GB596049A - Improved means for punching registration holes in photographic negatives and the like - Google Patents

Abstract

596,049. Punches. GENERAL ANILINE & FILM CORPORATION. July 16, 1945, No. 18187. Convention date, Sept. 29, 1944. [Class 31 (ii)] [Also in Group XX] A punch for producing holes in negatives used in colour photography for registration purposes is constructed with a base 13, Fig. 2, upon which the negative N, Fig. 5, is placed, and the negative is clamped to the base during the punching-operation which is effected by depression of a punching-member 21 attached to a tube 20 adapted to be guided by apertures in a frame 10. The actual perforation of the negative is effected by co-operation of the cutting end of the punch 21 and a die aperture 18 in the base, and accurate register of the negative with the punch is obtained by the aid of an optical magnifying system arranged in the member 20 and comprising an achromatic lens or objective 25 mounted in a holder 26,. and an eye piece 28, plano-convex lenses 29, 29<1>, and a plane glass 30<1> having cross-hair lines formed thereon by means of which one of a number of cross marks m on the negative is accurately registered relatively to the punch, several cross marks are photographed with the negative and the most suitable one selected. The punch is operated by pressing on a normally raised lever 30 with ends which bear on a collar 31<1> on the member 20. The negative, when in register, is first clamped by depression of a pivoted clamp 15, which is normally raised by springs 17, and then the punch is depressed against the action of a spring 33 which is stronger than the springs 17. The magnifying system may be illuminated by electric light.