GB197403A - Improvements in and connected with the actions of organs and like musical instruments - Google Patents

Abstract

197,403. Walker, F. P., and Walker &. Sons, Ltd., J. W. Feb. 10, 1922. Organ actions; soundboards.-A unit action to be inserted in a wall of a wind chest or duct other than the wall into which the pipes or reeds are inserted, comprises an electropneumatic motor connected to the pallet, the motor controlling valve being preferably formed as an armature-plate rocking on a fulcrum between two inclined ports. The pallet and its seating may be of stream-line formation. In the Figure, the unit action is carried on a base plug f of ebonite, metal &c., which on being given a slight turn when inserted in the wind-chest c makes the circuit connections of the electromagnet v. The pallet e guided by wires 7 is mounted with screw adjustment on the rod 2 which in turn is mounted with screw adjustment on the top board r of the cylindrical bellows-motor s, the lower end of the rod 2 cushioning in its lower position on a piece of resilient material 6 carried by a perforated disc o. Wind-pressure on the motors is normally equalised, reaching the interior by a groove l, passage k and port h, allowing a spring q to distend the motor and close, the pallet e. The wind-pressure normally tilts the valve-plate m of circular or other shape, to close the atmosphere port j. Energization of the electromagnet from a kev closes the wind-port h and opens the atmosphere port j, the air exhausting from the motor tending to hold the valve-plate m seated on the port h owing to the apertures in the disc o being arranged over that port. A second groove. l<1> may be provided to enable the unit to be inserted with the port k either to the right or to the left. In a modification the pallet e is mounted directly on the top board r of the motor, the pallet seating being carried at the lower end of a depending throat-tube. In another modification, the motor s constitutes a primary motor actuating, instead of the pallet, a rock-valve with inclined faces controlling a secondary motor on' which the pallet is mounted. The pallet may have a central cone 29 with concaved surface to seat on a wooden or metal annulus 28a of corresponding stream-line formation, and according to one of the Provisional Specifications the cross-sections may be other than circular. When the unit action is inserted in a side wall of the chest, the pipes may stand over ducts formed in a lateral extension of the lower part of the chest, a throatchamber extending across the chest. Accommodation for tall pipes is thus obtained and a second chest may be arranged over the first.