GB603502A - Method and apparatus for making collapsible tubes - Google Patents

Abstract

603,502. Making collapsable tubes. BOGOSLOWSKY, B. Oct. 22, 1945, No. 27729. [Class 83 (ii)] [Also in Groups V and XVII] A collapsable tube is made from a preformed blank 25 having an integral shoulder 26 and an elongated neck part, by first subjecting the neck part to a longitudinal pressure and then to an internal radial pressure further to compress the neck material and, when the neck is to be screw - threaded, force it into the screw-thread part of a hinged two-part die 6. The tube is mounted on a mandrel 1 which has an internal plunger 15, having parts of varying diameter, that can be moved vertically by a rack and pinion 17, 18. The die 6 has an upper cavity, in which the mandrel fits, and a lower cavity in which a bushing 10, fixed to a platen 8, slides. The bushing 10 has a bore in which the thinnest part of the mandrel slides. To apply the longitudinal pressure, platens 8, 8<SP>1</SP> are brought together causing the mandrel to move down into the die and grip the shoulder 26, and the bushing 10 moves up to compress the neck material. Stiff springs 9 are provided between the platen 8<SP>1</SP> and the die to ensure that the shoulder 26 is gripped before the longitudinal pressure is applied. A final forming pressure is applied to the shoulder by the platens after the springs 9 are fully compressed. To apply the radial pressure, the plunger 15 is lowered, causing the part 15b to move into the neck of the tube and expand it radially. A rubber gasket 4 is provided on the mandrel to prevent damage to the shoulder of the tube. The plunger and die may have heating and cooling means. The blank 25 is made according to the method and of any of the materials described in Specification 587,018. The materials include metal foil.