US2472865A - Gaseous discharge device - Google Patents

Description

June 14, 1949.

P. w. sTUTsMAN GASEOUS DISCHARGE DEVICE Filed Feb. 26., 1946 m l I 1 1 I in.. 'Hh hh lh. i. Il

| Il I w swr-MAN Patented June 14., 1949 assigner to.

Raytheon Marnfa'turingf.y Coinl any; Newfh, Massi, a corporation' of Delaware Th-is-Y invention relates to gaseous-discharge deA vicesand more particularlyl to suchdevices knownv tion with internal combustion motors. employed nvautomobilesand other types yof ground vehicles1v How--y ever, attempts to use such` devices fory aircraft. The reason.for

has attained a certain degree ofsuccess.

motors have` met with failure. this resides in the inability ofthe. device to With:- st andthe tremendous vibrations associated with aircra-ft motors. I u

It is,v therefore, themain object of this inventionrto provide a device of the type described which can be used in connection with all types. of` internal combustion motors.-

Another object is-to provide a device-Which Vcan remain operative over substantial periodsv of time under vibrations which result in accelerations ashigh as 1,000 gravties.

A further object is to provide a device of the type described in which the envelopethereof constitutes a cathode. v n These objects are attained,V in accordance with thefgeneral aspect of the invention,- by providingy a device, the envelope of which constitutes a cathode of. cold rolled steel,l for example,4 theA entire structure when assembled resulting in a very rigid device.

With the above and other objects in View,v the embodiment of the invention will be best understood by reference to the following specication and illustration in the` accompanying drawing, in which the singlegure is a cross-sectional view ofthe invention. l y y v Referring now more particularly to said gure, the device comprises a metallic envelope or cathode Ill,y `which can be of cold rolled-steel, forI ex-v4 ample, or other equally refractory metal. Said envelope or cathode contains an ionizable gas; which may be helium at a pressure of the order of 3` centimeters. Attached to the innerrwall of saidlcathode I isa relatively thin metallic strip I I, which may be composed of nickel forv example. Attached. to said strip Il is one or more hollow iron Wires I2 containing therein an electronemissiveV material which may be metallic barium'. Aperturas I3 are provided in said wires I2 whereby the active material therein may be readily released.

Mvans..rfor evacuatinglthecathode I- 15J-pro-i 55 bei'. 20E that yibratiorisrci?.l sch11ixrteffsityf and# vided-bythe opening-@Iii in the uppermost. end of said cathode. to whichy is attached a vitreous tubulation (.notshown)v, said'` tubulation being.v

sealedoif` to forman vairtight A vitreous material to-metal seal I5. As -added\ protection for saldi seal I5, acapfI-S is placed over saidl seal- `and affixed-to the-cathode: IIL

In Y order toconfine the discharge ywith-in the down and attachedjtoythe cathode` l' I fto-fiorme a hollow chamber, with the linner Wall of :said-'cathJ` ode.` Extending-. away from fthe-inside or cathodeI I0 isa pair of tubular membersl I8 attached-to said member Il.. theV members I8l sur-roundingik Witha/snug frtavpaircfextended vitreous.tubu-p larvmembers- ISLr Said. members.- I9 may/beV inte-i g-ralr` withn or fused to am. electrode supporti-ng,4

member or but-ton. 20;. said y supporting. memberbeing composed-ctvitreous-or other insulating. materials Positioned. within the 'tubular mem.-

bers I9- and inintimatefcontact therewithf arev metallic anodeshielding-members-2|; said last-l named members being imbeddedsa-id electrode supportingmember 20. Ihnthe center ofthe shielding. members I91are anodes o 22, said fanodesi bei-ng. preferably composedy of carbon,` andbeing bers 2I..afdistance whichvissufciently small'so'u that'a-discharge-.Will notl ordinarily occur in the@V space betweenthem.; y

'Tubular-l members I8,: tubular A shielding mem-f bers 2l'. and electrodes 22 are so'positionedtl'iat the-upper endsthereof: are substantially iiushfvr with the upper surfaceofmember II.`r The' dis#- tancerequired betweenv they outer surfaces of? shieldingmem-bers 2|. and. the* inner surfaces' of tubularvmembers I8-andthe heightof tubular* members I 9 surroundingsaidl shielding .members '2 Is' .will lbe explained-further along.-

An annular member 25 is rmly attached, as for'.` example, by welding, .toasecondV annular mem= ber 2li;A Member'25 in. turn is fused .to the/vitreous electrode supporting' member'ZU which is inthe form ofabutton molded within the: annularzmmeber 26, .and aflange Zf'Ifformed onv the.v memberl 26 is weldedv Within the ange'forinedl ons thel disk-r I l. The foregoingfarrangement'of thefparts just described-provide avery-rigid'assembly.'Av T61 22 vand electrode slrields.y 2|,.said elementsfaffef madeshort enough;adaresoimbeddedinfeiif periodicity as are encountered in aircraft motors will not deform or destroy them. In addition to the foregoing arrangement for insuring rigidity of the electrodes, the turned down edge of disk member i1 is firmly attached, for example, by welding, to the lower open portion of the cathode i3. The tubular extensions I8, which are attached to member i7, further reinforce the rigidity of the structure by their intimate contact with members i9 which in turn reinforce members 2 I. Now, when the cathode I0 is slipped over the aforementioned group of elements, a flange 29 formed on said envelope is welded to a flange 28 formed on the member 25. The result is a compact, rigid unitary structure. Lead wires 23 are attached by soldering or other means to a pair of flexible electrically conductive wires 30. Another flexible lead 3l is soldered or otherwise amxed to annular member 25 to provide means for the conduction of electrical current to the cathode i6. The use of electrically conductive flexible leads is desirable, since thepresent olevice is not intended to be mounted in a supporting socket as is ordinarily done in connection with non-vibrating equipment.

