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Publication numberUS2712095 A
Publication typeGrant
Publication dateJun 28, 1955
Filing dateJun 24, 1952
Priority dateJun 24, 1952
Also published asDE940663C
Publication numberUS 2712095 A, US 2712095A, US-A-2712095, US2712095 A, US2712095A
InventorsEdward B. Noel
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Flashtube lamp unit
US 2712095 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

June 28, 1955 E. B. NOEL 2,712,095

FLASHTUBE LAMP UNIT Filed June 24, 1952 Invent/or. Edward B. Nol

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His Atto Hey FLASHTUBE LAMP UNIT Edward E. Noel, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Application June 24, 1952, Serial No. 295,207

Claims. (Cl. 31557) The present invention relates to lamp units incorporating a fiashtube for use in photography and its principal object is to provide a compact unit of this type having a short light center length, positive starting characteristics, a high light output and a rugged structure. Funther objects and advantages of the invention will appear from the following detailed description of species thereof.

Flashtubes require the application of a starting potential thereto to initiate the high voltage discharge between the main electrodes mounted at the ends of the tube. The starting potential is usually applied by an exernal electrode, known as the triggering electrode, engaging the tubular envelope of the fiashtube and a transformer, known as the triggering coil, is used for supplying the required starting potential. According to the present invention improved results are obtained by a construction wherein the triggering electrode and the triggering coil are mounted within the turns of a helically coiled flashtube and constitute part of a support for the fiashtube Within the light transmitting jacket.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown, in which:

Fig. 1 is a perspective, partly sectional view of the lamp unit as seen from above with parts thereof broken away to show the internal structure;

Fig. 2 is a front elevational, partly sectional view on an enlarged scale of the flashtube support and starting apparatus for the flashtube shown in Fig. 1; and

Fig. 3 is a top plan view of the flashtube support shown in Figs. 1 and 2.

The lamp unit shown in the drawing comprises a tubular outer glass jacket 1 closed at one end and having its open end closed by a disc shaped base 2 of electrically insulating material, such as a ceramic material. The base 2 has a flange 3 which is cemented to the open end of the jacket 1. Three metal contact pins 4, 5 and 6 are secured to and project outwardly from the base 2 for connection to a power source. The base 2 is formed with an integral hollow centering pin 7.

The lamp unit also comprises a helically coiled fiaslrtube 8 which is supported within the glass jacket 1 by a metal rod 9 having one end cemented into the hollow centering pin 7 of the base 2. The fiashtube 8 is provided with electrical terminals 10 and 11 in the form of current inlead wires sealed into and extending outwardly from the ends of its helically coiled tubular glass envelope 12.

The structure for supporting the flashtube 8 within the jacket 1 includes, in addition to the base 2 and the rod 9, a triggering coil 13 in the form of a cylindrical transformer having a tubular core 14 of sintered metal powder which is mounted around and attached to the rod 9 at a portion of the rod near its inner end. The supporting structure also includes a triggering electrode in the form of metal sleeve 15, such as an aluminum sleeve, mounted around, gripping and frictionally engagnited States Patent 0 2,712,095 Patented June 28, 1955 ing the transformer 13. The sleeve is split longitudinally as shown at '16 in Fig. 3 to facilitate its mounting on the coil 13 and also to prevent a short circuiting turn effect. The sleeve 15 has outwardly curved support tabs 17 at each of its ends which engage the end turns of the helical flashtube 8 as shown in Fig. 1. The flashtube 3 thus is supported axially with the jacket 2 and all the turns of the helically coiled glass envelope 12 of the fiashtube are in contact with the metal sleeve 15.

The large area of contact between the sleeve 15 and the fiashtube envelope 1'2 facilitates starting of the discharge between the main discharge supporting electrodes mounted in the ends of the envelope 12 and the starting or triggering voltage required is substantially lower than that required when the triggering electrode is in the form of the usual thin wire wound on the turns of the fiashtube, and having a relatively small area of contact therewith. The triggering coil 13 supplying the triggering voltage thus may be of small size suitable for mounting within the turns of the helically coiled tube 12.

The electrical connections between the various electrical elements of the lamp unit are made through the usual current lead wires. The rod 9 is connected to the contact pin 5 by the lead 13, to one side of the primary 19 of the trigger coil 13 by the lead 20, and to the terminal It? at the anode end of the fiashtube by the lead 21. The support rod 9 thus serves as a common, low voltage lead for the flashtube 8 and the trigger coil 13.

