GB1449305A - Tape perforator - Google Patents

Abstract

1449305 Selective punching apparatus L N CANICK and C S ALDRICH 17 July 1974 [6 Aug 1973] 31698/74 Heading B4B A tape perforator comprises a pivotally mounted cradle 24, a plurality of punches 32 each mounted on a respective plurality of levers 28 pivotally mounted in the cradle, and a second plurality of levers 38 adapted to be moved from a position in which they allow the first levers to move without effecting operation of the punches, to a blocking position in which they thereby cause the first levers to be moved to effect operation of the punches. The cradle 24 is pivotally mounted about a pivot 26 in a bracket 92, Fig. 5, the cradle being pivotally connected to a link 22 which is eccentrically mounted on a shaft 20. The plurality of levers 28 are each pivotally mounted about a pin 30 in the cradle, each lever being connected to a respective punch 32 slidable in a block 96, Fig. 5 mounted on the bracket 92. Each lever 28 is held in an inoperative position in the cradle by means of springs 52 and is provided with a shoulder 108 adapted to be selectively engaged by extensions 42 formed on the levers 38; the levers 38 are pivotally mounted via knife edge bearings 40 and each provided with an extension 44 for co-operation with a respective solenoid 46. In operation the shaft 20 is continuously rotated thereby causing the cradle to be oscillated together with the levers. Since the point of connection of the punches with their respective levers 28 is substantially on the axis of the pivot 26, the operative ends of the punches remain almost stationary so they do not enter a die (33), Fig. 8 (not shown) to perforate the tape. Upon a particular solenoid being energized, the respective lever 38 pivots on its bearing to bring the end 110, Fig. 1, of the extension 42 into alignment with the shoulder 108. As the cradle continues to oscillate, the shoulder 108 engages the end 110 thereby causing the respective lever 28 to pivot about the pin 30 against the action of its spring 52 and so cause the punch to enter the die. The tape is fed through the perforator by means of a sprocket 166 mounted on a shaft 162 which is intermittently rotatable by means of a ratchet wheel 172. The ratchet wheel is incrementally rotated by means of a pawl 156, Fig. 12, mounted via a pin 140, on a lever 134 which is connected to a link 126 eccentrically mounted on the shaft 20. The pawl is selectively moved into engagement with the ratchet wheel by means of a pivotally mounted bracket 142 which is adapted to be selectively attracted by electromagnets 148 so as to thereby move the lever 134 together with the pawl. A spring- loaded detent 180, Fig. 12, is provided to accurately control the incremental movement of the ratchet 172. A backspacing device is provided for the tape and comprises a second ratchet wheel 184 on the shaft 162 and arranged to be rotated when desired by a pawl 248, Fig. 12, under the control of a solenoid 240. The leading end of the tape is fed into the perforator under a cover (198), Fig. 9 (not shown) below which is a pivoted guide arm (204) having steps (208) for accommodating different widths of tapes; the arms normally act on a switch (214) such that, if the tape breaks, the arm will rise and open circuit the switch.