CA2274376C - High speed fuse - Google Patents
High speed fuse Download PDFInfo
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- CA2274376C CA2274376C CA002274376A CA2274376A CA2274376C CA 2274376 C CA2274376 C CA 2274376C CA 002274376 A CA002274376 A CA 002274376A CA 2274376 A CA2274376 A CA 2274376A CA 2274376 C CA2274376 C CA 2274376C
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- terminal
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Abstract
The high speed fuse employs stamped end bell and terminals rather than forged or machined parts. A slot for the terminal is punched through the end bell. The terminal is inserted into the slot in the end bell and staked in position. This insures a strong tight fit without requiring welding or soldering. One end of each terminal has coined ridges to facilitate automatic welding of the fuse link to the terminals. Round balls are used to seal the fill holes for the arc quenching material. Metal pins secure the end bells within the fuse housing but are not electrically connected to the terminals because of the insulative end bells.
Description
HIC~i SPEED FUSE
This invention relates :a generel to :uses arc ..°.ore pa=zicu:a:~y to h~gn speed fuses.
High spaced fuses have bean used ~or a numasr of years nor the protec:i.:r. or isolation of sQ.miconauctor devices suc: as dioaes and thy: atora. There is vary l:~~lo safety ractc_ ~n these saaicordzc=a: devices anc they can ta:: ~:.:l:ly wnen sua~ected to overc::rrants. Therefore, a fLSe assigned to protect semiconductor aevicee must open quickly. each rpeed fuses nave vary ltitle thermal capacity, and in general open in the order c:
. ool to . ooa aeconda when inser:,:~.ting s.~.crt ci-c::_tc.
Proolems exist with high apsed fuses currently on the marxet because these tunes have been developed over time to meet apaeific applications, result=ng .n a large number of different :uses made in di~terent aizea and shapes to satisfy the voltage and amperage ranges expec=ed to be eneourtered. Several hunared different parts and subasaamb3les for these fuses may ce reqt:::ad. T:~us, =t would be dssirable to be able to manu:act::re fuses having standardized parts to reauce the total numaer c:
parts that need to be stocked in ord4r to manufacture a complete 'ins of high speed :uses.
Many applicaticna for high speed fuses require the uss o. a plurality cf =uses usually mounted side by side .n close prcxiaity o: one another. Many users wish to mount nultip-a !uses a. close together ss possible. Pro: art hiQn speea =uses nave metal end bells wriic.'~ are mscranically and thus electrical?y connectad to tho mounting terminals hale LD tile ln~Lltt~:lg tl:D6 with metal pins which are exposed flush with the tube sur;ace and are not sealed. Conseguently) when in use in an elec;.rical csrcuit, the pins are at the same elect::cal potential as she terminals and end bells. Typically, trrae phase electrical appliCatioris use a :use iri each phase mounted adjacent to each other and as close es possible to conserve space wit:::n the equipment. Ihduasrial standaras govern minimum spacing between slectrically rot parts and dictate the minimum distance between live or "siectrically hot" parts tsrough air as a :::::c~_o.~. c.
stand~otf voltage. Since the pins era elect=:tally hot ant exposed to the tuba surface, th~s minimum distance is measured between adjaosnt tube su::aces, as opposed to terminal distances.
Yet another C:=:iculty is encountered in manu:acturing high spaced iusea in that the end bell moat bs joined to the terminal !or mechanict3 s~:sagth o! the fuse package and, in most assigns, for the alect~:cal connection between the currant carryinc fusible nlamsnts within the ruse and the n~ountirg termi:.al.
Prior art high speed tutee accoWplishod whir by brazing, welG~ng or soldering the to Final to t.~e end ball or Wacraning the end bell and terz:nal °rom a solid piece o. metal cr by pressing the moral pins tn:oug:~ the tubs and end bell and into the nount:ng terminal. AlI theas techniques are labor intensive.
A further prcblam it anco~unterad with and bells in t~az tress cisc::lar places of metal era mos= often forged or mac'.~.:ned from rod stock aad coined, e:i:lad, and sized. :ras again requires exits time and add~t~onal la~cr a-c is :.:ZUS more expensive.
Yet another manufacturing p=oblem is encountered in mak_n;
high speed fuses. Thaee fuses, in general, are Zi?led with sand or other arc quaacz:nq materials. Tha motor=al is added tr.:ough a hole 1n the end ball after .:~.e end ball is assembled tc tho tugs tubo. Various methods o! pluggi~sg she hole have peen used, but all suffer ::om various l:witations. For exempla, cosily knurled plugs are used which require excessive pressure to insert the plug into the hole in the end ball. A more economical means to close tae sand hole is required.
