Patent ID: 8143506

Claim:
A hammer assembly for a grand piano comprising: a hammer, capable of striking a piano wire to produce a musical piano tone; a hammer shank ( 30 ), comprising an oblong shaped member with a first end and a second end; a moveable knuckle ( 240 ), comprising a cylindrically shaped member with a center line ( 246 ) that is the vertical bisection of the circular cross-section of said moveable knuckle; and a tubular lever interface ( 20 ), comprising a hinge lever fixture with a hinge end, an oblong rigid body, a fixture end, a bottom, a top, a front, and a back, further comprising, a deep socket ( 200 ) at said fixture end, a set of two hinge pin attachment holes ( 220 ) at said hinge end, a void area ( 230 ) at said hinge end, and a moveable knuckle visual location system ( 190 ) at said bottom, said front, or said back, wherein, said two hinge pin attachment holes are each coaxial and concentric with a hammer shank center-of-rotation ( 185 ) axis and each function to accept one end of a hinge pin, said void area is located between said two hinge pin attachment holes and functions to allow clearance for the male hinge portion of a shank flange during rotation of said tubular lever interface, said hammer is permanently affixed to said first end of said hammer shank, said tubular lever interface is permanently affixed to said second end of said hammer shank by insertion into said deep socket, and said moveable knuckle is permanently affixed to said bottom of said tubular lever interface, adjacent to said moveable knuckle visual location system.