Patent GB-419775-A (GB)
Title: Improvements in or relating to mechanism for correcting the feed of webs of continuous strip material
IPC: B41F13/02
Filed: 1933-11-07
Abstract: 419,775. Feeding webs. FORGROVE MACHINERY CO., Ltd., and GROVER, F., 432, Dewsbury Road, Leeds. Nov. 7, 1933, No. 30933. [Class 100 (i).] Relates to apparatus for maintaining a perforated web in register with a cutting-device or the like operating thereon, in which the web is fed by a pair of constantly-rotating feedrollers arranged to feed the web continuously throughout a cycle of operations except for a short interval during which they release their grip on the web and so interrupt the feed, a registering-pin carried by one of the feed-rollers being arranged to come into engagement with a locating perforation in the web during each idle interval of the feed-rollers, while a device which operates on the web, when the feed is interrupted, draws it backwards relatively to the pin until the locating perforation comes into registering engagement with the pin. According to the invention, the device for drawing the web backwards to bring the perforation into register with the pin comprises a resilient member which is arranged to be displaced from its normal position by the tension of the web while the latter is being fed forward, and to effect the backward movement of the web to register it with the pin by returning towards its normal position during the idle intervals of the web-feeding rollers. The web 11, Fig. 1, is fed from the reel 10 and over a jockey roller 16 by a pair of con. tinuously-rotating feedrollers 21, 22 and thence between a pair of intermittently rotating rollers 23, 24 to a cutter 25, which operates to sever the web into sheets of equal length. An adjustable stretcher bar 26 enables the length of the severed strips to be varied. One feedroller 21, Fig. 3, is of steel and is formed with a pair of longitudinal slots 30 in each of which is a registering pin 31; a circumferential slot 32 is also formed in the roller 21, the pins 31 being situated at the intersection of the slots 30, 32. The feedroller 22 is of rubber and is formed with a transverse slot 33 opposite the slot 32, and each roller carries a narrow steel roller at each end which contact together and are held in contact by adjustable pressure springs which serve to press the two feed-rollers together, while slightly deforming the rubber roller. The length of the arc between the two pins 31 on the roller 21 is made slightly greater than the length between successive registering perforations. The feed-rollers are continuously rotating, but the contact between them is interrupted by the slots 30, at which point a pin 31 engages a perforation. The web is drawn backwards relatively to the pin by the roller 16, which is mounted on a spring 14, until the front of the pin comes into engagement with the forward edge of the perforation. The intermittent feed-rollers 23, 24 are driven by a Geneva mechanism 37 actuated by pins 38 mounted on the driven shaft of the feed-roller 21. The rollers 23, 24 are geared together and are held in contact by a weight 43, and serve to feed the web slightly faster than the rollers 21, 22, so that a momentary tightening takes place, while the web is gripped by the rollers 21, 22, a slight slip occurring between the intermittently rotating rollers when any slack has been taken up. The knife 25 operates after this tightening has taken place. The flat spring arm 14 carries one end of a brake band 17, which acts on a drum on the web-reel spindle, the other end being secured to an adjusting-screw 20. A small sliding weight 48 on the arm 14 may be provided to vary the braking pressure, and at the same time adjust the period of vibration of the spring arm and consequently the time of the upward movement of the jockey roller, thus making it possible to alter the limit at which tearing of the web becomes noticeable. The spring arm 14 may be replaced by a spring- loaded pivoted lever or by two spiral springs supporting the jockey roller. The brake band is then attached to the springs near their top supports so that the movement of the brake band is only a part of the movement of the jockey roller. The term "perforation " includes depressions in the web and the cutter may be replaced by a printing, embossing, or like member. A second and unperforated web may be fed by the rollers 21, 22 &c., together with the web 11, a second spindle 112 with brake drum, band, spring arm, and jockey roller being provided.