US2249094A - Electric discharge tube - Google Patents

Electric discharge tube Download PDF

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Publication number
US2249094A
US2249094A US317603A US31760340A US2249094A US 2249094 A US2249094 A US 2249094A US 317603 A US317603 A US 317603A US 31760340 A US31760340 A US 31760340A US 2249094 A US2249094 A US 2249094A
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US
United States
Prior art keywords
lamella
rod
chamber
discharge tube
arc
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US317603A
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English (en)
Inventor
Seitz Ernst Otto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Quarzlampen GmbH
Original Assignee
Quarzlampen GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Quarzlampen GmbH filed Critical Quarzlampen GmbH
Application granted granted Critical
Publication of US2249094A publication Critical patent/US2249094A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/04—Electrodes; Screens; Shields
    • H01J61/06—Main electrodes
    • H01J61/073—Main electrodes for high-pressure discharge lamps
    • H01J61/0732—Main electrodes for high-pressure discharge lamps characterised by the construction of the electrode

Definitions

  • a cathode provided with these features possesses the required characteristics to a marked degree; this is because owing to the good thermal contact between the disks and the rod, the heat will be readily and rapidly conducted away from each individual disk to the rod. Furthermore, relatively large amounts of activating material can easily be placed on the electrode owing to the fact that the lamella are mounted above each other with small spaces between them, so that impoverishment of the said activating material can only occur after very long periods of use. Due to the presence of the rod, which extends through the lamella, there is, however, produced a supplementary effect which will be discussed hereinafter together with the description of the individual embodiments of the invention.
  • the distance between the lamella is preferably produced by means of protuberances on the lamella.
  • the electrode consists of a single zig-zag folded sheet. In this case also the hollow spaces between the individual layers serve for the reception of the activating material.
  • Figs. 1 to 3 show longitudinal sections through three different types of the electrodes of the invention.
  • Figs. 4-6 are transverse sectional views of the several embodiments.
  • Fig. 7 shows one of the electrode lamella on an enlarged scale.
  • the electrode I is disposed in the pole chamber 2 of a discharge tube which chamber connects with the illuminating tube 3. Between both of these there is an annular constriction l.
  • the electrode consists of a rod 5 of refractory metal, e. g. tungsten or molybdenum, positioned coaxially within the pole chamber and upon this red is mounted a large number of circular metal lamella 6 made, for example, of molybdenum, the holes in the lamella being of such size that they fit just snugly upon the rod 5.
  • a diameter of 2 to 3 millimeters, and a thickness of .1 millimeter has furthermore, are provided with a number of protuberances which are pressed out by an embossing operation. These are for the purpose of preventing the lamella from stacking tightly against each other.
  • a small space is produced between the individual lamella so that a large amount of activating material can be carried by the-electrode without fear of flaking off;
  • the protuberances 1 can be dispensed with if the individual lamella are bent up in irregular fashion or are provided with an embossed edge, irregularly disposed, so that at the time they are assembled they will not be able to lie against each other without leaving a space.
  • the necessary space between them can also be produced by initially positioning the individual lamella loosely and in spaced relation on the rod, and then'dipping the structure into a paste and then forcing the lamella together. In this manner an adequate but not excessive amount of activating material will be provided on the electrodes.
  • the lamella are held together by the rod 5 which at its upper end is notched, or bent over, or provided with a lug. In this case, it is preferable to keep them slightly pressed together so that they will make good con tact between themselves and with the rod and act as good conductors both for the electric current as well as for heat.
  • the rod is preferably used as a conductor, e. g. as a fused-in "lead-in insofar as this is possible.
  • the wall of the tube is not made of glass but rather of quartz, it is more advantageous to use thin foils I made of molybdenum and less than 20 microns thick which are fused in vacuum-tight relation into a capillary tube 9 of suitable size.
  • a suitable connection between the rod and the foil This can be effected, for example, by folding over the upper end of the foil 8.
  • the rod 5 Prior to fusing the foil in place, the rod 5 is inserted into the fold through a hole in the folded portion. The pressure of the atmosphere alone is suflicient during the fusion to eil'ect positive connection between rod 5 and foil 8.
  • any other type may be used.
  • the arc strikes over towards the rod since this offers a somewhat shorter path to the arc.
  • the operating voltage decreases about 20 volts. From this time on the arc plays exclusively on the rod.
  • the heat produced by the arc can, therefore, be conducted away without requiring a thermal path between two metal parts on the cathode, and which would interpose a certain amount of resistance to the heat conduction. Since the rod extends only slightly beyond the surface of the lamella, its supply of activating material can be continually replenished from the lamella.
  • the heat imparted to the cathode by the are (as soon as the arc has become a high pressure are) need no longer find its way over the thin lamella but rather solely through the rod, and without hampering the outflow of heat which would otherwise be caused by a thermal path on the cathode produced by two contacting metal portions.