Ths present invention satploya ecamped end balls and terminals rather than forQsd cr nac.~inec parse. A slot for the ~ 3 -tenainal is punched through tho and bell. The terminal .s inaertea irtta the alo: in the end bill and staked in posa:o:..
Ttis insures a st=ang tiCat fa wit :cut raqu~ring weld=rg o_-soidering. One end of eacz termina'_ has coined =:dges to 'acil i rate automat'_c welding c_' the :use link to trie terminals .
Round balls a~z usec to seal the _'..1 holes for the a=c quencr.~r.~
material. Altarnativaly, Lrie end bells may bn molded o'_ plastic.
Petal pins secLre the end bells within the fuse housing but are not electrically connected to the zerminnls because of t:~e insulative end bells.
FiCUre 111 snows a porspoctwe view pa= t_tlly cut away o. a prior art ~usa~
FigLre =~ aiiows a parcep:we view partially in section anG
axplode6 0: N :use accorGing to ~ho present invertio:::
Figure 2 shawa a tap view o: a zarm,inal o. the iusa shown i:.
Figure 18 ~
Figure 3 shows a front viow along the lines 3-3 0~ the tarainal shown is !'i~;ure 2 t Figure 4 shows a complete end bell assamblyt Fic~urs 5 scows a side cross-sectional vi,w of fns assembled ruse o: Figure 1 g;
Figure 6 is a zap cross-seet:onal ~r:ew o. the lure cnown ir.
Figure 1$~
-a -Figure 7 is a par:ial cross~esc~~onal view o. the installaticn o_" the ball in a sand hole na shown in Fiqurs 5:
Figure a is a c=oss-sect=:..:a_ view along t:~e lines e-o _..
FiSura 7t and Figure 9 snows tae cross section o: LWO ad]acan~ fuses illuszrat-ng positioning discnnce.
Figure 171 si~ows a prior art high speed :use 9. M~tal erc balls 13 with terminals 15 are housed witt~.in the ends of an insulating tune <C. ;t is seen .:.Lt LhB to winal 15 is walGcd c:
brazes at 17 onto the metal end bell .3. Tbus the and ball =~ is elect=_cally hot when ~~c fuse is moon=ed i:. an olac:r:cally energized c:~cua. Tho and b~11 is held in place in insulating tubs ~0 by mszal pins di which are aiso.a' the same voltage level as the and boll 13. Thus, as shown in Figure 9, the minimum distance "°" that prior art rigZ spud fuses can ae placed ad~ao~nz too aaoh other, as dictazad by induarial scanaards, is governed by the distance between the electrically l~.ot ping 41 0:
an~scent ruses.
In the fuse according to the present invention shown in Figures 18) 5 and 6 and raiarred to generally by numeral e, an sad ball assembly o. an sad ball lZ anc =or~irta= 14 are adapted co ba rscaivad in aacn end of is~sulatinQ housinr~ or tuba ao. The and bell =Z enc Lerinal 14 era s=rmped ::am a piece c. material and a slot 16 is punched in the end bell 12, The to~inal 14 is inserted into the slot 16 until shoulders 48 engage the end bell 12. The tee=nal 14 is then staked at 46 or coined c.
mechanically upset in position as shown in Figure 4 to at:ach terminal 14 to end bell 12. '1':~us the terminal and the end boll are joined witroL= braz:nQ, we=Cing or solder~:~g, anc witraut complicated mecranical assembly using add:.tional components.
is more cost et_=cient to proauce the parts by stamping ratrer than by forging. Stamping provides a scrap rsauct~on over making the parts from lorQing and also allows the celection of appropriate materials for the and ball 12 and terminal 14 whic:~
can be of dissimilar materials such as plastic and metal.
11s shown in Figures 2 and 3 ( a series of small rectangular cross-sectioned ricgea, weld pads or psojec~ions 44 are emcossed on tho inner end a: terminal 34 during labrication for welding terminal 14 to one end o! a fuse element 30, preferably by resistance welding. These weld projec=ions <4 may bs coined or machined into terminal 14. The height of sack of weld projections 44 is the same over the entire weld area. The nums~sr of projections ad is dszs~ained by the width of terminal 1G. Tha size and shape of the pads may vary from terminal to terminal depending upon the size of hiss element 30 and end bell :2. ~ saw toot. pattern may also ba used in soma applications.
- o -Tha pitc.'~ and depth o! the saw tooth will vary wit : 1! :.k =h-ckness.
