Patent ID: 9334959
Filing Date: 2016-05-10
CPC Classification: F16J

Claim Text:
1. A piston ring to be received within an annular groove having opposed radial surfaces and carried by one of a pair of relatively reciprocally movable members for sealing engagement with a sidewall of the other of said pair of relatively reciprocally movable members and for minimizing fluid leakage between said members, said piston ring comprises a tensionable annular member that includes a first radial surface for residing adjacent to one of the radial surfaces of said groove, a second radial surface for residing adjacent to the other one of the radial surfaces of the groove, 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, a length of the annular member from the first end to the second end, and annular member tension-relieving notches formed in the inner surface of the annular member, said notches are spaced-apart along the length of the annular member between the first end and the second end, 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, a notch spacing between each notch and an adjacent notch, the notch spacings incrementally decrease in size from the end gap to an end of the annular member opposing the end gap imparting a variable annular member tension-relieving property to the annular member enabling the annular member to impart an even pressure of the contact surface against the sidewall, when the annular member is received within the annular groove of the one of the pair of relatively reciprocally movable members.