  • Figs. 1 and 4 the lamella are shown as resting against the bottom of the pole chamber.
  • a space can be left between thelamella and the bottom of the pole chamber.
  • a tube may be inserted to keep the lamella at a distance from the bottom of the pole chamber, or else the rod can be bent in the form of a loop, or the rod may be squeezed fiat between the lamella and the bottom of the pole chamber to hold the lamella spaced from the bottom of the pole chamber.
  • the activating mass consists essentiallyof barium oxide to which other oxides or metals may be added in order to prolong its life. amount of mercury is introduced into the discharge tube and this is completely converted to vapor during operation with the formation of a highly superheated pressure vapor. Argon under 9. pressure of a few millimeters may be placed in the tube to serve as a starter.
  • Figs. 2 and 5 differ from the preceding in that in lieu of the circular lamella 6, square shaped ones III are used. Stacking the squares irregularly results in providing the necessary large surface-for the reception of the oxide so that, if desired, the use of protuberances or similar separatory means may be dispensed with, although in Fig. 2 embossed spacing protuberances I similar to those shown in Fig. '7 are illustrated.
  • Figs. 3 and 6 a plurality of individual lamella are not stacked in superposed relation as in the preceding figures.
  • the electrode I rather consists of a strip of refractory metal folded up in zig-zag fashion and forced upon rod 5.
  • the spaces between the individual layers permits the housing of a large quantity of oxide.
  • the advantage of this arrangement is that the conduction of heat from the point at which the arc strikes and the transmission resistance offered to the electric current from the sheet metal to the rod are very low.
  • the foil 8 is turned 90 with respect to that shown in Figs. 1 and 2 so that it is obvious how the rod rests within the folds. Otherwise what has been said in respect of Figs. 1 and 4 applies equally well to Figs. 2 and 3.
  • the electrodes of the invention will operate satisfactorily even if they are only a few millimeters in size, they are adaptable for use in the so-called super high pressure lamps. In such lamps the amount of space available in the pole chambers is very small.
  • the invention may be usedespecially for such discharge tubes as are employed as ultra violet ray producers intended for therapeutic or technical purposes, or as light sources.
  • a high pressure electric arc discharge tube walls forming a chamber, an electrode extending into the chamber from a wall and comprising a rod of refractory metal to serve as a current lead, a plurality of lamella of refractory metal mounted on said rod with their faces slightly spaced apart from the adjacent faces of adjacent lamella, the spaces between said lamella containing oxide, said rod extending through central portions of said lamella in heat transfer relation thereto, and the rod extending inwardly slightly beyond all parts of the end lamella at the .chamber end of the electrode to serve as a termi- A certain as a current lead, a plurality of lamella of refractory metal mounted on said rod, said lamella having protuberances maintaining the adjacent facesof adjacent lamella slightly spaced apart, the
  • a high pressure electric arc discharge tube walls forming a chamber, an electrode extending into the chamber from a wall and comprising a rod of refractory metal adapted to serve as a current lead, a thin sheet of refractory metal folded to zig-zag form mounted on said rod with the rod extending through central portions of the several plates of said sheet, the spaces between the faces of thezig-zag formation containing oxide, and the rod extending slightly beyond all parts of the end plate face of the zigzag formation at the chamber end of the electrode to serve as a terminal for the arc in operation and the zig-zag metal sheet serving to substantially uniformly dissipate the heat radially from the rod.
  • an electrode comprising a rod of refractory, electroconductive material of high heat conductivity, and sheet-like elements having large surface areas spaced apart and mounted on said rod with said rod extending through central openings thereof and in heat transfer connection therewith, the spaces between said elements containing an activating oxide and the rod extending inwardly beyond all parts of the innermost of said elements and serving as a terminal for the arc in operation while said elements serve for,
  • a plurality of lamella of refractory metal mounted on said rod said lamella be ing of non-circular form and being non-coaxially positioned so that large surface areas of said lamella are free of contact with each other, the spaces between the free surface areas of the lamella containing oxide and the rod extending slightly beyond theinner lamella within the ,chambenthe rod serving as a terminal for the arc in operation and the lamella serving to dissipate the heat from the rod.
  • a high pressureelectr'ic arc discharge tube according to claim 1, and in which the lamella have large surface areas spaced apart, the spaces between said elements containing barium oxide as an activating substance.
  • a high pressure ele'ctricarc discharge tube according to claim 1, and in which the chamber contains mercury and argon.
  • a high pressure electric arc discharge tube walls forming a chamber, an electrode extending into the'chamber from ,a wall and comprising a rod of refractory metal to serve as a current lead, a plurality of lamella of refractory metal mounted on said rod in stacked relation, said lamella having protuberances on their faces serving to maintain their faces slightly spaced apart from the adjacent faces of adjacent lamella, the spaces between said lamella containing 1 oxide, and the rod extending inwardly slightly prising a rod of refractory metal adapted to serve as a current lead, a plurality of lamella of refractory metal mounted on said rod in stacked relation, said lamella having embossed protuberdissipate the heat from the rod.