1~n advantage to using wale p:o~actions 44 on the te=-urinal 19 1s that it improves the welding of the fusible element 3 o to the terminal 14. Meld p:ajoct~cas 44 provide consistent welt quality and walaed surface area rasua:ng in consistent heat traneter and e3ect=_cal caacuc:.wity t.::ough the welded joi:~t betwaon the ~us3ble element 30 ana the terminal 1~ o~ :use e.
This results in pore reliable fuss perfozance and reauction in costs because al. welds can be mace simultaneously. T::!s p:oceaure also -enuces maintenarca of ttie weld electroces becnuse bat: elect=ooes are flat bla6as as compared ~o smal= poirttd eleotrodes. This type o! const~:ct:on ig also very useful for automating welding arid results in a mo:e consistent weld than that at=ordad by ps_a: tit spot weld3ag tecrniques. D=:act labar is roauoed because multiple welas can be mode with each eleetrece closure. Thus, the time required to weld t:~e st:-p to tae terminal is recucad, the eansistency of the weld arse is improved, and tae elect:ical coac~_=t:vity and heat tranaier from terminal strip to fuss clement is consistent.
The fuse alsment 30 1s preferably of a stanearc_zed planar design using an aeea:Cion shape which allows for the use of an element having a substantially longer overnll effective length than can be ac~ieved with a straigh t t:..ough element as in mos t prior art high speed fuses. The increase in effective leng~~
ennnncea the abili:y of the fuse to clear lower level overcu-:ent situations, aspscia'_ly on DC c=:~~=~s. As shown in Figures 5 and 6, a ruse element 30 may be welded to born sides of terminals 14 to provide a mLlt_rle element fuse.
Referring noW to Figures 9) since the te_~_::..~.al .4 pro3ec~s through the trc::: face and back :ace a: t.~a end bell 12, the :LSibla aiament 30 may be elect:=cally connectea cirertly to the terminal 14. Thus, the end bell 12 does »ot need to be mass or eiact-iCally corcucr:ng mazar:al, and may' ba made of pleat=c o.
zznar non-elect=:cally conduc:iva materials. Fed bells 12 ci insulat,ng material, such as plastic, era less expensive than metal end bells and can be molCed instead of machined allowinc for the use o. more in=::ca=a shapes when necessary. The insulating end bells 12 not only serve their normal turc~ion o:
closing off the ands o! tits insulating tube 40 of fuss a and provide the re~~~ od st:uctL:a1 integrity to the fuse package, their use results In the mesas p-ns 41) vetch sec::=a the end bell 12 within the tube 40, being insulated from tea elect=:gal circuit passing through terminal 14 and fusible element 30.
Jan advantage o= using plestic or other non-electrically concuctwo mata:ial for the end ball iZ is that pins 41, designed to project through the insulating tune 40 into the and ball 12, are not anergized~since the end ball is nom alact:~ca:ly _ conauctive. Since holding pine 41 acv not "electr,:cally hot~~
when mounted side by side, fuses can be positioned closer together thus conserving panel board space in equipment. In the prior err :use where the moral pin is elac;.r:cally hot, the adjacent !uses car..zo:~ be taaan:.ed side by side in close proxi~~;y more titan the distance "F" shown in Fi~~re 9. The separation between the fuses is governed by the distance between t.~e terminals which are electrically hot. Howwer) when mounted in an electrical circ;at, high speea fuses manutacturea according to the prsaen~ invent~on may be positioned closer to one anotzer since the miniaum distance "F" is measured between t!:e electr!cally hot terainals 14 aid not the pins 41 as shown 'r.
~iQura 9.
As she !uses are assuabled, t ~irsz terminal is ~o~nea to a :tier end bell, a second terminal is joined to a socona end bell, ana the fusible element 3o is welded between the twc tezminala. Because at the weld projoctions 4d on the terminal 14, the welding o: zhs fusible elament may be done by projection welding.
