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. 12, 1989
Filed:
Dec. 03, 1987
Tomokazu Umezaki, Himeji, JP;
Abstract
In a high-voltage transformer such as an ignition coil for internal combustion engines, a resin-crack preventing member is provided between an iron core and a resin which is impregnated into a coil case for electrically insulating a primary coil and a secondary coil in the coil case from the iron core as well as for firmly securing these coils and the iron core to the coil case. The resin-crack preventing member is moulded from a resinous material which is highly adhesive to the impregnated resin and which has a coefficient of thermal expansion similar to that of the impregnated resin. The resin-crack preventing member serves to prevent direct contact of the impregnated resin with the corners, side surfaces and inner surface of the iron core which has a coefficient of thermal expansion substantially different from that of the impregnated resin, thereby avoiding peeling off and cracking in the impregnated resin which would otherwise be caused by severe temperature changes. As a result, degradation of the electrical insulation of the transformer is effectively prevented.