US3138731A

US3138731A - Sealed beam high-intensity short arc lamp

Info

Publication number: US3138731A
Application number: US224593A
Authority: US
Inventors: Norman C Beese
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-09-12
Filing date: 1962-09-12
Publication date: 1964-06-23
Anticipated expiration: 1981-06-23

Description

June 23, 1964 N. c. BEESE SEALED BEAM HIGH-INTENSITY SHORT ARC LAMP Filed Sept. 12, 1962 I, INVENTOR. NORMAN C. BEESE United States Patent 3,138,731 SEALED BEAM HIGH-INTENSITY SHORT ARC LAMP Norman C. Beese, Verona, N.J., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Sept. 12, 1962, Ser. No. 224,593 '7 Claims. (Cl. 313- 113) The present invention relates to electrical discharge lamps and more particularly to high intensity short arc lamps which operate at high temperatures and pressures.

As is well known in the art, short are lamps consist generally of an anode and a cathode located within a sealed quartz envelope containing a gas such as xenon, mercury, krypton, etc., which is maintained under high pressure of the order of about 20 atmospheres. The anode and cathode are axially aligned within the envelope and relatively positioned with their tip ends spaced a short distance from each other for producing an intense arc having a very useful continuous spectrum adapting the lamp to a variety of uses.

High intensity short are lamps have not been used heretofore to an extent corresponding to their efiiciency since their use has been limited by some disadvantages. Difficulties have been encountered in starting the lamps since this requires high voltages and often results in damaging the quartz enevlope due to shock and vibration. It has also been diificult to properly mount the lamp in exterior supports or bases, since the high temperatures attained during use cause the connections to deteriorate. Furthermore, these high intensity lamps are, under some conditions of use, subject to occasional explosions of the quartz envelope which endanger persons or equipment in the proximity of the lamps.

It has been found that the various disadvantages of such high pressure lamps hereinbefore set forth may be avoided and the lamps used effectively by arranging the lamp unit within an enclosure formed of a sealed beam type housing having relatively thick walls and providing substantial space with the short arc lamp structure. Such housings, as is customary, are formed of two pressed glass shells, one shell being of parabolic shape and serving as a reflector and the other being shaped to function as a lens. According to the present invention, each shell is modified to provide an integral tubular neck portion which extends outwardly and generally centrally therefrom for receiving the end portions of the short arc lamp unit in a manner to permit movement of the short are lamp unit during use. Details of accomplishing this result will be explained in the detailed description of the drawings.

It is an object of this invention to provide a high wattage short arc discharge lamp construction which is arranged to minimize leakage or spark over voltages during its starting at requisite high voltages.

Another object of this invention is to provide a high wattage short are discharge lamp construction which may be safely operated at high temperatures and pressures.

Another object of this invention is to provide a high Wattage short are discharge lamp which is of rugged construction and capable of eifective operation under extreme impacts or sudden jars.

Other objects and advantages of the invention will become apparent from the detailed description read in conjunction with the accompanying drawings:

FIG. 1 is a view in sectional elevation of a short are envelope assembled within a housing and showing some details.

FIG. 2 is an enlarged view on the line 2-2 of FIG. 1 to show details of an element for mounting the short are lamp unit within the housing.

FIG. 3 is an enlarged fragmentary sectional view taken on the encircled portion of FIG. 1.

Referring to FIG. 1, the short are lamp envelope is indlcated generally at 10, while the housing therefor or sealed beam unit is indicated generally at 11. The envelope 10 of the short are lamp is constructed to form a central enlarged gaseous discharge section 12 and

end sections

13 and 14. An anode rod 15 of refractory material, such as tungsten, is mounted axially within the end section 13 and has an inner anode 16 located within the discharge section 12 while a cathode rod 17, which may be formed of the same or a similar material, is mounted axially of the end section 14 and has a cathode 18 located within the discharge section 12 and spaced from the anode 16 to provide a suitable are between the tip ends of 16 and 18. Although not shown in the drawings, the anode rod 15 and cathode rod 17 Will be understood to be sealed in the

respective end sections

13 and 14 of the envelope and the anode 16 and cathode 18 may be shaped and treated as desired to provide for extended usage of the unit.

