GB1314779A - Keyboard assembly for organ - Google Patents

Abstract

1314779 Electrophonic musical instruments MATTEL Inc 9 Dec 1971 [15 Dec 1970] 57187/71 Heading G5J An electronic organ is provided with a piano type keyboard which is played to produce tones of a particular pitch and a button switch section which is used to play chords or other special sounds. Each key 24, Fig. 2, is an elongated member comprising side walls 34, 36 an upper surface 38 and a base 40. Recesses 42, 43, which are of different shape to prevent binding, are formed in the base and extend into the side walls 34, 36 such that the keys may be pivotally mounted on a bar 44 attached to the housing 10. The bar 44 has an upright portion 46 covered by a strip 48 of bearing material to reduce noise and friction during pivoting. Protuberances 72 and 74 are provided on one side of each key to minimize rubbing and spacer fingers provided between groups of keys limit sideward shifting. A stop 52 limits the range over which the key may pivot and the front portion 26 of the key is biased upwards by the member 56 formed of resilient electrically conductive material. Side portions of this member are bent downwardly to press against the rear portion 28 and a central part 66, supplied with an electrical contact 32, is arranged such that on depressing the key the contact 32 touches a stationary contact 30. Each member 56 is connected to one stage of a tone generator and each contact 30 is connected to a common amplifier and loud-speaker such that when the contacts touch the corresponding note is produced. The button switch section comprises a sheet 80, Fig. 6, formed of resilient electrically conductive material which is positioned over a circuit board 82 and which is spaced from the circuit board by means of spacer rods 84. The circuit board is supplied with conductive strips 88 each of which is connected to a different output of a chord generator. A contact spot 90 is located on each conductive strip immediately below a corresponding tab 86 formed in the sheet 80. Buttons associated with the tabs are urged upwards by the spring force of the tabs. On depressing a particular button the tab is forced downwards to contact the associated spot 90 and a chord is produced.