Patent ID: 8122577

Claim:
A device for manufacturing a ball joint provided with a first member having a ball section and a second member having a substantially cylindrical socket which accommodates the ball section, the device comprising: a pair of dies for reducing the diameter of a wall which surrounds an opening of the socket of the second member; a rotating and supporting device which supports the first and second members in a state where the ball section is accommodated inside the socket, and which applies a rotational torque to the second member so as to rotate the socket relatively with respect to the pair of dies about the central axis of the socket; and a pressing device which supports the pair of dies such that the pair of dies sandwich the wall of the socket from an outer side thereof in a radial direction while the rotating and supporting device supports the second member and applies a rotational torque thereto, and which drives at least one of the pair of dies such that the pair of dies press repeatedly and intermittently in an inward radial direction against the outer surface of the wall of the socket.