| 摘要 |
It has previously been thought desirable when providing an internally screwthreaded socket (1) for use in studded foot-wear to provide each socket and a complementary stud (2) with complementary screw-threads with a small helix angle and many turns in order to maximise the frictional grip between the stud (2) and socket (1). The invention provides a multi-start thread requiring at most one and a half turns (560.degree.) to achieve full engagement, Contrary to conventional thinking such an arrangement is workable and has advantages over the known single start-threads for studded footwear. Arrangements of sockets and studs with two-start threads and retaining means (14; 16; 17 and 19) to prevent unscrewing of the studs are disclosed. |
