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. 26, 1999
Filed:
Aug. 05, 1998
Kazuo Ishikawa, Osaka, JP;
Yasushige Otani, Osaka, JP;
Tabuchi Co., Ltd., Osaka, JP;
Abstract
A rust-resistant cylindrical metal sleeve for preventing rust and corrosion from developing around the wall of a branch hole when the sleeve is rigidly fitted into a branch hole that is drilled through the wall of a metal conduit such as a water pipeline. The sleeve has a projecting portion on its outer circumference and an inner flange portion inwardly projecting at its lower end. The metal sleeve on its outer circumference is coated with a water-absorbing swelling rubber into which a synthetic resin rubber and a water-absorbing polymer are blended. Preferably, 100 parts by weight of styrene-butadiene rubber or ethylene-propylene-dienemetylene linkage rubber is blended with 10 to 40 parts by weight of the water-absorbing polymer. Since the water-absorbing swelling rubber increases its volume as it absorbs water, pressure in the rubber increases, preventing water ingress through between the metal sleeve and the wall of the branch hole.