Patent GB-698654-A (GB)
Title: Improvements in or relating to web-cutting apparatus
IPC: G03D15/04
Filed: 1952-04-18
Abstract: 698,654. Feeding webs. KODAK, Ltd. April 18, 1952 [April 18, 1951], No. 9845/52. Class 100(i) [Also in Group VIII] Apparatus for feeding a web, which is to be cut into pre-determined lengths in accordance with signal marks spaced along the length of the wen, comprises means for continuously feeding the web into a loop L, Fig. 2, and towards a normallyinoperative cutter 72, means 39 movable to and from an operative position in which it engages the web for intermittently feeding the loop to the cutter, a brake 43 located between the two feeding means and movable to engage the web at the leading end of the loop when the intermittent feed is inoperative, a normally-open switch C<SP>1</SP> disposed in the path of the web for closure by the signal marks on the web, and electric means energized by the closure of the switch for rendering the intermittent feed inoperative and the brake operative and for actuating the cutter. The apparatus, which is described as applied to the cutting of a web provided with a number of photographic prints, comprises a box 10, Fig. 3, having an inclined top plate 15 along which the web is fed from a roll 16 at one end. The web then passes between a driven rubber-covered roller 19, Fig. 2, and an adjustablymounted presser roller 20 from which it is fed into the loop L prior to passage under a transverse guide bar 25 carried by a pivoted arm 26. A spring ball is provided for holding this arm in either its lower operative position or a raised position in which manual feed of the web is permitted. Webengaging flanges 30 are adjustable along the bar 25 according to the width of the web and engage corresponding grooves 31 in the plate 15. The brake and feed device to which the web then passes comprises a driven rubber-covered roller 32 against which the web is pressed by a presser roller 39 freely rotatable on a lever 40 carrying a rubber brake pad 43 at its opposite end. The energization of a solenoid 44 acts through linkage 46 to turn the lever 40 so as to raise the roller 39 to interrupt the feed and lower the brake pad 43 to hold the web; a spring 48 reverses this action when the solenoid is de-energized. Drive of the roller 32 is from a motor 50 through gearing 54-59, and the drive of the roller 19 is taken from the shaft 34 of the roller 32 first through pulleys 60 and a spring belt 61 and then through chain-end sprocket gearing. The cutting mechanism consists of a knife carrier 72 which is carried by a yoke 73 for reciprocation to and from a fixed bed 71 under the action of a rotary cam 77 in the form of a bar having a diametrical slot containing three balls. The cam is rocked to lower the cutter against the action of springs 75 by a linkage 81, 82 actuated when a onerevolution clutch 84 driven by the motor 50 is operated by the energization of a solenoid 101. Between'the roller 32 and cutter 72 the web passes between a spring-pressed roller 105 and a pair of separated electric contacts C' which are adapted to be bridged by contact marks made by graphite pencil or carbon ink at suitable positions on the web. These contacts C<SP>1</SP> are so arranged in a control circuit (Fig. 8, not shown) that when they are closed by the contact marks they cause the closure of a switch which energizes a solenoid to close switches in the circuits of the solenoids 44, 101, thereby stopping the intermittent feed, braking the web, and driving the cutter through a cutting stroke. As the cutter starts its upward stroke, means such as a cam rotatable with the clutch 84, resets the control circuit for the next operation. The cut portions of the web are fed into a hopper by rollers 155, 156 driven from the motor 50. Should the loop L become too small and therefore tend to apply an excessive load on the intermittent feed means, the solenoid 44 is energized to stop this feed and apply the brake pad by the closure of a switch 141, Fig. 6, by means of a cam 142 on the shaft 143 of a pivoted arm 146 which has a feeler 147 engaging the loop and is urged upwardly by a spring; when the loop regains its normal size by the continued action of the feed roller 19, the arm rises to reopen the switch. The motor 50'is de-energized by the opening of a switch under the action of a second cam on the shaft 143 should the loop L become too large, the web break, or the supply become exhausted. When it is desired to feed the web by hand, the mounting of the arm 40 is raised by a handle 154, Fig. 2, to lift both the presser roller 39 and brake pad 43 from the web; in addition, the guide bar 25 is raised and in so doing swings the feeler arm 146 to cause the cam on its shaft to stop the intermittent feed and motor 50. The operation of the motor 50 is then controlled by another switch and the one-revolution clutch 84 controlling the cutter is operated when desired by a hand lever 97, Fig. 3. In this case, the cutting positions on the web are aligned with an index mark on a translucent portion of the top plate 15 which is illuminated from below. Instead of contact marks on the web, control may be effected by perforations or dark marks on the web co-operating with a light beam and photoelectric cell.