Patent ID: 7713302
Filing Date: 2010-05-11
Classification: A61F

Abstract:
1. An intervertebral spacer device comprising: first and second plates, each having inner and outer surfaces thereof, said plates being disposed in a spaced apart relationship such that the inner surfaces face toward one another, and the outer surfaces face away from one another, said first plate including a retaining wall extending outwardly from said inner surface of said first plate; and at least one belleville washer, having narrow and wide ends thereof, disposed with said wide end contacting said inner surface of said first plate within said retaining wall, such that a compressive load applied to the outer surfaces of said plates is counteracted by said at least one belleville washer, said at least one belleville washer including at least one radially spaced concentric groove and at least one spiral slot, wherein said at least one radially spaced concentric groove in said at least one belleville washer is at a respective distance from an outer edge of said at least one belleville washer, wherein at least one of either an at least one depth of said at least one radially concentric groove increases incrementally with decreasing said distance, or an at least one width of said at least one radially concentric groove increases incrementally with decreasing said distance, wherein said at least one radially spaced concentric groove in said belleville washer comprises a plurality of radially spaced concentric grooves, and wherein each of said plurality of radially spaced concentric grooves in said belleville washer has a respective length, a respective depth along said respective length, and respective width along said respective length, at least one of said respective depth and said respective width being uniform along said respective length, wherein said length forms a closed loop.