Patent GB-338820-A (GB)
Title: Improvements in and relating to phonographs
IPC: G11B17/02
Filed: 1930-02-19
Abstract: 338,820. Technidyne Corporation, (Assignees of Jones, L. L.). Feb. 19, 1929, [Convention date] Magazine gramophones; returning sound-box to starting point; starting and stopping.-The turntable of a magazine gramophone and a motor geared thereto are carried by a frame, and unidirectionally rotatable means are provided for tilting and restoring the frame with the motor and table as an integral unit during the recordchanging operation. As shown, the turntable 2 together with the driving motor 6 geared thereto are carried by a frame 40 which is tilted about its supporting trunnions 12 to move the turntable into a vertical position so that a record thereon is dislodged by arms 30 into a magazine 32 and the next record to be played is picked up by the centering pin of the turntable as the latter moves back to its normal position. The turntable spindle 4 is driven from the motor 6 by gears 8, 10, and carries a worm 52 meshing with a worm wheel 54 integral with a clutch wheel 56 having holes 58. Co-axially mounted with the wheel 54 is a loose wheel 42, having a crank pin 70 to which one end of a connecting rod 44 is connected and through which a pin 74 is slidably keyed. The other end of the rod 44 is hinged to a stationary framework 50. In operation, when the reproducer arm reaches the end of a record, a contact 122, Fig. 6, is closed in any known manner so that an electromagnet 92 attracts an armature 94 and a plunger 80 thereon engages the pin 74 and moves it into one of the holes 58. The motor 6 thus rotates the disc 42. Just before the end of a single revolution the disc 42 is stopped, due to the pin 74 being retracted from the hole 58, by the engagement of a cam 84 on the rod 44 with a follower 88 on the pin 74. This rotary movement of the disc 42 causes the turntable to turn about the trunnions 12 into a vertical position to discharge the played record and to return to its initial position, a fresh record being engaged with the turntable during the return movement. The perimeter of the disc 42 has a cam depression 62 engaged by a spring-urged follower 64 to ensure correct positioning of the frame at the end of the tilting movement. The pin 74 carries a curved shield 90 to prevent it jamming should the plunger 80 through some mishap not have been restored to its normal position. The arrangement of the tilting mechanism is such that there is a quick record-discharging movement and a slow neturn movement. During the downward movement of the table 2, a cam 26 and follower 28 act to move the reproducer 18 outwardly. As shown in Fig 6, the motor 6 is driven from mains 100, and the electromotor is energized by a solenoid 120<1>. There are three switches 102, 104, 106, in the motor circuit. The switch 102 has a pushbutton 126 for manual operation, the switch 104 is closed only when the turntable is in its normal position with a record positioned thereon, and the switch 106 is closed only during the tilting operation. The button 126 also operates a switch 124 for the electromagnet 92. To start, the button 126 is operated. As soon as the turntable tilts, the contact 106 is closed and the button 126 may then be released. As the table 2 returns to its operative position, the edge of the record thereon engages a roller 107 on the. switch 104 to close the latter, and the switch 106 is opened. When the whole series of records has been played, the table 2 fails to return with a record, so that the switch 104 does not close and the machine stops. A record may be discarded at any time during reproduction by actuating the button 126. Specifications 338,821 and 340,169 are referred to.