Patent GB-711855-A (GB)
Title: Apparatus for the continuous production of containers or packages from a tube-shapedelement
IPC: B65B9/12
Filed: 1951-05-24
Abstract: 711,855. Packaging-machines; making bags. HERMORIAN, Ltd. May 24, 1951 [Dec. 30, 1950], No. 12188/51. Classes 94 (1) and 94 (2) [Also in Group V] In a machine for making packages or bags, a continuously-moving tube made of, or coated or impregnated with, thermoplastic material is flattened and sealed transversely at intervals by heat and pressure applied by co-operating pairs of jaws carried by opposed endless conveyers, the jaws being pressed together by movable rollers. The machine shown in Fig. 1 is arranged to flatten and seal the tube in one or other of two mutually perpendicular planes to produce packages of tetrahedral shape and comprises two pairs of oppositely-disposed chain conveyers 16 arranged at right angles to one another, each conveyer consisting of two chains 22 passing over guides 58, 60 and sprockets 18 and 20 and interconnected by a series of transverse stays 24, 24a which are rotatably mounted in the chain links and carry shaping and sealing jaws 14. One conveyer of each pair carries. electrically-heated jaws 14a, Fig. 4, each comprising a base 38 carrying a head 40 which is fitted with inclined flanges 42, electrical heating units 44 energized through a contact 52 sliding on a conductor rail 54, and a thermostat 46. Alternatively, the jaws may be inductively heated. The other conveyer carries similar unheated jaws 14b, the surfaces of which are faced with resilient material such as silicon-containing synthetic rubber. The leading stay 24 of each pair engages a narrow slot in the base of the jaw and may be secured by screws passing through holes 26, and the trailing stay 24a passes through a wide slot 28, whereby the jaw is free to rock about the axis of the stay 24 against the action of springs 66 connected between the trailing stay and one of the flanges 42. The base of each jaw carries a roller 62 which engages a guide 64 to cause rocking of the jaw as it moves into engagement with the tube to minimize sliding between the surfaces of the jaw and tube. In a modification, Fig. 7, the base 86 of each jaw is slidable on bearings 88 relative to a member carried by the chains and carries a rack 92 meshing with a toothed sector 90 formed on one arm of a bellcrank lever pivoted at 96, the other arm of the lever carrying a roller 98 which is arranged to engage the guide. As each co-operating pair of jaws approaches the sealing station a plate 56 on the jaw 14a is engaged by rollers 80 on a wedge member 72 which is slidable on a needle bearing 78 and is moved upwardly to apply the sealing pressure by a plunger 70 acting through a spring 82 and operated by a cam 68 on the driving shaft of the sprocket 20. A similar arrangement may be provided for the jaws 14b. In a modi- .fication, Fig. 8, the rollers 80 are carried by a member 100 pivoted to parallel links 102. The material to be packaged may be fed into the tube continuously or intermittently and in the case of liquids sealing may be effected below the surface of the liquid in the tube. Alternatively, the machine may be arranged to produce empty bags and the jaws designed to leave a small unsealed portion to serve as a filling opening. Specification 691,649, [Group XXVIII], is referred to.