Re=erring now to Figures 5-8, the assembly of the and bell assemblies welded to the ends of the lusible element ~o is slipped into the insula::ng tuba 40 and the end bsilc are held in position within tuna <o by p:nr .t1 which are inserted into aligned aperruras fn tube 40 and end bells 12. Aligned .. " _ apertures era placed in the and bells 12 and tuba 4o by dr?1=irg just prior to insertion of pins 41. An arc quenching matariel «, shown in Figures 5 and 6, typically special sand, is poured into sand holes ZO in the end ball lZ. Altnr trio high speed fuss 8 is tilled with sand, the holes ZO are closed using a so=_C
spherical ball 18. These round balls 18 may be steal or attar material and are slightly larger than the hole 2o in the end bell 12. The ball 18 is prevented :raga misaliQnmsrt because it is guided by its cwn natural radio= irtc the hole 20. The balls .8 are thus self-centering and are held in place by =r:ctional :once. Alternatel y, pa:z:cularly where end belle 12 are metal, suc:. as.braas, the sand hots ZO may be coined after insertion of the bail 18 to hold the ball in. Tho balls 18 are iorcea or press4d into tba end ball 12 by an insert~on tool 45. The bail 18 is trapped between three smr=1 pins 47 which displace t::e metal 49 of the metal and bet= .2 over the ball 18 while the final insertion is boinQ accomplished. The =tat bottom of the insertion tool 45 p:oviaos autaaatic insertion doptn. over insertion is prevented by the design of the insertion tool a5.
Using balls 18 has several advantages. The harasnea steel ball 18 provides a low cost, salt-el'_QninQ, easily inserted means of plugging the l:11 hole ZO in the end bell 12 0= a fuse 8. The steel ball l8 requires leas lorce to insert and tanns to be selt-locking. This a significantly easier than prier art processes which often us.d p:na, hollow cloesc-end cylinders, or screws to seal trig bolos.
Zt 1s scan that high spood :uses ~nsn~::ac:Lraa eccarc:.~.g ;,o zee present inven:ian ars easier to const ~~~, reguire less laic:
anc are consequent3y less expensive to manu:t=;~_ro ar.,:, '_:z cae emaodimsnt, can De used closor t~ga-,.rier, Whan mounted acjacenL Lo ons another, wir: recucad danger o_~ short:.ng rrcm to:e to fuss.
_ " _
This invention relates :a generel to :uses arc ..°.ore pa=zicu:a:~y to h~gn speed fuses.
High spaced fuses have bean used ~or a numasr of years nor the protec:i.:r. or isolation of sQ.miconauctor devices suc: as dioaes and thy: atora. There is vary l:~~lo safety ractc_ ~n these saaicordzc=a: devices anc they can ta:: ~:.:l:ly wnen sua~ected to overc::rrants. Therefore, a fLSe assigned to protect semiconductor aevicee must open quickly. each rpeed fuses nave vary ltitle thermal capacity, and in general open in the order c:
. ool to . ooa aeconda when inser:,:~.ting s.~.crt ci-c::_tc.
Proolems exist with high apsed fuses currently on the marxet because these tunes have been developed over time to meet apaeific applications, result=ng .n a large number of different :uses made in di~terent aizea and shapes to satisfy the voltage and amperage ranges expec=ed to be eneourtered. Several hunared different parts and subasaamb3les for these fuses may ce reqt:::ad. T:~us, =t would be dssirable to be able to manu:act::re fuses having standardized parts to reauce the total numaer c:
parts that need to be stocked in ord4r to manufacture a complete 'ins of high speed :uses.
Many applicaticna for high speed fuses require the uss o. a plurality cf =uses usually mounted side by side .n close prcxiaity o: one another. Many users wish to mount nultip-a !uses a. close together ss possible. Pro: art hiQn speea =uses nave metal end bells wriic.'~ are mscranically and thus electrical?y connectad to tho mounting terminals hale LD tile ln~Lltt~:lg tl:D6 with metal pins which are exposed flush with the tube sur;ace and are not sealed. Conseguently) when in use in an elec;.rical csrcuit, the pins are at the same elect::cal potential as she terminals and end bells. Typically, trrae phase electrical appliCatioris use a :use iri each phase mounted adjacent to each other and as close es possible to conserve space wit:::n the equipment. Ihduasrial standaras govern minimum spacing between slectrically rot parts and dictate the minimum distance between live or "siectrically hot" parts tsrough air as a :::::c~_o.~. c.
stand~otf voltage. Since the pins era elect=:tally hot ant exposed to the tuba surface, th~s minimum distance is measured between adjaosnt tube su::aces, as opposed to terminal distances.
Yet another C:=:iculty is encountered in manu:acturing high spaced iusea in that the end bell moat bs joined to the terminal !or mechanict3 s~:sagth o! the fuse package and, in most assigns, for the alect~:cal connection between the currant carryinc fusible nlamsnts within the ruse and the n~ountirg termi:.al.
Prior art high speed tutee accoWplishod whir by brazing, welG~ng or soldering the to Final to t.~e end ball or Wacraning the end bell and terz:nal °rom a solid piece o. metal cr by pressing the moral pins tn:oug:~ the tubs and end bell and into the nount:ng terminal. AlI theas techniques are labor intensive.
