Patent ID: 7927035

Claim:
A metal ball joint for use with a pressurized lubricant, the ball joint comprising in combination: (i) an elongated shaft having an upper end and a lower end, said elongated shaft being threaded on the lower end; (ii) a ball rigidly fixed and surmounted on the upper end of the elongated shaft, said ball having a curved surface, and further having a truncated flat face at the highest point opposite the upper end of the elongated shaft; (iii) a housing having an outside surface, an upper flange with a threaded opening, a middle portion, and a lower end, said housing further having a curved seat formed at the lower end of the housing to seat and engage a first portion of the curved surface of the ball adjacent the elongated shaft and an opening formed in the seat for passage therethrough of the elongated shaft but not permitting passage therethrough of the ball such as to permit pivotal movement of the elongated shaft relative to the housing, said middle portion of the housing having an internal thread and said middle portion further comprising an external thread for attaching the housing to a socket; (iv) a retaining member having an upper surface and a lower end, said retaining member having a curved seat formed at the lower end thereof to seat and engage a second portion of the curved surface of the ball adjacent the truncated flat surface thereof and a lubricating port located in the upper surface of the retaining member, the lubricating port being in communication with a duct, said duct providing a passageway from the lubricating port to the truncated flat face of the ball, capable of permitting the admission of a pressurized lubricant, such that the pressurized lubricant exerts pressure against the retaining member and the truncated flat face of the ball to maintain pressure on the ball to maintain the ball against the seat of the housing, said retaining member having an external thread on said lower end thereof, the external thread being engageable with the internal thread of the housing to trap the ball within the housing and the retaining member; the retaining member being capable of maintaining a seal between the ball and the housing via the pressure of the lubricant on the truncated flat face of the ball; and (v) a set screw removably threaded into a the threaded opening in the upper flange of the housing into engagement with the retaining member such that the retaining member can be selectively removed from the housing by removal of the set screw.