GB966547A - Apparatus for closing and sealing lined containers - Google Patents

Abstract

966,547. Packaging machines. R. M. BERGSTEIN, and F. D. BERGSTEIN. Jan. 6, 1961 [Jan. 28, 1960], No. 702/61. Heading B8C. A packaging machine for closing and sealing lined containers comprises conveyer means having a first straight-line section provided with means to open the closure flaps at the upper end of each container and flatten and seal the mouth of a liner projecting therefrom, an intermediate arcuate section with means to engage and fold the leading and trailing closure flaps and to fold downwardly a third closure flap and a second straight-line section for folding and sealing the remaining closure flaps. A container 13 is placed on one of a number of interspaced carriage members 11 carried by a conveyer chain 8 mounted on a pair of horizontally disposed sprockets 6 and 7 and the container when locked by a coacting pair of arms 14 advanced with an upstanding liner portion 15 towards a pair of spreading fingers 16, 17 which flatten and elongate the mouth and in addition outfold the leading and trailing end closure flaps 18, 19, which are engaged by a hold-down bar 20, whilst a pair of sweeps 21, 22 simultaneously engages and outfolds end closure flaps 23, 24. The liner then passes between heating elements 26, 27 to activate a heat sealable coating on the liner, whereupon a pair of coacting pressure wheels 28, 29 seals the walls of the liner and the sealed end is contacted by a sweep 30 folding over the projecting end of the liner, which in turn is contacted by a hold-down plate 31 prior to the container entering the arcuate section, provided with a folding arm 33, a folding plate 32 and a rotary sweep 39. The folding arm 33 has a downwardly inclined leading part 34, a horizontally disposed intermediate part 35 and an upwardly inclined trailing part 36 with the configuration allowing upward folding of the leading and trailing flaps 18, 19 and holding down of the end closure flap 24 so that the latter may be engaged by a sweep 37 (Fig. 7), thereby assuring an unobstructed function of the rotary sweep in completing the folding of the end flap 19 prior to it being engaged by a sweep 38. During the advancement of the container along the arcuate path, the folding plate, which facilitates the folding of the liner along the articulation of flaps 18, 19 travels radially in and out by means of a pantograph linkage 43 fixed to a turret 41. As the container enters the second straight-line section of the machine the undersurface of the closure flap 23 is contacted by a sweep 55 which raises the flap into a vertical position for contact with a knurling wheel 56 to provide an embossed area 61 (not shown), extending along the flap 23, to facilitate an adhesive bond. If the surface of the flap is laminated with a foil, the knurling wheel may actually puncture the foil so as to provide interstices into which the adhesive may flow and bond. As the flap 23 is engaged by the knurling wheel, a sweep 64 aligns the closure flap 24 horizontally for passage between guide plates 65, 66 which position the flap for contact with a wheel 67, which is continuously or intermittently operated, and applying to the upper surface of the flap a strip of quick-setting thermoplastic adhesive 70, with the latter juxtaposed to the embossed area 61 of flap 23 by means of the sweeps 79, 78, whereupon the closure flaps are contacted by a pressure roller 80, which is followed by a series of spring-pressed rollers 82, whereupon the container arrives at the discharge station. In another embodiment (not shown), the guide plates 65, 66 may be replaced by an adjustable arm carrying a roller so as to secure a positive contact of the flap with the applicator wheel. To ensure satisfactory bonding of the quick-setting adhesive, the flap 23 is preheated by a heating unit 77 and the adhesive strip 70 is heated in a heating chamber 73 prior to deposition on the applicator wheel 67. U.S.A. Specification 2,114,622 is referred to.