CROSS-REFERESCE TO RELATED APPLICATION
'Ihis application claims priority from and claims the beneti t of LI. S.
Patent .4pplication Serial No. 14275,993. filed May L 3-20 14, which is incayvrated
by reference herein.
&Jj
1 0 The disclosed concept relates to vacuunl stvitchirtg apparatus and, in
particular. vacuirlxt switching apparatus st~chas . for exai~lplev:a cutxt11 interrupters.
The disclosed concept also relates to efectxode extension assenlblies and assanbly
nrcthods far vacuum interrupters.
Back~ri~tlIri1~fdor t11ation
15 Some circuit breakers such astsfo, r example. power circuit breakers,
employ vactiuin~i nternipters as the stvitching devices. Vacuum irtfempters generally
iacliide separable electricat contacts disposed an the ends of coz-respanding electrodes
willsin an instrlating housit~g.T ypically, one oft he cor~tactsis fixed relative to both
the housing and to at1 extexn.d electrical conducbr, which is electrically
20 interconnecttrl with a power circuit associated wit11 the vacuum itrterruptur. The other
co~lcacits pan of a movable co~ttacat sse~nblyil tcl~rdingan elatrude stern of circular
cross-section and a contact disposed on one end of the electrode stem and enclosed
within a vacuum chamber. A driving mecl~anisnis~ d isposed 011 the other end.
external to the vacuiun cl~a~nbaT..h e electrodes #re typically bmzcd or otltei~jse
25 suitable joi~ined together whas tlte vacuum irsterfuptm is nxide.
The external ends of the electrodes (i.e., electrode stetns) are
limited it] their capability for use it1 variotts different vacutiin itttermpter designs and
ability to meet custon~erd esigrl requiremettts. Further. there are a tlumbei of potential
problerrls assc~ciaiedw ith r~~cdifyinegle ctrode sretnb after t11c vacuurn itin renupier has
30 been otherwise assembled (1-e.,a tier the mcuum e~~velrrphaes beer1 sealed). i+r
exairlpte, oxidation of the elecr~odesc an occ~~asn.& or a connection having
undesirably lotv electrical and tl~eri~c~oanld uctivity or damage to the sealed vacuum
envelc~pto. ixld result.
I'ttrre is. ttlerefc)~r,o onl for impsot enlent it1 vaciwtn styitching
apparatus such as \.acui\m i~~terxup~aenrsti- i n eIectxotie extc~~sioasns emblies and
associated sssanbly mcthods tl~crefor.
5 SUM M,'1,I?.Y
'X'hese iteeds and others are nre1 by en~bodimentso f the disclosed
co~lcepiw, hich are directed to electrode extension asse~ttblieas td associated
assembly nrethotls for vacrtom switching apparatus, such as vacuum intem~pters.
As one aspect of tile disclosed concept, an electrode exte~~sion
10 assembly is provid~xlf or a vacumnt switcl~inpap paratus. Tllc vacuum switcl~illg
apparatus includes a vacuum envelope and separable contact assemblies. Tlle vacuirln
envelope hus an interior anti an exterior. Each of rhe contact assemblies includes u
contact disposed in the interior and an electrode stern extending our~\fardlfyr om the
contact to the exterior. Tire electrode extension iisscnibly comprises: a number of
IS estensio~m? embers each being strt~cturedto be joined to the electrode stem oCa
corresponding one of the colttact asselrrblies an tl~ex terior of the vacuum envelope.
Each of the exknsio~rn en1bei-s may be joined to the electraie stem by
a welded joi~rr- ?'he welded joint may be fonned by electron beam welding or plas~na
welding. The separable contact assemblies nlay comprise a fixed uonhct assernbly
20 md a movable contact assembly, and the rtuntber of extension rnenlbers may be a first
extension menlber and a second extension mernber. wllereiu tlie first extension
metl~bairs welded to the electrode stem of the fixed contact assernbly on the exterior
of the vacuum envclupe, and wherein the st-ond extensio~rr .~~endixsr w elded to tlie
electrode stan of the movaide co~~~aa-sascet i~lblyo n tl3e exterior of the vact~ttm
25 envelope.
Each of the electrode stems ntay k made from a first material. and at
least one of tile first extension ntember and the secot~de xtension rnemhei may be
lllade t*rom a second material, \vlzcrc"i~t\h e secar~dm iterial is JitTercni fk~>rtnh e tirst
material.