A further prcblam it anco~unterad with and bells in t~az tress cisc::lar places of metal era mos= often forged or mac'.~.:ned from rod stock aad coined, e:i:lad, and sized. :ras again requires exits time and add~t~onal la~cr a-c is :.:ZUS more expensive.
Yet another manufacturing p=oblem is encountered in mak_n;
high speed fuses. Thaee fuses, in general, are Zi?led with sand or other arc quaacz:nq materials. Tha motor=al is added tr.:ough a hole 1n the end ball after .:~.e end ball is assembled tc tho tugs tubo. Various methods o! pluggi~sg she hole have peen used, but all suffer ::om various l:witations. For exempla, cosily knurled plugs are used which require excessive pressure to insert the plug into the hole in the end ball. A more economical means to close tae sand hole is required.
Ths present invention satploya ecamped end balls and terminals rather than forQsd cr nac.~inec parse. A slot for the ~ 3 -tenainal is punched through tho and bell. The terminal .s inaertea irtta the alo: in the end bill and staked in posa:o:..
Ttis insures a st=ang tiCat fa wit :cut raqu~ring weld=rg o_-soidering. One end of eacz termina'_ has coined =:dges to 'acil i rate automat'_c welding c_' the :use link to trie terminals .
Round balls a~z usec to seal the _'..1 holes for the a=c quencr.~r.~
material. Altarnativaly, Lrie end bells may bn molded o'_ plastic.
Petal pins secLre the end bells within the fuse housing but are not electrically connected to the zerminnls because of t:~e insulative end bells.
FiCUre 111 snows a porspoctwe view pa= t_tlly cut away o. a prior art ~usa~
FigLre =~ aiiows a parcep:we view partially in section anG
axplode6 0: N :use accorGing to ~ho present invertio:::
Figure 2 shawa a tap view o: a zarm,inal o. the iusa shown i:.
Figure 18 ~
Figure 3 shows a front viow along the lines 3-3 0~ the tarainal shown is !'i~;ure 2 t Figure 4 shows a complete end bell assamblyt Fic~urs 5 scows a side cross-sectional vi,w of fns assembled ruse o: Figure 1 g;
Figure 6 is a zap cross-seet:onal ~r:ew o. the lure cnown ir.
Figure 1$~
-a -Figure 7 is a par:ial cross~esc~~onal view o. the installaticn o_" the ball in a sand hole na shown in Fiqurs 5:
Figure a is a c=oss-sect=:..:a_ view along t:~e lines e-o _..
FiSura 7t and Figure 9 snows tae cross section o: LWO ad]acan~ fuses illuszrat-ng positioning discnnce.
Figure 171 si~ows a prior art high speed :use 9. M~tal erc balls 13 with terminals 15 are housed witt~.in the ends of an insulating tune <C. ;t is seen .:.Lt LhB to winal 15 is walGcd c:
brazes at 17 onto the metal end bell .3. Tbus the and ball =~ is elect=_cally hot when ~~c fuse is moon=ed i:. an olac:r:cally energized c:~cua. Tho and b~11 is held in place in insulating tubs ~0 by mszal pins di which are aiso.a' the same voltage level as the and boll 13. Thus, as shown in Figure 9, the minimum distance "°" that prior art rigZ spud fuses can ae placed ad~ao~nz too aaoh other, as dictazad by induarial scanaards, is governed by the distance between the electrically l~.ot ping 41 0:
an~scent ruses.
In the fuse according to the present invention shown in Figures 18) 5 and 6 and raiarred to generally by numeral e, an sad ball assembly o. an sad ball lZ anc =or~irta= 14 are adapted co ba rscaivad in aacn end of is~sulatinQ housinr~ or tuba ao. The and bell =Z enc Lerinal 14 era s=rmped ::am a piece c. material and a slot 16 is punched in the end bell 12, The to~inal 14 is inserted into the slot 16 until shoulders 48 engage the end bell 12. The tee=nal 14 is then staked at 46 or coined c.
mechanically upset in position as shown in Figure 4 to at:ach terminal 14 to end bell 12. '1':~us the terminal and the end boll are joined witroL= braz:nQ, we=Cing or solder~:~g, anc witraut complicated mecranical assembly using add:.tional components.
is more cost et_=cient to proauce the parts by stamping ratrer than by forging. Stamping provides a scrap rsauct~on over making the parts from lorQing and also allows the celection of appropriate materials for the and ball 12 and terminal 14 whic:~
can be of dissimilar materials such as plastic and metal.
