Patent GB-664532-A (GB)
Title: Improvements relating to gramophone record changers
Inventor: RUSSELL LIONEL VIVIAN FRANK
IPC: G11B17/16
Filed: 1949-03-30
Abstract: 664,532. Magazine gramophones. AERONAUTICAL & GENERAL INSTRUMENTS, Ltd. March 30, 1950. [March 30, 1949] No. 8666/49. Class 40 (ii). An automatic record changing gramophone having a magazine for releasing records one by one on to the turntable has pick-ups capable of playing the top and bottom sides of records successively, relative movement between the turntable and the pick-ups and means for reversing the direction of rotation of the turntable being provided to enable the record surfaces to be engaged successively, the diameter of the turntable being smaller than the smallest diameter of playing surface, and after playing the record being lifted from the turntable and ejected. In the embodiment described the turntable 1, Fig. 3, and shaft 25 is lifted and lowered to occupy one of three positions, viz. (1) the upper position in which the upper pickup 6 engages the upper side of a record, (2) the lower position in which the lower pick-up 7 engages the lower side of the record, and (3) an intermediate neutral position. The shaft 25 passes freely through the bevel gears 21, 22 which are continuously driven by a bevel pinion on shaft 16 driven through a friction reduction gear by a motor 15. In the upper position of the shaft 25 engagement is made with the upper gear 21 so that the turntable revolves clockwise as viewed from above, and in the lower position engagement is made with the lower gear 22 and the turntable revolves in the opposite direction. In the intermediate position, the turntable is stationary. The sleeve 23 carrying the upper bevel gear 21 has a worm and wheel connection to a countershaft 43 which, when an automatic cycle is initiated, is coupled to a cam-shaft 44 by means of a ratchet wheel 45 on the countershaft 43, and a spring-loaded pawl 46 on the cam-shaft 44. The pawl 46 is held disengaged from the ratchet wheel 45 during the playing of a record by the turned down end 51, Fig. 8, of a lever 144, or by the similarly turned down end 52 of a lever 142, until one of the pick-ups, which are mechanically linked together by steel tapes 87, 90 and sprockets 88, 89, Figs. 2 and 2A, reach the run-off groove of the record. During a normal operation when both sides of the records are being played the cam-shaft 44 performs a half-revolution at each automatic cycle. At the end of one half-revolution the shaft 25 is lifted by the cam 40 for the playing of the upper side of the record, as shown in Fig. 8, and at the end of the second halfrevolution the shaft 25 is lowered for the playing of the lower side of the record. The pick-ups are swung outwardly at the end of the playing of a record by means of a cam 77, Figs. 3, 6 and 10, operating a bellcrank lever 79 which moves a slide 81, the opposite end of which engages a pin 84 on an arm 85 attached to the shaft carrying the upper pick-up 6. The arm 85 is moved counterclockwise, as viewed in Fig. 6, against the action of a spring 121, through the medium of an extension 116 on the arm 85, and a pin 117 on an arm 118 of a lever 119 pivoted at a point 120. After the pick-ups have been moved outwardly beyond the edge of the record, the follower on the bellcrank lever 79 begins to descend the surface of cam 77 and the pick-up arms move inwardly again under the influence of spring 121 until, should the next record be a 10 inch diameter one, a stop 122 comes into contact with an abutment 123 corresponding to the starting diameter of a 10 inch record. Should there be a 12 inch record on the turntable, a lever 124, Fig. 4, will have been tripped by the record when released from the magazine so that a lever 131 will also have been released and its hooked end 132 act as a stop to the lever 119. The lever 131 remains set in this position until the mechanism for ejecting the record from the turntable comes into operation, i.e. until both sides of the record have been played. This mechanism comprises a lever 65, Figs. 4 and 9, which is moved counterclockwise by an arm 62 and a cam 53 on the camshaft 44, whereby an arm 66 pivoted at a point 65A on the upper end of the lever 65 and carrying a wheel 69 and having an extension 67 is moved clockwise under the influence of a fixed-position roller 68 and the record is lifted from the turntable, as shown by the dotted outline in Fig. 4, and slides over rollers 72 into a tray 8, Fig. 1. The arm 66 carries a hooked member 72 which serves to unseat the next record from the magazine by means of the hooked end 72 if the next record be a 12 inch one, or by the edge 73 if the next record be a 10 inch one. When the last record has been unseated from the step 75, the steadying disc 194, Fig. 4, slides low enough on the pin 76 to permit the end 196 of a trigger member 197 pivoted at 198 to be moved counterclockwise under the influence of a spring-loaded wire loop 199 so that a stop 203 tilts a lever 200 which permits a spring-loaded cranked lever 205 to be released clockwise and a dependent member 214, having a hooked end 217, lowered into the path of a leaf spring 119A, Fig. 6, on lever 119 to effect engagement when the pick-ups next move to the outermost position. The clockwise movement of the lever 205, however, is delayed until after the last record has been ejected, by means of a latch lever 221 pivoted at 222 and biassed by a spring 223 to engage beneath a ledge 224 on lever 205, which is prevented from movement until arm 119 comes into contact with the tail end of lever 221 during the movement of the pick-ups to the outermost position, when the hooked end 217 and the leaf-spring 119A will hold the pick-ups in this position until the motor circuit is broken by switch 104, Fig. 11, carried by the plate 85 and operated by a lever 93, and a cam 92 on the cam-shaft 44. A record may be repeated by pressing a button which moves a member 184, Fig. 2A, to the right so that the stop 60, Fig. 9, will be brought into operation to prevent the operation of the record ejection and pusher mechanism by striking the arm 59, Fig. 9, of a clutch 57 whereby rotation of the cam 53 is arrested, until the member 184 is released to its original position by the operation of a "Reject" push button. This button also moves a lever 160, Fig. 2A, so that its other end 161 operates levers 142 and 144 as when the pick-up reaches the run-off groove of the record. The upper pick-up 6 rests by gravity on the record and is prevented from falling below a certain level by a rest 113, Fig. 2A, but the lower pick-up 7 is pressed upwardly by the action of a spring 115, Fig. 2, and in the absence of a record presses against a rest 114. The inoperative pick-up is open circuited by means of insulated blocks 230, Figs. 3 and 12, on a cam 229.