GB686543A - Improvements in or relating to apparatus for cutting lengths from a web of paper, cardboard or similar material - Google Patents

Abstract

686,543. Cutting paper &c. webs. POWERS-SAMAS ACCOUNTING MACHINES, Ltd. June 19, 1950. [July 26, 1949] No. 19660/49. Class 31 (i). [Also in Group XVI] In an apparatus for cutting lengths from a web of paper, cardboard, or similar material, a positively rotated feed roller feeds the web continuously to a pair of knives movable through circular paths in opposite directions by cranks, so that at the instant of cutting the knives have a linear speed substantially equal to that of the web. A web 1 is drawn from a spool by rollers 6 and 7, the roller 6 being spring-urged towards the roller 7 which feeds the web continuously at a constant linear speed. The roller 7, apart from driving a printing roller 8 through gearing, serves as a platen roller for that roller which is inked by rollers 9 and 10. A knife 13 has a straight cutting edge 15, while a knife 14 has a cutting edge 16 of V or inverted V-form. The knife 14 is attached to plates 25 pivotally mounted by plates 26 on slotted plates 23 and 24, adjustable screws 44 on the knife 14 being urged into engagement with stops 42 by springs 41, thus permitting relative adjustment of the cutting edges 15 and 16. The plates 23, 24 are supported by rotatable cranks 17 and 18, while sliding blocks 27, carried by further rotatable cranks 17 and 18 support the knife 13 and engage slots 28 in the plates 23, 24. Thus, as the four cranks are rotated synchronously with the roller 8 through gearing, the knife 13 is reciprocated by movement of the blocks 27 along the slots 28. Also, the knives 13 and 14 move in circular paths about the axes of stub shafts 19, 20 associated with the cranks 17 and 18, the radius of the circular paths being slightly greater than that of the roller 7, such that the knives have a component of movement in the direction of the web feed and move at substantially the same linear speed as the web. The cranks are so timed that cutting is effected when the knife 14 is at its lowest point and the knife 13 at its highest point. Register between the knives and the roller 8 may be adjusted during operation through a slidably adjustable spiral gear meshing with a gear in the drive from the knives to the roller 7.