Patent GB-564853-A (GB)
Title: Improvements in automatic record changing devices for gramophones
IPC: G11B17/16
Filed: 1943-03-18
Abstract: 564,853. Automatic gramophones. AGABALTIC AKTIEBOLAG. March 18, 1943, Nos. 4409 and 4410. Convention dates, March 20, 1942, and Sept. 5, 1942. [Class 40 (ii)] A device is provided to delay the operation of an " impelling " member of the recordchanging mechanism of a magazine gramophone, whereby a delay is introduced between successive playings. The delay may be adjustable and'may be set to occur only alternately with undelayed operations. As shown in Figs. 1 and 2, the gramophone is of the kind described in Specification 568,663, comprising a stem 12 projecting upwards centrally of the turntable 10 and offset to support a stack of records on a shoulder 13 from which the records are dislodged one at a time by the reciprocation of a side pusher 15 controlled by a cam disc 19. The records are confined on the stem by an arm 14. The cam 19 which operates the record changing mechanism and the pick-up return mechanism is adapted to be driven by a friction pinion 29 on the shaft 11 of the turntable. During the playing of a record, the pinion 29 lies freely in a recess 30 in the periphery of the cam 19, and the cam is at rest. At the end of the playing operation, a lever 28 is deflected and strikes a pin 26 on the cam 19 thereby imparting to the cam a counterclockwise impulse. The pinion 29 then grips the cam and drives it round until another recess 31 in the periphery of the cam comes opposite the pinion 29. At the same time the pin 26 on the cam deflects an impelling member constituted by a lever 32 clockwise about its pivot 33. During this partial rotation of the cam 19, a part of the record changing and pick-up return operation is performed. If this lever remains deflected, the cam stops with the pinion 29 loose in the recess 31. If the lever 32 is swung back counterclockwise after being deflected clockwise by the pin 26, an inclined face 34 on the lever strikes the pin 26 and gives a counterclockwise impulse to the cam, causing the pinior 29 again to grip the periphery of the cam, which is thereby again driven counterclockwise until the recess 30 again reaches the pinion 29, when the cam stops after completing one operation of the record changing mechanism and the pick-up return mechanism. All this proceeds in known manner. Now, according to the invention, a device is provided to delay the return swing of the lever 32. In a simple form of delay-device shown in Fig. 2, a disc 36 is rotatably mounted on the outer end of the lever 32 and is urged counterclockwise by a spring 37. During the playing of a record, a notch 44 in the disc 36 is in engagement with a fixed pin. When, after the playing of a record, the cam 19 is rotated and the pin 26 thereon deflects the lever 32 clockwise as mentioned above, the slot 44 is disengaged from the fixed pin and the disc 36 is rotated counterclockwise by the spring 37 until a finger 38 on the disc meets a fixed abutment 39. So long as the slot 44 is out of line with the fixed pin, the lever 32 is held off and cannot impart an impulse to the pin 26 on the cam 19. The clockwise deflection of the lever 32 also affects a lever 41 pivoted at 41 on the lever 32, causing the inner arm of the lever 41 to come within reach of a finger 43 on the turntable spindle 11, and a pawl 61 at the outer end of the lever 41 to engage ratchet teeth on the disc 36. At every revolution of the turntable, this ratchet mechanism is operated one step until this gradual rotation of the disc 36 brings the slot 44 again in line with the fixed pin. When this occurs, a spring 60 swings the lever 32 back counterclockwise, thereby giving the impulse to the cam 19 through the pin 26, as required to complete the operations of this cam. The time of the delay may be varied by adjusting the position of the abutment 39. In a modification, Figs. 4, 5 and 6 (not shown), two slots are provided in the disc 36 and the associated parts are arranged to make these slots alternately operative, one giving a comparatively short delay and the other a longer delay. In another delay device shown in Fig. 7, a lever 118 co-operating with a pin 117 on the cam 114 is connected by a link 124 to a lever 129 urged by a spring 133 towards an abutment 135 at the inner end of a lever 136 pivoted at 131 on a rotatable stud 114 and adjustable by a cam 145 set by hand. In a certain range of positions of the setting cam 145, the lever 136 lifts a lever 148 and this in turn lifts the left end of the lever 129 off a ratchet device 153. Adjustment of the setting cam 145 within this range of positions enables the distance of the abutment 135 from the rest position of the lever 129 to be varied to determine the delay. When the lever 118 is deflected counterclockwise by the pin 117, the lever 129 moves to the right, a lug 130 on the lever 129 is released by the end 141 of a shaft 134 mounted on a bracket 137, and the spring 133 turns the lever 129 about its pivot 128. The abutment 135 limits this turning movement of the lever 129. When the pin 117 passes the apex of the lever 118, a spring 150 urges the levers 118 and 129 back, but the lug 130 then bears against a screw-thread on the end 141 of the shaft 134. The bracket 137 carrying this shaft is pivoted at 138 and is normally held against an abutment 140 by a spring 139. When the lug 130 is pressed against the screw-threaded end 141 of the shaft 134, the bracket 137 turns clockwise and a gear-wheel 142 on the inner end of the shaft 134 is brought into mesh with a pinion 143 on the turntable spindle. The rotation thus imparted to the screw-threaded shaft 134 drives the lug 130 until this lug slips over the end of the shaft, whereupon the lever 129 moves back to the left and the lever 118 imparts the desired impulse to the pin 117. At the same time also, the spring 139 restores the bracket 137 against the stop 140, thereby disengaging wheel 142 from pinion 143. In another range of positions of the setting cam 145, the lever 136 allows the lever 148 to fall sufficiently to enable the left end of the lever 129 to co-operate with the ratchet device 153 to turn that device one step at each stroke of the lever 129. Alternate positions of this device allow the lever 129 to return to the left at once or cause the return to be delayed by the engagement of the lug 130 with the screwthreaded shaft 134, so that two playings occur with no delayed interval, then there is a delayed interval before the next two playings and so on. A spring snap is provided to locate the ratchet device accurately in its successive positions, A lever 162 is provided to operate the ratchet device one step when it is desired to change its normal function.