AU598796B2 - Fuse link - Google Patents
Fuse link Download PDFInfo
- Publication number
- AU598796B2 AU598796B2 AU69577/87A AU6957787A AU598796B2 AU 598796 B2 AU598796 B2 AU 598796B2 AU 69577/87 A AU69577/87 A AU 69577/87A AU 6957787 A AU6957787 A AU 6957787A AU 598796 B2 AU598796 B2 AU 598796B2
- Authority
- AU
- Australia
- Prior art keywords
- fuse
- connecting means
- fuse element
- tube
- fuse link
- 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.)
- Ceased
Links
- 238000010791 quenching Methods 0.000 claims description 16
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 9
- 239000004327 boric acid Substances 0.000 claims description 9
- 239000007789 gas Substances 0.000 claims description 6
- 229910000906 Bronze Inorganic materials 0.000 claims description 4
- 239000010974 bronze Substances 0.000 claims description 4
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 claims description 4
- 238000013022 venting Methods 0.000 claims description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims 1
- 239000000919 ceramic Substances 0.000 claims 1
- 229910001120 nichrome Inorganic materials 0.000 description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 238000002788 crimping Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 229910001369 Brass Inorganic materials 0.000 description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical group [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 4
- 239000004809 Teflon Substances 0.000 description 4
- 229920006362 Teflon® Polymers 0.000 description 4
- 239000010951 brass Substances 0.000 description 4
- 239000004677 Nylon Substances 0.000 description 3
- 229910001128 Sn alloy Inorganic materials 0.000 description 3
- 229920001778 nylon Polymers 0.000 description 3
- 229910000978 Pb alloy Inorganic materials 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000009970 fire resistant effect Effects 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
- H01H85/02—Details
- H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
- H01H85/041—Fuses, i.e. expendable parts of the protective device, e.g. cartridges characterised by the type
- H01H85/042—General constructions or structure of high voltage fuses, i.e. above 1000 V
Landscapes
- Fuses (AREA)
Description
59796C, Form AU ST'R ALIA PATENTS ACT 1952 COMPLETE SPECIFICATION (ORIGINAL)0 FOR OFFICE USE Short Title: Int. Cl Application Number: Lodged: 1-57 7/8 7 Complete Specification-Lodged: It Lapsed: cc C CPublished: ""Priority: C t: C This d'cme~ C-tj~ uh amnendmnleits made fd~ section a9 ad is Correct for Printinig.
Related Art:
C
Name of Applicant: Address of Applicant: TO BE COMPLETED BY APPLICANT Sc ?!ERLYNRN STANC[ERflf ITEC.3b6L MfORk.YNWJ cSRrmicS FerY.~ ITN~ tT~ 194 Miller Street, West Pl-egton, 3072, Victoria, Australia.
Rainer Dornauer Actual Inventor: Address for Service: CLEMENT HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.
Complete Specification for the invention entitled: FUSE LINK It to me:- PF/CPlF/2/80 -2o 0 9t SFUSE LINK This invention relates to a fuse link, and more particularly but not exclusively, to a fuse link incorporated in an expulsion fuse for use in connection with high voltage *09 Selectrical transmission lines.
It is the practice with high voltage transmission lines to incorporate expulsion fuses across selected insulators from which electrical transmission cables or wires are suspended. An expulsion fuse consists of a fuse carrier formed from a hollow tube through which a fuse link passes Swhich is adapted to be in electrical conducting relationship with the electrical cables or wires at either end of the tube.
Sn rThe lower end of the fuse carrier when installed is open to I'u C C Ct C t.: i_ I i 3 allow the tail at one end of the fuse link to pass therethrough, whilst the upper end of the fuse carrier carries a top casting with which the other end of the fuse link is mechanically connected in electrical conducting relationship.
