Patent GB-569789-A (GB)
Title: Improvements in magazine gramophones
IPC: G11B17/02
Filed: 1943-09-28
Abstract: 569,789. Magazine gramophones. HOLSTENSSON, A. H. Sept. 28, 1943, No. 15935. Convention date, Sept. 24, 1942. [Class 40 (ii)] Relates to magazine gramophones of the kind in which the records to be played are stacked above the turntable and dropped one at a time thereon, and consists mainly in the arrangement of a cam disc having a concentric groove and an eccentric groove opened and closed by a point-lever to determine whether a fresh record will be dropped or not when the automatic cycle is performed. The machine described includes many other features. Turntable.-The turntable 3 is fast with a hub 4 rotatable on a ball-bearing 5 supported by a fixed central post 6. The hub has a groove 7 for an endless elastic cord 8 for driving the turntable from a pulley 9 on the spindle 10 of an electric motor 11 which is mounted on a hinge 12. Magazine.-The records to be played are stacked eccentrically above the turntable 3 over two diametrically-opposite ledges 20, 21 on side pillars 18, 19 which can be adjusted towards and away from each other according to the diameter of the records to be played. For this purpose, the pillars are slidably mounted and connected by links 39, 40 to a disc 41 rotatably adjustable about the centre 42 of the magazine by means of a link 43 from a control knob 46. The lowest record is fed from the magazine to the turntable by the reciprocation of a side pusher 55. This pusher is carried by a bent member 57. 58, 94 fitted with a roller 96 in engagement with a cam disc 65, which is mounted below the turntable concentrically therewith, and is driven for one revolution at a time to perform the automatic operations of record-changing and pick-up repositioning. The cam-disc is driven by a friction pinion 76 on the shaft 10 of the motor, when the cam disc is imparted an initial counterclockwise rotation by a tap-tap mechanism sufficient to bring the pinion 67 in engagement with the periphery of the cam disc, the pinion being normally loose in a recess 66 in the periphery of the cam disc. Record changing is performed when the roller 96 travels in an eccentric groove 97 in the cam disc 65. The inward stroke of the pusher 55 then brings the lowest record axially over the turntable ; the central hole of the record comes over the bevelled end of a fixed central post 26; the edge of the record leaves the ledges 20, 21; and the record falls on the turntable. If the record is a small one, its edge is released by the part 47 of the edges of the ledges 20, 21 ; if the record is a large one, the release is by the edge part 48. These two edge parts 47, 48 are curved respectively to correspond to the curvature of the edge of the small and large records. The records are confined and guided in the magazine by curved slightly conical walls 22, 23 ; and additional guidance is given to a large record at the moment of release by fixed ledges 53, 54 which are in line with the ledges 20, 21 when the record supports are set for records of large diameter. Pick-up movements.-The pick-up arm 13 is connected by an horizontal hinge 14 to a stirrup 15 attached to a sleeve 16 rotatable about its vertical axis. The lifting and lowering of the pick-up arm about the hinge 14 is performed by a vertical rod 17 extending through the sleeve 16. The lower end of the rod 17 bears down on a lever 71 pivoted on an horizontal hinge 72 and provided with a roller 69 adapted to fall into a groove 68 in the cam disc 65 to lower the pick-up near the end of each revolution of the cam disc and to be lifted up at the beginning of the revolution. The rotation of the sleeve .16 carrying the pick-up is performed by an arm 73 fast with the sleeve and connected by a pin-andslot joint 75, 74 to a lever 76 pivoted at 77 and formed with a lug 78 adapted to be operated by a pin 79 on the cam disc 65 to move the pick-up to its outer position. Another arm 80 also fast with the sleeve 16 is connected by a pin-and-slot joint 82, 81 to an angular lever 83 pivoted at 84 and adapted to be operated by the cam disc 65 to move the pick-up from its outer position inwards to the starting groove of a record. The extent of this movement is made to depend on the diameter of the records for which the magazine has been set by the disc 41. The cam disc 65 has two pins 88, 89 at different distances from its centre ; and the pivot 84 of the angular lever 83 is carried by the disc 41. According to the setting of this disc for small or large diameter records, a lug 86 at the end of the angular lever 85 lies in the path of the pin 88 or 89, to cause the pick-up to be brought over the edge of the small or large record respectively. The groove 68 then reaches the roller 69 and lowers the pick-up, and the pin 88 or 89 bears on a spring tongue 87 on the lug 86 and teases the needle into the starting groove of the record. When the machine is stopped, the pick-up should be left in its outward position on a side support. For this purpose, the arm 207 of a trigger 203 is provided with a lug 223, which, when the trigger is turned away from a notch 205 to allow the motor switch 188 to open as described below, comes in the path of a pin 224 or 226 on the lever 83 according to the setting of the magazine for small or large records. In either case, the counterclockwise movement of the lever 83 by the pin 88 or 89 is prevented, and these pins are allowed to pass the lug 86 by deflecting the end 85 of the lever 83 about a spring hinge 225. The pick-up remains in its outer position and when dropped by the groove 68 of the cam disc comes to rest on a side support. Record chamging and repeating.