Patent GB-533356-A (GB)
Title: Improvements in or relating to apparatus for playing gramophone records
IPC: G11B17/032
Filed: 1939-06-09
Abstract: 533,356. Gramophones. ELECTRIC & MUSICAL INDUSTRIES, Ltd., STERNBERG, W. D., METCALFE, C., and SHAW, M. N. H. .Tune 9, 1939, Nos. 16909/39 and 9825/40. [Class 40 (ii)] Relates to gramophones fitted in a casing with a door or lid or mounted on a drawer movable in and out of a casing. According to the invention the lid or drawer is inter-connected with the pick-up in such a manner that the opening of the lid or drawer lifts and returns the pick-up and the closing of the door lowers the pick-up on the starting groove. The lid mechanism may also start and stop the motor. In addition, the motor may be automatically stopped when the play of a record is completed. As shown in plan in Fig. 1, a lid 6 is connected by a link 8 to a slide 110 guided by a groove 111 in a base plate 1 fastened by screws 2 to a motor board 3. A pin 114 on the slide 110 engages a slot in a member 116 attached to a slide 39 itself fitted with a pin 38 engaging a notch in an arm 31 of a three-armed lever 31, 32, 33, pivoted at 34. The arm 33 is connected by a spring 46, see inverted plan Fig. 4, to a lever 44 pivoted on the same pivot 34. The lever 44 carries a pin 47 and an adjustable screw stop 49. The pin 47 is adapted to bear against an arm 41, which follows the horizontal movements of the pick-up arm. The screw stop 49 is adapted to abut against a pin 50 when the record is a 12 inch record. In addition the lever 44 is formed with a shoulder 48 adapted to abut against an adjustable screw stop 54 when the record is a 10 inch record. The pin 50 is carried by a bell-crank lever 59 pivoted at 56. The lever is normally urged by a spring 64 to the position 56a, in which position the pin 50 is out of the path of the lever 44. When a 12 inch record 67 is on the turntable 61, the lever 59 is deflected to the position 56b, in which position the pin 50 is in the path of the lever 44. The other arm 32 of the three-armed lever is adapted to bear against an arm 23 depending from a pick-up arm lifting member 20, pivoted at 24. The member 20 is arcuate about the vertical pivotal axis of the pick-up arm 12, and this arm is formed with a rounded projection to bear smoothly on the member 20. Assuming that the lid is open and the pick-up arm in its outer position, the operation of the mechanism proceeds as follows. A record is placed on the turntable. If the record is a 10 inch one, it does not reach the lever 59 which remains in position 56a. If the record is a 12 inch one it deflects the lever 59 to the position 56b. The lid is then closed, whereby the three-armed lever 31, 32, 33 is rocked clockwise as viewed from above. The lever 44 is pulled in the same direction by the spring 45 connecting it to lever arm 33. The pin 47 on the lever 44 bears against the arm 41 and turns the pick-up arm inwards. If the record is a 12 inch one, a ramp 49a on the lever 44 engages the pin 50 and rocks the lever 59 to the position shown in full lines in Fig. 5 to leave the edge of the record free ; and the pin 50 then abuts against the stop 49 thereby arresting the inward movement of the pick-up arm. If the record is a 10. inch one, the pick-up arm is moved further inward until the shoulder 48 of the lever 44 is arrested by the screw stop 54. In either case, the spring 46 allows the rotation of the three-armed lever to continue. The arm 32 of that lever then rocks the member 20 to lower the pick-up on the starting groove of the record and play may begin. When subsequently the lid is opened, the three-armed lever is turned in the opposite direction, and a spring 25 rocks the member 20 upward again. This lifts the pick-up arm and then causes it to move out by sliding down the now inclined member 20. The shutting and opening of the lid serves also to start and stop the motor. For this purpose, the arm 33 of the three-armed lever is connected by a pin and slot joint 77, 79 to a slide 72 provided with a hook-shaped end 73 and a pawl 92 co-operating with a pin 91 on a lever 86 pivoted at 85 on a lever 80 pivoted at 83 and coupled to the switch 84. When the lid is closed the slide 72 is moved towards the left and the lever 86 turned clockwise until a shoulder 89 thereon abuts a lever 82 also pivoted at 85 and prevented from turning by a fixed stop 97a on the base plate 1. Continued movement of the slide 72 to the left then causes lever 80 to turn counter-clockwise about its pivot 83, thereby switching the motor on. Near the end of the stroke of the slide 72, the pawl 92 is rocked and disengaged from the pin 91 by the engagement of its tail 98 with a fixed guide 76, so as to leave the switch mechanism free to be operated automatically when the play of a record is completed. The automatic mechanism operating at the end of play of a record is as described in Specification 332,004, [Class 40 (ii)]. During play, a pin 99 on arm 26 moving horizontally with the pick-up arm comes against lever 86 frictionally coupled to lever 82 and causes the bevelled part 102 of dog 101 to move into path of lug 103 on spring sleeve 106 on turntable spindle 4 ; and said lug rocks lever 82 back. At the end of play, however, the quick pitch groove on the record causes the unbevelled part 102a of the dog to come into the path of the lug 103 which causes the lever 80 to turn clockwise about its pivot 83 thereby opening the switch 84. The lid mechanism may be put out of action by disconnecting the slide 39 from the lever arm 31. As shown in Fig. 1, the slide 39 is guided by slots 126, 127 on pins 124, 125 on bell cranks 120, 121 the other arms of which are linked by an operating bar 129 provided with a knob 130 movable in a slot 131 in the motor board 3 between positions marked " ON " and " OFF." In the " ON " position shown, the lid mechanism is operative. When the knob 130 is moved to the " OFF " position, the slide 39 is moved to the right by the bell cranks 120, 121, thereby disengaging the pin 38 of the slide from the slot of the lever arm 31 and rendering the lid mechanism inoperative. In a modification, Fig. 10, the link 8 from the lid is provided with a foot 141 formed with an L-shaped slot 142 co-operating with a pin 140 on the lever arm 31 and with a pin 149 on a lever 145 pivoted at 146 and provided with a knob 147 movable in a slot 148, the lever 145 being also formed with a slot 150 for the pin 140 and a cut-away portion 151 concentric with the pivot 34 of lever arm 31 to allow free movement of pin 140. In the " ON " position shown, the pin 140 is in the transverse part of the L-shaped groove 142 and the movements of the lid are transmitted to the lever mechanism. When the knob 147 is moved to the " OFF " position, the pin 140 comes in line with the longitudinal part of the L-shaped slot 142 and the lid mechanism is out of action.