摘要 |
A frictional coupling for a male member inserted in the bore of a female member, to couple together the two members when at a pre-determined axial position. The opposed surfaces of the male and female members define a clearance the radial dimension of which varies as the members are moved axially relative to one another. A frictional coupling element is provided in said clearance, which element comprises a strip of resilient material preformed into a helical coil of polygonal cross-section, such that the outer corners of the coil contact the bore of the female member and the inner flats contact the male member. |