Patent GB-191014030-A (GB)
Title: Improvements in or relating to Apparatus for Mechanically Operating Musical Instruments.
Inventor: COLDMAN HENRY CHARLES
Filed: 1910-06-09
Granted: 1911-06-09
Abstract: 14,030. Coldman, H. C., and Webb, C. F. June 9. Player-pianos; actions; blowing and exhausting air; treadles; winding-mechanism.-In an automatic musical instrument, the valves controlling the connexion of the note-operating pneumatics to high pressure or suction are arranged to operate under low pressure or suction in order to reduce the drag on the tunesheet. To reduce the pressure or suction, a pressure-regulating device of special construction is introduced between the pressure or exhaust pumps and the chambers containing the valve-operating plungers. Flexible connexions are provided between the note-operating pneumatics, which may be of the piston and cylinder type, and the wippens of a piano action. The pumps comprise pistons working in cylinders, and may be adapted to supply both pressure and suction. The apparatus shown in Fig. 1 operates entirely by suction, and comprises a valve chest formed of three blocks d<1>, d, d<2>, which are made of brass or other material. Paper may be placed between the blocks to form air-tight joints. Chambers b are formed in the block d and contain loosely-fitting plungers b<1> for operating ball-valves a<1> through loose rods c. The chambers b are connected by pipes d<4> to the tracker-bar, and by ducts g<4> to a chamber g<3>, which is connected through a pipe g<5> and pressure-regulating valve to exhaust. This pressure-regulating valve may also control the winding-motor. The valves a<1> control passages g leading to a chamber g<1>, which is directly connected to the exhaust by a pipe g<2>. When air is admitted from the tracker-bar to a pipe d<4>, a plunger b<1> is operated, causing a valve a<1> to close a port a<6> and open a port g, so connect. ing a cylinder e to exhaust through the ducts a<4>, a<5>. A piston e<1> is forced up, and operates a wippen f through a flexible connexion f<1>. Owing to the loose fit of the plungers b' in their cylinders, it is unnecessary to provide bleed-holes for exhausting the chamber beneath the plungers. A valve may admit air to a chamber b, if the suction becomes excessive. The valves a<1> may be arranged between the winding-roller and immediately behind the tracker-bar. Valves operated by suction may be arranged to control a supply of wind under pressure or vice versa. Alternatively, valves operated by pressure may control a supply of wind under pressure. Three constructions of pressure-regulating valves are described, one of which is shown in Fig. 7. The pipe o is connected to the tube g<5>, and the pipe o<1> is connected to exhaust, and also by a pipe o<5> to an annular chamber o<4> surrounding a cylinder o<Î> and connected thereto by ports o<3>. A spring- pressed carbon piston o<0> slides in the cylinder o<Î> and controls the ports o<3>. Alternatively, one end of the piston may be exposed to atmospheric pressure, the chamber o<4> being connected to exhaust and the pipe o<5> dispensed with. In a modification for use with air under pressure, a diaphragm-operated ball valve is employed. An exhausting-apparatus for supplying both pressure and suction comprises pistons which are reciprocated in cylinders by the operation of treadles. The air in the cylinders is thus compressed on one side of the pistons and rarefied on the other. The opposite ends of the cylinders are connected to different reservoirs, comprising spring-pressed pistons sliding in cylinders. Flexible connexions, which pass over pulleys, are provided between the piston-rods and the treadles.