30 As a~lotlrear spect of the disclosed ccmcept, a xfucuurn s~vitdrtng
apparatus eon~prisesa: ?racutun envelope having interior at~da1 1 exterio~.s eparable
contact assemblies each inclrtding a contact disposed in the interior and an electrode
stem extending snt\i~asdlyj? c)nl the contact to the exterior: and an electlode exteizsitrri
assembly co~npsisinga: nuatber uf extenhion rtlemI~esse ach. being joit-1ed ro rhe
electrode sten1 of a corresponding one of the o~ltacats setnblics on the exterior of rhe
ttacuur-rl a-r velope.
5 As a fw-tlier aspect of t11e disclosed concept. a method of assembly
coittprises: providing a \:mllm switching apparatus includiitg a vacrtum etrvelnpe and
separal~lec ontact assenlblies, the vacuum envelope having UI interior and an exterior.
each of the contad assemblies including a co~rti\cdt ispost~lit ? the interior ;ind an
electrode stem extending oubvardly fiom tlie contact to tile exterior, providing it11
10 ekctxode exte~~sioasns enlbl y cornprising n number of ex tensioli xnenlbers, and
welding at least one of tlie extension t~iernbersto the electrode stel11 ofa
corresponding one of the contact assemblies ttn the exterior of the envelope.
The u~eldilrps tep rnny ftxnf~ecr conlprise er~~ployinelge ctrot1 heam
welding or plsnxa welding to form the welded joint between each of tile extension
I5 memtwrs and t&e electrode stem, and may still further cotnprise: employirtg a fixtare
to position the electrode extensions wit11 respect to the electrade stetns within a
vacuum cf~arnbrw, eiding the electrode extensions to the electrode steras, and
removing the welded a...sen~bfy from t1t.e \racuunl chamber.
20 BRIEF DESCRIPTfOM OF THE DKhWlNGS
A fa11 understanding of the disclosed concept wn be gained &om the
folbwing description of the preferred emboditnents wlten read in coi~ju~~cwtioithr~ th e
acconlpanying drawings in whicll:
Figure 1 is a section view of a vact~tui~nlt errupter and electiocie
25 extension assembly therefor. in accordance with ax enlbodinxalt of the disclosed
concejtt:
I'isure 2 is a1 elevatior~v iew of the vacuum interrupter and electrode
esiensioi-1a ssembf y the~ukor f Figure 1. atsa sf~owitxagr t assanbly merhc?ii in
accordance with the disclosed concept; aild
30 Figure 3 is an elevation view of u vacuum ilrterrupter and electrode
extension assembly therefor, in accordance with another ernbdirnent of the disclosed
c.oncept.
DESCRIPTION OF TI-1E PREFERRED E3klBC)DIMENTS
The disclosed concept is described in association with vacuum
interr~rptcrsa. lthough the disclosed co~~ceips ta pplicable to a wide range of contact
5 asse~nbliesfo r use wit11 other vacuum sivitching apparatus and electrical switcbirtg
apparatus.
Directional phrases used herein. such as, for example, rip, dt3u.11 and
derivatiws tliereof; relate icj the orientation of the elements slro\vn in the drawings and
are not limniti~lgu pon the cclaitns u~lessex pressly recited thereill.
10 As e~nployedh erein, the statement that two or n~orep arts axe
"ct>~~aecteo&r '' 'coup'lt4" together shall mean that the parts axe joined together either
dire~t.o1r~ jo ined through one or more intermediate prts. Further. as employed
herein. the slatetxjent that l14~oo r itlore parts are "attached" crr "af'fixet1" shi~iml ean
that the yiuts are joined together direct1 y.
15 As employed herein. tlte term "vacuum e~~velopern"e ctrls an e~lvelope
employing a partial vacuum therein.
As employed herein, the term 'hrmber" sl~dml an one or an integer
.g"r eater than erne (i.e., a plttraiity).
