Abstract: In a piano a panel, which takes the place of the usual cast iron string plate or frame, is provided for supporting the strings. The panel is a sandwich construction making it exceptionally strong and capable of withstanding the string loads without bending or otherwise yielding and without requiring auxiliary support such as the massive wooden backs or trusses to which cast iron string plates are usually attached. The string panel has a relatively thick low modulus of elasticity core layer, a portion of which is made of laminated hard wood to serve as a pin block, and relatively thin layers of high modulus of elasticity material, such as steel, bonded to the core layer. If desired the string panel may be used as the main frame of the piano to which other major components, such as the soundboard, key bed, side cheeks, housing and feet, are directly attached.

Abstract: A soundboard assembly for use in a piano, harpsicord or similar stringed musical instrument comprises a thin, laminated soundboard consisting of a center sheet of wood and two outer layers of composite material. The center wooden sheet has a substantially unidirectional grain and the two outer layers of composite material are made of unidirectional carbon fibers embedded in a resin matrix. A plurality of ribs, which may also be made as laminations of wood and layers of composite material, are secured to one face of the soundboard, and the ribs, grain of the wood, and direction of the carbon fibers are so related to one another and to the associated bridge as to produce a desirable reaction from the soundboard in response to string vibrations transmitted to it through the bridge.

Abstract: A back frame for a piano or like instrument is comprised by a laminated composite structure having outer laminates of sheet steel and an intermediate laminate which is formed by a reconstituted wood product. The steel laminates are joined to the intermediate laminate and the intermediate laminate is substantially thicker than the sheet steel to offset the outer laminates from one another and increase the stiffness of the structure. A plurality of integral beam elements extend through the laminated structure in the same general direction as the tensioning load of the strings in the piano, and the elements are spaced from one another and define openings in the frame through which sound is emitted from the sounding board of the instrument.

Abstract: A key bed for a piano or the like is comprised by a laminated structure having two outer layers of sheet steel and an intermediate layer of a wood product. The steel layers are bonded to the intermediate layer, and the intermediate layer is substantially thicker than the outer layers of steel to offset the outer layers from one another and thereby increase the stiffness of the key bed.

Abstract: A piano case or frame includes a laminated key bed and side arms joined with the bed at each end. The key bed supports the keyboard and associated portions of the piano action, and is assembled with each side arm of the frame by means of a rabbet joint. Fastening screws extending through the laminated bed into barrel nuts within each of the side arms develop significant pressure in the rabbet joints to hold the key bed and the supported keyboard in a level, undistorted position.