Patent GB-714224-A (GB)
Title: Self-closing container for liquids
IPC: B65D30/24
Filed: 1952-09-01
Abstract: 714,224. Non-return valves. DREYER, A., and TOLEDO, M. DE. Sept. 1, 1952 [Sept. 7, 1951 ; March 4, 1952], No. 21976/52. Class 135. [Also in Group XVII] A flexible self-closing container for liquids comprises a filling and/or emptying conduit extending within the container and made of flexible material so that under the internal pressure of the contents the conduit flattens itself to form a check valve preventing the egress of liquid, the conduit being constricted along part of its length behind its orifice into the container and provided with a stiffening along the edges of the flattened part to prevent its folding back on itself. Figs. 1 to 4 show a container made of flexible impervious resilient material (e.g. polythene sheet) folded at edge 1 and welded along edges 2, 3 and 4 and along lines 7, 8 to provide lifting lobes having holes 9, 10. A narrow rectangular conduit 11 extending to the interior through edge 3 is made by welding together the edges 12, 13 of two sheets of the flexible material and is welded to the edge 3 of the container, the conduit being constricted by welding along lines 15, 16 and 17, 18, having a diminishing cross section towards its orifice 19, and being stiffened by the welds along edges 12, 13 to prevent the inner end folding over itself. The container is filled by inserting a rigid tube 20 in the conduit and forcing in the liquid and after withdrawal of the tube the internal pressure holds the inner lips of the conduit together to prevent loss of liquid, which is extracted by a similar tube or by tearing the container. In a modification, Figs. 9, 10, the container is made from a flat tube closed by welding along its ends 3, 4 and the conduit 11 is comprised by two edge welded sheets internally welded to the container wall at each side of a slit orifice 29. In a further modification, Figs. 15, 16, 17, the container is similarly made by closure of a flat tube by a weld across its lower end 4 and spaced welds 3, 3' across its upper end, through which a flat conduit 11 comprised by two edge welded sheets passes to the interior, and is fixed and constricted by welds 15, 16 and 17. 18. The inner end of the conduit containing the orifice 19 is formed to roll up spirally round itself, and the conduit is solidly welded to side 5 of the container at 34 so as to leave a housing between the conduit and side 6 of the container which may carrv a filling and emptying tube 20. In other modifications. Figs. 5 to 8, 11 to 14 (not shown), the constricted filling conduit is formed by folding inwardly two adiacent corners of a container made from edge we'ded sheets and partially welding along the adiacent external and internal edges of the lobes thus formed. or bv welding two parallel V-ended rectangular sheets into the upper end of a flat tube closed at the lower end, the inner lips being partially closed and a constriction formed in the conduit where it enters the container bv welding. The lins may be of gradually diminishing thickness towards the inner orifice. The inner surfaces of the conduit may be coated with a non-drying adhesive at the constriction to assist in closure after filling, and the welding may be effected by high frequency radiation in known manner.