| 摘要 |
A two-section tool joint comprises a support member including a polygonal ball knob disposed on one end thereof; an acting head including a receiving chamber fixed on end thereof, and on a side wall of the receiving chamber being arranged a plurality of raised rims in response to the ball knob; a limiting structure defined between the support member and the acting head so that the ball knob of the support member is limited in the receiving chamber and moves between a first and a second positions; wherein the raised rims are longitudinally defined on a side wall of the receiving chamber and spaced apart equally from each other, the number of the raised rims is in response to that of the angles of the ball knob, and each raised rim is provided with a convex arc contacting surface so that the support member rotates with the acting head. |
