GB1085834A - Improvements in or relating to the sealing of containers - Google Patents

Abstract

1,085,834. Capping containers; closuring containers. FORDS (FINSBURY) Ltd. April 1, 1964 [April 1, 1963], No. 12806/63. Headings B8C and B8T. A container is sealed by heat sealing a cap to the upper part of the container lip and at the same time crimping or folding the periphery of the cap beneath the lip. The sealing apparatus may comprise a plurality of arms 14 each hinged at 15 to a plate 12 which supports a platen 10 containing a heating element 13. Each arm carries a segment 16 at one end and a bearing 18 at the other end which rides up a tapered wall 23 of a drum cam under action of spring 27, when a container and cap are raised upwardly against the platen, so causing the lower end of the arm to swing in so that the segments 16 fold the periphery of the cap beneath the container lip. In the embodiment of Fig. 7 a copper heated platen 30 is moved upwardly against the action of a spring 42 by a container C until the upper face of the platen contacts the under side of a flange 51 of a resilient annulus 50. Further upward movement causes the annulus 50 to be deformed so that its shoulder 52 swings in contact with the cap periphery. The crimping may alternatively be effected by means of a circumferential spring which is caused to move radially inwards while the container cap is in contact with the heated platen. To prevent overheating of the container and cap, the containers may be elevated into the sealing heads by an elevator mechanism actuated by a cam rail with a shape which corresponds to a suitable time cycle for the containers to be in contact with the platen. Alternatively, to prevent overheating the platen may be continuously heated but a switch which energizes a solenoid whose armature is connected by a linkage to a rod arranged to cause movement of the sealing head towards the container may limit the period of contact between the container and platen. The sealing head movement may alternatively be controlled by a mechanical, hydraulic, or pneumatic means associated with a suitable time delay arrangement. In a modification, the platen may be heated in impulses. The container may be made of a synthetic organic thermoplastic material such as polythene and its cap from a metal foil lined with similar thermoplastic material. Alternatively the container may be made of waxed paper or a rigid material such as glass or metal and its cap of metal foil or paper or card with a wax layer therebeneath.