GB955244A - Improvements in or relating to conveying and sealing apparatus - Google Patents

Abstract

955,244. Making bags etc.; cutting &c. DOUGHBOY INDUSTRIES Inc. Nov. 30, 1962, No. 45445/62. Headings B4B and B5D. [Also in Division B8] Polythene sheet F is conveyed on spikes 25 carried by a chain 21. In Figs. 3, 4 the sheet F is in the form of a flattened tube of polythene film and is intermittently fed by rollers 13, 13 into the position shown in dotted lines (Fig. 3). During a dwell period of the feed rollers 13, 13, a head 20 is slidable rightwards (Fig. 3) under the action of a spring 55 and as permitted by the low sector of a cam 62. The head 20 presses the sheet on to the row of spikes 25 carried by the L.H. run of the chain 21. A further cam 77 (rigid with the shaft 18 of the cam 62) engages a follower 75 to release a locking pin 72 thereby freeing a drum 68 for rotation. The latter results from the action of a chain 64 carried by a sector 63 rigid with the cam-shaft 18, as it comes into operative engagement with a sprocket 66 rigid with the drum 68. A cam track 69 (Fig. 4) of the drum 68 displaces a pin 78 rigid with a slide 79 mounted between pulleys 80, 80. The slide 79 acts through linkage 82, 83, 85 to displace a slide 44 along a slot 45 (Fig. 4). The slide 44 carries a sprocket 43 which engages a fixed run of chain 46. The sprocket 43 is thus caused to rotate and drive (at twice the speed of the slide 44) an endless chain 41 carrying a knife 39 which thereby severs the length of sheet carried by the spikes 25. As the high portion of the cam 62 engages its follower, the slide 20 is retracted and a linkage 86, 87 is deflected to operate a clutch 30 which restarts the chain 21. The severed sheet is thus fed to the nip between engaging runs of two endless conveyers 49, 50. The latter lead the sheet into engagement with endless bands 52, 52, of heat conducting material such as stainless steel. Associated with the latter are heat applying bars and cooling bars (Fig. 5, not shown) which effect heat sealing of the severed edges of the flattened tube of polythene. This action also serves to remove the holes produced by the spikes 25. In the embodiment of Fig. 6, polythene bags 90 filled with articles (e.g. folded bed sheets or fruit) are carried on a conveyer 91 with their open ends supported on an auxiliary coil-spring type conveyer belt 92. This leads the flattened bag mount up a ramp 93, the end of which has a slot through which protrude spikes 95 on an endless conveyer chain 101. A brush 98 is carried periodically by a linkage 99, 100 into engagement with the bag to drive it on to the spikes 95. A vertical plate 102 serves to prevent the articles in the bag fouling the conveyer 101. The longitudinal axis of the conveyer 101 slants slightly away from the longitudinal axis of the plate 102 so as to tension the bag mount away from the articles in the bag. The bag mouth is thereby conveyed to sealing apparatus (not shown) similar to that described above.