GB150286A - Improvements in and relating to centrifugal pumps for use with pneumatically operated mechanisms - Google Patents

Abstract

150,286. Cramer, S. S. Aug. 21, 1919, [Convention date]. Exhausting air; expressioncontrolling.-A pneumaticallyoperated piano-player is connected to the casing of a centrifugal pump driven by an electric motor; a spring-controlled valve for relieving the vacuum is secured to the casing, and is set at its minimum limit to permit air to enter to cool the motor; it may be moved by hand to permit air to enter at varying rates. The casing is constructed to minimize the sound escaping. The casing is made in two parts 1, 4, Fig. 1, and the inner surface of the sections 6. 7 are covered with fibrous material 9, with apertures 10 registering with apertures 8 in part 7 of the casing. A baffle-plate 11 with sound-insulating walls is secured on the outside of the casing bottom. A pipe 91 from the piano mechanism conveys air to a large aperture 90 in the casing, and the opening is screened by a mesh section 94, Air is also admitted through apertures 98 which may be opened to varying degrees by means of a cover disk 100 with a similar series of apertures and which can be rotated on a spindle 101. The disc has an operating-arm 102 movable between limit screws 106, and held by a spring 109 in a predetermined position to permit air to enter to cool the motor under any conditions, The disc 100 may be adjusted to allow a high pressure in the piano mechanism to produce sounds of low intensity or to produce loud crash music. The complete arrangement may be supported on flexible supports inside or outside the piano.