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  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamp (AREA)
US317603A 1936-08-04 1940-02-06 Electric discharge tube Expired - Lifetime US2249094A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1936Q0002124 DE694486C (de) 1936-08-04 1936-08-04 Elektrische Hochdruckmetalldampfentladungsroehre

Publications (1)

Publication Number Publication Date
US2249094A true US2249094A (en) 1941-07-15

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Application Number Title Priority Date Filing Date
US317603A Expired - Lifetime US2249094A (en) 1936-08-04 1940-02-06 Electric discharge tube

Country Status (5)

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US (1) US2249094A (en(2012))
DE (1) DE694486C (en(2012))
FR (1) FR824959A (en(2012))
GB (1) GB488516A (en(2012))
NL (1) NL47141C (en(2012))

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2499506A (en) * 1944-09-11 1950-03-07 Gen Electric Electric discharge device and electrode therefor
US2542348A (en) * 1949-09-16 1951-02-20 Gen Electric Electrode structure
US2606307A (en) * 1946-01-29 1952-08-05 Marshall C Pease Tunable magnetron
US2667592A (en) * 1951-01-11 1954-01-26 Hanovia Chemical & Mfg Co Electrode for compact type electrical discharge devices
US2682007A (en) * 1951-01-11 1954-06-22 Hanovia Chemical & Mfg Co Compact type electrical discharge device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE931970C (de) * 1950-10-21 1955-08-22 Max Boie Raumsparende Elektrode fuer Leuchtroehren

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2499506A (en) * 1944-09-11 1950-03-07 Gen Electric Electric discharge device and electrode therefor
US2606307A (en) * 1946-01-29 1952-08-05 Marshall C Pease Tunable magnetron
US2542348A (en) * 1949-09-16 1951-02-20 Gen Electric Electrode structure
US2667592A (en) * 1951-01-11 1954-01-26 Hanovia Chemical & Mfg Co Electrode for compact type electrical discharge devices
US2682007A (en) * 1951-01-11 1954-06-22 Hanovia Chemical & Mfg Co Compact type electrical discharge device

Also Published As

Publication number Publication date
FR824959A (fr) 1938-02-21
NL47141C (en(2012)) 1939-11-15
DE694486C (de) 1940-08-02
GB488516A (en) 1938-07-08

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