GB554554A - Improvements in or relating to gramophones and the like - Google Patents

Abstract

554,554. Positioning gramophone pick-ups. SHAW, M. N. H., and METCALFE, C. Sept. 29, 1941, No. 15104/42. Divided out of 554,530 [Group XXXV]. [Class 40 (ii)] In gramophones adapted to play records of different sizes, the pick-up is automatically positioned on the record in accordance with the size of the record by an arrangement of stops 3, 4 on levers 5, 12, each stop being independently adjustable, and at least one of the stops being adapted to be moved in and out of operative position. The stop lever 5 is adjusted about its pivot 6 by means of a lug 7 projecting above the motor board through a slot 8, and is clamped in adjusted position by a screw 9. The stop lever 12 is pivoted at 13 on an arm 14 pivoted at 15. The operative position of the stop is adjusted by an adjustment of the arm 14 about its pivot 15 by a lug 16 projecting above the motor board through a slot 17. The arm is clamped in adjusted position by a screw 18. The stop lever 12 is pivoted at 21 to a link 22 by means of which the stop lever 12 can be moved to place the stop 4 in or out of operative position. When a 10 inch record is to be played, the stop 4 is, as shown in full lines, out of the path of a lug 46, Fig. 2, moving in with the pick-up arm, so that this arm moves in until the lug 46 abuts the stop 3; the pick-up is then over the edge of the 10 inch record. When a 12 inch record is to be played, the stop 4 is automatically moved to the operative position shown in dotted lines and causes the pick-up to stop over the edge of the 12 inch record. The automatic setting of the stop 4 is performed by the link 22, which may be controlled by the trip device described in Specification 554,553. The pick-up arm (not shown) is carried by a spindle 40, Fig. 2, and can be raised and lowered in known manner by a central rod 41. A drive arm 42 is fast with the spindle 40 and has a projection 43 which can move between a reset lever 44 and the end 47 of a drive lever 45 while a record is being played. A follower arm 60 frictionally gripped to the pick-up arm co-operates with cams on the turntable spindle as described in Specification 554,530 to form a tap-tap mechanism adapted to set the record changing mechanism in operation at the end of the playing of a record. When this occurs, a link 51 controlled by a cam of the mechanism turns the drive lever 45 clockwise, the projection 43 is engaged by the end 47 of the drive lever; and the pick-up arm which meanwhile has been lifted is turned outwards ; the projection 43 also engages the reset lever 44 and turns this clockwise. After a fresh record has been fed, the cam mechanism releases the link 51, a spring 48 then turns the reset lever 44 counterclockwise, and this acting on the projection 43 turns the pick-up arm inwards until the lug 46 of the reset lever 44 meets the stop 3 or 4 according to the size of the record. After this, the pick-up is lowered on the record.