Patent GB-647162-A (GB)
Title: Record changer
Filed: 1947-10-07
Abstract: 647,162. Magazine gramophones. A.M.I., Inc. Oct. 7, 1947, No. 26952. Convention date, Oct. 21, 1946. [Class 40 (ii)] In a magazine gramophone of the type described in Specification 641,441 in which records are stored edgeways in a horizontally reciprocating magazine and are lifted therefrom by an arcuate arm for placing either side up on the turntable, the magazine traverses a bank of selector levers, the interaction of the magazine and an operated selector lever serving to operate switching means for stopping the magazinetraversing motor. Fig. 2 illustrates in simplified form the arrangement of selector levers and magazine in which only four records 37-40 and eight selector levers 57-60, 77-80 are shown. The magazine carries two trip switches 113, 115 which are connected in series with the magazinetraversing motor 98, the circuit, of which is completed by one or other of the parallel connected contacts of a bail switch 123 operated by the lifting of one of the bail bars 121, 122 by one of the selector levers 57-80 which may be operated by solenoids controlled by a coinfreed device. The magazine is reciprocated by means of a coupling rod 189 connected to a link in the chain 187. The switches 113, 115 are designed so that during the forward traverse of the magazine only the switch 113 may be tripped and broken by one of the selector bars, while during the backward traverse only the switch 115 may be tripped and broken. During the forward traverse the plate 114 rests in the position shown in Fig. 2, having been set in that position by the bar 119 which comes into contact with the arm 116 of the said plate 114. The right-hand arm of the plate 114 pushes forward a plunger 334, Fig. 1, which enters a groove 336, Fig. 30, in the mushroom-shaped end 298 of the gripper arm shaft when the record is swung over to the turntable and turns the said shaft 90 degrees so that the record is laid front face uppermost on the turntable. During the backward traverse of the magazine the plate is in a position in which a plunger 333 is pushed forward and enters the groove 335, Fig. 24, and turns the gripper arm shaft so that the rear face of the selected record is placed on the turntable. The record transfer mechanism 287 and pick-up arm control cam 104 is driven through a single shaft 347 and a reduction gear 348 by a reversible motor 100 which rotates in one direction while a record is being transferred to the turntable, and in the other direction when being returned to the magazine. During the initial movement of the shaft 347, the lobe 326, Fig. 30, on the gear 307 moves clockwise against a projection 309 on a gear 305 and moves the grippers 296, 120, Fig. 25, to the record-gripping position shown in Figs. 26 and 30. The teeth of the gear 307 then engage a gear 313, Fig. 27, whereby the gripper arm assembly is rotated bodily to a position over the turntable, when the lobe 316, Fig. 30, on the gear 307 engages a recess 317 on the gear 305 and gives additional rotation to the shaft 291, Fig. 26, to release the record on to the turntable. At the same time, the counter-clockwise rotation of the shaft 347, as viewed from the front, moves the cam 104, Figs. 31 and 32, from the chain-dotted position to the full line position to raise the pick-up arm by means of the sloping surface 362, to feed it over the start of the record groove by means of the surface 361 and pin 359, and to lower it to the record after the passing of point 363. At the end of the playing of the record when the direction of rotation of shaft 347 is reversed the point 363 lifts the pick-up arm from the record and the pick-up arm is swung outwardly by means of the sloping surface 364, Fig. 31, which acts on the pin 358. At the same time the gear 307 is rotated in the opposite direction to cause the record to be gripped, transferred to the magazine and released. The turntable motor 102 is switched on by a switch (not shown) ganged to the bail-bar switch 123 and thus remains on while any of the selector levers are in the operated position. Attached to the pick-up arm cam 104 is a cam-surface 371 having a raised part 368 and a sunk part 369 to operate switches 129 and 131. The switch 129 is connected in series with the magazine-traversing motor 98 and is closed while the pick-up arm is in the non-operative position. The switch 131 is closed while the pick-up arm is in the operative position and closes the circuit of one or other of solenoids 132, 134, Figs. 1 and 11, carried by the magazine, to release the particular selector which has initiated the operation in progress and thereby release the appropriate switch 113 or 115. The switches 113, 115 have extra contacts 142, 150, respectively, which are closed when the switches 113, 115 are tripped, and serve to short-circuit and brake the armature of the magazine-traversing motor 98, and to close the circuit of the transfer-mechanism motor 100. The pick-up arm is provided with a pin 181, Fig. 1, which, when the pick-up reaches a certain point at the inner part of the record, strikes a switch member 179 of a switch 167 which energizes a relay 133, Fig. 11, so that the transfer-mechanism motor 100 is reversed, the circuit being locked on by contact 169 through switch 131, Fig. 32, which remains closed until the member 370 enters the sunk part 369 of the cam surface 371. When this happens, relay 133 is released and the circuit of the transfer motor 100 is broken and all circuits returned to normal, after which the next record is transferred to the turntable, should any other selector levers have been operated.