The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 2008
Filed:
Mar. 03, 2004
Bernard Prevotat, Marnes la Coquette, FR;
Bernard Prevotat, Marnes la Coquette, FR;
Alphacan, la Celle Saint-Cloud, FR;
Abstract
The invention relates to a method for continuously producing plastic tubes by biaxial drawing consisting in producing a blank (E) by extrusion, heating said blank to a molecular condensation temperature, radially dilating it by the internal pressure of a fluid applied between two axially distant obturator rings () and in carrying out a calibration () and cooling () associated with an axial tension produced on a tube at the output thereof. A pressure opposite to the internal pressure is applied to the blank wall from the outside in at least one area which is exposed to the radial dilation. Said opposite pressure is selected such that it is lower than the internal pressure, thereby preventing a counteraction to said dilation and remaining sufficient in order to control the dilation growth in such a way that it is possible to ensure a substantially constant material thickness on the same circumference.