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:
Oct. 25, 1988
Filed:
Sep. 15, 1986
Hermann Stover, Twistringen, DE;
Alfons Meyer, Twistringen, DE;
Corma, Inc., Ontario, CA;
Abstract
Method and apparatus for encasing drainage pipes, using fibrous or particulate loose filler material guided onto the drainage pipe by means of a hollow screw and held there with a permeable envelope material preferably wound round with a filament. The pitch or number of threads on the screw, the height thereof and the speed at which the screw rotates determine the amount of filler material applied to the drainage pipe per unit of area. The apparatus comprises a machine consisting of a guide tube carrying an internal hollow screw, the drainage pipe being guided in the interior of the screw, the encasing envelope material being placed externally upon the said guide tube and preferably being wound around with a filament at the end of the screw.