Patent GB-602924-A (GB)
Title: Improvements in or relating to traversing mechanism for the cutting heads of sound recording apparatus
IPC: G11B3/36
Filed: 1946-01-31
Abstract: 602,924. Recording on disc records. KATZ, L. NAMENYI-. Jan. 31, 1946, No. 35321/45. [Class 40 (ii)] In an apparatus for recording on disc records the traversing mechanism for the cutting head comprises a carriage for said head constrained to move radially over the record, on the frame of the apparatus, inter-engaging screw threaded members mounted re spectively on the frame and the carriage with their axes parallel tc the direction of the carriage movement, and independently-engage. able drives for the screw-threaded members, one of which transmits a quicker movement to the carriage than the other. Both drives may be reversible and recording may take place either from the periphery of the record towards the centre or vice versa. As shown, two vertical members 16, 17 support V slides 13, 14. upon which the carriage 15 moves, and between which extends a screw-threaded shaft 18 carrying at one end a bevel gear 21 (Fig. 3) which may be engaged with either of the gears 22, 23, mounted on the vertical driven shaft 24, under control of the solenoids 30, 31 (Fig. 5) to transmit forward or reverse drive to the carriage. Mounted above and parallel to the shaft 18 is a square shaft 40 having two externallythreaded members 47, 48 splined thereon between two plates 45, 46 attached to the carriage, through holes in which the shaft 40 passes, these members both engaging the threaded shaft 18. The square shaft carries a bevel gear 50 at one end, which is engageable with two pinions 53, 54 mounted on the driven shaft 51, under control of a solenoid 81 (Fig. 2). Arrangements including the cam 80 are provided to ensure that successive energizations of this solenoid connect and disconnect the drive in turn, either forward or reverse drive being pre-selected. The first of the two drives is employed to produce the fast traverse, and the second the slow traverse. The turntable is belt driven, the drive being selectively taken from one of a number of driving pulleys driven at different speeds by a motor. The mechanism for raising and lowering the cutter head includes a swinging cam-plate which may be retained on either side of a dead-centre position and is arranged so that successive energizations of the controlling solenoid alternately raise and lower the head. Circuit arrangements, Fig. 11. The cutter head carriage 15 incorporates the control solenoid 114, while micro switches 129 ... 134 are mounted in its path so that their operating arms 126-are engaged successively by a wiper (not shown) mounted on the carriage during its progress across the record. Limit-switches 135, 136 are opened by the carriage at the ends of its traverse. To commence recording, the carriage is brought into position just in front (i.e. to the right) of contact 136 and the pushbutton 118 is operated momentarily, thus energizing the solenoid 81 to engage the gears for the slow traverse of the carriage. The switch 129 is opened without effect following which the switch 130 is operated and solenoid 114 lowers the cutter head 125 closing the contacts. 128. Operation of 131 then momentarily energizes the solenoid 31 to engage the fast drive for the lead-in groove after which the carriage proceeds at the slow speed until closure of switch 132 brings up relay 116 to energize 31, thus re-engaging the quick drive until operation of switch 133 releases 116. Relay 115 comes up on operation of switch 134, whereupon 114 is energized to raise the cutter head and solenoid 30 operates to engage the fast reverse drive, contact 129, being subsequently opened to release relay 115 and switch 136 being finally opened to interrupt the current supply. Relay 117 is operated when any of the push-buttons 118 ... 121 is depressed and disconnects the automatic operation.