US2388090A - Electrode assembly - Google Patents

Description

Oct. 30, 1945. w SCOTT ELECTRODE ASSEMBLY Fi led June 22, 1944 Inventor. Edwin W. Scott, b 79 6A4 y His 2t torney.

Patented Oct. 30, 1945 Edwin W. Scott,- scotia, N. L,- essi' noi te Gen- Electric Company, a corporationctNew York "Ap licants-mane 22, 1944, sesame. 5411537" (chast -27.5)

6 Claims.

My invention relates electrode assemblies more particularly to an. improved starting electrode assembly adapted for use with electric discharge devices employinga pool-type cathode.,

Electric discharge devices employing a cathode of conducting liquid and a startingelectrode a portion of (relatively high. resistance material. immersed in' the. liquid have 4 been I widetee Pa t cu ar w 'e large c r nts" Qonsiderable 'Tef has been experienced. with. the starting. lectrodel assemblies y used in. devices or this character. In

lone. the starting electrode assembly ina; support and supply, conductor? in v the form of ametalstrap Whichis bent around the end of the starting electrode at'the end thereof remote from the cathode. The ends ofthe strap eitendlatereuy fi'oin the starting electrode and ar' wit weidedt'ogetherf to close the loop tightbolit the eie trede; 'Wiiil this construction lials g'lvn re sonably good service, there has been ,e tendend for the electrode to become loose in theft-lender siterip'r omnged'service, particularly in; installations where. men eperati'ng t'emperatures, such as sco 'te 1000'" c. are encountered.

Even where the? hoider is formed of a: metal havre nico the difference in expansion" between rorxnbetweeu the holderand the" 'eiectrode. 1 As soonas appreciableioosening occurs; tnestarting actioh oi the electrode becomes erratic and re- Placement or the electrode assembly is required. In accordance witl'i'th'e' teachings er my invention, rprovide anilmproved electrode" structure, of

the type described above; in which the tendency of the electrode to become loose'in the holder is eliminated. v

It lS an object of my invention to provide a new and improved electrode assembly.

It is another object of my invention to provide a new and improved holder for the starting a electrode of an electric discharge device.

It is a still further object of my invention to provide an improved starting electrode assembly for electric discharge devices of the mercury pool type which is characterized by long life and consistent operating characteristics.

For a better understanding of my invention,

reference may be heats the ic11ewing'deseriptien taken in connection witntheeecompanying drawing, and its scope will be pointed out in the appended claims. In the drawing, Fig. 1 illustrats my invention applied tdar'i electric discharge device of the mercury-p601 type; Fig. 2

is an enlarged: view in pers ective of my 1thproved electrode holder, and Fig. '3 is an enlarged. View, partially in section, showing the details of construction of" improved electrode assembly;

Referringnow to the drawing, I have shown my invention inbddid iii an electric discharge deviceeomprising' a meter cylindrical envelope I within. which'is supported anap ode 2 6i graphite or other} suitable'i'natrial. aiiddei generally cylindrical in fo'fm' and has the lower face thereof supported in opposed relation to a cathode'31 which ecmprisesa pool of conducting liquid such as mercury. The anode is supported in insulated relation with respe'et'tc the envelope f by means of a seal construction including a glass sleeve 4 which is sealed to anupstandm flange 5 supported on the upper end of the en} velope I. The upper end of" the sleeve 4 is closed by a metal eaptto which is secured an anode lead-in conductor T. It will be understood that the mode 2 iS supported from the cover 6 by a connecting stud I.

' T'he lower enact the enveiepe I is emsed by a header 8 which may; be resistance welded to the wallsoftheenvlope l'. A starting electrdde 9" is. providedwith the Ievver end thereof iliir'nrsed' in the cathode for the purpose of initiating. a cathode spot when it: isoesired' to initiate conduction by the electficdischarge device; The tip. of the electrode 9 may be any one of e number of" the high resistance composition which have been employed for this urpose and preferably comprise a mixture of high resistance materials such as boron carbide and boron nitride.

