Title:
MANUFACTURE OF DOUBLE PIPE
Document Type and Number:
Japanese Patent JP3822693
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To make a sheathed pipe separable, and permit also an inner pipe to be pulled during the pulling period by a pulling machine by providing protrusions for supporting the inner surface of an inner pipe in the inner surface of a sheathed pipe continuously in the longitudinal direction.
SOLUTION: An inner pipe 1 and sheathed pipe 2 extruded from mold are placed in contact with each other by protrusions, and 2mm interstices are provided elsewhere. Then, the extruded inner pipe 1 and sheath pipe 2 are sized into a true circle by a sizing device set in the front of a water cooling unit to subsequently be cooled and cured by a cooling device. Next, the sheath pipe 2 is held to be pulled by its outer surface. In this instance, no sliding movement exists between the sheathed pipe 2 and inner pipe 1, so that the inner pipe 2 is held at its outer surface through the pulling force of the pulling machine via the protrusions, thereby pulling also the inner pipe. Each protrusion is formed into an acute cross-sectional configuration, wherein the wall thickness of the sheathed pipe 2 is made, e.g. 1.0mm, the inner pipe 1 is made 1.5mm in its wall thickness, and the protrusions 3 are made 1.2mm in its height.
Inventors:
Masakatsu Sakamoto
Tsutomu grandmother
Tsutomu grandmother
Application Number:
JP221597A
Publication Date:
September 20, 2006
Filing Date:
January 09, 1997
Export Citation:
Assignee:
Sekisui Chemical Co.,Ltd.
International Classes:
B29C47/02; B29C47/06; B29D23/00; F16L9/12; B29L9/00; B29L23/00; (IPC1-7): B29C47/02; B29C47/06; B29D23/00; //B29L9:00; B29L23:00
Domestic Patent References:
| JP50015850A | ||||
| JP55105546A | ||||
| JP63098413A |