Referring to Figire 1, a vacuum switchitig apparatus, such as a \;ac.curxtn
20 iaterri~pter2 , is shoixs. 71.1e vacuum intempter 2 includes a vac.um ex~~elo4p,e
which is sho\vn in section view in Figuse f to &ow llidden structures. The vactlwn
envelope 4 has an interior 6 and an exterior 8. Ihe vacuum interrupter 2 employs
sepwnble c.ontacx assemblies 10.1 2. Specifically, a tixed contact assen~bly 10
itlcludes a cor~tact 14 disposed in the itlteriur 6 cof the vacuum envelope 4, and at1
25 electrode stem 18, whic.h extends out\vardty fro111 the fixed co11t;tct 14 so the exterior 8
of the vacuum envelope 3. 'I'l~em ovable contact assembly 12 also inclt~desa movable
contact 16 disposed on the interior 6 of the vacurun envelope 4, and a corresponding
eIectrodc"s tern 20 exte~~dionust wardly from the mc~vohiec oitracl 16 rr:, the exrerior P
of the vacuturl emelope 4, as sho\v~~?'h. e movable cot~tacta ssembly 12 is movable,
30 for example and \.t.ithout limitittior~u. p and down it1 the direction ot'antw 10, in
order to move tl~em ovable contact 16 thereof into and out of electrical contact with
the stationary contact 14 of the fixcd contac-t assembly 10.
Contim~ingto refer to Fig~reI. arrd also to Figure 2. in accordance
with an cinbuditnent of the disclosed concept. each contact assenlbly 10.1 2 further
includes an electxode exte~isiona ssembly 100,100' (sue also electr~feex tension
assemMies 200,200' of Figtlre 3 1.
5 It tvill be appreciated that, fbr ease of illustratiolt and economy of
disciost~reo, nly electrode exteltsior\ assenlbly 100 (see also electrode cxteitsion
assembly 100') is described, in detail herein, and is only described herein with
to the vacatrsn interrtrpter 2. shown (see also sacuum in terntpter 2' of Figure 3).
However, it will he utlderswod that electrode esensiot~as semblies (e.g., without
10 limitation, 100.1 00',200,200f) in axordance with rhe discloseti concept. could be
etnployecl in any know11 or suitable combitratiort or alternative arrattgetnent (not
shotn~w~i)t h any kmom or suitable alternative vacuum switching apparatus (not
shotvn) a~rd!or sepmhle co~~tancsts e~riblies(e .g,, withcrul limitation, 10,12) therefix.
without departing fioin the scope of the disclosed co~lcept. For exanple and without
15 lirnitalion, electrode extension asselnblies 100,100',200,200', could be employed with
a vacuum switching apparatus having two xno\able contact assemblies (nat sl~own)
rather than the aforentendoned ant\rtgeTnent crf a f i s d contact assembly 10 and a
tnovable contact assembly 12.
Each of the elcqtrodc estensic)~as~s emblies 100, LOO' it~cludesa n
20 extension mentbrs iQ2,lQ4s tructured to be joined to a comespoltdirtg dectrode stem
18,20 of a corresponding one of the contact wsselnblies 10,12, respectively, on the.
exterior 8 of the vacuum envelope 4, That is, in accordance with the disclosed
conc~'13ts,t lcfi extensioa tnemt~ers1 02,104 are advantageotsipjoined to t11c
corresponding electrode stems 18,20, respectively, afier the vacuu111 envelope 4 has
25 bee11 ~acuun~eseda led. in other twds. rhe extension n~embers1 02.104 are joined on
the exterior 8, or outside, of the \.acutun etrvelope 4, as shown.
Among other advanta~eous,t he electrode extel~siona ssen~bite s
100,100' (see also, electruth extcosion assenzblies 200.200' of 1:igur.l-c 3) allost SOr
ctistcrmieatioa of the contact crssetnblies 10.1 2, to meet castonter dernattds in llew or
30 existing applications and:lor to relatively easily modify a11 existing vactcuirm intempter
2. For esanlple and witl~out iinritaticm, relatively complex geometries can be
acconmodated through use of the extension members i02, f 04 of the disc.losed
c.Iectrodc.P X T ~ ~ I Sa~sOseIln~b lies '1 00,100'. This. in turn. imprc?ves n~anufacturirtg
efl icieacy by elr:jbling tlre ilbiliiy to r-elali~el)e asily tnake a wide \:at iet y of differei~t
customized electrode configurations to an otl~et~visstea rdard vacuuni intempter 2. Jt
also eilaklcs the ability to attach a wide variety of alternative rnaterisls (e 2.. without
5 limitatiot~a. luminum) to the electrode steirts 18.20, at least some of tvhicll are not
compatible with traditional vacuum brazing or other vacuum interrupter assernbiy
processes. For exainpk and without litnitation, use of aluminum extension ntembers
t 02,104 can advantagmtrsly reduce the total weight of the x7acuumi ntem~pte2r . A
still further advanage is that exte~~siomne rntxrs 102,104 which are, for esatnple and
10 \li4tl1out limilation, already silver piated, can be joitted lo tl~ee lectrode stems 1 X,20.
