Abstract: A seal assembly includes a tensionable annular member and a gap seal annular member that are axially juxtaposed and configured to be carried by one of a pair of coaxially movable components for sealingly engaging another one of the pair of components. The tensionable annular member includes first and second radial surfaces, an inner surface, and an outer contact surface. Rounded bottom grooves are formed across the first radial surface from the outer contact surface to the inner surface. In another embodiment, notches are formed across the inner surface from the first radial surface to the second radial surface.

Abstract: In an annular groove carried by one of a pair of reciprocally movable members, a piston ring is carried by the annular groove for sealing the reciprocally movable members for minimizing fluid leakage between the members. The piston ring is an annular member that includes an outer contact surface engagable with the sidewall, an opposed inner surface, an end gap that severs the annular member and that defines spaced-apart first and second ends of the annular member, and annular member tension-relieving notches formed in the inner surface of the annular member. The notches are spaced-apart along the length of the annular member between the first end and the second end, and each notch has a blunt notch tip for inhibiting crack propagation in the annular member from said blunt notch tip when the annular member is tensioned.

Abstract: In an annular groove carried by one of a pair of reciprocally movable members, a piston ring is carried by the annular groove for sealing the reciprocally movable members for minimizing fluid leakage between the members. The piston ring is an annular member that includes an outer contact surface engagable with the sidewall, an opposed inner surface, an end gap that severs the annular member and that defines spaced-apart first and second ends of the annular member, and annular member tension-relieving notches formed in the inner surface of the annular member. The notches are spaced-apart along the length of the annular member between the first end and the second end, and each notch has a blunt notch tip for inhibiting crack propagation in the annular member from said blunt notch tip when the annular member is tensioned.

Abstract: Finishing a seal assembly as a unit is proposed, which prevents alignment of the end gaps of the annular body and the annular ring of the seal assembly, provides the ability to manufacture the seal assembly to very low tolerances, and establishes virtually perfect parallelism between the upper and lower surfaces of the seal assembly. A finishing process is characterized by lapping a seal assembly as an assembled unit with a lapper using gritted oil as a polishing medium.