Patent ID: 8735699

Claim:
A main action rail for an upright piano, wherein said main action rail is a stationary rail running horizontally across the width of said upright piano, said main action rail comprising an upper half with a front and rear surface and a lower half with a front and rear surface, said upright piano comprising a front side, a rear side, a plurality of hammer butt flanges, each attached to said upper half of said main action rail to yield a horizontal row of hammer butt flanges running parallel to said main action rail, and a plurality of whippen flanges, each attached to said lower half of said main action rail to yield a horizontal row of whippen flanges running parallel to said main action rail, each of said whippen flanges comprising a front surface and a rear surface and said horizontal row of whippen flanges comprising a front side and rear side, and said main action rail has a special cross-sectional shape so that the rear surface of said upper half of said main action rail is located on said front side of said horizontal row of whippen flanges and said front surface of said lower half of said main action rail is located on said rear side of said horizontal row of whippen flanges, thereby offsetting said lower half of said main action rail to said rear side of said horizontal row of whippen flanges, to provide a mass of material on said rear side of said horizontal row of whippen flanges and a void or clearance space on said front side of said horizontal row of whippen flanges below said horizontal row of hammer butt flanges.