The housing 11 for the unit 10 is formed of a pressed glass shell 20 which forms the lens section of the assembly and a pressed glass parabolic shell 21 which forms the reflector section of the assembly and for this purpose has its inner face provided with a reflecting surface or coating 22. The

shells

20 and 21 are each formed with a hollow neck portion which provides axial extensions for receiving the end portions of the envelope 10. As shown in FIG. 1, the neck portion 23 extends outwardly from the shell 20 while the neck portion 24 extends outwardly from the shell 21 and is positioned diametrically opposite the neck portion 23. The neck portion or extension 23 has its outer end formed to provide a hollow stem or sleeve 25 while the outer end of the neck portion or extension 24 is provided with a similar hollow stem or sleeve 26. The anode rod 15 is provided with a separate outer end portion 15' and is interconnected therewith by an expansion joint 27 which is formed of conductor material and C-shaped in order to be flexible and similarly the cathode rod 17 has a separate outer end portion 17' which is similarly connected with cathode rod 17 by element 28. The outer end portion 15' of the anode rod 15 is mounted in the stem or sleeve 25 in fixed and sealed relation therewith while the outer end portion 17' is mounted in the stem or sleeve 26 in fixed and sealed relation therewith, consequently the

expansion joints

27 and 28 permit axial movement of the envelope 10 relative to the housing 11. In final assembly, the

shells

20 and 21 will have their peripheral edges fused together as indicated at 29 to provide a sealed chamber including the

neck portions

23 and 24.

Prior to fusing the

shells

20 and 21 and in order to permit the envelope 10 to move relative to the housing 11, a spring sleeve 30 is fixedly secured between the end section 14 of the envelope 10 and the neck portion 24 of the housing 11 and a similar spring sleeve 31 is fixedly secured between the end section 13 of the envelope 10 and the neck portion 23 of the housing 11. The

spring sleeves

30 and 31 may be of any suitable design and, for example, may take the configuration as shown in FIG. 2 in order to provide some resiliency for the lamp assembly and permit its efficient use under shock and vibration conditions. As shown, the spring sleeve 31 of FIG. 2 is of the split ring type having an inner ring or arcuate portion 40 which snugly receives the end section 13 of the envelope 10 and an integral outer ring or arcuate portion 41 which is received within and is snugly pressed against the inner wall of the neck portion 23 of the housing 11. Flexible heavy current leads 42 and 43 are provided for the respective anode and cathode rods through the

couplings

44 and 45.

FIG. 3 is presented to show details of one arrangement for effecting current flow from the

leads

42 and 43 to the anode and cathode and which is described in my prior application Ser. No. 180,421, filed March 15, 1962, for High Intensity Short Arc Lamp. This arrangement consists of a quartz coupling block 50 which is located in each end section of the envelope 10, and for this explanation the block 50 forms a part of the anode 15. The anode 15 as shown in FIG. 3 is formed in two sections a and b which are secured in block 50 and a thin molybdenum ribbon conductor 51 has one end suitably attached to section a to extend between the block 50 and the inner wall of end section 13 of the envelope and its other end positioned between the other section b of anode rod and a quartz collar 52 mounted on section b. After assembly of the described elements, the end section 13 of envelope 10 will be shrunk on to the elements to provide a rigid structure. It will be understood that the cathode rod 17 will be assembled in end section 14 of the envelope 10 in a similar manner.

The described lamp assembly of this invention mini mizes the development of shadow areas over those which would be developed if the short are envelope 10 were to be mounted transversely of the axis of housing 11 rather than longitudinally or axially thereof as shown. Since the short are lamps shown require high voltage of the order of 15 to kv. for starting, the design or configuration of the housing and the described arrangement of the envelope 10 therein produce very good insulation for the starting pulses. The spring sleeves between the short are lamp envelope and the housing provide for ready adjusting of the short are envelope in the housing and permits proper focusing of the light source in order to insure good optical performance of the assembly.

In the lamp assembly shown in FIG. 1, the short arc lamp envelope 10 is ideally provided with xenon gas and is designed for DC. operation and for this purpose the cathode is disposed below the anode as is shown in the figure. Additionally, the reflecting surface 22 is formed of vaporized silver since this has been found to have greater beam intensity than the usual aluminized reflector surface. The lamp assembly which is shown in the vertical position of FIG. 1 may be used for signalling in a horizontal direction by utilizing a plane surface mirror set at an angle of to the light source or the lamp assembly may be used as an omnidirectional beacon by utilizing an inverted conical reflector of 90 apex angle disposed above the lamp source. Also the lamp assembly of FIG. 1 may be disposed horizontally and operated with good stability by providing a magnetic field of suitable intensity and orientation for the assembly.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

