GB407232A - Improvements in automatic musical instruments - Google Patents

Abstract

407,232. Automatic musical instruments. ILES, G. B., The Gap House, Broadstairs, Kent. July 3, 1933, No. 18872. [Class 88 (i).] In a note-accenting device for an automatic piano or organ, each striking-pneumatic is provided with two valves b, c both of which, in the normal position, place the striking-pneumatic duct a in communication with the atmosphere through upper seats o, o<1>, and movement of one or other of which places the duct a in communication with high- or lowtension vacuum chambers d or e respectively through seatings n<1> or n, closes the open-airseat o or o<1> of that valve, seals the open-air-way through the air seat of the other valve and closes the communication to the vacuumchamber of the other valve. In the form shown in Fig. 1 the last-mentioned action is attained mechanically by means of a pivoted balanced lever g carrying cups i, i<1> which are pivoted downwards onto sheepskin seats r, to close the open-air-way of either valve, by the suction in the striking-pneumatic duct a, and there is a direct mechanical connection between the valves b, c, by means of stems b<2>, c<2> and the lever g, so that as one valve is lifted the other is lowered onto its seat n or n<1>. Fixed or screwadjustable leather buttons k may be provided on the stems b<2> c<2> or lever g. A modification, also shown, dispenses with this mechanical connection by providing one-way valves between the low-tension chamber and the striking-pneumatic duct a, which seal the lowtension chamber from the duct a even through the low-tension valve has been lifted from its seat n by the high-tension vacuum in the duct a. For this purpose a sealing-disc and washer rest looselv beneath the seat n on a collar provided on the valve-stem so as to be drawn up against the seat n independently of the valve by the high-tension vacuum. Alternatively a common low-tension vacuum-chamber is arranged below individual vacuum-chambers for each valve and communicates therewith through a one-way sheepskin flap-valve. In these forms the upper valve-seats o and r are both formed by a flat wood or fibre plate and the sealing-cups i, i are of wood and carry sheepskin seats. In a modification of the form shown in Fig. 1, the valves b, c are horizontallyopposed with aligned valve-stems b<2>, c<2> adjacent and bearing, if desired through leather-buttons, on opposite sides of a pivoted plate, the opposite cupped or flat faces of which form the seats for sealing the open air-ways. In all forms the valves are operated by supplying atmospheric air from the tracker-duct to purse-chambers m or ml, the purses l or l<1> of which have the usual bleed-holes.