Patent GB-825588-A (GB)
Title: Improved information storage system
Inventor: MACDONALD DUNCAN NORTH
IPC: G11B15/68
Filed: 1957-08-21
Abstract: 825,588. Electric digital-data-storage apparatus. BURROUGHS CORPORATION. Aug. 21, 1957, No. 26347/57. Class 106 (1). An information storage system comprises means arranged selectively to engage one of a plurality of elongated recording media supported in side-by-side relationship and transport the selected medium through an operational zone which includes a transducer adapted to record information on or read information from the selected medium. As described, a plurality of magnetic tapes are draped over rods 2, 3, 4 and have end portions loosely held in compartments in bins 7, 8 which may be as described in Specification 825,587, [Group XXXVIII]. A carriage 9 slidably mounted on a support rod 14 bears transducers 10, 11 and is transported by a band 18 supported by sheaves 19, 20, the sheave 20 being driven by a motor 21 through a flexible coupling 23 and the sheave 19 rotating a notched disc 32 (Fig. 6, not shown), having notches of adjustable width, which disc periodically interrupts the passage of light from a lamp 33 to a photo-cell 34, each interruption corresponding to a tape position thus enabling the position of the carriage 9 to be identified by an electronic counter. The tapes are transported by two motor driven rollers 35, 36, each held by pivoted arms so that the rollers may be swung away to load the machine with tapes as shown by the full line representation of the roller 35, Fig. 3, the direction of tape transport being determined by which of the two pinch rollers 12, 13 carried by the carriage 9 is actuated to place the selected tape in contact with the corresponding roller 35, 36. The carriage 9, Fig. 5, comprises a frame 45 supporting two electromagnets 46 which when energized attract the armature 50 to cause the transducer support frame 47 to raise the transducers 10, 11 into engagement with a selected tape. The transducers 10, 11 each comprise six separate magnetic recording and reproducing heads which are interleaved so that twelve tracks on each tape may be utilized, but only one of the heads 10, 11 is normally active at a time. The tapes are accurately aligned by separators such as steel rings 52, Fig. 2, slipped into milled slots in the guide rods 2, 3, 4, and a notched indexing strip (not shown) serves to align the carriage by providing a notch for each tape position for engagement by a spherical pawl 54 carried by the support frame 47, the initial position of the transducers being adjusted by screws 55-62. Each pinch roller such as 12 is mounted on an arm 65 which is rocked on energization of the electromagnetis 70 to pivot the roller 12 outwardly to engage the selected tape with the appropriate roller 35, 36. The drive band 18 is attached to the carriage 9 by a pin 74. The tape transport rollers are held supported on idler rollers 80, 81 attached to the machine frame 1 by idler rollers 82 attached to the pivoted arms 38 and are driven from the drive motors 42 by rubber covered idler wheels 84. Spring fingers 90, Fig. 3, mounted on bars 91 hold the tapes lightly in engagement with the support rods 2, 4. Control circuit, Fig. 7. The motor 21 is controlled by a circuit which includes a register 110 for registering the input number for the selected tape and a counter 111 which counts up or down in response to pulses produced by the photo-cell 34 indicative of the changing position of the carriage 9, the direction of count being dependent on the output voltage of a coincidence circuit 113 which is fed with the outputs of the register 110 and the counter 111. A given phase of A.C. current is applied to the motor winding 117 and a phase displaced from this by Œ90‹ is applied to winding 116, the motor 21 thus being driven in either direction depending on the position of the carriage 9 in relation to the selected tape. The electromagnets 46 which raise the transducer support frame are energized over the lead 119 from the circuit 115 thus locking the carriage 9 in its selected position, subsequent energization of one of the pinch roller magnets 70, 72 over the manually operated or automatic switch 122 then causing the selected tape to be transported. The magnetic tape may be replaced by magnetic wire.