The expulsion fuse is arranged so that a tensile force is normally applied to the fuse link between the fuse tail and other fixed end of the fuse link, whereby when the fuse link fuses, the fuse tail is expelled to ensure that an open circuit occurs. The configuration and operation of expulsion fuses is well known in the art and a further description will not be included herein. An example of such an expulsion fuse is described in copending Australian Patent Application No. 55261/86.
A prior art fuse link for an expulsion fuse is 15 illustrated in Figures 1 and 2 shown slightly smaller than actual size. With reference to Pigure 1 there is shown a fuse link comprising an outer assembly 10 which consists of a nylon tube having a screw head terminal 12 attached to one end thereof. Outer assembly 10 houses electrical connecting means 14 having a first portion connected to the screw head terminal 12 and a second portion protruding from the other end of the outer assembly 10. The connecting means 14 typically comprises two lengths of 1/8 inch diameter brass tubing.
Between the first and second portions of the connecting means 14 there is provided a strain element 16 having a fuse wire 17 wound thereon. Strain element 16 is typically made of terelene cord and fuse wire 17 is typically made of a tin/lead alloy. The portion of the connecting means 14 protruding from the end of the outer assembly 10, has a fuse tail 15, which 30 consists of a tinned copper flexible cable, connected thereto.
There may also be provided an insulating tube 11 surrounding the protruding portion of connecting means 14 and the cable in order to prevent flashback of the discharge arc produced when the fuse blows. Brass ring 13 provides a crimp connection for fastening the tube 11 to the protruding portion of the connecting means 14.
iF, I i 4 i Referring to Figure 2 there is shown an enlarged partial-cutaway view of a portion of the fuse link of Figure i. In Figure 2 it can be seen more clearly that the fuse tail and the protruding portion of the connecting means 14 are joined by means of a joint terminal 19 which is crimped to the fuse tail 15 and connecting means 14 respectively. The strain element 16, having fuse wire 17 wound thereon, can also be seen more clearly, serially connected between the first and second portions of the connecting means 14. Strain element 16 and fuse wire 17 are typically held in the ends of the respective portions of connecting means 14 by crimping of the ends of the brass tubing. In this manner an electrical current path is provided through the fuse link from the terminal 12, through the first portion of connecting means 14, 15 through fuse wire 17, and through the second portion of ng Sconnecting means 14 to the fuse tail In use, when fuse wire 17 is subjected to excessive :current it fuses and the heat generated due to the fusing and 4, the consequent arcing between the first and second portions of the connecting means 14, severs the strain element 16 which is under strain due to a tensile force applied to the fuse link by the expulsion fuse arrangement. Consequently, the fuse tail 15 and the second portion of the connecting means 14 are expelled from the outer assembly 10 of the fuse link to ,25 establish an open circuit. In Figure 2 there is also shown an S inner nylon tube 18 coaxially surrounding the connecting means 14, the fuse wire 17 and strain element 16. Tube 18 is fastened to the protruding portion of connecting means 14 by the action of crimping ring 13. Nylon tube 18 is provided in S 30 order to limit the volume of air entering the outer assembly when the fuse tail is expelled and thereby minimize the arcing that occurs at higher current levels.
A number of disadvantages of the prior art fuse link illustrated in Figures 1 and 2 have become evident in practice. Firstly, both before and during installation in an expulsion fuse by linesmen, it has been found that the tail of the fuse link is often subjected to twisting. Rotation of
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1 A- :i -ii ii i i i 3 the tail 15 is transferred to the protruding portion of the connecting means 14, which is in turn connected to the strain element 16 and the fuse wire 17. The fuse wire 17, made of a tin/lead alloy, has a relatively low tensile strength and therefore it requires only a few turns of the tail 15 in order to break the fuse wire 17. However, the strain element 16 made of terelene cord is quite capable of withstanding a number of turns and would not normally break. Therefore the linesmen installing the fuse link has no way of knowing that the fuse link is no longer operative as the protruding portion of the connecting means 14 is still held firmly by the strain element 16.