quartz tubular envelope having a central gaseous discharge section between end sections, a first conductor rod disposed axially of the envelope and in sealed relation with one end of the envelope, said first rod having its inner end within the discharge section providing an anode and its outer end exteriorly of the envelope, a second conductor rod disposed axially of the envelope and in a sealed relation with the other end of the envelope, said 1. A gaseous discharge lamp and housing therefor in V combination, said discharge lamp comprising an elongate second rod having its inner end within the discharge section providing a cathode spaced from said anode and its outer end exteriorly of the envelope, said housing being formed of a parabolic reflector shell and a light transmissive shell, said reflector shell having a first tubular extension centrally thereof, said transmissive shell having a second tubular extension centrally thereof, said shells having their rim edges secured together positioning said extensions in diametrically opposed relation, said envelope extending axially of the housing with its end sections disposed within the tubular extensions and end portions of the conductors disposed exteriorly of the extensions, securing means fixing and sealing the conductors in the tubular extensions and an expansion joint in at least one of said conductors permitting axial movement of the envelope relative to the housing.

2. The combination of discharge lamp and housing as in claim 1, further characterized by means between the lamp envelope and the housing for guiding the envelope in its axial movement.

3. The combination of discharge lamp and housing as in claim 1, further characterized by a first sleeve means between one end section of the lamp envelope and the first tubular extension of the housing and a second sleeve means between the other end section of the envelope and the second tubular extension of the housing for guiding the envelope in its axial movement.

4. The combination of discharge lamp and housing as in claim 3, further characterized by said first and second sleeve means each comprising an inner ring for snugly receiving an end section of the lamp envelope and an integral outer ring for reception within a tubular extension in snug engagement with its inner wall.

5. The combination of discharge lamp and housing as in claim 1, further characterized by said expansion joint being formed of conductor material which is generally C-shaped to provide flexibility and connected to separate sections of said one conductor.

6. The combination of discharge lamp and housing as in claim 1, further characterized by said securing means for fixing and sealing the conductors in the tubular extensions comprising a hollow stem formed in the end of each extension.

7. The combination of discharge lamp and housing as in claim 1, further characterized by the parabolic reflector shell having its inner surface coated with vaporized silver.

Thouret Mar. 7, 1961 Story Dec. 17, 1963

Claims

1. A GASEOUS DISCHARGE LAMP AND HOUSING THEREFOR IN COMBINATION, SAID DISCHARGE LAMP COMPRISING AN ELONGATE QUARTZ TUBULAR ENVELOPE HAVING A CENTRAL GASEOUS DISCHARGE SECTION BETWEEN END SECTIONS, A FIRST CONDUCTOR ROD DISPOSED AXIALLY OF THE ENVELOPE AND IN SEALED RELATION WITH ONE END OF THE ENVELOPE, SAID FIRST ROD HAVING ITS INNER END WITHIN THE DISCHARGE SECTION PROVIDING AN ANODE AND ITS OUTER END EXTERIORLY OF THE ENVELOPE, A SECOND CONDUCTOR ROD DISPOSED AXIALLY OF THE ENVELOPE AND IN SEALED RELATION WITH THE OTHER END OF THE ENVELOPE, SAID SECOND ROD HAVING ITS INNER END WITHIN THE DISCHARGE SECTION PROVIDING A CATHODE SPACED FROM SAID ANODE AND ITS OUTER END EXTERIORLY OF THE ENVELOPE, SAID HOUSING BEING FORMED OF A PARABOLIC REFLECTOR SHELL AND A LIGHT TRANSMISSIVE SHELL, SAID REFLECTOR SHELL HAVING A FIRST TUBULAR EXTENSION CENTRALLY THEREOF, SAID TRANSMISSIVE SHELL HAVING A SECOND TUBULAR EXTENSION CENTRALLY THEREOF, SAID SHELLS HAVING THEIR RIM EDGES SECURED TOGETHER POSITIONING SAID EXTENSIONS IN DIAMETRICALLY OPPOSED RELATION, SAID ENVELOPE EXTENDING AXIALLY OF THE HOUSING WITH ITS END SECTIONS DISPOSED WITHIN THE TUBULAR EXTENSIONS AND END PORTIONS OF THE CONDUCTORS DISPOSED EXTERIORLY OF THE EXTENSIONS, SECURING MEANS FIXING AND SEALING THE CONDUCTORS IN THE TUBULAR EXTENSIONS AND AN EXPANSION JOINT IN AT LEAST ONE OF SAID CONDUCTORS PERMITTING AXIAL MOVEMENT OF THE ENVELOPE RELATIVE TO THE HOUSING.