GB616469A - Improvements relating to gramophones and the like - Google Patents

Abstract

616,469. Gramophones. MORTIMER, E. W., WILKINS, E. W., and GARRARD ENGINEERING & MANUFACTURING CO., Ltd. Sept. 4, 1946, No. 26616. [Class 40 (ii)] In a gramophone, the pick-up 1 is mounted on a movable carriage 7 which slides along a rod 8 carried by an over-arm 2 which is movable, about a pin 3 on a fixture 4, under the control of the movement of the lid of the gramophone, whereby the pick-up 1, after being lifted from the record by a bar 9 on the over-arm 2, slides by gravity with carriage 7 on the rod 8 to its starting position ready for lowering on to the next record to be played, a stop-member 44 and sliding rod 42, Figs. 3 and 4, being provided for automatically setting the starting position according to whether a 10 or 12 inch record is to be played. The stop-member 44 and rod 42, which return by gravity to the setting for a 12 inch record when the over-arm 2 is lifted, is enabled to be reset for a 10 inch record, after re-lowering of the over-arm 2 by means of a lever 37 according to the position of a feeler-member 35 on an arm 33 pivoted at a fixed point 34 and supported by a spring 36. The feeler-member 35 is located so that it may contact a 12 inch record but not a 10 inch record. When a 12 inch record is placed on the turn-table, the engagement of the feeler-member 35 with the record causes the lever 33 to be depressed so that a pin 39 on lever 37 is freed from a recess 40 and engages a surface 41 and holds the feelermember 35 out of contact with the record, the upper end of the lever 37 being meanwhile held out of engagement with the end of the rod 42. When however a 10 inch record is placed on the turn-table, the lever 33 remains in its upper position and the lever 37 remains in the locked position, by means of the pin 39 and recess 40, a position to which it has been returned by the lifting of the over-arm 2. When the over-arm 2 is re-lowered the upper end of the lever 37 urges the rod 42 and the stop-member 44 to the starting position for a 10-inch record, Fig. 3. During lowering of the over-arm 2, a bell-crank lever 16, Fig. 7, engages a switch lever 17 carrying a contact 18 which is brought into engagement with spring contacts 19, and closes the circuit of the turn-table motor. Secondary switch contacts 25, 26, Fig. 4, are provided, which are closed by the pressure of a record on the turn-table acting on a plunger 30, and are connected in series with the above-mentioned primary switch, so that the motor circuit is not completed in the absence of a record on the turn-table. When the pick-up 1 reaches the run-off groove of the record the carriage 7 comes into contact with a rod 14 coupled by a block 13 to the end of a rod 11 passing through the rod 8 and having a collar 12, Fig. 5, at its other end which pulls the limb 15 of the bellcrank lever 16 so that the switch-lever 17 is released and the motor circuit interrupted.