High intensity lamp containing internal shorting fuse

Claim 2

A vacuum jacketed high intensity vapor arc lamp comprising: an evacuated vitreous outer envelope having inleads sealed therein; an inner elongated envelope containing ionizable vapor and having electrodes sealed into its ends; said inner envelope requiring a starting voltage high enough to start a discharge in said outer envelope should the vacuum therein be destroyed; means supporting said inner envelope within said outer envelope and including conductors connecting said electrodes to said inleads; and a short-circuiting arcing fuse in said outer envelope comprising metal conductors connected to said inleads and defining, at the closest spatial approach between opposite current conductors, a gap across which an arc forming in said outer envelope will occur, said conductors being interlinked in such fashion that heat deformation thereof by an arc will cause one conductor to bridge over to the other about said gap for any orientation of said lamp.

Claim 3

A lamp as in claim 1 wherein each of the metal conductors defining said gap makes a part loop around the other but spaced one from the other the distance of said gap, saId conductors being of metal that will soften and flow under heat without excessive oxidation.

Claim 4

A lamp as in claim 2 wherein said metal conductors making said loops are of nickel.

Claim 5

A vacuum jacketed high intensity metal vapor lamp comprising: an evacuated vitreous outer envelope having a pair of stiff inleads sealed therein at the neck end side by side through a press; an inner elongated arc tube containing metal vapor and having electrodes sealed into its ends; said arc tube requiring a starting voltage high enough to start a discharge in said outer envelope should the vacuum therein be destroyed; means supporting said arc tube within said outer envelope and including conductors connecting said electrodes to said inleads; and a short-circuiting arcing fuse in said outer envelope comprising a metal conductor connected to one inlead close to the press and extended into a loop which encircles the other inlead, said loop defining a gap which is the closest spatial approach between opposite current conductors so that any arc forming will occur at said gap, said metal conductor being of metal that will soften and flow under heat without excessive oxidation whereby to bridge over said gap upon occurrence of an arc thereat.

Claim 6

A vacuum jacketed high intensity metal vapor lamp comprising: an evacuated vitreous outer envelope having a pair of stiff inleads sealed therein at the neck end side by side through a press; an inner elongated arc tube containing metal vapor and having electrodes sealed into its ends; said arc tube requiring a starting voltage high enough to start a discharge in said outer envelope should the vacuum therein be destroyed; means supporting said arc tube within said outer envelope and including conductors connecting said electrodes to said inleads; and a short-circuiting arcing fuse in said outer envelope comprising a metal conductor connected to one inlead close to the press and extended into a loop which encircles the other inlead, said loop defining a gap which is the closest spatial approach between opposite current conductors so that any arc forming will occur at said gap, said metal conductor being of metal that will soften and flow under heat without excessive oxidation whereby to bridge over said gap upon occurrence of an arc thereat.

Claim 7

A lamp as in claim 4 wherein said metal conductor is of metal selected from the group consisting of iron, nickel and alloys thereof.

Claim 8

A lamp as in claim 4 including a short sleeve of low melting point lead glass placed around said other inlead and encircled by said loop.

Claim 9

A lamp as in claim 4 including a base attached to the neck end of said envelope to which said inleads are connected, and an additional self-shorting arcing fuse located in said base.

Claim 10

A lamp as in claim 4 wherein the metal vapor includes sodium.

Claim 11

A lamp as in claim 4 wherein the arc tube contains sodium, mercury and xenon.