GB693594A - Improvements in and relating to sound reproducing apparatus - Google Patents

Abstract

693,594. Magazine gramophones. GUEST, L. V., and BIRMINGHAM SOUND REPRODUCERS, Ltd. Feb. 8, 1952 [Feb. 13, 1951], No 3532/51 Class 40 (ii). An automatic gramophone of the kind in which records are stacked on a centre post, has means for automatically locating the reproducer at the start of a record, irrespective of its diameter, comprising a finger 31 and plate 29 which are rocked, by an amount dependent on the diameter of a falling record, so that the lower end of plate 29 engages one of the abutment surfaces 28 of a spring-loaded movable member 26 which has a further set of abutment surfaces 39, 40, 41, arranged for selective engagement with an arm 42 movable with the reproducer arm 3. The reproducer arm is carried on a horizontal pivot 21 mounted on the upper end of a bracket 12 which is free to rotate about a vertical rod 9 which is movable up and down in a fixed bearing 16 for the purpose of lifting the reproducer arm 3 about the pivot 21. When an automatic cycle is initiated 2 member 22, Fig. 2, is moved to the right, as viewed in that figure, whereby a ramp 23 on the said member 22 lifts the rod 3 and the reproducer is raised from the record. At the same time, the bracket 12 is pressed upwards by a spring 17 on the rod 9 but is restrained by the hooked end 48 on arm 42. Further movement of the member 22 causes its end 52 to come into contact with a pin 14 on the bracket 12 and rotate the latter counterclockwise so that the reproducer is swung outwardly across the record. During this rotation the hook 48 enters a recess 47 in the bracket 12 and the arm 42 rotates therewith against the tension of spring 46, the bracket 12 being restricted from further upward movement by a shoulder 15 on the bearing 16. During this operation a member 50 presses the member 26 downwardly until the lower end of plate 29 becomes latched with the uppermost abutment surface 28. When the next record is then released, the finger 31 and plate 29 is moved about pin 30 by an amount depending on the diameter of the record, and the member 26 is moved upwardly by the spring 35 until the lower end of plate 29 engages the appropriate surface 28. As the member 22 is then withdrawn, arm 42, and the bracket 12 locked thereto, is moved by the spring 46 until the appropriate surface 43, 44 or 45 engages the surface 41, 40 or 39, respectively, on the member 26, and the reproducer is then held over the start of the record on the turntable. Further movement of the member 22 allows the rod 9 to descend and the reproducer lowered on to the record, and the lower end of bracket 12 to descend below the hook 48, whereby the reproducer arm 3 is free to traverse the record.