This significantly sin~plifietsh e silver plating process by allowing plating of loose or
separate extension menlbcrs 102.104. for example, before they art? J joined to the
vacuum inrerrupter 2, rather tt~aiut ~~dergc>init rgr \ore complex silver platitlg process
that would be required if the electrode stems 18,20 md extension meinbers 102,104,
1 S respective1 y, therefor! were plated after Being attached to the vacuum interrupter 2.
The electrode exte~rsiana ssenlbly 100,1U0',2001200'a f the disclosed
concept and the advantages they aRc>rdw ill be fi~rrhera ppreciated with reference to
the following EXAMPLES, wkicll will aatv be described wit11 reference to Figures 1 -
3. It \%rilbl e appreciated tliat the .following F-YAMPL,ES are provided solely for
20 purposes of illrrstrtltion, and are rmt intended to limit tile scope of the disclosed
concept.
EXAMPLE 1
Each of the cxtc=nsioti rnerntters 102,104,202,204. nlay bePitled to a
cc>~xespondinegle c!ctrodes tem 122,263 by electron bean) or plastrta welding rising a
25 welder 300 (S~O'LiVn sIiIm plified forni in Figure 2). A welded joint '106,106' (Figures
t and 2),206,2WJ (Figttie 3) may be formed by the welder 300 on the exterior 8 of
the iacuuxlz ert \.elope 3.
EX.&MPI.,E 2
Each electrode stem 18.20 stlay have a stem diameta- 22-24 'I he ilrsrst
30 extension menlher 10 1 (Fi~ures1 and 2). 283 (Figure 3) has Grsr and second upposing
ends iO8,11 O (Figures 1 and 2): 208,210 (Fi~ip~r3r1e, and the second extension member
104 (Fi~ares1 and 2). 204 (Figure 3) has c~ppjosingf irst and secolld en& 1 112, f 14
(Figures I and 2). 212.214 (Figure 3 \. As shown in Figures 1 and 3, the fjrst ends
IOS,L t 2.305.2 12 may have a diameter 1 t 6,115,2 t6,2 1 S, respccrively, that ib
strbstartially the same as the corresponding stew diameter 22,34.
EXAMPIX 3
5 Altenlalively, it will be appreciated that tlte dianete~ms ay be different
(not shotvtt ) an&or tlte first ends Itlay be desig~tedto have my k~~oito-rt s~u ital~le
alternative geometry a~d.'osri ze (not sltotvn) other than that which is shtxw wit11
respect to the nm-limiting examples shown and dcsctibeil herein.
EXAMPLE 4
10 As shi)svn in simplit'ieii form iit Figure 3, the wci)nd ends 2 10.2 14 of
the mtertsio~iln embers 202,204 of the elecirocte exte~~sioanss enlblies 200,200f,
respectively. may have a g~wrnetsyth at is riiffere~ltth an the fiixt encis 208,212 of the
ecte~~siomne mbers 202,201,
EXAMPLE 5
IS Eac11 of tite etearode stems 18,20 n~ayhe n~adefr om a first material,
and at least one of tile first extension rrzenltrer 102 and the second extension member
i 04 may be made froin a second material. which is different I'rm tl~efi rst materid.
EXAMPLE 6
The second different material of tl-re exterlsion members 1 02,104 may
EXAhfPLE 7
Alternrttivdy, it will be appreciated tltat the second material may be
any known or suitable ttlternativc nrateriai, ~niitl~o~dtterp ttrtit~gfr o111 rhe scope ofthe
disclosed cmlcept..
25 EXAMPLE 8
At least oix of the firsf and second extetrsion nlexnbers 103,i 04 may he
silver plated.
EXAkfPLE 9
A tnahod of assembly in accordance with the disclosed cc~~~cmepaty
30 inctudi: steps of prcwiiling a tradiiional vacuum irttemipter 2; prczvirliny an electrode
extensior~a ssenlbly 100 ir~cludinga number of extension nlernbers I02.104, and
welding at least one of the extension members 102,104 to the electrc~dset em i8 .20 of
s cotrcsl~ondinga rte of the colrtact assemblies 10.12, respecti~felyo,n the t.?iterior 8 of
the vacuum envelope 4 of the vacrc\rum interrupe~2 .