-The automatic mechanism may be set to operate in three different ways, namely (1) to play the records successively once, (2) to play each record twice before passing to the next, and (3) to repeat a record indefinitely. The setting is performed by a knob 108, Fig. 1, at the end of a lever 110 pivoted at 111 and connected by a pin-and-slot joint 107, 106 to a lever 104 pivoted at 105. When the knob 108 is set at the front end of a guiding slot 109 as in the position shown, the records are played once only one after another. At the end of play of each record, a tap-tap mechanism described below sets the cam disc 65 in motion to perform one rotation. During this rotation, the following operations are performed. The roller 69 rides up from the groove 68 and lifts the piok-up. The pin 79 strikes the lug 78 and swings the pick-up outwards. The roller 96 is guided by a point-lever 99 into the eccentric groove 97 and the pusher 55 is reciprocated to drop a fresh record from the magazine. Soon after the roller 96 enters in the groove 97, it strikes the inner prong of a fork 101 on the tail of the point-lever 99 and swings this lever to close the eccentric groove 97 and open the concentric groove 98; but near the end of the revolution of the cam disc a pin 102 on the lever 104 strikes the outer prong of the fork 101 and restores the pointlever 99 to the position shown, so that at the next revolution of the cam disc, the same operation of feeding a fresh record will be repeated. Near the end of the rotation, the pin 88 or 89 strikes the lug 86 of the angular lever 83 and swings the pick-up in over the edge of the record small or large, the groove 68 then comes under the roller 69 and allows the pickup to come down on the record, and the pin 88 or 89 bears on the spring tongue 87 and teases the needle of the pick-up into the starting groove of the record. These operations are repeated after the playing of each record. When the knob 108 is set to the opposite end of the guiding slot 109, the magazine mechanism is put out of operation and the record on the turntable is repeated indefinitely. This is due to the lever 104 being swung about its pivot 105 by the knob 108 to a position where the pin 102 on the lever 104 is moved out of the path of the fork 101 and another pin 103 on the same lever is moved into the path of the same fork but on the opposite side, so that near the end of each revolution of the cam disc, the point-lever 99 is turned by the pin 103 to close the eccentric groove 97 and open the concentric groove 98. The roller 96 then travels in the concentric groove and no reciprocation is imparted to the record pusher 55. The roller 96 in its travel in the concentric groove 98 encounters and deflects a flap 90 pivoted at 92 on the cam disc, and the flap is thus made to cover the groove 68. This flap 90 is required for the interval delay described below. For the present operation, this flap must be moved back before the end of the rotation of the cam disc. A pin 125 on the lever 104 strikes an inclined lug 124 on the flap 90 and turns the flap back to uncover the groove 68. The pick-up operates as before to perform a playing operation after each rotation of the cam disc. When the knob 108 is set in the mid position of the guiding slot 109, the mechanism is set to play each record twice before the next record is fed. In this position of the knob 108, both pins 102, 103 of lever 104 are out of reach of the fork 101. In the first cycle of operation starting with the point-lever 99 in the position shown, roller 96 enters the eccentric slot and then encounters the inner prong of the fork 101 thereby turning the point-lever to close the eccentric groove 97 and open the concentric groove 98. During this cycle a record is changed. In the next cycle, the roller travels in the concentric groove 98 and no record is fed, but this time the roller 96 encounters the outer prong of the fork 101 thereby returning the point-lever 99 to the position shown in order to perform again a record feed at the next rotation of the cam disc. When the roller 96 travels in the concentric groove 98, it turns the flap 90 over the groove 68. To uncover the groove before the end of the cycle, a pin 115 is provided on a plate 114 slidably mounted on the lever 110 and normally held out of action by a spring 118. Wh