GB341846A - Improvements in and relating to phonographs and the like - Google Patents

Abstract

341,846. Gramophones. JONES, A. D., 247A, St. Vincent Street, and SMITH, S. J., 39, Randolph Road, Broomhill, both in Glasgow. Sept. 20, 1929, No. 28533. [Class 40 (ii).] Multiple machines; ,' returning sound-box to starting point sound boxes, arrangement of.-In a magazine gramophone, the record changing mechanism and the stylus re-positioning mechanism are driven by a separate motor which is started up when the stylus reaches the end of the record groove. As shown, a motor 4, Fig. 3, which continuously drives the turntable 1 also rotates a threaded spindle 2 so that a member 7 engaging the thread groove moves at the same rate as the tone arm 8 during reproduction. The tone arm pillar 9 carries a fork 11<1> having contact pins 12 adjacent the member 7. When the stylus reaches the end of the record groove the relative movement of the members 7, 8 causes the former to contact one of the pins 12 to close a relay operating the switch of the motor driving the record-changing mechanism. The said motor rotates a spindle 15, Fig. 4, carrying three cams 39, 40, 41 and a pin 24. The pin 24, and a cam 25 on the cam 39, respectively oscillate and raise and lower the record change-arm 20 so that it moves to disengage a pin 28 thereon from the central hole of the played record and engage the hole of the uppermost record on the magazine platform 21 and to slide the fresh record on to the turntable 1, the played record being pushed into a receiver 30 by a pin 29 on the arm 20. The pin 24 engages a slotted link 23 on the changearm pillar 22 the angular movement being limited by a detent pawl and stop. The platform 21 is carried by a tubular stem 31 through which passes a rod 34 engaging the central holes of the records and a spring 36 moves the platform 21 so that the uppermost record is ready for transfer to the turntable. Rollers 38 on a pivoted arm 37 lightly press upon the top record. The cam 39 operates a connection 43 so that at the proper times the arm 8 turns about a bearing 44 to raise the stylus from the played record and lower it upon the fresh record. The arm 8 is swung outwardly by the cam 41 which operates a connection 54 secured to an arm on the tone-arm pivot pillar 9. The outward movement of the arm 8 is limited by a stop 62 carried by a lever 49 and engaged by an arm 55 on the pillar 9. The position of the stop is adjusted to suit the size of record used. For this purpose the lever 49 has a pin 50 projecting through an arcuate slot 51 in the machine casing 10 and a record in passing from the magazine to the turntable engages the pin 50 to position the lever 49. The lever 49 is held in the adjusted position by the engagement of a brake shoe 47 with a block 48 on the lever 49, the shoe 47 being operated by a cable 46 controlled by the cam 40.