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:
Nov. 01, 1994
Filed:
Dec. 02, 1992
Takashi Ito, Katsuta, JP;
Hiroshi Watanabe, Takahagi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An ignition coil for an internal combustion engine has a corrodable metallic core (9, 10) about which is provided a circumferential primary coil former (1) upon which is wound a primary coil (2). Circumferentially disposed around the primary coil is a secondary coil (3) located on a former (13). So as to prevent the corrodable metallic core ( 9, 10 ) from fracturing the primary coil former, there is disposed an absorbing layer (12) between the core and the primary coil. The stress absorbing layer may be provided between the primary coil and the primary former or the primary former may comprise a deformable inner cylindrical member (1b) and a substantially rigid outer cylindrical member (1a) with the stress absorbing material (12) located in the annular space between the inner cylindrical member and the outer cylindrical member. The stress absorbing material in such an alternative embodiment may be formed of foamed rubber-like material or may be an air gap. In yet another embodiment the former about which the primary coil (2) is wound may be formed of a stress absorbing material.