The lead 22 of the other side of the primary 19 of the trigger coil 13 is attached to the contact pin 6 on the base 2. The terminal 11 connected to the cold cathode 23 of the flashtube is connected to the contact pin 4 on the base 2 by the short, high voltage lead 24. The short lead 24 is widely separated from the outer leads to avoid fiashovers therebetween. The sleeve 15 is connected to the secondary 25 of the trigger coil 13 by the lead 26.

The above connections are made by soldering or welding the leads to the various metal parts.

The outer surface of the sleeve 15 is smooth to reflect outwardly of the lamp unit the light incident thereon from the fiashtube 8.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A lamp unit comprising in combination, a tubular glass jacket having one open end, a helically coiled flashtube and a support for said fiashtube in said jacket, said support comprising an insulating base provided with electrical contacts and closing the open end of said jacket, said base having also an externally protruding hollow centering pin, a support rod having one end secured within said centering pin and extending from said base axially inward of said jacket, a trigger coil mounted on the inner end portion of said rod and a metal sleeve around and gripping said trigger coil, said sleeve being electrically connected to said coil to serve as a trigger electrode and having at each end a plurality of tabs engaging an outer turn of said flashtube, rality of tabs engaging an outer turn of said flashtube, the said tabs on said sleeve holding said flashtube with the turns thereof in contact with the said sleeve to facilitate ignition of the discharge in said fiashtube, said lamp unit comprising also electrically conducting means connecting said trigger coil and said flashtube to said base contacts.

2. A lamp unit comprising in combination, a tubular glass jacket having one open end, a helically coiled flashtube and a support for said fiashtube in said jacket, said support comprising an insulating base provided with electrical contacts and closing the open end of said jacket, said base having also an externally protruding hollow centering pin, a support rod having one end secured within said centering pin and extending from said base axially inward of said jacket, a trigger coil mounted on the inner end portion of said rod and a metal sleeve around and gripping said trigger coil, said sleeve being electrically connected to said coil to serve as a trigger electrode and having at each end a plurality of tabs engaging an outer turn of said fiashtube, the said tabs on said sleeve holding said flashtube with the turns thereof in contact with the said sleeve to facilitate ignition of the discharge in said fiashtube, said lamp unit comprising also electrically conducting means connecting said trigger coil and said fiashtube to said base contacts, said support rod being electrically connected to one of said contact pins, to a terminal of said fiashtube and to one side of the primary of said trigger coil to serve as a common lead therefor.

3. In a lamp unit comprising a glass jacket and a helical fiashtube within the jacket, a support for the flashtube comprising a support rod, a trigger coil around and attached to said rod and a trigger electrode around and attached to said coil, said trigger electrode being a longitudinally split metallic sleeve, said fiashtube being mounted around said sleeve, said support comprising also a lead connecting one side of the primary of said coil to said support rod and a lead attached to and extending from said rod for connection to a terminal or" said fiashtube.

4. A lamp unit comprising in combination, a glass jacket, a helically coiled flashtube having electrodes at its ends, and electrically conducting means supporting said fiashtube in said jacket, said means comprising a trigger coil and a trigger electrode around said coil and electrically connected thereto, said trigger electrode being a longitudinally split metallic sleeve, said flashtube being mounted on and around said sleeve.

5. A lamp unit comprising in combination, a glass jacket, a helically coiled fiashtube having electrodes at its ends, and electrically conducting means supporting said fiashtube in said jacket, said means comprising a trigger coil and a trigger electrode around said coil and electrically connected thereto, said trigger electrode being a longitudinally split metallic sleeve having a reflecting outer surface, said flashtnbe being mounted on and around said sleeve.

References Cited in the file of this patent UNlTED STATES PATENTS 1,963,963 Barclay June 26, 1934 2,492,619 Casellini Dec. 27, 1949 2,624,858 Greenlee Jan. 6, 1953

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1963963 *Jun 1, 1931Jun 26, 1934Fed Electric CoDischarge apparatus and method
US2492619 *Jan 2, 1948Dec 27, 1949Sylvania Electric ProdElectrical discharge tube
US2624858 *Nov 15, 1948Jan 6, 1953William B GreenleeGaseous discharge lamp
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4463282 *May 10, 1982Jul 31, 1984Federal Signal CorporationFlash lamp
US4791333 *Jan 30, 1987Dec 13, 1988Gte Products CorporationElectric lamp with internal conductive reflector forming part of the circuitry thereof
Classifications
U.S. Classification315/57, 336/192, 313/594, 336/92, 313/25
International ClassificationH01J61/84, H01J61/54, H01J61/90
Cooperative ClassificationH01J61/90, H01J61/545
European ClassificationH01J61/90, H01J61/54B