j Th starting. eieetre'ae supported ininsulated re aticn with ri spect te tueenvelope lby a suitebiesear censtraction maladies; a metal eyelet changes and modifications as fall' within the trated in more detail in Fig. 2. As illustrated in Fig. 2, the starting electrode 9 includes a cylindrical shank portion I which may be formed of graphite and a starting tip I6 which is formed of a high resistance material or a mixture of such materials. Near the upper end of the shank is provided a circumferential recess to receive the holder H which, f as illustrated, is formedfrorn a fiat strip of-meta1 which is wrappedi..about the shank and has the ends spot welded together at 2,388,096 v x I 18, In order to improve the mechanical strength of the connection between the holder and the starting electrode and to prevent the formation" having a first portion surrounding said electrode of small arcs between the holder and the sl anl; of the starting electrode,rtparticularly.at high operating temperatures, I provide an additional connection between the starting electrode and the arms of the holder.

"th'eiull current of the starting electrode; it may 'be of relatively small sizeso' that the insertion of 'the end of the Connector within the shank of the starting electrode does not becomefa source of trouble or require that alarger shank be employed;

WhileI have shown and described a particular embodiment of my invention, it will be obvious/to those skilled in the art that changes and modificationsmay be made without departing from my invention in its broader aspects, and I, therefore, aim in the appended claims to cover all such spirit and scope of my invention. l

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

1. An electrode assembly for an electric discharge device comprising an elon'gated'electrode having a, resistance which is relatively high with respect tothe remainderof the circuit in which it is c'onnected,a first conductor'for supporting and supplying current to said electrode including a portion encircling and tightly gripping one end of said electrode and provided with a portion for supporting said electrode from a lead-in conductor of the device and a secondconductor having one end secured in an opening formed in said electrode and the other end'secured to said first As illustrated in Fig. 2, this connection comprises a substantially.TU-;shaped true di s chaig device offthetyp empmymg a. liquid cathode com rising a' starting electrode having a,

tivelyhigh with respect to the remainder of the supporting said electrode from a lead-in conductor of the device, and a rigid conductor of substantially U shape having one end secured in an ropening formed: in said one endoi the :electrode and the other .end securedito said first-conductor.

3. An electrode assembly comprising an elongated electrode of carbonaceous material, a first conductor for supporting and supplying current 'to said electrode including a metallic conductor near one end thereof and a second portion extending laterally from. said electrode, and means for preventingarcing between said electrode and said conductor including a second conductor having one end connected to said second portion of said first conductor and the other end secured to said electrode in good electrical contact therewith.

' 4. An electrodeassembly-comprising anelon gatedelectrode of carbonaceous 'material,"-a'first conductor for supporting and supplying current to said electrode including a metallic conductor having a' first portion surrounding said electrode near on'e'end thereof and a 'second-portionextending laterally from saidelectror le,- and means for preventing arcing between said electrode and said conductor includ ng a rigidcondu'ctor of sub' 'stantially' U shape having one: arm 'connectedto said'second portion of saidifirst' conductorfand the other arm secured-in 'an' opening formedin said one end of said electrode to form agood electrical'connection between said U- shapedco'nduc tor and said electrode; f

5. A starting electrode assembly for an electric discharge device of the type" employing a liquid cathode comprising a. starting electrode'having a substantially cylindrical shank portion andjatip portion adapted to be immersed 'injthe "liquid of the cathode, a support and'current supply canductor for said electrode including Tanietallic niembersurroun'ding the shankjof fsaid electrode,

and a rigid conductor or substantially U"sha'pe having one end secured to said current supply conductor and the other end positioned injan axially extending opening formed in saidshank and having good electrical contact therewith.

6. AstaitihQ eIectr de assembly for: anfleotr'ic substantially cylindrical shank portion? and a'tip 1 portion adapted to immersed in thefliifuid- 'oi the cathode, a first conductor for supportingand supplying current to said electrode including'a mjeta'l' strap. surrounding the shank of said electrode', and ajrigid ccn'ductcr of slibstalfitiiillj'y "U shape having one end scure'd'to' said first conductor and the dtherffid, positioned ifi a'jlld threadlng ly engagillg the walls of anaxianyier- F e P ie ere hi1 ea he s.

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