Universal joint for piston-connecting rod assembly

Claim 1

In a miniature damping dashpot for use in electromagnetic assemblies or the like, a piston-connecting rod assembly for universally pivotally mounting a connecting rod in force transmitting relationship to a piston comprising a ball-like member rigidly mounted on said connecting rod, an element operatively connected to said piston and having an open-ended chamber therein, said connecting rod extending into said chamber with said ball-like member received therein, and retainer means having an aperture through which said connecting rod extends with lateral clearance therearound; the improvement comprising a socket member formed substantially completely of soft easily deformable rubber-like elastomeric material received, with substantially no deformation thereof, within said chamber and having a concave ball-like inner surface adapted to operatively engage the outer surface of said ball-like member along an area shaped to conform to a substantial portion of the surface of said ball-like member with substantially no deformation of said concave surface, said socket member surface having an aperture in registration with said aperture on said retainer means through which said connecting rod extends with lateral clearance therearound, the lateral clearance between said connecting rod and both said apertures being sufficient to permit said connecting rod a degree of universal movement relative to said element as it moves angularly relative to said cylinder, said socket member aperture being of a size normally insufficient to allow passage of said ball-like member therethrough, said elastomeric material surrounding said aperture in said socket member being yieldable to allow insertion of said ball-like member through said socket member aperture, thereby to provide for the mounting of said socket member on said connecting rod prior to insertion of said socket member into said chamber, whereby said socket member is effective to provide a bearing surface for universal rotation of said ball-like member within said socket member to act as a resilient linear force transmitting member between said connecting rod and said piston, and to act as a soft shock-absorbing and wear-resistant element, said retainer means engaging said socket member and retaining it substantially immovably in said chamber.