Патент USA US2087754код для вставки
July 20, 1937. L J‘ DAVlEs 2,087,754 ELECTRIC DISCHARGE LAMP Filed Oct. 28, 1936 INVENTOR V I Leonard J. Dav: 5 BY we‘! ATT RNEY 2,087,754 Patented July 20, '1937 _ \‘UNITED STATES PATENT OFFICE 2,087,754 ' ELECTRIC DISCHARGE LAMP Leonard J. Davies, Rugby, England, assignor to General Electric Company, a corporation of New York Application October 28, 1936, Serial No. 108,113 In Great Britain November 1, 1935 1 Claim. (Cl. 176-122) ‘ This invention relates to electric discharge lamps and more particularly to lamps in which the discharge takes place in a vapour or gas. It has been found possible to increase the wattage input to such lamps, and thereby in crease the light output and. the intrinsic bril liancy of the lamp, by operating them under arti ?cially cooled conditions. Since for high effi ciency such lamps are constructed‘ to operate on m voltages of between 100 and 1000 or even higher, with some liquids used for cooling, and especially if water is used, electrolysis currents may ?ow in the water between the lead in wires to the lamp. While this is not detrimental to the light 15 output or to the e?iciency, since only a small portion of the total energy is consumed in elec trolysis, it does give rise to trouble connected with the inleads to the lamp, for these are rapidly dissolved and the lamp fails through this reason. 20 This electrolysis may be prevented by preventing _ access of liquid to the leads by shielding them with insulating material, but in order to cool the seals of the lamp it is desirable that the cooling liquid should have free access to the leads, or method of capping the lamp, in such a way that the caps can be put on with the lamp held in a jig, so that the light center is always symmetri cally axial and at the correct distance from the caps, which means that the lamp can be easily 5 plugged into a holder situated in an optical de vice where it is important to secure the correct location of the light source. The large size of such caps furthermore mean that considerable electrolysis can take place before any serious 10 diminution in the size of the inleads occurs. Fur thermore the thermal conduction along the in lead secures that the actual seals in the lamp are kept at a reasonably cool temperature and pre vent trouble arising from the melting, or destruc- 15 tion by heat of the seals. . If it is desired to prevent electrolysis completely then such caps or “enlarged” inlead wires may be painted with an insulating paint or varnish or coated with vitreous enamels, since the large area 20 ensures su?icient cooling of the inleads even though thermal conduction is hindered by the presence of a poorly conducting varnish or enamel. ‘ 25 that the leads should be so designed that even if they are protected by a coating of poor ther mal conductivity they can lose a good deal of A further feature of the cap additions to the 25 lamps, described above is that they can be ar ranged to‘ extend over the lamp for varying dis heat to the liquid. The object of this invention is to provide an 30 improved arrangement of lead-in wire and ter tances and thus by the heat shielding they offer, a?ect the electrical characteristics of the lamp, minals for such lamps so that they can be op erated in cooling mediums in which electrolytic action may take place without the inleads being affected. 35 The lamps to which this invention applies more speci?cally are, to give a typical example, constructed of quartz of approximately 1A" in diameter and are tubular in shape. An electrode is sealed in at each end and inleads correspond 4O ‘ing to these electrodes extend from each end. To overcome the trouble due to electrolysis dis solving away these inlead wires, and also to pro vide a lamp that is readily interchangeable in a suitably designed holder I propose extending 4 01 the tubular shape of the lamp at each end by tubes of copper or other high conductivity metal, or metal designed specially to reduce electrolysis. To support these extension pieces and to provide electrical and thermal conduction from the in 50 leads to them, the space in between the inlead which passes down the centre of this tube and the inner wall of the- tube is ?lled with a good conductor of electricity of a suitable nature, such as lead. The extension is further secured by 55 paste if necessary. This provides a simple should such‘ a control be found desirable. In the drawing accompanying and forming" part of this speci?cation an embodiment of the invention is shown in a side elevational, partly sectional View. 35 Referring to the drawing the'gaseous electric discharge device comprises an elongated tubular container l having an outside diameter of about one quarter of an inch. Said container i has electrode chambers 3 and 4, one at each end thereof. Said electrode chambers 3 and 4 have electrodes 5 and 6 mounted therein, respectively, and a quantity P2 of mercury therein in which the electrodes 5 and b are immersed for the greater part of their length. The structure and 45 operation of gaseous electric discharge lamp de vices of this type are described in the co-pending application of Cornelis Bol, Willem Elenbaas, and Hendricus J. Lemmens, Serial No. 46,952, ?led October 26, 1935 and assigned to the assignee of 50. the present application. The lamp illustrated is provided with and mounted in a ?uid cooling system (not shown for purposes of simplicity.) Metal tubes 1 and 8 are mounted on said elec trode chambers 3 and 4, respectively, and said 55 2 9,087,754 tubes 1 and 8 are coaxial with the current leads 9 and HI, respectively. Each of said tubes 1 and 8 are made of metal having good electrical con ductivity characteristics, such as copper. The 5 space between the tubes 1 and 8 and the leads 9 and Ill, respectively, is ?lled with a metal body ll having good electrical conductivity charac What I claim as new and desire to secure by Letters Patent of the United States is: A gaseous electric discharge device comprising in combination a tubular- container tapered at each end, electrodes and electrode leads sealed therein, a vaporizable material therein,v a current lead extending therefrom, a tube of electrically ' conducting material surrounding said current The advantages and modi?cations of lamps ' lead, said tube being appreciably larger in diam 10 of the above type have been pointed out above eter than said current lead and having approxi 10 and it will be understood of course that I con mately the same diameter as said container, the template that still i'urther changes and modi? tapered end of said container extending into cations may be made in the device illustrated and said tube and an electrically conducting solid described without departure from the spirit and body ?lling said tube. 15 scope of the invention. LEONARD J. DAVIES. 15 teristics, such as lead.