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:
Mar. 25, 1980
Filed:
Feb. 14, 1978
Toyo Kogyo Co., Ltd., Hiroshima, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
An ignition device for rotary piston engines. The device has an ignition plug disposed in a bore formed in an inner wall surface of a casing of the engine. The plug is of the surface gap and air gap discharge type and has a discharge end constituted by inner and outer electrodes spaced apart from each other through a surface gap discharge distance defined by a surface of an insulative sleeve encircling the inner electrode and an air gap discharge distance defined between the insulative sleeve and the outer electrode. The surface gap discharge distance is not less than 0.6 mm and not greater than 1.3 mm. The air gap discharge distance is not less than 0.7 mm and not greater than 1.4 mm. The surface gap discharge distance is not greater than the air gap discharge distance. The outer electrode has a tip end axially retreated with respect to the surface of the insulative sleeve by a distance between 0.3-1.0 mm. The ignition plug is located with the discharge end disposed in proximity to the inner wall surface of the casing.