Abstract: An acoustic upright piano, an electronic sound system and a hammer stopper form in combination a keyboard musical instrument for generating acoustic sounds in an acoustic sound mode and electronic sounds in an electronic sound mode, and the hammer stopper has a rotatable shaft extending in a lower space under damper blocks of damper assemblies, cushion members projecting into an upper space over the damper blocks and connecting brackets provided between the rotatable shaft and the cushion members, thereby perfectly interrupting hammer motions before an impact on strings in the electronic sound mode.

Abstract: A keyboard musical instrument selectively generates acoustic sounds and electronic sounds depending upon a mode selected by a player, and has a hammer stopper for interrupting hammers before strikes at strings and an escape accelerator for accelerating an escape of a jack from the hammer assembly in the silent mode earlier than an escape in the acoustic sound mode, thereby preventing the hammer assembly from capture between the jack and the hammer stopper without deterioration of the piano key touch.

Abstract: A piano has a regulating button mechanism so as to cause a jack to escape from a hammer assembly, and the regulating button mechanism has a first regulating button and a second regulating button with which the jack is selectively brought into contact; and the jack imparts a force variable in dependence on the regulating button to the hammer assembly so as to generate loud or soft tones.

Abstract: A key action mechanism incorporated in an upright piano is accompanied with a repetition mechanism having a repetition lever rotatably supported by a butt and pushed by a jack after an escape from the butt for producing a gap between a leading end thereof and a back check, therefore, the butt and, accordingly, hammer assembly can rotate backwardly over a predetermined angle due to the gap, after the striking or after the escape of the jack, and, as a result, the hammer assembly is prevented from double-strike.

Abstract: A muting device of an upright piano which includes butt, a wippen, a capstan button and a muting mechanism (15). This butt rotates with a hammer which strikes a string of the upright piano. In addition, a jack is provided to come in contact with a lower surface of the butt, and rotates the butt in response to displacement of the key. The jack is supported by the wippen such that it can freely rotate. The capstan button is provided at a back edge portion of the key to transmit displacement of the key to the wippen. The muting mechanism is designed to reduce a string-striking stroke by rotating the hammer. Further, there is provided a key-displacement-transmission-rate changing mechanism. When reducing the string-striking stroke by the muting mechanism, this mechanism raises a displacement transmission point, at which displacement of the key is transmitted to the wippen, toward a rotation center of the key from the capstan button.

Abstract: In a sound board assembly for a musical instrument, a plurality of straight-grain wood veneers are joined together in a plane to form a plate unit having front and rear surfaces. Each of the wood veneers has two lateral sides which extend in a direction along the grain of the wood veneer. The lateral sides of the wood veneer serve respectively as a pair of abutments. One of the pair of abutments of one of each pair of adjacent wood veneers is abutted against and joined to one of the pair of abutments of the other wood veneer. A plurality of voids are formed inside of the plate unit. Substantially, the voids are formed along a neutral plane of the plate unit which is in the middle of the two surfaces.

Abstract: A mechanical keyboard according to the present invention has a main sostenuto pedal mechanism for holding off a damper associated with a key depressed and an auxiliary sostenuto pedal mechanism provided for keys of a bass range for holding off the associated damper or dampers, and the auxiliary pedal is provided in the vicinity of a soft pedal for easy depression.

Abstract: A key-driving/detecting mechanism for performing automatically a keyboard instrument is constituted by a plurality of keys arranged on a key bed, each key being rotatable about a balance pin secured to a balance rail, and an electromagnetic device interposed between a lower surface of each key and the key bed at a position to the rear of the balance pin. Each electromagnetic device comprises an electromagnetic oil mounted on the key bed and a permanent magnet secured to a rear surface of the key. The simplicity of the key-driving/detecting mechanism is implemented by this disposition of the electromagnetic device. In a modification a pair of electromagnetic devices are provided in front of and in rear of the balance pin.

Abstract: In a coupling construction of a wooden base with a striking head of a piano hammer, at least one gap is left between a longitudinal end of the striking head and the longitudinal end face of the wooden base which serves as a refuge for unexpected deformation of the elastic insert, thereby avoiding separation of the striking head from the wooden base and development of cracks in the wooden base when striking the string.