GB709472A - Improvements in or relating to talking machines - Google Patents

Abstract

709,472. Gramophones. ELECTRIC & MUSICAL INDUSTRIES, Ltd. Feb. 20, 1950 [March 3,1949], No. 5867/49. Class 40 (2). A gramophone pick-up is provided with two reproducing styli which can be selectively employed, according to whether a normal record or a slow-speed micro-groove record is to be played, and so arranged that when the stylus for normal records is in the operative position it is disposed at a greater radial position with regard to the record compared with the position occupied by the other stylus when said other stylus is in its operative position. The pick-up is designed for use with micro-groove records having a starting diameter smaller than that of normal records, which records form the subject of Specification 709,485 and having a separate outer groove, so that if the stylus for normal records is lowered thereon, as in an automatic gramophone in which the pick-up is lowered at a fixed radial position, no damage may be done to the micro-groove record. The separate outer groove may have a warning signal recorded therein and may be terminated with an eccentric groove in order to switch off the machine. In one embodiment, Fig. 2, the pick-up 3 may have a rotatable head having styli 5, 6 on opposite faces and displaced from the axis of rotation so that when the head is rotated 180 degrees the stylus 5 comes to rest at a smaller radial position 7 on the record. In an alternative embodiment, Fig. 3, both styli are on the same face of the head and contact is made bv one or other styli by a small angular movement of the head.