EXAMPLE 10
'I'he assembly method may further itlclude the step of enlploying a
5 fixture 400 (shawl in sintplified fomt in Rptire 2) to suitaldy position and secure the
electrode extel~sions1 02,104 with respect to the electrode stems 18.20. respectively,
to perforin tl~ed esired \velditlg operation using the afore~nentionedw elder 300
(Figtrre 2).
EXAMPLE 11
10 The steps of employing the fix ttm 400 and eleotrc~xot r plasnla welding
111q be perfomwd within a vacuti111 chamber 500 (show11 in sinlplified hrm in T<'1k 'U re
2). wherein the welded assembly is remc)sert fronr the vactjtun cllarnber 500 after
successfully welding the electrocte extensicm assemblies 100, LOO'.
EXAMPLE 12
IS 'The method may optionally further imlclude the step of atidirrg a
number of hear sink elements 600 an one, the other, or both of the electrode stems
t 8.20 (e.g., without limitation, one Ireat sink elemet~t6 00 is shown in sirnplified foml
in phantott.~li ne drawing on stel11 IS in Figure 21, It will be appreciated that such fieat
sink elements 605 may comprise any known cjr witable tnechanistn or structure (e.p.,
20 ~iithotl~titn ~itatio~filn, ; heat pipe; forced air active coolix~ga ttachment; water active
cooling attachnlett) for suitably dissipating undesirable excess heat. Specifically,
altltough tile therlnal effects from electron beam welding afe sul?stantially less than
other welding metl~cKtsd, .lc heat sink etenlents 600 may nanettt~elessb e er~rploycdi,f
desiredr to decrease thermal rise arid insulate f~earta dia~ionc rated fioix~th e welding
25 process. The heat sink elements 600 nzay be made &an any known or sr~itable
material (e.g., wit11out litnitation, copper; alt~minuxn)a, nd nlay be re~t~oveafdt er dxe
tt-elding uperation has beeit. completed.
EXAk1PI.T: t 3
SirniiuIy- a number of themla1 nt.anagemc?nt members 700 may kw
30 incorporated on one, the other, or both of the extension metxbcrs 102,104 (e-g..
witl~oulti mitation, one tltermal managenlent n~ernl~7e0r 0 is sho\vn in sirnplified fmlz
in phantonr line ctmwing on extension member 104 in Figun: 2). It will be appreciated
tt~is~utc l-it ttemral nlatlagement ~nenlbers7 00, like the aforen~cntiouedh eat sink
elenrents 600. may comprise anq kr~owno r suitable ~x~echanisomr stluctrlre (e.g.,
tvithoot limitation, fin: heat pipe; forced air active cooling attachment; water active
coaling attachment ) ibl- suitably dissipating undesirable excess heat Specifically, the
5 contiuuous current that can be caried by a vacuunx interrupter is limited by the heat
gemrated by ctlrrent passing t11roupt1 the interrupter. Use of such therlr~al
n~anegemenrtn ernbers 700 serves to decrease the rhernral rise due to colrtinuous
current, which improves the vacuum intem~ptw. The thermal matragenlent tnen~bers
700 may be made froin any ~IIO\VTI or suitable material (e,g., without lirnitatio~~.
10 coppeq aluminl~tn).
Accordir~glyt,h e disclosed vacuum switching apparatus 2 includes a
uniyttc. eiecrrode extension assembly 1W,I 0Of,200,200', wherein a number of
e3lte11sion members 1 02,t U4.202,20;1 are welded to ceomspot~ctiape ltxzrc~ries terns
18,20 of the previously assembled and vacuum sealed tiactittrn switching apparatus 2.
1 5 7'11at is, the exte~~sionn~ ernbers1 02,104,202,204 are welded to tht: electrode stems
18-20 on the exterior 8 of the vacuum envelope 4. Thus, a wide variety of relatively
cornplex geometries ca~bte added to electrode sterns 18,20 and,%r existirng vacnurrI
switchix~ga 1~paat112s ca11 be nrodified or custonlized to meet a wide variety of
customer dei.trands.
