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US 4,570,104 AGranted
Electric lamp having a fuse in a feed-through molding
AssigneeU.S. Philips Corporation
InventorsEduard J. P. Janssen, Victor R. Notelteirs
Life of this patent
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Abstract
A lamp having a ceramic molding between a cap and a lamp envelope, the current supply conductors passing through the molding between the cap and the envelope. The conductors pass through separate ducts in the molding, one of the conductors includes a fuse accommodated entirely within the duct, and that duct is sealed at an end adjacent the lamp cap by a coherent mass of material such as a base cement. Flashover from a fuse arc to either the other conductor or the lamp cap is prevented.
Claims2
An internally fused electric lamp, comprising
- a lamp cap having at least two insulated electrical contacts,
- a ceramic molding disposed at least in part within said cap and fixed thereto,
- a sealed lamp envelope having a wall surrounding a light source, and an end secured to said molding,
- at least two current supply conductors extending from respective contacts on the lamp cap through said molding and said wall to said light source, and
- a fuse included in one of said conductors,
- wherein said molding has a respective individual duct therethrough for each current supply conductor, each of said ducts having an end adjacent the lamp envelope and an end remote from the lamp envelope,
- said fuse is completely accommodated within one of said ducts, and
- said one duct is closed by a coherent mass at said end remote from the lamp envelope,
- whereby a discharge arc caused by operation of the fuse is blocked from flashing over to the lamp cap or another current conductor.
6 more elements
Dependencies are inferred from the claim text.