Patent EA-000321-B1 (EA)
Title: Improvements relating to containers
IPC: B29C49/00
Filed: 1996-11-29
Abstract: 1. A method of making a container to which entry is via an opening having a detent (5) for positively retaining a closure member within that opening, the material of the container being susceptible to deformation when heated, characterised in that in a first stage an embryo container (1) is formed as a closed end tube (2) with an outward, generally radial flange (4, 7) at its mouth, part of the upper surface of which flange is to provide the inside of the opening, the detent (5) being simultaneously formed as a projection from or depression in said surface, and in that in a second stage the outer peripheral portion (7) of the flange is held fast while the tube (2), at an elevated temperature, is expanded by differential pressure, this drawing down and forcing outwardly the inner portion (4) of the flange and transforming said upper surface from an upwardly facing one into a passage providing the opening with the detent (5). 2. A method of making a container as claimed in Claim 1, characterised in that the formation of the embryo container (1) in the first stage is by moulding in a two part mould one of which has a core subsequently extractable through said opening. 3. A method of making a container as claimed in Claim 2, characterised in that the formation of the embryo container is by injection moulding. 4. A method of making a container as claimed in Claim 1, 2 or 3, characterised in that the transformation from embryo to finished container in the second stage is by blow moulding via the opening. 5. A method of making a container as claimed in any preceding Claim, characterised in that the detent (5) in the embryo container is a spiral or part spiral to form screw threading in the finished container. 6. A method of making a container as claimed in any one of Claims 1 to 4, characterised in that the detent is at least one L-shaped indentation to form part of a bayonet fitting. 7. A method of making a container as claimed in any one of Claims 1 to 4, characterised in that the detent is at least one stud to form part of a bayonet fitting. 8. A method of making a container as claimed in any one of Claims 1 to 4, characterised in that the detent is an annular ring formation for the retention of a roller ball. 9. A method of making a container as claimed in any preceding Claim, characterised in that the embryo container (1) has a generally cylindrical flange (6) on the radial flange (4, 7) projecting downwardly to surround the opening end of the tube (2). 10. A method of making a container as claimed in Claim 9, characterised in that the under surface of the inner portion (4) of the radial flange, when that is deformed downwardly and outwardly by the tube expansion, co-operates with the inside of the cylindrical flange (6). 11. A method of making a container as claimed in Claim 11, characterised in that in the finished container said under surface bonds to the cylindrical flange (6). 12. A method of making a container as claimed in Claim 10 or 11, characterised in that the material of the container is transparent and a data band is provided on the inside of the cylindrical flange (6) of the embryo container to be legible therethrough, the band being made captive by the deformed portion of the radial flange (4). 13. A method of making a container as claimed in any one of Claims 10 to 14 as appendant to Claim 4, characterised in that the outer peripheral portion of the flange is a stepped up rim (7) projecting beyond the cylindrical flange (6), its underside providing means for locating the embryo container (1) during the blow moulding while its inside (8) provides a seat for a blow pin. 14. A container made by the method of any preceding Claim.