| 摘要 |
1,226,485. Recording and playback. INTERNATIONAL BUSINESS MACHINES CORP. 11 Nov., 1969 [20 Nov., 1968], No. 55071/69. Heading G5R. A record/playback head 16 is moved backwards and forwards over a record card (14, Figs. 2 and 3) by a reversible, rotary driving means 44 which is reversed when the arrival of the head 16 in a limit position in either direction is detected by a sensor 93 or 94. As shown, the head carriage 26 is driven by a perforated belt 43 engaging pins 50 on the pulley 44. Engagement of the head carriage 26 with either of the limit sensors 93, 94 causes a link 90 to disengage one or other of two latches 82, 83 from a slide 75 which is then moved by a spring 76 so that a pivoted member 70, 73 connected to the slide 75 by a spring 74 withdraws one or its shoes 71, 72 and advances the other shoe. These shoes 71, 72 co-operate with respective clutching members 57, 69 and a constantly-rotating shaft 52 of a motor 51 clutching members 57, 69 and a constantly-rotating shaft 52 of a motor 51 to produce opposite directions of rotation of the pulley 44. A nut 77 travels backwards and forwards along a screw-threaded extension 60 of the pulley 44 to alter the direction of action of the spring 76 on the slide 75 according to the position of the head carriage 26. An alternative drive-reversal arrangement is described with reference to Figs. 7 and 8a to 8d (not shown). At each reversal of the carriage 26 in the X direction it is also stepped in the Y direction as described in Specification 1,192,511, which describes also the manual control of such stepping. |
