GB1230745A - - Google Patents

Abstract

1,230,745. Cutting webs. METEOR-SIEGEN APPARATEBAU PAUL SCHECK G.m.b.H. 24 Feb., 1969 [12 Oct., 1968], No. 9867/69. Heading B4B. [Also in Divisions B8 and G2] In a method of servering web material while the leading portion thereof is moving continuously, the material to the rear of the leading portion is first accelerated relative to the leading portion to form a loop of predetermined length and then is stopped, the stationary web being severed while the loop is drawn away with the leading portion. A photo-copying machine embodying apparatus for performing said method comprises support means for copying paper storage rolls 4-6; first sets of transport rollers 9-12 for drawing paper from one of the rolls 4-6 to convey it past a cutter 16, 17 to continuously driven second transport rollers 22; a variable speed drive gear-box 42 for the first rollers 9-12; and means, Fig. 3 (not shown), for operating the cutter 16, 17 to sever the paper when brought to a stand. Cut sheets are delivered over a table 21 and guide 23 to transport belts 26, a master sheet introduced over a track 1 being superimposed at rollers 24, prior to reaching an exposure drum 27. Photo-electric devices 33, 36 for sensing the master sheet control the cutting and feeding mechanism to ensure correct superimposition. Drive mechanism.-The first rollers 9, 10 or 11 and 12 are each connected through a clutch, e.g. 12a, and through a common chain drives 12c, 40, to an output sprocket 37 of the gear-box 42. Input power is through a shaft 46 driven by a vee-belt 44 from a main drive regulated in speed according to the master copy density, and a gear 47 on the shaft 46 co-operates via a further gear 48 with a gear 51 fast with the sprocket 37 through a differential gear system. A pulse from the device 36 as it is passed by the trailing edge of the master sheet energizes a magnetic clutch 53, linking the shaft 46 with a cam disc 58 through spur gears 54-56 for one revolution of the disc, and a roller 63 follows the cam track 59, constraining a spindle 41 bearing planetary pinions 50 to rotate therewith via a lever 66, such that the pinions 50 cause an increase in the sprocket 37 speed, followed by a deceleration to rest. A further roller 64, Fig. 5 (not shown), co-operates with the cam track 59 to control a push-rod 67b for actuating the cutter knife 17. At the end of a cam disc revolution a pawl 69 enters a slot 11 in the disc 58, which may overrun slightly until a mounting arm 75 is stopped by the force of a spring member 76, whereupon it returns to the correct inoperative position. A lever 81 bearing a peg 80 which runs in a track 73 round the spur gear 55 is thus reversed slightly, the pin 80 entering a chord-like track 77 so that the pawl 69 is withdrawn.