US2781470A - Electrical connection means - Google Patents

Description

Feb. 12, 1957 E. M. BELLOTT ELECTRICAL CONNECTION MEANS Filed Oct. 21, 1955 INVENTOR United States Patent ELECTRICAL CONNECTION MEANS Emile Melvin Bellott, Little Rock, Ark., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Application October 21, 1955, Serial No. 542,116

8 Claims. (Cl. 313-112) This invention relates to connectors for electrical lamps and more particularly to means for making electrical connection to multiple foil quartz lamps.

in the fabrication of multiple foil seal quartz lamps, one of the outstanding difficulties encountered is the provision of suitable means for making proper electrical Contact to the lamp electrodes and for providing sufficient mechanical strength and stability for such contact. Heretofore, a conventional device for making such electrical and mechanical contact has been a split compression type ring. However, with present lamps such as mercury vapor lamps operating at high currents and elevated temperatures, the use of the split compression type ring results in the overheating of the lamp seal, the oxidation and burning of the thin ribbon foils (usually molybdenum), and consequent failure of the lamp.

Accordingly, it is the primary object of the present invention to provide a means for making electrical connec tion to the electrodes of a quartz vapor type lamp Wherein large currents can be carried, high temperatures tolerated and wherein lamp failure is prevented due to overheating, oxidation, and burning of the foil ribbons.

It is another object to provide a means for making positive electrical contact with the ribbon foils of a multiple foil quartz lamp.

It is still another object to provide a means of making electrical contact with the electrodes of a multiple foil quartz lamp which is of rugged mechanical construction and which may be utilized in centering the lamp.

in accordance with the present invention, there is provided in combination with a lamp comprising a vitreous envelope wherein each of the electrodes contained therein is maintained in contact with one end portion of a plurality of electrically conductive ribbon foils and the other end portion of the plurality of foils extends beyond the envelope, means for making electrical connection to the electrodes. The latter comprises an electrically conductive filamentary element closely wound about the other end portion of the ribbon foils and a ring comprising an electrically conductive material intimately embracing the wound wire.

Also in accordance with the present invention, there is provided in combination with a lamp comprising a qnartz envelope having opposed aligned narrow extremities. The lamp includes a plurality of spaced electrodes therewithin having opposing faces, the electrodes extending partially into the extremities. A plurality of molybdenum or other suitable metal ribbon foils have one end portion in contact with each of the electrodes and the other end portion of the foils extend to a point without the envelope. A quartz member partially extending into each of the extremities serves to position firmly the intermediate portion of the foils within the extremity and provides a support for the other end portion. Means for connecting the electrodes to a source of electricity is provided and comprises an electrically conductive wire closely wound about the other end portion of each of the foils, a member consisting of an electrically con- 2 ,781,470 Patented Feb. 12, 1957 ductive material engirdling the wound wire and in soldered contact therewith, and means for connecting the electrically conductive member to a source of electricity.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a side elevation of a preferred embodiment of the present invention; and

Fig. 2 is a sectional view of the device depicted in Fig. 1.

Referring now to Figs. 1 and 2, the lamp 10 comprises a vitreous envelope which may preferably consist of quartz. Two extremities 12 and 14 extend from diametrically opposed portions of a bulb 16 and are in aligned relationship. The ends of extremities 12 and 14 terminate in enlarged bulbar portions 18 and 20. Positioned within bulb 16 are electrodes 22 whose faces 23 are in opposed spaced relationship. In the case of a vapor type lamp such as a mercury arc lamp, the arc is provided between the faces of these electrodes, the distance therebetween being of a chosen magnitude. Electrodes 22 extend longitudinally into the respective corresponding extremities 12 and 14 substantially as shown. It is understood of course that in a case of a mercury vapor lamp, a well of mercury would be contained inside the bulb (not shown). Inserted within and partially extending from the ends of bulbar portions 18 and 2b are vitreous members 24 and 26, also preferably consisting of quartz. Members 24 and 26 are similar in configuration to that of bulbar portions 13 and 20 so that the respective inner surfaces of the bulbar portions are substantially coincident with the outer surfaces of members 24 and 26. Members 24 and 26 may preferably have respective small necklike portions 28 extending into the extremities to permit the positioning therearound of the ends of electrodes 22 which are usually in the form of hollow cylinders closed at one end by the electrode faces 23. Interposed between the inner surfaces of bulbar portions 18 and 20 and members 24 and 26 is a plurality of conductive ribbon foils 30 which may consist of a high melting point conductive metal such as molybdenum. Foils 30 are longitudinally disposed in a radial array about the periphery of members 24 and 26 and extend from the ends of members 2-6 and 26 through bulbar portions 18 and 2t and along the electrodes in extremities 12 and 1'4 to a point in bulb it) slightly beyond the commencement of the extremities.

