Patent GB-929388-A (GB)
Title: Improved control apparatus of an incremental drive
IPC: F15B21/08
Filed: 1962-03-01
Abstract: 929,388. Selective punching machines. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 1, 1962 [March 27, 1961], No. 7966/62. Class 31 (2). [Also in Group XXIX] Control apparatus for an incremental drive of the feed means of a record card punching machine comprises a plurality of actuators energizable successively to advance the drive, and electrically controlled by a control-ring having a plurality of stages each connected to control the energization of an actuator, and a programme device connected to the control ring to control the operation thereof selectively to energize the actuators in sequence. The incremental drive consists of a toothed stopping- wheel 100, Fig. 2, fixed to an output shaft 101 and engageable successively by actuators in the form of pistons 102 to 104 which are actuated by pressure liquid applied to the pistons under the control of valves 106 to 108 which are controlled by magnets M1 to M6. The magnets are connected to magnet drivers, e.g. thyratrons 67, 69, 72, 74, 77, 79, Fig. 1, controlled by a control ring 65 comprising interconnected latches 61 to 63. The latches are connected to a power inverter 58 which is connected to the output of a logical AND circuit 46. The circuit 46 has connected thereto the output of a logical OR circuit 43 as well as the output of a latch 48 and the output of a bi stable latch 53 connected to a programme unit 37. Connected to the input of the circuit 43 are the outputs of logical AND circuits 29, 32. The input of circuit 29 is connected to the output of a shaping amplifier 25 which is also connected to both inputs of a binary trigger 27 which functions as a frequency divider. The amplifier 25 has connected thereto, through an emitter follower 23, a coil 19 in which signals are developed at, say, the rate of 400 per second by means of a rotatable emitter disc 10 fixed to the shaft 11 of the pump 12 supplying pressure liquid to the pistons 102 to 104. As a result, the circuits 29, 32 have applied thereto signals occurring at the rate of 400 per second and 200 per second, respectively. The circuits 29, 32 are selectively conditioned to pass the signals applied thereto by means of a bi-stable latch 33, the states of which are controlled externally by means of the programme unit 37. The frequency at which the magnets M1 to M6 are energized and de-energized determines the output motion of the shaft 101. When the magnets are operated at the 200 signals per second rate, the pistons successively advance the wheel 100 one increment and then dwell so as to provide intermittent rotary motion. When the magnets are operated at the 400 signals per second rate, the pistons continuously advance the wheel 100 to provide continuous rotary motion. Deceleration of the wheel is achieved by means of spring-biased damping pistons 122 to 124. The shaft 101 is connected to drive feed roll 150, Fig. 4, co-operating with a feed roll 151 which is normally held out of engagement with the roll 150 until a record card is registered in the punch station by means of a retractable gate 166. Punching takes place when the card is at rest (i.e. during the dwell periods of wheel 100) relative to punch 170. Card lever CL operates to close contacts CL1, Fig. 1, to set latch 48 just after the trailing edge of the card leaves the card lever. The latch 48 can, alternatively, be set by a programmed signal. In a modification, Fig. 3 (not shown), the programme unit 37 and latch 53 are replaced by a programme ring and a manuallyoperated switch.