Patent GB-627304-A (GB)
Title: Improvements in or relating to pianofortes and like keyboard instruments
IPC: G10C3/12
Filed: 1946-08-08
Abstract: 627,304. Pianofortes. WRIGHT, C. E. Aug. 8, 1946, No. 23488. [Class 88 (ii)] A handle at the end of the keyboard is set according to the key signature of the composition to be played and the appropriate white notes are automatically sharpened or flattened. The black keys are required only for accidentals. The white keys may be coloured to identify them with the notes they represent. Auxiliary keys provided between B and C and between E and F may also be distinguished by colouring and are used to play the naturals of these notes when they occur as accidentals. Piano action, Figs. 2, 16 and 29. Each hammer is operated by a jack J mounted on a lever H1 which is coupled to a similar lever H2 pivoted at a lower level. Each white key LK is coupled by a wire W to a lever or lift MIL pivoted at PC to a control lever L. When the key is pressed, the lift MIL engages H2 to operate the hammer. The control lever L is adjustable about a vertical pivot NL so that he lift MIL may engage the lever H2 of a note a semitone above or below the note which is normally operated by the key. Each black key SK is similarly associated with a lift MIS and a control lever M so as to engage an upper lever H1. The tail ends of the control levers are coupled by tie rods KR (Fig. 2) to levers LV in the control mechanism, which is operated by the handle HA. Corresponding notes in different octaves are coupled together by ties (not shown). The auxiliary keys are normally inoperative as the associated lifts MIS engage stops HL in lieu of levers H1. When the auxiliary control lever is adjusted to either side, however, the key operates the adjacent natural E or F, B or C. The lower levers H2 on either side of a stop HL are provided with wide ends HT so that the B and E lifts may be able to engage the C and F levers H2 and vice versa in spite of the intervening stops HL. Control mechanism, Figs. 2, 5, 17, 19, 25 and 30. Locks LO carrying the levers LV, to which the coupling rods KR are connected at LU, are arranged in two series of seven (Fig. 30). The locks are held in their normal positions by spring catches SP (Fig. 17). Turnkeys TIC (Fig. 19) carrying keys KE can together be moved along and rotated about their axes by means of the handle HA, which is guided by a slotted plate 7 (Fig. 5). As the handle is advanced along the slot 75, the keys KE displace the catches SP .and unlock the levers LV encountered in the forward movement. When the handle is turned to one side, the unlocked levers are displaced to operate the control levers. The levers LV of the left-hand series of locks (Fig. 30) are tied by rods KR to the control levers of the auxiliary keys relating to E, F and to B, C, and to the black keys F#, C#, G#, D# and A#. The inverted levers of the right-hand series are tied to the control levers L of the white keys F, C, G, D, A, E and B. The righthand turnkey TK (Fig. 19) operating the control lever for the white keys carries a single long key KE which can operate seven locks together. The left-hand turnkey operating the control levers for the black notes carries one long key which can operate nine locks together and a short key which can operate only two locks together. The locks corresponding to E, F and B, C (Fig. 25) can be turned only by the short key. As the turnkeys are advanced two positions into the locks (Figs. 19, 30), the locks are unaffected as locks E, F and B, C are not released by the long key. With subsequent advances and turning of the handle to the right, F will be sharpened and F# flattened, C sharpened and C# flattened &c. The auxiliary key E, F is brought into use for the key of six sharps when the short key enters the first lock, and the auxiliary key B, C is also brought into use for seven sharps. Turning the handle HA to the left and further advances of the turnkeys provide adjustments in the range seven flats to one flat (Fig. 5). A bar HS (Fig. 16) may be turned about a hinge Z by means of a pedal so as to lift all the levers H1, H2 clear of the lifts MIS, MIL and to avoid fouling whilst the control is adjusted.