Patent ID: 9422986
Filing Date: 2016-08-23
CPC Classification: B62D,F16C,F16D

Claim Text:
1. A telescopic shaft comprising: a male shaft having an outer circumference on which a plurality of protruding teeth are formed; and a female shaft having an inner circumference on which a plurality of tooth grooves are formed, wherein the tooth grooves of the female shaft are fitted onto the protruding teeth of the male shaft such that the male shaft and the female shaft are relatively slidable in an axial direction and such that a rotational torque is transmittable between the male shaft and the female shaft, wherein a covering portion, made of an elastic material, covers a tooth surface of the protruding teeth to reduce sliding resistance between the protruding teeth and the tooth grooves of the female shaft, and wherein a tooth surface of a center part of the covering portion is formed in an arc shape convex toward an outer side of the male shaft in a radial direction, and a curvature radius corresponding to the tooth surface of the center part of the covering portion is smaller than a curvature radius corresponding to a tooth surface of a center part of the tooth grooves.