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:
Sep. 19, 1989
Filed:
Jun. 15, 1987
Noboru Matsushima, Fukushima, JP;
NOK Corporation, Tokyo, JP;
Abstract
A lip-type oil seal for use with a rotary shaft is manufactured by a method wherein different elastomeric materials for forming respectively the sealed liquid side and the atmospheric side of a tip portion of a sealing lip of the oil seal have different moduli of elasticity or hardnesses and are placed in a superposed condition within a mold prepared for vulcanization molding the oil seal. The mold is then clamped and the materials are heated and compressed so that an elastomeric material is fluidized and is vulcanization molded together with the other material to form an integral structure while a surplus portion is allowed to remain on the atmospheric side, thereby forming a sealed liquid side surface of the sealing lip. After the fluidized material has been hardened, the mold is opened and the surplus portion is then cut off, thereby forming an atmospheric side surface of the sealing lip.