Another disadvantage of prior art fuse links used in expulsion fuses has been the tendency to release a shower of p.
15 sparks when a fuse blows. It will be appreciated that such a release of sparks may be hazardous, particularly where the fuse is located on transmission lines passing through bushland where there is a high fire danger. Various attempts have been made to modify the design of expulsion fuses and fuse links in 20 order to minimize the release of sparks and produce a so-called sparkless fuse. These include the provision of various forms of shielding surrounding the fuse to capture any sparks which may be released when the fuse link blows.
Another approach has been to select a material for the fuse 4 25 wire 17 which would fuse in such a manner that the release of St sparks due to arcing between the respective portions of the connecting means 14 was minimized. However these methods have only met with limited success and there remains a window in Sthe current rating of the fuses, between approximately e 30 ampere to 60 ampere, where there is still substantial release of sparks due to arcing when the fuse blows under a condition of excessive current.
atpIt is therefore an object of the present invention toattempt to overcome one or more of the above disadvantages of prior art fuse links.
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6 According to the present invention there is provided a fuse link for an expulsion fuse, said fuse link comprising: an outer assembly comprising an elongate tube having an insert at one end and the other end being open; a fuse element; an inner assembly provided within said outer assembly tube, for containing an arc-quenching medium in close proximity to said fuse element, said inner assembly comprising an elongate tube arranged coaxially with, and having an outer diameter which is smaller than the inner diameter of, the outer assembly tube; electrical connecting means serially connected to said fuse element for providing a current path through said fuse element, Ssaid electrical connecting means comprising a first portion fixedly held within the outer assembly tube by said insert, and a second portion that is expelled when the fuse element fuses in use, said fuse element being disposed between said first and second portions, said inner assembly tube coaxially surrounding said fuse element and a part at least of said first and second portions immediately adjacent the fuse element, said inner assembly tube being sealingly connected at one end to said second portion of I the electrical connecting means whereby, in use, when said fuse crf element fuses due to excessive current, and said second portion of the electrical connecting means is expelled from the outer assembly tube, said inner assembly tube is also expelled from the outer assembly tube and said arc-quenching medium inhibits a discharge of sparks due to arcing.
In order that the invention may be more clearly ascertaLned several preferred embodiments of the fuse link will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side view of a prior art fuse link; Figure 2 is a partial-cutaway view of a portion of the fuse link of Figure 1; Figure 3 is a side view of a first embodiment of a fuse link -AI according to the invention; ,S-n i c 1
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i iij a li:i i-i ~1: -7- Figure 4 is a partial-cutaway view of a portion of the fuse link of Figure 3; Figure 5 is a side view of a second embodiment of a fuse link according to the invention; and, Figure 6 is a partial-cutaway view of a portion of the fuse link of Figure Referring to Figures 3 and 4 of the drawings there is shown a first preferred embodiment of a fuse link according to the present invention in which the like reference numerals refer t a, to the same parts as in Figures 1 and 2. A comparison of the 41 fuse link illustrated in Figures 1 and 2 with the fuse link *Saw illustrated in Figures 3 and 4 reveals that the most significant saw changes in the fuse link illustrated in Figures 3 and 4 are the I 7 provision of an arc-quenching medium 24 and of a fuse element comprising strain wire 21.
Strain wire 21 replaces the strain element 16 and the fuse wire 17 of the prior art fuse link shown in Figure 1, and is preferably made from nichrome wire. Nichrome wire has been V a chosen because it provides both adequate tensile strength and a predetermined melting point under current overload conditions.
It will be appreciated that strain wire 21 is capable of p~withstanding a tensile force applied to it prior to fusing whereby the problem of breakage due to twisting of the fuse tail is substantially obviated. The strain wire 21 is connected to the respective ends of each length of brass tube. NOT0 -8 comprising the first and second portions of the connecting means 14 by crimping. Surrounding the exposed portion of the strain wire 21 is a small diameter teflon sleeve 22 which is provided to restrict the volume of air surrounding the strain wire 20 and thereby inhibit arcing when the fuse blows as well as protecting the strain wire from corrosion. Teflon sleeve 22 also provides thermal insulation around the fuse element whereby the rate of fusing is improved, particularly at low currents.