11s shown in Figures 2 and 3 ( a series of small rectangular cross-sectioned ricgea, weld pads or psojec~ions 44 are emcossed on tho inner end a: terminal 34 during labrication for welding terminal 14 to one end o! a fuse element 30, preferably by resistance welding. These weld projec=ions <4 may bs coined or machined into terminal 14. The height of sack of weld projections 44 is the same over the entire weld area. The nums~sr of projections ad is dszs~ained by the width of terminal 1G. Tha size and shape of the pads may vary from terminal to terminal depending upon the size of hiss element 30 and end bell :2. ~ saw toot. pattern may also ba used in soma applications.
- o -Tha pitc.'~ and depth o! the saw tooth will vary wit : 1! :.k =h-ckness.
1~n advantage to using wale p:o~actions 44 on the te=-urinal 19 1s that it improves the welding of the fusible element 3 o to the terminal 14. Meld p:ajoct~cas 44 provide consistent welt quality and walaed surface area rasua:ng in consistent heat traneter and e3ect=_cal caacuc:.wity t.::ough the welded joi:~t betwaon the ~us3ble element 30 ana the terminal 1~ o~ :use e.
This results in pore reliable fuss perfozance and reauction in costs because al. welds can be mace simultaneously. T::!s p:oceaure also -enuces maintenarca of ttie weld electroces becnuse bat: elect=ooes are flat bla6as as compared ~o smal= poirttd eleotrodes. This type o! const~:ct:on ig also very useful for automating welding arid results in a mo:e consistent weld than that at=ordad by ps_a: tit spot weld3ag tecrniques. D=:act labar is roauoed because multiple welas can be mode with each eleetrece closure. Thus, the time required to weld t:~e st:-p to tae terminal is recucad, the eansistency of the weld arse is improved, and tae elect:ical coac~_=t:vity and heat tranaier from terminal strip to fuss clement is consistent.
The fuse alsment 30 1s preferably of a stanearc_zed planar design using an aeea:Cion shape which allows for the use of an element having a substantially longer overnll effective length than can be ac~ieved with a straigh t t:..ough element as in mos t prior art high speed fuses. The increase in effective leng~~
ennnncea the abili:y of the fuse to clear lower level overcu-:ent situations, aspscia'_ly on DC c=:~~=~s. As shown in Figures 5 and 6, a ruse element 30 may be welded to born sides of terminals 14 to provide a mLlt_rle element fuse.
Referring noW to Figures 9) since the te_~_::..~.al .4 pro3ec~s through the trc::: face and back :ace a: t.~a end bell 12, the :LSibla aiament 30 may be elect:=cally connectea cirertly to the terminal 14. Thus, the end bell 12 does »ot need to be mass or eiact-iCally corcucr:ng mazar:al, and may' ba made of pleat=c o.
zznar non-elect=:cally conduc:iva materials. Fed bells 12 ci insulat,ng material, such as plastic, era less expensive than metal end bells and can be molCed instead of machined allowinc for the use o. more in=::ca=a shapes when necessary. The insulating end bells 12 not only serve their normal turc~ion o:
closing off the ands o! tits insulating tube 40 of fuss a and provide the re~~~ od st:uctL:a1 integrity to the fuse package, their use results In the mesas p-ns 41) vetch sec::=a the end bell 12 within the tube 40, being insulated from tea elect=:gal circuit passing through terminal 14 and fusible element 30.
Jan advantage o= using plestic or other non-electrically concuctwo mata:ial for the end ball iZ is that pins 41, designed to project through the insulating tune 40 into the and ball 12, are not anergized~since the end ball is nom alact:~ca:ly _ conauctive. Since holding pine 41 acv not "electr,:cally hot~~
when mounted side by side, fuses can be positioned closer together thus conserving panel board space in equipment. In the prior err :use where the moral pin is elac;.r:cally hot, the adjacent !uses car..zo:~ be taaan:.ed side by side in close proxi~~;y more titan the distance "F" shown in Fi~~re 9. The separation between the fuses is governed by the distance between t.~e terminals which are electrically hot. Howwer) when mounted in an electrical circ;at, high speea fuses manutacturea according to the prsaen~ invent~on may be positioned closer to one anotzer since the miniaum distance "F" is measured between t!:e electr!cally hot terainals 14 aid not the pins 41 as shown 'r.
~iQura 9.
As she !uses are assuabled, t ~irsz terminal is ~o~nea to a :tier end bell, a second terminal is joined to a socona end bell, ana the fusible element 3o is welded between the twc tezminala. Because at the weld projoctions 4d on the terminal 14, the welding o: zhs fusible elament may be done by projection welding.
