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. 10, 1987
Filed:
Nov. 27, 1985
Gilberto Izzi, Milan, IT;
Abstract
The glow plug comprises a tubular metal sheath (5) closed at the tip, in which an electric spiral (7) is placed as embedded within a powder (6) of electrically insulating material. The filament of the initial length (L.sub.1) of the spiral, from the connection location with the current feeder (4), is coated with high electric conductivity material, the resistance of which has a very high positive temperature coefficient with respect to that of the filament. For the filament an alloy of Fe--Cr--Al is advantageously used and for the coating a Ni-based conductive material. Thus, the end length (L.sub.2) of the spiral acts as sheath heating element, while the initial coated length (L.sub.1) acts as supply current control element. Application: preheating plugs for diesel engines of motor vehicles. Advantages: reduced cost of the glow plug due to construction simplicity. Possibility of varying the electric and thermal characteristics of the glow plug by simply varying the dimensions of the conductive coating. The invention is shown in FIG. 1.