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:
Jul. 20, 2004
Filed:
Dec. 10, 2001
Hitachi, Ltd., Tokyo, JP;
Abstract
An independent ignition type ignition coil for an internal combustion engine, comprising, arranged concentrically in a coil case ( ) and with the innermost one mentioned first, a center core ( ), a secondary coil ( ) wound on a secondary bobbin ( ) and a primary coil ( ) wound on a primary bobbin ( ), with epoxy resin ( ) and soft epoxy ( ) filled between these component members, wherein a coating is formed on the outer surface of the primary coil ( ) so as to facilitate the separation from the epoxy resin ( ) and the presence of this separation portion ( ) between the primary coil ( ) and the resin and in an interlayer of the primary coil ( ) can reduce from a thermal stress produced within the secondary bobbin ( ) a stress which is produced in the secondary bobbin by a heat contraction difference between the primary coil ( ) and the secondary bobbin, thereby reducing the thermal stress of the secondary bobbin of the independent type ignition coil exposed to a rigorous temperature environment to prevent bobbin cracking and ensure an integrity of electrical insulation.