GB611937A - An improved gramophone pick-up - Google Patents

Abstract

611,937. Gramophone pick-ups. RADIO GRAMOPHONE DEVELOPMENT CO., Ltd., and HAIGH, R. W. May 9, 1946, No. 14081. [Class 40 (iv)] In a balanced-armature type of pick-up, the armature consists of two separable flexibly mounted side pieces 10, 11 between which the stylus is held, the supporting members 12, 13 for the side pieces 10, 11 being urged together by the pressure of a spring 19. The said side pieces 10, 11 are suspended on wires 21 soldered in slots in the supporting members 12, 13, and blocks 14, 15 of resilient material are provided between the side pieces 10, 11 and the supporting members 12, 13 in order to damp the armature movement. The supporting member 12 is immovably fixed to the pick-up base, whilst the supporting member 13 is movable in a direction along the axis of a projection 16 which extends through a fixed part of the pickup. A flat U-shaped member 17 having an extension piece 18 rests on the supporting members 12, 13 and is fixed to the member 13. The extension piece 18 projects through the side of the pick-up, so that external pressure may be applied to move the supporting member 13 away from the supporting member 12 when desired to release the grip on the needle or stylus. The magnetic system consists of a bar magnet 2, side members 3, 4 and U-shaped polepieces 5, 6, which have depending members 7, 8 which are terminated just above the side piece 11 of the armature and which are surrounded by the output coil 9. In an alternative construction, Fig. 6 (not shown), the suspension wires 21 are omitted and the side pieces 10, 11 have projections which are bonded to the insets of resilient material 14, 15.