of the chassis, when said axle is in a normal operating position.

7. A vehicle anti-roll device as claimed in claim 6 wherein said respective axes are substantially parallel, when said axle is in its normal operating position.

8. A vehicle anti-roll device as claimed in any preceding claim wherein said second ends of said rods are positioned forwardly of said first ends thereof.

9. A vehicle anti-roll device substantially as hereinbefore described with reference to Figures 2 and 3 of the accompanying drawings. Dated this 15th day of January, 1992 PACCAR AUSTRALIA PTY. LTD. By its Patent Attorneys DAVIES COLLISON CAVE 4* S0 0 A o 1 8 A• ''ol :J a *!902'qa '021688'