GB813436A - Apparatus for scoring sheet material - Google Patents

Abstract

813,436. Perforating-apparatus. ST. REGIS PAPER CO. Nov. 17, 1955 [Nov. 30, 1954], No. 32956/55. Class 31 (2). [Also in Groups XVI and XVII] An apparatus for scoring pieces of sheet material, e.g. tubes from which bags are formed, comprises a conveyer 10 for conveying a succession of pieces of sheet material along a predetermined path with a predetermined frequency past a pair of score bars 33, 34 which extend along the direction of movement of the pieces and between which each piece is pressed for scoring, and means for reciprocating the bars toward and away from the path of the pieces and for simultaneously moving the bars in the same direction as the movement of the pieces during the passage of each piece therebetween. As shown, the endless conveyer 10 carries a succession of pieces of sheet material, such as 11 and 12, past the score bars 33 and 34 to score the pieces along a line 28 prior to bending by strips 26, 27. The bar 33 carries a blade 35, Fig. 5, while the bar 34 has a co-operating groove 36, the edge of the blade 35 being rounded to prevent cutting through the material. Alternatively, the score bars may penetrate and weaken the material and may form intermittent cuts through the material separated by portions which are uncut. The bars 33, 34, Fig. 1, are parallel to the direction of movement of the conveyer as indicated by the arrow 21. The bars are reciprocated, in parallel relationship towards the pieces by cranks 37, 38 mounted for rotation on shafts 37a, 38a respectively, and cranks 41, 42 mounted for rotation on shafts 41a and 42a, the shafts carrying the cranks being driven in synchronism by gearing. The conveyer 10 is driven by an electric motor 45 drivingly connected to sprocket wheels 15 and 17 over which gripper-carrying chains 13 and 14 pass ; the chains also pass over sprocket wheels 16 and 18 respectively. In order that the bars may perform a scoring operation on each piece as it passes therebetween, the cranks 37, 38 and 41, 42 are driven at a varying angular speed such that the angular speed increases as the bars approach each other in order that bars may move at the same linear speed as the conveyer during scoring co-operation of the bars. For this purpose, the cranks are driven by the motor 45 through elliptical gearing 48, 49 eccentrically mounted on shafts 50 and 53, Fig. 6 (not shown). Alternatively, a crank and slotted disc may be used for driving the cranks at a varying speed.