Patent attributes
A connecting shaft includes a fixed connecting part on one end and a connecting part on the other end for engaging with a socket, the connecting part is in curved part, a shoulder for connecting to the inner circumference of the socket is disposed between the connecting part and the connecting shaft, the purpose of the shoulder is for the connecting shaft to be able to turn or position with the socket, an axial hole is disposed inside the connecting part for a axial rod to insert into, a ball hole is disposed on each side of the connecting part and the two ball holes are connected to the axial hole, a steel ball is inserted into each ball hole, when the axial rod moves, it will also drives the two steel balls to move, one end of the axial rod is connected to a sliding control element, so that the sliding control element will drive the axial rod to move together on the axis, so as to control the two steel balls to allow the socket to turn upon the connecting shaft or to engage together in position.