Tube bending mandrel

Abstract

This invention relates to an improved tube bending mandrel of the general type having fixed and bendable sections and wherein the latter comprises a chain of ball and socket elements linked together in end to end relation with each such element being encircled by a ring of the same diameter as the fixed section cooperating therewith and with one another to define limited movable universal connections therebetween. More specifically, the instant invention relates to an improved ball and socket assembly wherein the ball portion comprises two or more spherically-surfaced ring segments which cooperate with each other and with a spherically-concave head formed integral with the body in which the socket is formed on the opposite end of the link to form the ball. The improved mandrel also encompasses dimensioning the socket in the head in relation to the neck of the adjacent socket around which the ball-forming segments are disposed such that the latter can neither be removed nor inserted until the ring surrounding same has been removed and the assembled ring and socket thereabove are tilted to one side and seated within a suitably placed recess. The improved mandrel further includes an expandable ring detent surrounding the ball that temporarily seats with an annular groove in the socket to releasably maintain the elements of the bendable section in axial alignment with one another and with the fixed section.