GB1201412A - Musical instrument keyboards - Google Patents

Abstract

1,201,412. Keyboards for electronic musical instruments. NIPPON GAKKI SIEZO K.K. 25 April, 1968 [26 April, 1967; 27 Dec., 1967 (2)], No. 19700/68. Heading G5J. A keyboard is constructed so that individual keys can be shifted laterally to produce a vibrato or like effect. The keyboard frame 10 is equipped with a plurality of hollow keys 12 each having a key arm (not shown) fixed to the rear of the keys and pivotally attached to frame 10. A key guiding plate 16 having guides 18 for each key is elastically supported on frame 10 by a plurality of rubber bushes 24 held in slots 22 in plate 16 and screwed to frame 10. Each key guide 18 has a felt cushion 20, wound thereon which engages the key when depressed so that lateral movement of the key causes plate 16 to vibrate in sympathy. Relative movement between plate 16 and frame 10 actuates an capacitive transducer, 28, 28<SP>1</SP>, to produce the vibrato effect. Bushes 24 may be replaced by leaf springs Figs. 5 and 6 (not shown). In Figs. 7 and 8 (not shown), the vibrato effect is achieved by arranging a metal or plastic tape (54) underneath the keys along the length of the key board at such a height that the underside of the key, when depressed, contacts the tape and causes vibration to be imparted thereto. The tape is held tight by coil springs attached to its ends and to the frame of the instrument. In a further arrangement, Fig. 9 (not shown), the stopper which limits the downward movement of the key is formed by an inextensible tape and a brush-like layer (68) attached to the tape and the key board frame such that lateral movement of the key, when depressed, causes the tape to move against the brush-like layer. In both these latter cases the movement of the tape is picked up by a transducer. Fig. 12 (not shown), is a block diagram showing an arrangement of the key board and tone generators with their associated elements in which the transducer is connected through an amplifier to frequency modulate a tone generator. A vibrato oscillator is alternatively selectable to modulate the tone generator.