GB1380686A - Slitting machine - Google Patents

Abstract

1380686 Cutting apparatus ARMSTRONG CORK CO 19 Feb 1973 [29 June 1972] 7950/73 Heading B4B [Also in Division F2] A machine for slitting tubes of plastics material, e.g. for use in insulating pipes, comprises means 15, 17, 18 for removably supporting a tube 16, a radially retractable and extensible cutting blade 32 mounted on a slide 60, Fig. 4, which is reciprocated in a two-stroke cycle by actuators 39, 40, Figs. 1, 2, such that in one of the strokes the cutting blade is retracted and in the other of the strokes the cutting blade is in a cutting position. The tube supporting means includes a stem 15 secured to a frame structure 10, 12 to which is pivotally mounted a pair of tube positioning shoes 17, 18 which may be adjusted by linkage mechanisms, Fig. 3 (not shown) in order to accommodate tubes of different bore size. The guide 49 for the slide 60 is mounted on a rail 34 and provided with cover members 52, 53 having curved surfaces 52<SP>1</SP>, 53<SP>1</SP> for locating engagement with the bore of the tube; the rail is adjustably mounted on the frame structure via holes 14. A pair of guide rails and co-operating cutter slides are mounted on the frame. The cutter blade is clamped in a hub 64, Fig. 5, which is pivotally mounted in the slide 60 and urged to the cutting position by a spring 66; adjustable stops 72, 73 are provided and set such that one blade cuts completely through the wall of the tube while the other only partly severs the wall. The slides are connected to a pair of fluid-pressure actuated rams 39, 40. In operation, after an uncut tube is placed on the supporting means the rams are actuated to cause the blades to effect the cut during their rearward travel. The cut tube is then removed and replaced by a further uncut tube. When the slides are returned for the start of a cutting stroke the blades are pivoted by the end surface of the tube, against the action of the springs 66, such that the blades travel back through the tube with their unsharpened edges in contact with the bore of the tube.