GB1120302A - Apparatus for automatically cutting film negatives - Google Patents

Abstract

1,120,302. Cutting apparatus. FRANCIS FOLD Ltd. 16 Feb., 1967 [16 Feb., 1966], No. 6775/66. Heading B4B. Apparatus for automatically cutting film negatives comprises means, viz. a drive roller 5, Fig. 2, for moving a film 4, having apertures 1, Fig. 1, at spaced points where it is to be cut, between ultrasonic transducer heads 11, 12. A beam of ultrasound passes through an aperture 1 and is received by the head 12 to energize electronic means to control a guillotine cutter 15. The film is gripped by an armature 9 co-operating with a solenoid 10 and cut, when stationary, by the solenoid-operated guillotine 15. In operation, ultrasound from a generator 13 and transducer 11, Fig. 5, distorted on passing through a hole 1, is fed via a tuned amplifier 17 to a discriminator/trigger 18, which distinguishes a " cutting " pulse from the continuous wave resulting when the film clears the transducer heads, and prevents the guillotine operating. A delay circuit 19 and gate circuit 20 prevents guillotine operation until a hole 1 is directly below the blade; simultaneously a brake pad (not shown) is operated to stop the film, control being effected respectively by guillotine and transport stop pulse generators 21, 22. The solenoid 10, energized by generator 21, raises an arm bearing a jockey pulley 6 to stop the drive, and grip the film against the armature 9. A counter 25 registers each hole, but is preset to allow guillotine operation only when the preset number on the counter is reached.