Land vehicles – Wheeled – Running gear
Patent
1987-04-30
1988-10-25
Weaver, Ross
Land vehicles
Wheeled
Running gear
267 52, 280669, 280694, B60G 2104
Patent
active
047798947
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a vehicle suspension comprising a spring in the form of an elongate leaf of composite, fibre reinforced plastics, material extending transversely of the vehicle and supported, for generally pivotal movement relative to the vehicle about axes extending transversely of the spring (i.e. longitudinally of the vehicle), at two positions spaced lengthwise of the spring between the ends thereof, the ends of the spring being connected to wheel carrier members. Such a suspension will hereafter be referred to as a suspension of the kind specified.
One example of a suspension of the kind specified is disclosed in WO No. 83/01758. The free end portions of the spring, outboard of the pivotal supports of the spring, are of increasing thickness and decreasing width towards their ends, so that they deflect relatively little in use compared with resilient deflection of the spring between the pivotal support thereof. In effect, such outboard spring portions act as lower wishbone members in respect of constraining the wheels to a desired movement and relationship relative to the vehicle, in addition to their springing function. The suspension further comprises damper struts one connected to each wheel carrier.
The present invention is applicable to a suspension of the kind specified as disclosed in WO No. 83/01758. The invention is also applicable to a suspension of the kind specified wherein the outboard portions of the spring do not act as lower wishbone members but, instead, bear upon or otherwise engage separate wishbone members or links to which the wheel carrier members are connected.
In a suspension of the kind specified, when it is applied to the front wheels of a front wheel drive motor vehicle, the only convenient position in which the spring, extending transversely of the vehicle, can be accommodated is directly beneath the engine-transmission unit of the vehicle. However, the centre of the spring undergoes a considerable vertical displacement when the vehicle's wheels move in bump and rebound in use, and hence when such a spring is mounted with adequate clearance from the engine unit, the ground clearance of the spring may be undesirably limited.
It is one object of the present invention to provide a suspension of the kind specified in which this disadvantage is overcome or reduced. Further objects and advantages of a suspension according to the invention will be pointed out hereafter.
According to the invention, we provide a suspension of the kind specified wherein there is provided resilient support means engaging or arranged to engage at least one surface of the spring at a central region thereof between said positions, to constrain bending of the spring with bump and/or rebound wheel movement in use, and wherein the stiffness of the spring in such bending decreases from said positions to said central region of the spring.
In a suspension according to the invention, the constraint of the central region of the spring by the resilient support means has the effect that the deflections thereof with wheel movement are limited. The spring as a whole does not have to be mounted at such a great distance from the part of the vehicle nearest the centre of the spring, and hence an increase in ground clearance can be achieved.
In the spring of a suspension of the kind specified, the bending moment in the spring increases from its ends to the positions of support of the spring relative to the vehicle structure, and is constant between such positions. In a suspension according to the invention, the engagement of the spring by the resilient element or elements between said positions has the effect that the bending moment in the spring, instead of being constant is reduced, possibly to zero. For constant stress in the spring, which is desirable, the bending stiffness of the spring can be reduced from its support positions to its central region.
In a suspension according to the invention, the springing characteristics are determined by the resilient support means as well as by the bending resilience o
REFERENCES:
patent: 4557500 (1985-12-01), Collard et al.
patent: 4619466 (1986-10-01), Schaible et al.
GKN Technology Limited
Weaver Ross
LandOfFree
Vehicle suspension does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle suspension, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle suspension will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2265307