GB1333093A - Blank cutting apparatus - Google Patents

Abstract

1333093 Cutting-out apparatus ST REGIS PAPER CO 13 Nov 1970 [22 Jan 1970] 54207/70 Heading B4B An apparatus for cutting a blank 38, e.g. for an envelope from a moving web 68 of sheet material comprises a rotatably mounted knife roll 30 carrying a raised knife blade 36, for co-operation with an anvil bar 41 having a wear strip 51 which is formed with a concave surface for co-operation with the knife 36 and tilted with respect to the longitudinal axis of the bar so as to permit cutting of the web by point-to-point contact and shearing motion of the rotatable knife blade against the moving web of sheet material passing between the roll and the anvil bar. The knife roll 30 is rotatably mounted in side supports 26, Fig, 2, which also mounts the anvil bar 41 via a support 40. The wear strip may be made from tungsten carbide. The web 68 is fed between the knife blade and anvil bar by feed rolls 12, Fig. 1, the blank being retained on the knife roll 30 by suction via holes 72 until the blank reaches a transfer roll 55 at a region 76. At this region the suction is released so that the blank moves round with the roll until it is picked up by a finger roll 58 and then transferred on to conveyer belts 60. The waste web material 82 continues around the knife roll until it reaches the nip between the knife roll and a waste roll 62, the waste then being held on the waste roll by suction until it is taken away via a suction shoot. In a modification, Fig. 7 (not shown), the web is fed past the cutting station by feed rolls (100), (116) each engaging with a common feed roll (102); the rolls (100, 116) are mounted eccentrically so that they can be adjusted by means of piston- and-cylinder devices (122) in order to vary the rate of feeding and tension of the web.