SPRING ELEMENT INCLUDING A CONTINUOUS BAND OF FIBER REINFORCED PLASTIC MATERIAL, SPRING DEVICE INCLUDING MULTIPLE SUCH SPRING ELEMENTS, AND COMPLETE SPRING CONSTRUCTION INCLUDING MULTIPLE SINGLE SPRING.

摘要

A spring element (12) comprises a strip of fibre-reinforced plastics material formed as a zig-zag consisting of a plurality of limbs lying in substantially the same plane and joined at their ends by reflex portions (14). The strip includes at least a proportion of fibres aligned in its generally longitudinal sense, sufficient to spread stress concentrations away from the reflex portions, in use. The ratio of the limb length to the radius of the reflex portions is desirably in the range 0.2 to 200, preferably 0.5 to 30, and this leads to an extremely compact spring. Several elements (12) can be assembled together, possibly in different planes to produce a spring assembly whose spring rates in different modes of deflection are easily controlled. The spring elements (12) may include elastomer either as blocks (17) in the relex portions (14) or as layers interleaved with fibre reinforced plastics layers . The elastomer and plastics materials can be cured in mutual contact, to provide cross-linking between them.