METHOD AND APPARATUS FOR PERFORATING HELICALLY GROOVED PLASTICS TUBING

• Main Authors: DEREK CHARLES LOCKINGTON, GORDON RALPH WOLFE BARRY, THOMAS SMITH, GERALD GARTH WRIGHT
• Format: Patent
• Language: English
• Published: 06.04.1972
• Subjects: CUTTING; CUTTING-OUT; HAND CUTTING TOOLS; PERFORATING; PERFORMING OPERATIONS; PUNCHING; SEVERING; SEVERING BY MEANS OTHER THAN CUTTING; STAMPING-OUT; TRANSPORTING

1,269,397. Cutting sheet material. BOWATER FLEXPIPE Ltd. 25 Sept., 1970 [27 June, 1969; 15 Jan., 1970], Nos. 32615/69 and 2046/70. Heading B4B. [Also in Division F2] Helically grooved plastics tubing T is fed through a piercing station comprising a number of circumferentially spaced and radially disposed, with respect to the tubing, piercing pins or blades 21, whereby the pins or blades produce spaced holes due to their reciprocating action. Each pin or blade 21 is mounted in a block 5 radially adjustable for different tube diameters. The block 5 contains a disc 8, beltdriven, having a helical projection 15 for half its periphery and a circumferential projection 24 for its other half, so that during one half rotation of the disc the tube T is axially indexed one pitch length and during the other half-rotation the tube is held stationary. An eccentric pin 16, on the disc 8 and located in a slot 20 in a slide 18, produces corresponding radial movement of the pin or blade 21 to rotation of the disc, the pin or blade entering the tube T during the stationary half-rotation part of the disc rotation. The blade 21 is flat with an inclined curved leading edge 25 and a notch 27 just behind the leading edge so that when the blade is pulled out of the tube T after piercing, the surplus material is removed by the blade.