Patent GB-1165352-A (GB)
Title: Welded Portable Containers
Inventor: WATERER JOHN WILLIAM
IPC: B29C65/00
Filed: 1966-07-12
Abstract: 1,165,352. Bags. BARROW HEPBURN & GALE Ltd. 3 Oct., 1967 [12 July, 1966], No. 31288/66. Heading A4G. [Also in Divisions B5 and B8] A army kitbag is made by bending a strip or band composed wholly or in part of electrically conductive material to form a peripheral wall 2 and joining the strip or band in edgwise-on-relationship to the margin of a panel 1 forming another wall of the bag by softening or fusing thermoplastics substance in situ at the joint by high frequency heating using the strip or band as an electrode or to provide at least a part of a conductive path between electrodes E, E1 in the high frequency heating operation. In Fig. 1, the bottom panel 1 is formed of reinforced polyvinyl chloride to which further reinforcing media, e.g. fibre board or resin-impregnated cellulose fibre materials, may be added or of fibre-board covered with polyvinyl chloride. The wall 2 comprises a strip of aluminium alloy covered on the outside with polyvinyl chloride wrapped around the edges of the strip. The electrodes E, E<SP>1</SP> may be flat, as shown, or may be formed with ribs to weld only along their lines of contact with the bag. In modification, (a) the panel 1 and the wall 2 are provided with thermoplastics material only at their contacting portions; (b) a thermoplastics beading (7), Fig. 2 (not shown), extends between the margin of the panel (1) and the bottom of the wall (2) and the panel (1) and the wall (2) may or may not have a thermoplastics cover; (c) the wall (2) is formed of plywood or hardboard carrying a deposited metallic surface coating or coatings or preformed film or sheet components, e.g. metal foil, in an appropriate position or positions; (d) a lining material (8), Fig. 3 (not shown), is positioned over the panel (1) and the inner surface of the wall (2) and the upper margin thereof is covered by a channel section thermoplastics beading strip (9) bonded thereto by the high frequency heating operation; and (e) both a top panel (10) and a bottom panel (1) are secured to the wall (2) in one operation using beading strips (13), (14), Fig. 4 (not shown), and the wall (2) may extend around three margins only of the panels (1), (10). In a further embodiment, Fig 5, seams of the lid and container portions of an article of luggage are simultaneously welded. The lid portion comprises a laminated top panel 15, a beading 13 and a flange 16 formed of an electrically conductive strip 17 having a metal layer 17a and a thermoplastics strip 18 wrapped around the strip 17. The container portion comprises a laminated bottom panel 1, a beading 14 and a peripheral wall 2 the electrically conductive layer 11 of which is extended upwardly at 11a to form a rebate groove for the lid flange. The electrically conductive layers 17, 11 of the lid and container portions are temporarily electrically connected by at least one connector 19, e.g. pieces of metal foil located at intervals inside the case, during welding between electrodes E to prevent the two portions from being welded together. In a modification Fig. 6, electrical contact to prevent welding between the lid flange 20 and the peripheral wall 21, each formed of an aluminium strip 22, 23 covered with a polyvinyl chloride fabric layer 24, 25, is provided by mating aluminium extrusions 26, 27.