US3551719A - Arc lamp with concentric electrodes - Google Patents

Description

United States Patent Inventors Teddy .1. Peacher:

' Dorwin L. Kilbourn. Huntsville, Ala. [21] Appl. No. 789.526 [22 Filed Jan. 7, 1969 [45] Patented Dec. 29, 1970 [73] Assignee The United States 01 America as represented by the Secretary of the Army.

[ 54] ARC LAMP WITH CONCENTRIC ELECTRODES 4 Claims, 1 Drawing Fig.

[52] U.S.Cl. 313/110, 3l3/184,313/2l7.313/220 [51] Int. Cl. ..1-1 01j 61/06, H01 j 61/30 [50] Field ofSearch 313/184. 209, 210, 217. 220, 231, 110(Cursory). 110

[56] Y Re ferences'Cited UNITED STATES PATENTS 2,629,836 2/1953. Deri 3 l 3/209X 2.802.130 8/1957 Engelman et a1. 313/210X 3.188.512 6/1965 Moore 313/110 3.317.777 5/1967 Algar et a1. 313/182 3.465.194 9/1969 Hall 313/217X Primary E.ran1iner-John Kominski Assistant Examiner-Palmer C Demeo Atlorneys- Harry M. Saragovitz. Edward .1. Kelly. Herbert Berl and Harold W. Hilton PATENTED UEC29 1975 Teddy J. Pacher Dorwin L.Kilbourn, INVENTORS.

AW Lf M 1/ My ARC LAMP WITH CONCENTRIC ELECTRODES BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The present invention relates to an arc lamp having a pair of electrodes disposed in spaced concentric 'relationyThe electrodes are partially enclosed in an envelope having a gas therein disposed for energization responsivelto activation of the electrodes.

It is an object of the present invention, therefore, to provide an arc lamp in which radiation emanates therefrom without being restricted or blocked by internal structure such as electrodes.

It is another object of the present invention to provide such an arc lamp in which the electrodes aremounted in concentric relation for unrestricted radiation flow from the lamp.

These and other objects and advantages of the present invention will be more readily apparent from the following description and drawing.

BRIEF DESCRIPTION OF THE DRAWING The FIG. is an elevational sectional view of the lamp of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the FIG., an arc lamp 10 includes a window 12 of ceramic, quartz or the like, sealed to an annular anode 14 by a metal ferrule 16. Anode l4 isprovided with a central opening 17 which substantially encloses a tip l8of a hollow cathode 20. Cathode 20 includes a portion 22 extending out of opening 17. I

A ceramic insulator 24, in the form of a cylinder or sleeve, partially encloses the cathode and is sealed thereto by a ceramic to a metal seal 26. Anode 14 is sealed to-the ceramic insulator by a metal seal 28 which is secured to a metallized band disposed around the insulator 24.

The anode is generally annular in shape with stepped annular shoulders 30 and 32 and a conical portion 34 terminating into a flat inner anode reflecting surface 36. The anode structure can also be shaped to serve as a multifunction device including electrode, heat sink, reflector, resonance shield, and basing member. If desired, the anode may have screw threads on the outer periphery or lugs for bayonet mounting.

The cathode 20 includes a central hollow portion 38 communicating into a chamber 40 through passages 39. Chamber 40 is formed by sealing window 12 to the anode and the anode to the cathode. An end portion 22 of the cathode is pinched off to seal the opening therein responsive to filling chamber 40 with gas through passages 38 and 39.

The tip 18 of the cathode may be in the form shown, as a flat recessed surface, or, if desired, the cathode tip may be shaped as a flat disc slightly suspended above the anode. In any event, the tip is of a refractory material, such as tungsten.

Obviously, many modifications of the present invention may be resorted, to by one skilled in the art; however, such modifications are within the spirit and scope of the appended claims.

We claim:

1. An arc lamp comprising:

a. an anode having an annular configuration provided with a first reflecting surface, said anode having a central opening therethrough; b. a transparent envelope secured around the periphery of said annular anode and forming a chamber between said envelope and said first surface of said cathode;

c. a cathode mounted in said opening of said anode, said cathode being sealed to an inner annular surface of said anode formed by said opening and having a portion extending into said chamber;

(1. a gas disposed in said chamber;

e. means for applying a potential between said cathode and said anode; and

f. passage means provided through said cathode, said passage means disposed in communication with said chamber for insertion of said gas therein.

2. A device as set forth in claim 1 including a ceramic insulating collar disposed around said cathode in spaced relation thereto, said collar being disposed in concentric spaced relation in said opening of said anode, and first seal means secured around said collar and in secured relation to said inner annular surface of said anode for securing said cathode in said anode opening, second seal means secured to said cathode and. said insulating collar for retention of said cathode and said collar in the spaced relation.

3. The device as set forth in claim 2 wherein said envelope is a hemispherical shaped window having the edges mounted on said anode; and, means for sealing said envelope to said anode.

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