GB332683A - Improvements in and relating to sound reproducing devices - Google Patents

Abstract

332,683. Columbia Graphophone Go., Ltd., (Capps, F. L.). May 28, 1929. Tool-arms. -In electric pick-ups having a stylus formed by a length of thin wire, provision is made for feeding forward the wire when required, for limiting the feed, and for preventing the stylus-holder contacting the record when the projecting wire wears away. The stylus wire is led from a coil 75, Fig. 3, over a plate 74 having a struck-up tongue 77 which prevents backward movement of the wire, and passes through the coil 66 of the pick-up and through the stylusholder 68 which is attached to the armature 67 carried by a flexible member 69 secured by bolt 71. The wire can be fed forward, when worn, by a lever 83 pivoted to a block 78, Fig. 4, which is provided with a shoulder 82 and pivoted on a frame 72 secured to the magnets. On rocking the lever 83, a lug thereon first pinches the stylus wire against the shoulder 82 and further movement feeds the wire through the holder 68 until arrested by a stop 94, which has been moved opposite to the holder by the movement of the lever 83. This stop, which normally protects the end of the stylus-holder, comprises a V.shaped frame with bent-up end and with bent side lugs forming pivots against a plate 85 on the pick-up against which it is held by a spring. A projecting end 89 of the frame extends into the path of an arm 91 of the lever 83, whereby the stop is operated by movement of the lever, the return movement of which is effected by a spring 80. The passage through the stylus-holder may be heart-shaped providing a V which grips the stylus when in operation, and the end of the passage may be curved as shown in Fig. 6, to increase the grip. Specification 332,889 is referred to.