| 摘要 |
<p>1,244,671. Punching apparatus. INTERNATIONAL BUSINESS MACHINES CORP. 30 Aug., 1968 [7 Sept., 1967], No. 41414/68. Heading B4B. A cyclically operating apparatus comprises an incrementor for feeding a workpiece, e.g. a record card 14, Fig. 1, step by step through a work station, an operating mechanism, e.g. a punch 70, for performing an operation on the workpiece in the work station, a single source 52 of alternating current supplied continuously to the incrementor, e.g. a synchronous motor 20 and Geneva mechanism 12, and intermittently through a switching means to the operating mechanism, and a control system 54 including means, e.g. a voltage discriminator 94, Fig. 2, for deriving timing pulses from the source of A.C., and gating means G controlled by the timing pulses for controlling the supply of operating signals to the switching means in order to ensure that the operating mechanism is only supplied with said A.C. so as to operate on the workpiece during the same portion or portions of each cycle of the A.C., which portion or each of which portions corresponds to a dwell time of the feeding operation of the incrementor. As described, the Geneva mechanism 12 drives rolls 42, 46 which advance the card 14 step-by-step, and the punch 70 is operated when coils 61, 62 about a magnetic core 60 are energized. The Geneva mechanism is so positioned on the shaft of the motor 20 that the card is stationary when the A.C. line voltage reaches a peak or trough. At each peak or trough the voltage discriminator 94 sends a timing pulse to an AND circuit in a duo-level pre-driver 98. When a data pulse is also fed via line 102 to the AND circuit the combined pulse energizes gate G of a Triac 88 to allow current to flow via line 86 to the punch coil 62. A line 106 leading to a voltage polarity sensor in pre-driver 98 determines the polarity of the pulse to gate G so that the flow of operating signals can be made possible once every halfcycle of the A.C.</p> |
