Patent GB-395137-A (GB)
Title: Improvements in or relating to sound reproducing machines
IPC: G11B17/16
Filed: 1932-05-30
Abstract: 395,137. Magazine gramophones. WILKINSON, H. G. C., 184, Kew Road, Richmond, Surrey. May 30, 1932, No. 15275. [Class 40 (ii).] A magazine gramophone comprises a pair of turntables arranged one above the other in a framework which is rotatable about an horizontal axis. Records are arranged in a pile on one turntable, and when the upper side of the top record has been played the tone-arm is moved out of the way, and the framework is rotated ; during the rotation, a device comes into operation for separating the top record from the rest of the pile, whereupon this record slides on to the second turntable and the second side of the record is ready for playing when the framework comes to rest with the positions of the turntables interchanged. Both sides of all the records may be played successively in this manner. The rotation of the framework and the necessary movements of the tone-arm may be effected by hand, but they are preferably brought about automatically. Each turntable spindle is provided with means whereby, when it is in the lower position, it may be clutched to a driving motor, and disconnected when the positions of the turntables are to be interchanged. In the construction shown, a light metal frame 1, rotatable about an axis A-A, carries two turntables 7, 8 having the inner ends of their spindles 9, 10 closely adjacent. A pair of cam discs 12 are fixed to the spindles 3 on which the frame is journalled, the discs each having three face cams concentrically arranged and of different lengths. These are adapted to actuate, through slidable tappets 28, record-holding devices comprising two groups of rocker arms 20, 21, 22, one rocker 20 in each group being pivoted at one end of a bridge 17 in the framework, and the others 21, 22 being pivoted at the other end of the bridge. Springs tend to hold the rockers vertically against the bridge-pieces until they are protruded as required, by the action of the cams and tappets, so that lips 26 on the rockers engage with records threaded on the spindles 9, 10. The driving shaft 30 of a motor 50 has a spindle 83 slidable therein and coupled to it, the spindle 83 carrying a clutch member 32 adapted to engage with either of a pair of clutch members 33, 33<1> on the spindles 9, 10. In use, a pile of records is arranged on one turntable 7, as shown in Fig. 1, and the clutch members 32, 33 are engaged. When the upper surface of the top record a has been played, the tone-arm is lifted and swung clear, the clutch is disengaged, and the framework 1 is rotated through 180‹. The arrangement of the face cams on the discs 12 is such that during this movement the rockers 20, 21, 22 are so actuated as to separate from the rest of the pile the record a, and to allow it to slide down the spindles 9, 10 on to the turntable 8 (then in the position previously occupied by the turntable 7), leaving the bulk of the records supported by the lips 26 of the rockers 22. Fig. 4 shows the rockers in the act of separating the record a from the others. The second side of this record can then be played, the clutch 32, 33<1> having been engaged. Both sides of all the records in turn can be subsequently brought into position for playing, in the same manner. The initiation of each of the above-described cycles of operations is brought about by the usual rapid inward movement of the pick-up arm that occurs at the termination of the playing of a record. For this purpose, mechanism shown in Fig. 6 is provided, comprising an arm 40, frictionally mounted on the pivotal support of the pick-up arm and connected to a rod 46 having a pin-and-slot pivot mounting 47. One end of the rod coacts with a pin 52 on a disc 53 rotated by the motor 50, and whilst tending to be moved towards the axis of the disc 53, as a result of the normal movement of the pick-up arm, it is repeatedly pushed' aside by the pin 52. The rapid inward run of the pick-up at the end of the record causes the inner end of the rod 46 to move into the path of the pin 52, which thereupon pushes the rod 46 endwise. A lever 48 connected to the other end of the rod is thus turned about its pivot 49, Fig. 1, and allow a clutch 69 to come into operation, coupling a shaft 62 driven by the motor to a cam shaft 63. One revolution of this shaft occurs, at the end of which a cam 78 resets the lever 48 so that the clutch is put out of action. During the rotation of the shaft 63, a bevel wheel 65 thereon drives a drum cam (not shown) which actuates a lever 91 whereby the pick-up arm is raised and swung outwardly, and subsequently moved into position for the playing of a fresh record. A cam 64 actuates a lever 81, to disconnect the clutch member 32 from the one member 33 or 331 and afterwards to engage it with the other. Meanwhile, sprocket and chain gearing 85, 86, 87 is driven from the shaft 63 so as to rotate the framework 1 through 180‹ in order to change the record as described above. Means mav be provided for adjusting the machine to operate either with 10-inch or 12-inch records.