GB317357A - Improvements in talking machines - Google Patents

Abstract

317,357. Gramophone Co., Ltd., and Thompsett, H. A. May 14, 1928. Magazine gramophones adapted to play records of various sizes, and having adjustable means for varying the extent of the return movement of the tone-arm to suit the size of record, are so arranged that the tone-arm is moved outwards by contact with a member the extent of whose movement is variable, the outward movement of the tone-arm being limited by a stop member, the position of which is also variable. In the form shown, cams 34, 51, Fig. 5, respectively for lifting and returning the tone-arm, are driven by a gear 5<1> on a plate 5 which is automatically clutched to the turntable spindle 3 in the usual manner. Fig. 2 shows in full and dotted lines the setting of the parts for returning the tone-arm for twelve-inch and ten-inch records, respectively. The return lever 46, operated by a lever 48 engaging by its roller 50 the cam 51, is pivoted at 47 to a stop or positioning lever 54 which rocks about a pivot 55. To return the tone-arm to starting position, the free end of the lever 46 engages a pin 16 depending from an extension 17 on the tone-arm and swings the pin against an auxiliary lever 57 spring-mounted on the free end of the lever 54. Assuming a twelveinch record has been played, the parts are in the position shown in full lines and are automatically moved to the dotted-line position by the engagement of a pin 79 on the cam disc, Fig. 5, with a lever 77 connected at 76 with a link 74. This link is attached at one end to the lever 54 and at the other end engages a bell-crank lever 61, the arm 63 of which then moves from the notch 66 of a spring-controlled detent 67 into a second notch 65. If ten-inch records are played, the setting remains unchanged, but, when a twelveinch record is fed to the turntable, the edge of the record engages a pin 81 on the crank 80 extending from the lever 63 and moves the parts into the full-line position.' The auxiliary lever 57 exerts a spring pressure on the tone-arm to feed the needle into the groove. The tone-arm 14 is lifted about pivots 27, Fig. 4, by the cam 34 engaging a lifting-lever 32 which bears on the lower end of a pin 30 carrying a plate 35 on which rests a pin 36 extending from a member 37 on the tone-arm. Specification 317,358 is referred to.