GB262603A - Improvements in or relating to electric motors - Google Patents

Abstract

262,603. Wade, H., (Mills Novelty Co.). Dec. 23, 1925. Alternating - current motors; motors, controlling. - An induction motor, more particularly for rotating the bows or sounders of a bowed stringed instrument such as a violin, operated either automatically or from a keyboard, has a number of windings selectively connected in the circuit to determine the speed of the motor. The motor consists of a squirrelcage rotor 27, and a laminated stator 30 with teeth 32, 33 on which are provided four-pole windings 34, bipolar windings 35 of fewer turns and larger wire, and split-phase windings 36. The normal motor circuit is from main 40, Fig. 4, through lead 42, coils 34, lead 44, and coils 35 to main 41. In this circuit the effect of the coils 34 preponderates. To increase the speed and produce a louder tone, a tracker-bar contact 47 or a pedal contact 47<a> connects the main 40 to lead 44, shunting out the coils 34. To decrease the speed and soften the tone, a tracker-bar contact 49 or pedal contact 49<a> connects the main 40 to the coils 36, the connection through the coils 34, 35 remaining. The notecircuits completed by tracker-bar contacts 52 or keys 56 include string-stopping electromagnets 14<a> and bow-depressing magnets 25. The bowshafts 16, Fig. 3, carry worm wheels 20 rotated by a worm 19 on the motor-shaft, and rotate in bearings 17 in sleeves 18 which partially surround the worm and allow depression of the bow-shafts for sounding the strings. Specification 262,956 is referred to.