GB1186497A - Player Piano Key Actuating Assembly - Google Patents

Abstract

1,186,497. Players for keyboard instruments. DALE ELECTRONICS Inc. 4 Feb., 1969, No. 5961/69. Heading G5J. A player-piano comprises two rows of solenoids, positioned either above or below a keyboard, having plungers 12 which operate the keys when the solenoids are energized. Each solenoid comprises a coil 35 insulated by a thin insulative tube 30 from an inner metal tube 24 containing a plunger 12, preferably of steel, into one end of which is pressed a push-rod 16 preferably of steel having a cushioning felt pad 22 on its end 20. Movement of plunger 12 is limited and cushioned by a rubber element 82, and, when the solenoids are placed beneath a keyboard, by a felt sheet 92 on a board 90 adjustably secured to channels 50, 50A. If the solenoids are placed above a keyboard, felt sheet 92 is replaced by biasing springs secured to each plunger 12 at a groove 14. The solenoids are mounted in two pairs of channels 50, 50A by an abutting insulating washer 32 clipped into a groove 34 at one end of tube 30, and also an adapter 40 pressed into the other end of tube 30 and clamped to a pair of channels by a nut 42. Adapter 40 has shoulders abutting the edges of the channels to prevent rotation of the solenoid. The channels act as magnetic paths and heat sinks, and the pairs of channels are joined via an insulating board 70. In an alternative arrangement (Fig. 3, not shown) two pairs of channels (100, 102) are arranged one vertically beneath the other, and are secured together at one side by a board (120). At the other side, terminal boards 122 are provided. The lower solenoids (116) have long push-rods (118) which extend upwardly between the upper pair of channels with their ends (108) level with the ends of the rods (106) of the upper solenoids. Movement of each rod is limited by an adjustably positioned collar (112) on the rod which abuts a felt collar (114) on top of the adapter (36).