20 111 addition, external electron beam welding in accardance with the
disclosed concept. provides the ability to join extension n~enlbers 102,104,202,204
made kom a wide variety of different rx~ateriitlsw, hich tnateriais may be difkrex~t
frorzr the material of ttze elecrruzfe stems 15,20 to ~hiulrt.h ere bdng ~e1ded.T his
advantage is r~otp ossible t ~ i x j gco nvent ioi~avl acuutx~b riilzii~go r other vacuum
25 interrupter assenlbly processes which yield a joint or connection having poor
electrical conductivity. Electma bean1 tvelditlg in accordance with tile disclosed
concept also avoids oxidation of the surface of the electrode stems 18.20 and avoids
requirements, nick as machining, or cl~ernicsol r mechanical clcanir~ga ftel xvelding.
tvhich could damage components of the uacurltn itrtenupter 2 a~I&oi.jer>j3ardit~he
30 vacuum seal of the vacrtutn e~rvetope4 tl~ereof:I t will be appreciated, tbcrefore, tl~at
the disclosed electrode extension asseinbly 100,100',200,200' and associated
assenlbly method arfdress and overcome a ?vide vxiety of problems associated with
the prior art, aud sigilifjcanily expartij the utility of ia~.uum stvitctling apparatus 2 in a
wide var ietg of di ffereni applications.
While spccific ctnlbodimerrts of the disclused concept hate been
described in detaii. it will be appreciated by those skilltd in the ad thal various
5 tnodifications and alternatives to those details could be debeloped in light af the
overall reachir~oo~f the disclos~~reA.c cc7rdingly. tlte particular wran$ernents
disclosed are meant to be iiiustrati\te only and not limitin3 as to the scope of the
discloser1 concepl \vhich is to be given the ti11 1 breadth of the clairns uppur~ded and
any a11d all equivalents thereof.

claim
I . Ail electrode cxtunsion assembly ( 100.200) Sc~r a vacwml switchins
apparatus (2.2'), said vacutun switching apparatus t3.-2') including a vacuiun ct~velope
(4) and scparahle contact assembiies ( 10,121, the vacuum e~~velcrp(4e ) having an
interior (6)a ~lda n exterior (81, each of said contact assemkfies ( 10,12) i~~cludina g
coiltact (14.1 6) disposed it1 tlte intefior (6) aid an electr-ode stem t 18.20) extending
outcsardly from said contact (24.16) to the exterior (81, said electrode exrension
assetnbly ( 100.200) comprising:
s number of extensiot~n lelnbe1.s (1 02.1 04: 202.204) each being
strucrtxred to be joined to the dectr-ode stem (15,20)o f a co~xuspondingo ne of said
cc>~-lt+alscst em1,llies (1 0, t 2) 011 the exterior (8) of the vacuum et~velc>p(e4 ).
2. The electrode extension assen~biy(1 00,200) of claim 1 wherein each
of said extensic~xn~~ et~~\l(e1s0s2 ,104; 202,204) is joir~edt o the elecwode slem ( L8,20)
by a welded joint (1 06,206).
3. 'The electrode exte~sionas sembly (100,200) of claim 2 wllcrein said
\velded joint (106206) is forrned by electron beam weldi~lgo r plsnta welding.
4. Tfie electxtde extet~siona sstivlbiy (100,200)o f claim 1 wherein said
separable contact assemblies cornprise a fixed contact assen-ll~f(y1 0) and a mo\.ablc
contact assembly (1 2); wherein said number of exteirsic~nin embers is a iirst extension
member ( 102,202) and a second extensiort member (1 U4,204): wl~ereins aid first
extension lneniber f 102,202) is welded to the electrode stem (18) of said fixed contact
~SSGIXIM(V1 0) an the exterior (6)o f the vacuum envelope (4); and wherein said
scc.otld extension me~nbe(~ 1-0 4.2W) is wrt'lded tu the dwtrode sten] (20)o f'said
movable coiltact assembly (1 2) 01% the cxterios (6) of the vacurrin envelope (4).
5. The electrode extension rtssen~bly(f 00.200) of clainr 4 wherein each
of the electrode steltls (1 8.20) has a sten1 diameter (22,24); wherein each of' said first
exte~~siomne mber ( 102,202) artd said second extension member (104.203) has a first
end ( 108.1 1 3: 308.2 1 2) and a seco~lde nd ( 1 lC1.114: 2 1 0.3 14) disposed opposite a3ld
distal h - n the first end (108,112; 208.212); and wilerein at least the Rrst end
(1 08, i 12; 308.2 17,) has a diameter (I 16,118; 2 16.2 t 8) st~bstantiaflyth e same as the
stern diamerer (22,23).
