| 摘要 |
A fastener (20, 50), particularly for orthopedic use, structurally adapted to be driven into a member somewhat like a nail and to be secured therein by rotating the fastener through a predetermined angular displacement to secure threads on the fastener in the thus-fastened member. The fastener includes a head portion (21, 51) structurally adapted to receive a force axially applied to the fastener, a tip portion (30, 53) structurally adapted for leading the fastener into a member to be fastened, and a shank portion (25, 52) between the head portion and the tip portion, which includes a thread-bearing zone (31, 67) and a thread-free zone (32, 68) circumferentially spaced about the shank portion which together comprise the entire circumference. Preferably, the fastener (20, 50) includes a pair of opposed threadbearing zones (31, 67) spaced intermediate a pair of opposed thread-free zones (32, 68) each occupying 90<o> of angular displacement about the shank. The angular displacement of a thread-bearing zone may lie in the range of about 120<o> to 240<o>. |