Referring to Figure 4 there is illustrated an enlarged partial cutaway view of a portion of the fuse link of Figure 3. In Figure 4 it can be seen that an arc-quenching medium 24 is provided surrounding the fuse element 20 as well as a substantial length of the first and second portions of 15 the connecting means 14. The arc-quenching medium 24 is contained within the outer assembly 10 by means of an inner assembly 26 comprising an elongate tube arranged coaxially with outer assembly 10 and connecting mean's 14, and having an outer diameter which is smaller than the inner diameter of the I* 20 outer assembly tube. The inner assembly tube is sealingly connected at one end to the second portion of the connecting :V means 14 by crimping ring 13 so that when the fuse element fuses, the inner assembly 26 is also expelled from outer assembly 10. Using teflon as the material from which the tube of inner assembly 26 is made has been found to result in less carbon deposition and less friction when the fuse blows and therefore results in a better separation of the two portions k of the fuse link. Inner assembly 26 also functions similarly C C to the tube 18 of the prior art fuse link in sofar as it t 30 limits the entry of air (oxygen) into the outer assembly when the fu.i tail 15 is expelled and thereby minimizes the amount of arcing that occurs.
Arcquenching medium 24 may be of any suitable flame retardant material and in particular boric acid has been found 35 to be quite suitable. When the strain wire 21 fuses due to excessive current the small teflon sleeve 22 is consumed or expelled and as the two portions of connecting means 14 -1 W. ns j s 14 1-1~1~ ^a'S'SiSawJLdaAl^.'; F. I L_
II
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9 separate sparks produced to arcing between the respective portions of the connecting means 14 are extinguished due to the presence of the boric acid. Boric acid produces an inert gas when subject to elevated temperatures such as occur due to the fusing and arcing with the fuse link under overload current conditions. A substantial length of the inner assembly tube extends over the first portion of the connecting means 14 and contains therein the arc-quenchirg medium 24 in particulated form. Therefore the gap between the respective ends of the first and second portions of the connecting means 14 is continuously supplied with arc-quenching medium 24 whilst the second portion is being expelled. When the free end of the inner assembly tube finally emerges from the outer assembly 10, azcing has ceased and substantially all of the sparks have been quenched.
Boric acid has been found to operate satisfactorily as an arcquenching medium over the complete current range of about 2 ampere up to 63 ampere for fuse links used in this type of expulsion fuse. Under laboratory test conditions it has been found that even up to a short circuit breaking current of 600 ampere not all of the boric acid has been consumed and therefore reliable operation is anticipated at even higher breaking current levels. It is not necessary for the arc-quenching medium to contain 100% boric acid and indeed it is preferable to include other inert substances, such as silica sand, in order to reduce the overall cost of the fuse link. It has been found that between 70 and 100% boric acid with the remainder comprising silica sand has resulted in satisfactory performance of the arcquenching medium.
Using nichrome wire for the strain wire 21 of the fuse element 20 will provide satisfactory performance of the fuse link up to operating current levels of approximately ampere. Above this current level a second fuse wire is provided connected in parallel with the nichrome wire, which fuse wire has a higher conductivity than the nichrome wire. A suitable material for the parallel fuse wire is silver wire.
Because of the increased conductivity of the silver wire the i,, a a parallel fuse wire will carry most of the current passing through the fuse link whilst the nichrome wire continues to provide the tensile strength. The actual current rating of the fuse element will be a function of the respective conductivities of the parallel connected nichrome wire and silver wire.