6. The electrode extension assembly (200) ofclaifn 5 wherein the seconcl
end (2 10.2 14) has R diflesent gi'cmetq than the end (208,212).
7. The electrode exte~~sioanss tnxbly (100) of cisin1 4 tlihercin each of the
electrode stems (18.20) is nladc fro111 a first nlatel-ial; wtlerein at least one of said first
exte~lsian~ ~tetnb(e 1r0 2) and said second extertsion menlher (104)i s made from a
seco~tdm aterial; and w11erein tile second n~areriails different fxom the first material.
8. 'The eleckrode extension assentltiy ( I 00) of claim 4 wherein at least one
caf said first extension member f 102) and said siwnd extension member (104) is silver
plated.
9. The electrode extertsio~ul ssembl y ( 100) of claim 1 whereirl at feast one
of said extension members ( 1 02,104) illc1rtdc.s a ~tunlbero f thermal managernent
nrembers (700).
10. A vacrttur.1 swi tchiny apparatus (2) conlprising:
a vacuum envelope (4) Having an interior (6) and a11 exterior (Y );
separable contact assemblies (10,12) each inclr~dillga eo~ltir(~ 1t4 .1 6)
disposed in the interjar (6) and an electrode stenl(18,20) extending ouhvardly fiom
said cotrtact (1 4-16) to the exterior f 23); and
a11 electrode extensiott asse~nbly( 1 0 0 j according to ally of C hiins 1 -9.
1 1. A rnerllod of assembly comprising:
providing a. vzrc;uuxn switching apparatus (2,2') including a vacuum
envelope (4) and separable contact assemblies (10.12), the vacrrurn emelope (4)
having at1 interior (6) arid an exterior (81, each of said contact assemblies (1 O,12)
including a contact (14,'16) disposexi in the intefior (6) atld an electrode stem f 18,20)
extending outwardly from %aid contact to the exkrior (8).
providing an electrode extension asscnlbly ( f 00.200) comprising a
x~tunbeor f extension memltea ( 102,104: 202,2043, md
welding at least clile of said extension nle1111xr-s ( 102,104: 202,204) to
the eiectrcxle stern (1 8.211) crf a conespunding one ot.' said collmcr r~ssen~blieI bf 0 .12)
on the exterior (8) of the vitctulrn envelope (4).
12. The method of claiin 1 1 lvlrereitr said welding step f'urther conlpriscs
enlpioying electrort bean? welding or planla welding to form the welded joirlt
(1 05.206) bebvcten each cjf said extension rnemb21-s ('1 02.1 04; 202,204) and the
electrocic sfern ( 18,201.
13. The method of claim 12 \ttllerein said welding step further comprises:
employing a fixture (40()) to position said extension n~embm
f 102.. 104; 202,204) with xeslzect to the electrode stems ( 18.20) within a vacuum
ci~runbe(r5 04)),
said ex tension n~embers( 10 2.1 0.1 1 to tile electrode sterns
f t8.20), a c t
remnoving the welded assembly from said vacuum c.l\amber (500).
I-?. The method of claim 1 1 whtwin said separable contact asstmblies
co~t~pri2s1 ef ixed contact assembly f 10) and a movable contact assembly (1 2); xvl~erdn
said number of extension memhers is a fits extension member (1 02,202) and a
s~~oie~xtcett~ siotml ember 4 LfW,2(W-);s vherei~s~a id first extension metnber { 102,202)
is welded to tlre efec.trode stem (1 8) of said fixed cantact assembly (1 0) on the
exterior (6) of the vacuum elrkfelope (4); and wherein said second extension mealher
t 104,204) is welded to the electrode stem (20 t of said movable contact assen.rbly (1 2)
mi tlre exterior (6) of the vncutmm envelope (41.
15, Tile nxetl~odo f clifin~1 L wherein said welding step furt11er camizrises:
attacking a number of heat sink elements (600) to at least one af said
electrode stems ( lS,ZQ),
welding said extension nten1bei.s ( 102.104) to the electrode stems
(1 8,20), and
remnoving the r~uinbos f heat sink elcn~etlt(s6 QO).