A feature of this invention is the use of the metallic envelope IS as a cathode. It was found that devices of the type herein described, when comprising an envelope containing a cathode supported in the usual manner and used in connection with ignition systems mounted on aircraft motors, were unable to withstand the tremendous vibrations generated by said aircraft motor. If the cathode were supported within a glass envelope, said cathode would invariably :"f

burst through the envelope. Attempts to use a metal envelope only resulted in the destruction of the cathode, when supported in a like manner within said envelope. However, the rigid construction of the present device as described herein provides an assembly well able to withstand vibrations resulting in accelerations of the order of 1,000 gravities.

Another feature of this invention is the spacing of the anode shields 2| with respect to the tubular extensions i8 of the member Il and the height of the vitreous tubular members I9 with respect to the surface of said member Il. In order to prevent the accumulation of electron emissive particles from building up a short circuit path between the anode shields 2l and the tubular extensions l 8, the distance between these elements is less than the mean free path of said particles. Hence, a particle entering the spaces between the elements i8 and 2l will suffer insuicient elastic collisions with gas molecules to enable it to reach the member I9 before depositing upon either of said elements. However, the distance between the tops of the vitreous tubular members I9 and the effective surfaces of member il is at least twice the distance between members I8 and 2i, said last-named spacing allowing the particles, should any of them fall into the space between members i8 and 2l, to be attracted to the inner surface of either of said last-named members before they can fall to the bottom of the recess formed by the members i8, I9 and 2|. This arrangement of the electrodes prevents a short circuit due to the deposition of particles between the anode shielding members 2l and the cathode tubular members I8.

While one embodiment of this invention has been described and illustrated, it is of course understood that many modifications and alterations may be made wherein the relation of various electrodes may be altered to achieve the pri'- mary concepts of this invention; therefore, the constructional limits of the invention are to be confined within the scope of the appended claims.

What is claimed is:

1. A gaseous discharge device comprising an envelope containing an ionzable gas, at least one electrode supported within said envelope, means for supporting an electron-emissive material within said envelope, shielding means electrically insulated from and surrounding said electrode, insulating means surrounding said shielding means, and electrically conductive means surrounding said insulating means, said insulating means being shorter` than said shielding and conductive means to provide an annular space between said last-named means which is less than the mean free path of the particles of said electron-emissive material, said insulating means being terminated a distance from the effective ends of said shielding and conductive means which is at least twice the distance between said last-named means.

2. An electrode assembly comprising an electrode imbedded in a button of insulating material, an electrically-conductive annular member fused to the outer periphery of said button and extending upwardly therefrom, a second electrically-conductive annular member flanged at its edge and welded to the upwardly extending portion of said first-named annular member, an electrically-conductive tubular member surrounding said electrode and insulatedly spaced therefrom by said button, and a second electrically-conductive tubular member surrounding said first-named tubular member and being insulatedly spaced from the latter by said button.

3. A gaseous discharge device comprising an electron-emissive envelope, said envelope having an open end terminating in a flange, at least one electrode imbedded in a button of insulating material, an electrically-conductive annular member fused to the outer periphery of said button and extending upwardly therefrom, a

1 second electrically-conductive annular member flanged at one edge thereof and welded to the upwardly extending portion of said first-named annular member, an electrically-conductive disk having an aperture in register with the effective end of said electrode and being welded within the open end of said envelope, an electricallyconductive tubular member having one end thereof welded to the aperture in said disk and the other end resting on said button, said tubular member being electrically insulated from and surrounding said electrode, a second electricallyconductive tubular member disposed between said last-named insulating means and electrically insulated from said electrode, said second conductive tubular member being supported at one end thereof by said button, and said envelope being welded at the flange thereof to the flange of said second annular member to form a rigid unitary structure.

4. A gaseous discharge device comprising an electron-emissive envelope, said envelope having an open end terminating in a flange, at least one electrode imbedded in a button of insulating material, an electricallyconductive annular member fused to the outer periphery of said button and extending upwardly therefrom, a second electrically-conductive annular member flanged at one edge thereof and welded to the upwardly extending portion of said first-named annular member, an electrically-conductive disk having an aperture in register with the effective iai', the ange thereof to the flange of said second end of said electrode and being welded Within vannular member to form a rigid unitary structhe open end of said envelope, an electricallysture.

conductive tubular member having one end PAUL W. STUTSMAN. thereof welded to the aperture in said disk and 5 the other end resting on said button, an insulat- REFERENCES CITED ing tubular member integral with and extending The fouowing references are of record 1n the upwardly from said button, said last-named infue of this patent;

sulating member tting snugly Within said firstnamed conductive tubular member, a second elecl0 UNITED STATES PATENTS trically-conductive tubular member disposed be- Number Name Date tween said last-named insulating means and said 1,920 649 Lederer Aug 1 1933 electrode, said second conductive tubular mem- 1,992493 Los Feb '26 1935 ber beingr supported at one end thereof by said 2 134939 Green Dec' 26 1939 button and iitting snugly within said insulating 15 2:4041413 Stutsman Jun; 231 1946 tubular member, and said envelope being Welded

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