GB764807A - Improvements in or relating to machines for forming, filling and closing bags - Google Patents

Abstract

764,807. Packaging machines; making bags. BARTELT ENGINEERING CO. Feb. 17, 1955 [March 3, 1954; Nov. 1, 1954], No. 4808/55. Classes 94(1) and 94(2). A packaging machine includes means for filling, compacting the contents of, and stretching, flattening and closing the top portion of a bag. The machine described forms the bags by folding, pleating and heat sealing a web of thermoplastic coated material, Making bags. The web 45, coated side uppermost is folded to form the two bag sides 32, 33 and a bottom gusset by apparatus as described in Specification 702,723. At station 49 heated shoes 69, Figs. 1, 5, form transverse heat seals 50 and diagonal corner seals 38, while at station 77 the seals are engaged by water cooled shoes 78 to rapidly strengthen them. A knife 85 cuts individual bags from the web, the bags being engaged by grips 89 on an intermittently moving chain conveyer 84 for transit along a rail 91 through the machine. The web is advanced intermittently by rollers 61 operated by an indexing mechanism including a yieldable crank 64 driven from a main cam shaft 72 and rotating a shaft 65, Fig. 1, geared to the rollers. The indexing mechanism may include a photoelectric eye 67 detecting spaced marks on the web and operating to energize a brake 68 stopping the shaft 65. Bag filling and closing. The mouth of each bag consists of free flaps, Fig. 6, between which engages a bar 105 having downwardly directed air passages through which air is blown to partly open the bag. During such opening at station 52, bars 109, Fig. 16, move in to clamp the upper part of the bag against the bar 105 and plates 123, 124 are positioned to shape the expanding bag. At station 53, Figs. 2, 5, plates 126, 127, Fig. 20, initially flat, are introduced into the bag by the lowering of arms 129, 130. These arms then approach each other to bow the plates, opening out the bag and enabling a filling charge to be dropped into it by conventional filling means 155. In passage to the compacting station 54, an arm 218, Fig. 5, taps the bag base to settle the contents. At station 54, a plunger 94, Figs. 22, 25, enters the bag to compress the contents, fingers 197 swinging downwardly to spread the bag mouth and permit entry of a ring 185, slidable on the plunger, against which ring the mouth is clamped by plates 156 to prevent wrinkling. The plates 156 also support the bag sides. As the plunger is withdrawn, a brush, Fig. 24 (not shown), wipes surplus material from its base. At station 96, the side seams of the bag are gripped adjacent their upper ends by inwardly advancing jaws 225, Fig. 27, which are then moved by pneumatic means 234 to stretch the bag mouth. At station 251 opposed jaws and shaped plates, Fig. 31 (not shown), press the mouth and body of the bag to shape it preparatory to folding of the top at station 55. At station 55 plates 264, 265, Fig. 40, engage the bag mouth below the desired folding line 39 and a bar 268 moves horizontally to turn through 90 degrees the bag portion projecting above the plates. A bar 267 descends to fold the turned over portion down against the plate 264. At station 101 pressers, Fig. 41 (not shown), consolidate the fold and heated members lightly tack down the fold side seams. Identical mechanism (not shown) to that at station 55 forms a second fold along a line 40 at station 56 and further pressers (not shown) consolidate the fold at station 103. Finally ends 42 of the top fold are turned through 90 degrees by mechanism at station 57 comprising two rubber faced jaws 301, 302, Fig. 43, which clamp the bag mouth, one jaw 302 being slidable relative to its operating member 311. After the jaws have engaged the bag, the member 311 continues to advance against springs 312 so that rollers 303 fold the ends 42 against the sides of the jaw 301. The finished packages are removed from the conveyer by means 315, Fig. 2 (not described) for insertion into cartons.