GB836526A - Improvements in tone-arms for gramophones - Google Patents

Abstract

836,526. Gramophone pick-ups. PHILIPS ELECTRICAL INDUSTRIES Ltd. Sept. 23, 1958 [Sept. 26,1957], No. 30351/58. Class 40 (2). The roller 3, in the solid-line position of Fig. 2, contacts the surface of the record 7 and holds the stylus 8 clear of the record in known fashion during record diameter-gauging. The member 12, pivoted at 11, is urged downwardly when clear of the edge of the record, bringing the brake shoe 13 into contact with the drum 14 and braking the previously freely-rotating roller 3; the roller, now acting on the record as a friction shoe, causes the assembly 2 to swing to the right in Fig. 2 around the axis 5 and the spring 9 then holds the assembly in the dotted-line position of Fig. 2, allowing the stylus 8 to engage the run-in groove of the record. In a further embodiment (Fig. 3, not shown), the member 12 is replaced by a second roller on the now common shaft 4, the shaft being journalled in a hole in the left-hand side of the frame 2 and only partially supported in a vertical slot in the right-hand side. The shaft 4 can thus pivot about the left-hand bearing hole and when the right-hand roller descends over the edge of the record, a projection on the shaft 4 engages a detent on the frame 2 to brake the roller 3, so that a similar retraction of the frame 2 occurs.