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.

Date of Patent:
Aug. 19, 1997

Filed:

Oct. 31, 1995
Applicant:
Inventors:

Randall J Houck, Brevard, NC (US);

Michael H Houck, Brevard, NC (US);

Harold J Houck, Pisgah Forest, NC (US);

Assignee:

Other;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D / ;
U.S. Cl.
CPC ...
29429 ; 295272 ;
Abstract

A method for manufacturing preassembled drainage line units comprises feeding a length of perforated vent pipe along a direction of manufacture longitudinally through a tubular mandrel, feeding a continuous sleeve of netting concentrically over the vent pipe along the direction of manufacture from a front end of the mandrel and continuously supplying quantities of artificial aggregate into the space between the sleeve of netting and the vent pipe. A low friction coating is applied to the inside surface of the mandrel to reduce the surface friction of the artificial aggregate caused by compaction, and to permit high speed manufacture.


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