Following experimental trials of the fuse link illustrated in Figures 3 and 4 a number of limitations of this first embodiment were discovered, particularly at higher current levels. In Lhe second embodiment illustrated in Figures 5 and 6 these limitations were overcome and scveral further improvements to the design of the fuse link were incorporated. In the second preferred embodiment phosphur bronze wire was employed rather than nichrome wire for the V. 15 strain w,,ire 21 of fuse element 20. Phosphur bronze wire is preferred because it has a lower melting poinZ- temperature to that of nichrome wire. It was found that heat generated by the fuse element 20 prior to fusing using nichrome wire was damaging the inner assembly 26, and sometimes even outer assembly 10, and therefore impairing proper operation of the fuse link. The operating current range of the fuse link using a single phosphur bronze strain wire is about 2 to 10 ampere.
By adding one or more parallel fuse wires to strain wire 21 the current rating of the fuse element 20 can be extended to cover the complete current range for this type of fuse link.
Suitable metals for the parallel fuse wires are for example silver or various tin alloys. The tube of outer assembly 3is preferably made from a fire resistant plastics material.
Referring to Figure 5 it can be seen that the tube 3of inner assembly 26 is provided with a necked portion 27 of reduced diameter to aid in retaining the arc-quenching medium 24 within the inner assembly 26 both prior to use and during expulsion. When the fuse element 20 fuses and heat due to arcing is generated causing the production of gaF from the boric acid, the pressure within the inner assembly 26 increase sgiicantly and causes a jet of gas to be expelled from the free end of the tube of inner assembly 26.
11 9, t r fl 1 $trr r tr, t ,e te f The jet of gas thus produced significantly increases the speed at which the second portion of the connecting means 14 is expelled from the outer assembly 10, so much so that the fuse tail 15 may actually fracture or separate from the joint terminal 19. Furthermore, at high breaking current levels, e.g. in excess of 1000 ampere; the rate at which the gas in produced may in fact be explosive and it was found desirable to provide some means of venting the gases produced without reducing the arc-quenching effect. For this purpose, the second embodiment illustrated in Figures 5 and 6 is provided with venting means 30 consisting of two holes, approximately 4 mm in diameter, provided in opposite sides of the tube of outer assembly 10. The position of the holes relative to the position of fuse element 20 is significant to allow gas to escape during the departure of the expelled portion of the fuse link without impairing its arc-quenching ability. The distance A indicated in Figure 6, for this purpose, is preferably 5 mm.
A further improvement in the fuse link of Figures and 6 is the provision of a slot 28 in the open end of the outer assembly tube which cooperates with a transverse portion of the crimping ring 13 to lock the second portion of the connecting means 14, and thus prevent rotation or twisting during handling.
Although in the above preferred embodiments an inner assembly 26 is provided to contain the arc-quenching medium 24, it will be obvious that other means for containing the arc-quenching medium 24 within the outer assembly 10 may be employed. For example, the arc-quenching medium 24 could be held within the outer assembly 10 by providing some form of seal at the open end of he tube of outer assembly 10 which is expelled with the second portion of the connecting means 14.
It will be apparent to persons skilled in the electric transmission arts that there are other practical embodiments of the present invention and that it is not limited to the preferred embodiments hereinbefore described.
cc c V V~t V r i
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12 All such modifications and variations are considered within the scope of the present invention, the nature of which is to be determined from the foregoing description.
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Claims (8)
1. A fuse link for an expulsion fuse, said fuse link comprising: an outer assembly comprising an elongate tube having an insert at one end and the other end being open; a fuse element; an inner assembly provided within said outer assembly tube, for containing an arc-quenching medium in close proximity to said fuse element, said inner assembly comprising an elongate tube arranged coaxially with, and having an outer diameter which is B. smaller than the inner diameter of, the outer assembly tube; t electrical connecting means serially connected to said fuse element for providing a current path through said fuse element, said electrical connecting means comprising a first portion fixedly held within the outer assembly tube by said insert, and a second portion that is expelled when the fuse element fuses in use, said fuse element being disposed between said first and second portions, said inner assembly tube coaxially surrounding said fuse element and a part at least of said first and second portions immediately adjacent the fuse element, said inner assembly tube being sealingly connected at one end to said second portion of the electrical connecting means whereby, in use, when said fuse element fuses due to excessive current, and said second portion of the electrical connecting means is expelled from the outer assembly tube, said inner assembly tube is also expelled from the outer assembly tube and said arc-quenching medium inhibits a i discharge of sparks due to arcing.
