Patent GB-402779-A (GB)
Title: Improvements in and relating to automatic record-changing means for gramophones and to records for use therewith
IPC: G11B17/16
Filed: 1932-03-08
Abstract: 402,779. Magazine gramophones. MANN, G. S., 101, Rosehill Road, Ipswich, Suffolk. March 8, 1932, Nos. 6894 and 25023. [Class 40 (ii).] An automatic magazine gramophone is equipped with two record-removing devices respectively adapted to be moved into a position over the turntable and over a record magazine, and to be traversed simultaneously to carry a played record away from the turntable and to bring an unplayed record from the magazine into position over the turntable, the records being then released. The records 1 are lifted by magnetic attraction, for which purpose they may be provided with steel centre pieces or, as shown in Figs. 2 and 4 a loose apertured steel disc 2 may be associated with each record as described in Specification 403,786. A record magazine 3, Fig. 2, is disposed at one side of a turntable 4 on the other side of which is a well 5 for receiving played records. The turntable 4 is driven continuously by an electric motor 6, Fig. 16. Upon the rear wall of the cabinet is a pair of rails 9, 10 upon which is adapted to run a carriage 11 having rail-engaging rollers 12 as shown by Figs. 4 and 6, which are sectional elevations on the lines IV-IV and VI-VI, respectively, of Fig. 1. The carriage 11 carries two arms 13, 14, shown in plan view by Fig. 1, which carry electro-magnets 15, 16, respectively, Fig. 2, which effect the lifting of the records. The carriage 11 is traversed along the rails 9, 10 by a cable 19 passing over pulleys to a winding drum 21 which is rotated first in one direction and then in the other by an electric motor 22, Fig. 16, which by means of a flexible shaft 23, Fig. 9, drives a main shaft 24 which rotates the drum through reversible gearing driven from a pinion 28 which is in mesh constantly with toothed wheels 29, 30 fixed on shafts 31, 32 rotatably mounted between the two arms of a lever 33 free to rock about the shaft 24. The ends of the lever 33 are coupled to the cores of solenoids 38, 39, Figs. 2 and 9, and when both solenoids are de-energised the gear is in its neutral position but when one or the other is energised the lever 33 is rocked to bring the wheel 40 or the wheel 41 into the drive train to the drum 21 to drive the drum in one direction or the other. The records in the magazine are placed upon a lifting platform 50, Fig. 4, supported by a spring 51 and guided by rollers 52 which engage the sides of the magazine and by a vertical threaded rod 53. The top record of the pile is pressed normally against a stop 54 carried by an arm 55 pivoted for horizontal movement upon the end 56a of a lever 56 pivoted at 57 so that when the lever 56 is free to pivot at 57 the stop 54 is free to rise. Normally, the lower end of the lever 56 is locked by a detent 59 which carries an armature 59a so that upon energisation of an electromagnet 61 the lever 56 is freed and the stop 54 lifts as the top record is raised from the pile. To control the other records in the pile during removal of the top record a locking device as described in Specification 403,773 is employed, comprising a pair of horizontal levers 63 surrounding the threaded rod 53 and pivoted to a plate 62. Springs acting on the levers 63 normally maintain notches thereon out of engagement with the threaded rod 53, but upon energisation of an electromagnet 67, Fig. 16, the levers 63 are drawn inwardly to engage the threaded rod 51 and lock the platform against being raised. The platform is held depressed during loading of the magazine by asliding bolt 68 which engages a hole 69 in a bracket 70 and is operated from a knob 7 4. The main shaft 24, Fig. 9, drives a shaft 84 which carries a series of seven cams 85-91 which serve to close for the desired periods seven spring-biased switches 93-98, Fig. 16, which control the elements of the electric circuit. The shaft 84 also carries two cams 102 for raising and lowering the pick-up. These cams 102 co-operate with rollers 103 provided upon a rocker frame 104, Fig. 6, pivoted at 105 to a bracket 106. The end of the rocker frame 104 is pivoted to a cross bar carrying a pair of vertical links 107 jointed to the rear ends of lifting levers 108. The levers 108 are pivoted to a pair of pick-up carrier rods 111 the rear ends of which are slidably mounted on a cross-shaft 112 rotatably supported between pillars 110. A pick-up 113 and a switch carrier 114 are slidable on the rods 111, the carrier 114 carrying spring contacts 115 which are normally kept separated by an insulated wedge member 116 on the pick-up 113. When the needle moves into a run-off groove at the end of a record the wedge member 116 is withdrawn from contacts 115 due to the inertia or the friction of the rods 111 and a circuit is thereby completed through a relay 100, Fig. 16, to connect the motor 22 to the supply mains. The cams 102 thereupon operate to raise the rods 111 so that the pick-up 113 and switch carrier 114 are slid back until arrested by a stop lever 118. The lever 118, pivoted at 119, is subsequently adjusted, in its angular position, according to whether the next record to be played is a 10- inch or 12-inch record. For this purpose a slot 120 in the lever 118 is engaged by a pin 121 on a horizontal lever 122, Fig. 9, pivoted at 123 and connected to a slide 124 normally drawn back by a spring 126. The slide 125 carries an upstanding peg 127 projecting through a slot 128 in the top board 8, Fig. 1, to be in the path of a 12-inch record. Thus when a 12-inch record strikes the peg 127 the lever 118 is moved to the dotted line position of Fig. 6 so that the pick-up 6 slides further along the rods 111 into a starting position suitable for the playing of a 12-inch record. The lever 118 is retained in this position by a trip lever 129 and is released when an electromagnet 131 is energised by the closing of the switch 96, In operation, after the playing of a record the circuit through relay 100 is completed by the tone-arm switch 115 to start the motor 22 whereupon the pick-up is raised and slid back and switch 115 opened, the circuit to the motor 22 being maintained closed by the operation of switch 92. Operation of switches 93 and 94 effect the locking of the magazine through the lever 63 and the release of the stop 54. At the same time the lifting magnets 15, 16 are energised and the carriage 11 is then traversed to transport the new record to the turntable and the played record to the well 5 when the records are released by the opening of switch 95. The closing of switch 98 effects reversal of the winding drum 21, and the pickup is next lowered to play the next record. By moving a switch 132 into the dotted line position of Fig. 16, the solenoids operated by switches 93-98 are cut out so that the record on the turntable may be repeated indefinitely. In order that any record may be removed before it is played completely a switch 135 is provided to close the circuit to the switch 100. The gramophone is stopped automatically when the last record has been played by operation of a spring-biased switch 186, Figs. 6, 9 and 16, which is closed when the needle of the pick-up is lowered into a groove 140 on the turntable 4 when no record is present thereon so raising the rods 107 to raise the plunger of the switch 136. The spring-supported platforms of the magazine 3 and well 5, respectively, are interconnected by cables running over pulleys.