As can be seen, foils 3t) tend to converge where the bulbar portions 18 and 20 narrow to the extremities 12 and 14 so that the outer periphery of the electrode areas within the extremities are substantially completely in contact with the foils. Since the extremities l2 and 14 are only a little greater in diameter than the diameter of electrodes 22, the small amount of clearance therebetween serves to maintain the foils in close contact with the electrodes. Wound about the portions of [oils 30 extending from the end of bulbar portions 18 and 29 and supported by underlying members 24 and as is a close winding 32 of an electrically conductive filamentary element, preferably consisting of a material such as soft copper. A bushing type ring 34 of oxidation corrosion resistant and good conductivity material is positioned around winding 32 so that it firmly embraces it and is soldered thereto with a high temperature solder. Ring 34 may preferably consist of nickel, a nickel alloy or the like and may have an end plate 36 consisting of like material. To avoid any cracks occurring as a possible result of solder flowing on to the quartz during the positioning of ring 34 about winding 32, a strip of molybdenum 35 or like material of a thickness say of about 0.002 inch is wrapped around and between the respective member 24 or 26 and foil ribbons prior to winding the latter with wire. To inhibit the flow of solder to regions other than the winding 32 ring 34 junction, the surfaces involved may be given a light coating of a material such as magnesium hydroxide (milk of magnesia). A flexible lead 38 or other suitable device may be utilized to make connection between ring 34 and a source of electricity.

In Fig. 2, there may be clearly seen the disposition of the ribbon foils 30 between members 24 and 26 and the bulbar portions 18 and 20. Also, Fig. 2 illustrates the relationship of ring- 34, copper winding 32, wrapping 35, ribbon foils 30 and members 24 and 26.

It is to be seen that the present invention provides means for making positive electrical contact to the ribbon foils 30 with the winding 32. Ring 34 provides a rugged mechanical feature which may be utilized in the centering of the lamp. The presence of the ring serves to prevent lamp failure as a result of overheating due to oxidation and burning of the foils. Thus, high operating temperatures are possible and high current loads such as 150 amperes or more can be carried.

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:

1. In combination with a lamp comprising a vitreous envelope wherein each of the electrodes contained therein is maintained in contact with one end portion of a plurality of electrically conductive ribbon foils longitudinally disposed in a radial array about the inside of the envelope extremities, the other end portion of said foils extending without said envelope; means for making electrical connection to said electrodes comprising an electrically conductive filamentary element closely wound about said other end portion of said foils and a ring comprising an electrically conductive material intimately embracing said filamentary element. 1

2. In combination with a lamp comprising a vitreous envelope wherein each of the electrodes contained therein is in contact with one end portion of a plurality of electrically conductive ribbon foils disposed between the periphery of the electrodes and the inner surface of the envelope, the other end portion of the foils extending beyond the envelope and being longitudinally supported by a rigid member extending partially into said envelope whereby the intermediate portion of said foils is firmly positioned between the outer surface of said rigid member and the inner surface of said envelope; means for making electrical connection to said electrodes comprising an electrically conductive wire closely wound about said other end portion of said foils and said rigid member, and a member consisting of an electrically conductive material embracing and in contact with said wound wire.

3. In combination with a lamp comprising a quartz envelope having opposed aligned narrow extremities and containing a plurality of opposing spaced electrodes dis posed therewithin, the electrodes extending partially into said extremities, a plurality of molybdenum ribbon foils having one end portion in contact with each of said electrodes, the other end portion of said foils extending to a point without said envelope, a quartz member partially extending into each of said extremity, said quartz member firmly positioning the intermediate portions of said foils within said extremity and providing a support for said other end portion; means for providing connection of said electrodes to an electric source comprising an electrically conductive wire closely wound about said other end portion of each of said foils, a member consisting of'an electrically conductive material engirdling said wound wire and in soldered contact therewith, and means for connecting said electrically conductive member to an electric source.

4. In the combination as defined in claim 3 and further including a foil Wrapping about said rigid member interposed between said ribbon foils and the surface of said member.

5. In the combination as defined in claim 4 wherein said foil wrapping comprises molybdenum.

6. In the combination as defined in claim 3 wherein said wound wire comprises soft copper.

7. In the combination as defined in claim 3 wherein said electrically conductive member comprises a ring and end plate therefor.

8. In the combination as defined in claim 7 wherein said electrically conductive member comprises nickel.

References Cited in the file of this patent UNITED STATES PATENTS 2,200,939 Trebbin et al. May 14, 1940

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