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:
May. 18, 1999
Filed:
Oct. 10, 1995
Angus J McCamant, Aloha, OR (US);
Other;
Abstract
An incandescent bulb having a looped filament within an evacuated bulb containing a gas mixture including a halogen employs magnetic means external to the bulb to provide inductive heating of the filament so that there are no connections passing through the bulb envelope. Alternative embodiments include a toroidal bulb wherein a second arm of a magnetic circuit passes normally through the center of the bulb toroid, alternating voltage excitation being supplied to a first arm of the magnetic circuit; and an elliptical bulb that is disposed between oppositely facing ends of a two-part second magnetic arm that is similarly excited. In a further embodiment, an additional arm of the magnetic circuit serves to form a non-uniform field in the vicinity of the filament, thereby to provide a lift force against the force of gravity so as to minimize filament sagging.