Re=erring now to Figures 5-8, the assembly of the and bell assemblies welded to the ends of the lusible element ~o is slipped into the insula::ng tuba 40 and the end bsilc are held in position within tuna <o by p:nr .t1 which are inserted into aligned aperruras fn tube 40 and end bells 12. Aligned .. " _ apertures era placed in the and bells 12 and tuba 4o by dr?1=irg just prior to insertion of pins 41. An arc quenching matariel «, shown in Figures 5 and 6, typically special sand, is poured into sand holes ZO in the end ball lZ. Altnr trio high speed fuss 8 is tilled with sand, the holes ZO are closed using a so=_C
spherical ball 18. These round balls 18 may be steal or attar material and are slightly larger than the hole 2o in the end bell 12. The ball 18 is prevented :raga misaliQnmsrt because it is guided by its cwn natural radio= irtc the hole 20. The balls .8 are thus self-centering and are held in place by =r:ctional :once. Alternatel y, pa:z:cularly where end belle 12 are metal, suc:. as.braas, the sand hots ZO may be coined after insertion of the bail 18 to hold the ball in. Tho balls 18 are iorcea or press4d into tba end ball 12 by an insert~on tool 45. The bail 18 is trapped between three smr=1 pins 47 which displace t::e metal 49 of the metal and bet= .2 over the ball 18 while the final insertion is boinQ accomplished. The =tat bottom of the insertion tool 45 p:oviaos autaaatic insertion doptn. over insertion is prevented by the design of the insertion tool a5.
Using balls 18 has several advantages. The harasnea steel ball 18 provides a low cost, salt-el'_QninQ, easily inserted means of plugging the l:11 hole ZO in the end bell 12 0= a fuse 8. The steel ball l8 requires leas lorce to insert and tanns to be selt-locking. This a significantly easier than prier art processes which often us.d p:na, hollow cloesc-end cylinders, or screws to seal trig bolos.
Zt 1s scan that high spood :uses ~nsn~::ac:Lraa eccarc:.~.g ;,o zee present inven:ian ars easier to const ~~~, reguire less laic:
anc are consequent3y less expensive to manu:t=;~_ro ar.,:, '_:z cae emaodimsnt, can De used closor t~ga-,.rier, Whan mounted acjacenL Lo ons another, wir: recucad danger o_~ short:.ng rrcm to:e to fuss.
_ " _
Claims (16)
1. A fuse comprising:
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end having weld projections;
a second end bell having a second terminal;
a fuse element having one end welded to said weld projections on said first terminal and another end welded to said second terminal;
a housing receiving said end bells, terminals, and fuse element;
said housing having a plurality of circumferentially spaced holes in each end of said housing;
said first and second end bells having a plurality of bores circumferentially spaced around the periphery thereof adapted for alignment with said holes;
said first and second end bells being made of a non-electrically conductive material; and metal pins received within said aligned holes and bores for securing said end bells within said housing, said pins in non-electrical contact with said terminals and fuse element.
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end having weld projections;
a second end bell having a second terminal;
a fuse element having one end welded to said weld projections on said first terminal and another end welded to said second terminal;
a housing receiving said end bells, terminals, and fuse element;
said housing having a plurality of circumferentially spaced holes in each end of said housing;
said first and second end bells having a plurality of bores circumferentially spaced around the periphery thereof adapted for alignment with said holes;
said first and second end bells being made of a non-electrically conductive material; and metal pins received within said aligned holes and bores for securing said end bells within said housing, said pins in non-electrical contact with said terminals and fuse element.
2. A fuse comprising:
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end being staked to attach said first terminal to said first end bell;
a second end bell having a second terminal;
a fuse element electrically connecting said first and second terminals;
a housing receiving said end bells, terminals and fuse element;
said housing having a plurality of circumferentially spaced holes in each end of said housing;
said first and second end bells having a plurality of bores circumferentially spaced around the periphery thereof adapted for alignment with said holes;
said first and second end bells being made of a non-electrically conductive material; and metal pins received within said aligned holes and bores for securing said end bells within said housing, said pins in non-electrical contact with said terminals and fuse element.
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end being staked to attach said first terminal to said first end bell;
a second end bell having a second terminal;
a fuse element electrically connecting said first and second terminals;
a housing receiving said end bells, terminals and fuse element;
said housing having a plurality of circumferentially spaced holes in each end of said housing;
said first and second end bells having a plurality of bores circumferentially spaced around the periphery thereof adapted for alignment with said holes;
said first and second end bells being made of a non-electrically conductive material; and metal pins received within said aligned holes and bores for securing said end bells within said housing, said pins in non-electrical contact with said terminals and fuse element.