2. A fuse link as claimed in claim 1, wherein said inner assembly tube is connected to the second portion with a fastener having a portion with a transverse dimension which is greater than the inner diameter of said outer assembly tube, and wherein the open end of said outer assembly tube is provided with a slot glk 4, to receive said fastener portion whereby the second portion of gw -oS u~ 14 the connecting means is prevented from rotating prior to expulsion.
3. A fuse link as claimed in any one of the preceding claims, wherein said fuse element comprises a fusible strain wire capable of withstanding a tensile force applied to the fuse element, in use, via said electrical connecting means prior to fusing.
4. A fuse link as claimed in any one of the preceding 0o claims wherein said fuse element consists of a plurality of fuse wires connected in parallel, at least one of said fuse wires being capable of withstanding a tensile force applied to it in o°j use via said electrical connecting means prior to fusing.
A fuse link as claimed in claim 4, wherein said at least one fuse wire consists of a phosphor bronze wire. e*
6. A fuse link as claimed in any one of the preceding claims, wherein said arc-quenching medium comprises at least boric acid.
7. A fuse link as claimed in any one of the preceding claims, wherein said outer assembly is provided with means for venting gases produced when the fuse element fuses in use.
8. A fuse link substantially as herein described with reference to and as illustrated in Figures 3 to 6 of the accompanying drawings. Dated this llth day of April 1990. MORLYNN CERAMICS PTY LTD By Its Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. .D-f 1
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU69577/87A AU598796B2 (en) | 1986-02-28 | 1987-02-27 | Fuse link |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPH4833 | 1986-02-28 | ||
| AUPH483386 | 1986-02-28 | ||
| AU69577/87A AU598796B2 (en) | 1986-02-28 | 1987-02-27 | Fuse link |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU6957787A AU6957787A (en) | 1987-09-03 |
| AU598796B2 true AU598796B2 (en) | 1990-07-05 |
Family
ID=25635983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU69577/87A Ceased AU598796B2 (en) | 1986-02-28 | 1987-02-27 | Fuse link |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU598796B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU608370B2 (en) * | 1987-08-18 | 1991-03-28 | A.B. Chance Company | Pultruded or filament wound synthetic resin fuse tube |
| AU654206B2 (en) * | 1991-09-10 | 1994-10-27 | Australian Electrical Maintenance Pty Limited | Drop out expulsion fuse |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2750470A (en) * | 1954-01-28 | 1956-06-12 | Southern States Equipment Corp | Electric fuse |
| US3374329A (en) * | 1966-10-31 | 1968-03-19 | Mc Graw Edison Co | Fuse cutout |
-
1987
- 1987-02-27 AU AU69577/87A patent/AU598796B2/en not_active Ceased
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2750470A (en) * | 1954-01-28 | 1956-06-12 | Southern States Equipment Corp | Electric fuse |
| US3374329A (en) * | 1966-10-31 | 1968-03-19 | Mc Graw Edison Co | Fuse cutout |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU608370B2 (en) * | 1987-08-18 | 1991-03-28 | A.B. Chance Company | Pultruded or filament wound synthetic resin fuse tube |
| AU654206B2 (en) * | 1991-09-10 | 1994-10-27 | Australian Electrical Maintenance Pty Limited | Drop out expulsion fuse |
Also Published As
| Publication number | Publication date |
|---|---|
| AU6957787A (en) | 1987-09-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |