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:
Dec. 05, 2000
Filed:
Mar. 31, 1998
Applicant:
Inventors:
Manfred A Lupke, Thornhill, Ontario, CA;
Stefan A Lupke, Thornhill, Ontario, CA;
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
4253261 ; 425336 ; 425384 ; 4253871 ; 425392 ; 425396 ; 425464 ;
Abstract
A pipe molding apparatus for forming double walled plastic pipe comprises an extruder which feeds first and second parisons of flowing plastic material to a moving mold tunnel to make respectively the outer and inner walls of the pipe. The moving mold tunnel includes a cooling plug over which the second parison moves to form the inner pipe wall while the outer wall of the pipe is formed against the interior surface of the mold tunnel. An air assist is provided internally of and helps to move the inner parison onto the cooling plug.