3. A fuse comprising:
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end being staked to attach said first terminal to said first end bell;
said inner end having weld projections;
a second end bell having a second terminal;
a fuse element having one end welded to said weld projections on said first terminal and another end welded to said second terminal; and a housing receiving said end bells, terminals, and fuse element.
a first end bell having an opening therethrough;
a first terminal having an inner end extending through said opening and projecting from said first end bell;
said inner end being staked to attach said first terminal to said first end bell;
said inner end having weld projections;
a second end bell having a second terminal;
a fuse element having one end welded to said weld projections on said first terminal and another end welded to said second terminal; and a housing receiving said end bells, terminals, and fuse element.
4. A fuse as in claims 1 or 3 wherein said weld projections are parallel with the longitudinal axes of said terminals and said fuse element.
5. A fuse as in claims 1 or 3 wherein said weld projections have a longitudinal length substantially the distance said inner end of said first terminal projects from said opening.
6. A fuse as in claims 1 or 3 wherein said weld projections are disposed on both sides of said inner end of said first terminal.
7. A fuse as in claims 1 or 3 wherein said weld projections are alternating ridges and grooves around said inner end with said grooves and said ridges being in alignment on each side of said inner end.
8. A fuse as in claims 1 or 3 wherein said weld projections are alternating ridges and grooves.
9. A fuse as in claims 1 or 3 wherein said weld projections and alternating ridges and grooves and said grooves have a depth less than one-half the thickness of said first terminal.
10. A fuse as in claims 1 or 3 wherein said weld projections are alternating ridges and grooves and said ridges are rectangular in cross-section forming a flat projecting surface.
11. A fuse as in claims 1 or 3 wherein said weld projections are alternating ridges and grooves and said grooves have a bottom perpendicular wall.
12. The fuse as in claim 10, wherein said end bells and terminals are stampings.
13. A fuse as in claims 1, 2, or 3 wherein said fuse element is an elongated planar element having an accordion shaped cross section.
14. A fuse as in claims 1 or 3 wherein said weld projections are coined onto said first terminal.
15. A fuse as in claims 1, 2, or 3 wherein said first end bell has at least one aperture with a circular cross-section therethrough; and a spherical solid ball has a cross-section greater than said cross-section of said aperture for insertion into said aperture, said ball self-centering as said ball is inserted into said aperture and frictionally held within said aperture.
16. A fuse as in claim 3 wherein said first and second end bells having a plurality of bores circumferentially spaced around the periphery thereof adapted for alignment with said holes; said first and second end bells are made of a non-electrically conductive material;
and metal pins are received within said aligned holes and bores for securing said end bells within said housing, said pins being in non-electrical contact with said terminals and fuse element.
and metal pins are received within said aligned holes and bores for securing said end bells within said housing, said pins being in non-electrical contact with said terminals and fuse element.
Applications Claiming Priority (11)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/344,717 US4949063A (en) | 1989-04-24 | 1989-04-24 | End closure system for high speed fuse |
| US07/344,719 | 1989-04-24 | ||
| US07/344,717 | 1989-04-24 | ||
| US07/344,796 US4935716A (en) | 1989-04-24 | 1989-04-24 | Fuse having a ball plug |
| US07/344,718 US4949062A (en) | 1989-04-24 | 1989-04-24 | Fuse having a non-electrically conductive end bell |
| US07/344,796 | 1989-04-24 | ||
| US07/344,718 | 1989-04-24 | ||
| US07/344,719 US4951026A (en) | 1989-04-24 | 1989-04-24 | Weld projections on fuse terminals |
| US07/436,893 US4972170A (en) | 1989-04-24 | 1989-11-15 | High speed fuse |
| US07/436,893 | 1989-11-15 | ||
| CA 2015285 CA2015285C (en) | 1989-04-24 | 1990-04-24 | High speed fuse |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2015285 Division CA2015285C (en) | 1989-04-24 | 1990-04-24 | High speed fuse |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2274376A1 CA2274376A1 (en) | 1990-10-24 |
| CA2274376C true CA2274376C (en) | 2003-07-15 |
Family
ID=27617924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002274376A Expired - Lifetime CA2274376C (en) | 1989-04-24 | 1990-04-24 | High speed fuse |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2274376C (en) |
-
1990
- 1990-04-24 CA CA002274376A patent/CA2274376C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2274376A1 (en) | 1990-10-24 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKEX | Expiry |