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:
Mar. 28, 2000
Filed:
Apr. 22, 1998
Usui Kokusai Sangyo Kaisha Limited, Shizuoka Prefecture, JP;
Abstract
A multi-layered metallic pipe having resistances to the chipping of pebbles and splashing of muddy water while driving a vehicle and excellent corrosion resistances. The multi-layered metallic pipe is piped without scraping and does not need an insulator. The multi-layered metallic pipe includes a metallic pipe having a relatively small plated diameter with a film made of zinc, aluminum or a zinc/aluminum based alloy on the outer circumference of the metallic pipe. A first layer of a polyamide resin, a polyviny fluoride, or a polyvinylidene fluoride having a film thickness of 20 to 50 microns is applied to the plated film. A second layer made of an extrudible resin having a film thickness of 100 microns to 1.0 millimeter and a chipping resistance is coated over the first layer along an entire length of the first layer. The second layer is formed to have stepped portions of different thickness. A method of coating the multi-layered metallic pipe includes forming the first layer on the outer circumference of the plated metallic pipe and the subsequent step of forming the second layer with stepped portions of different thicknesses by extruding the resin at an intermittently different feed rate.