GB1146525A - Improvements in or relating to mechanisms for producing wrapping blanks - Google Patents

Abstract

1,146,525. Cutting and slitting webs; making wrappers. CANADIAN INTERNATIONAL PAPER CO. 6 May, 1966 [7 May, 1965], No. 20120/66. Headings B4B and B5D. [Also in Divisions B6 and B8] A web is advanced to a packaging machine via transverse cutting means C, Fig. 7, by a roller 37 and spring-urged, co-operating discs 65 driven by a clutch and brake assembly (57, Fig. 10). The web is withdrawn from a band-braked supply roll R via a decurling edge 30, when a floating roller 34, Figs. 7 and (14), moves up and allows a two armed lever 40, 42 to pivot at 41 thereby enabling spring urged driven discs 38 to nip the web W against a continuously driven roller 33. A tear strip feeding device 13 is provided together with longitudinal slitters S. Cutting mechanism.-The cutting means includes a vertically displaceable cutter 90, Fig. 11, having a shallow inverted V cutting edge and fixed cutter 91, having a straight, horizontal cutting edge. The cutters 90 and 91 are fixed on strengthening box-section members 90A and 91A. The member 90A is displaceable vertically by a linkage including a pair of rods 97 and a pair of levers 98. The longer arm 101 of one of the levers 98 is connected to an air-cylinder plunger 102. Springs (90B, Fig. 12) restrain sideways movement of the cutter 90. Slitting arrangements.-A shaft 111, Fig. 15, is rotatably supported between the depending arms of an inverted channel-shaped support (110, Fig. 16). The lever 113 of a collar 112 fixed to the shaft 111 is connected to the plunger of an air cylinder (115). An arm (118) of a further collar 117 fixed to the shaft, carries a slitting blade 119 at the end thereof. A sleeve 120 rotatably mounted on the shaft 111, carries fast therewith a collar arrangement 121 carrying two parallel slitting blades 122 and 123. An air cylinder 124 rotates the sleeve 120 in the same way cylinder (115) rotates the shaft 111. The air cylinders could be replaced by solenoids or cam devices. Tear strip feeding arrangement.-A reel 132, Fig. 9, of tear strip T is rotatably mounted on a bracket 130 attached to the machine frame. A pneumatically operated gluing arrangement 134 applies adhesive along a thin zone of the web W. A spring 136 acts through arms 137 and 140 to urge a roller 141 downwardly to squeeze tear tape T and the web W against a roller 36. A roller (139, Fig. 8) with a deep peripheral groove, serves to guide the tear strip on to the web. Control system.-The web feeding apparatus operates cyclically under the control of a series of cams on a cam shaft (75, Fig. 13), and the signal setting the cycle in operation is received from the packaging machine when a wrapping blank is required. When this signal is received, the clutch and brake assembly (57, Fig. 10) operates to feed the web past the cutting means C. A feeler 150A detects the passage of the leading edge of the web and transmits a signal to rotate the cam shaft (75) through one revolution and one of the cams actuates the gluing mechanism 134, Fig. 9. Two more cams actuate respectively the slitting mechanisms to cut slits 150, 151, Fig. 17, and an electric eye is activated by a further cam. When the electric eye detects a registration mark on the web, the feed ceases due to disengagement of the clutch and engagement of the brake of the assembly (57). The cutting means C is then actuated by a further cam, the gluing mechanism ceases to operate and the electric eye is deactivated. The system then waits for the next signal from the packaging machine. Wrapping blank.-The slits 150, Fig. 18, allow the end of the tear strip to be gripped, and slits 151 facilitate folding of the blank around the package to be wrapped.