GB446153A - Improvements in or relating to vibration translating devices - Google Patents

Abstract

446,153. Phonographic recorders and reproducers. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A. Sept. 25, 1935, No. 26541. Convention date, Sept. 29, 1934. [Class 40 (iv)] In a vibration-translating device having a magnetic circuit formed with a gap in which is mounted a coil capable of vibration in two different modes corresponding to vertical and lateral vibration of a stylus attached thereto, means are incorporated for reversing the direction of the magnetic field at one side of the coil to correspond to the change in the manner of vibration of the stylus. The coil 17 is mounted on a cup which carries the stylus 21 and which is mounted on a non-magnetic supporting piece 25 by springs 23, 24. Windings 10, 11 are mounted on cores 12, 13 having a common yoke member 14 and terminating in opposed polepieces 15, 16. A central polepiece 18 extending into the coil is connected to the yoke by the bar 19. Pairs of terminals 28, 29, Fig. 3, connected to the windings 10, 11 are also connected to a source of potential 32 directly and through a reversing switch respectively. For lateral-cut records the switch 33 is closed to the right so that the movement of the coil in opposite direction on opposite sides of the polepiece 18 will generate additive currents in opposite sides of the turns of the coil. For vertical cut records, the switch 33 is moved to the left so that the flux flows towards the polepieces 15, 16 across the air-gap and back to the yoke 14 through the polepiece 18 and bar 19. As each side of the coil moves vertically in the same sense the current in opposite sides of the coil is additive.