US3781746A - Expulsion fuse and support means - Google Patents

Expulsion fuse and support means Download PDF

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Publication number
US3781746A
US3781746A US00278030A US3781746DA US3781746A US 3781746 A US3781746 A US 3781746A US 00278030 A US00278030 A US 00278030A US 3781746D A US3781746D A US 3781746DA US 3781746 A US3781746 A US 3781746A
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United States
Prior art keywords
fuse
housing
support member
fixed position
terminal
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Expired - Lifetime
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US00278030A
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English (en)
Inventor
R Cuzzone
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General Electric Co
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General Electric Co
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Publication date
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Publication of US3781746A publication Critical patent/US3781746A/en
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    • 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
    • H01H85/20—Bases for supporting the fuse; Separate parts thereof

Definitions

  • ABSTRACT An expulsion fuse that is adapted to be immersed in operating position in a fluid coolant of a transformer is provided with a support means to facilitate installation of the fuse in vibration-resistant relationship within the transformer.
  • the support means includes a rigid angle support member having a coupling stud positioned on it for clamping a lead from the transformer primary winding in operating relationship to one terminal of the fuse.
  • the fuse is also characterized by having a baffle means that restricts the flow of transformer coolant around the fusible link of the fuse when it is immersed in the coolant.
  • a primary object of the present invention is to provide a fuse and fuse support means that are economical to manufacture and assemble in operating position while at the same time being adapted to afford a-vibration resistant assembly.
  • Another object of the invention is to provide a fuse and support therefore that is readily adaptable to rapid, high-torque connection with an air-driven connector fastener.
  • Still another object of the invention is to provide an expulsion fuse, that is adapted for immersion in the coolant of a transformer, with coolant-restricting baffle means that are operable to prevent distortion of the fuse interruption characteristics due to circulation of coolant through the fuse body.
  • a further object of the invention is to provide a primary expulsion fuse with a rigid support member that affords a readily accessible and easily employed means for making a vibration-resistant connection between the fuse link and a primary winding of a transformer.
  • an expulsion fuse having a rigid, insulating tubular housing, is provided with a rigid angle support member mounted adjacent to, and extending beyond, one end of the housing.
  • a fuse link is connected between a terminal mounted at the other end of the fuse housing and a second terminal rigidly fixed on the angle supporting member.
  • the support member also has a threaded stud mounted in fixed position on it adjacent the second terminal.
  • the stud is adapted to have a threaded nut, or other suitable clamping means, driven onto it by an airactuated wrench, thereby to readily effect a vibrationresistant electrical connection between the fuse link and an end of a transformer primary winding that is clamped in position around the stud by the clamping means.
  • the fuse housing is provided with a baffle means that restricts the flow of coolant around the fuse link, thereby to prevent distortion of the interruption characteristics of the fuse, due to the flow of such coolant in response to cyclical heating of the fuse link.
  • FIG. 1 is a side elevation view, partly in cross section, of a fuse and support therefor, constructed pursuant to the teaching of the invention, and shown with respect to a transformer bushing and associated portion of a transformer tank and some coolant with which the fuse and support means are adapted to be utilized.
  • FIG. 2 is an enlarged side elevation view, partly in cross section and partly in phantom, of the fuse and fuse support means illustrated in FIG. 1.
  • FIG. 3 is an end view of the fuse support means depicted in FIG. 2, omitting the related fuse structure and winding connector shown in FIG. 2.
  • the fuse 1 having an integral fuse support 2 that is constructed according to the teaching of the present invention. More specifically, the fuse 1 comprises an elongated, tubular housing 3 that is formed of a suitable dielectric material, such as bone fiber or other conventional expulsion fuse housing materials that are designed to evolve arc extinguishing gases when exposed to an are by the interruption of a fuse link therein. Threaded into fixed position on one end (3a) of housing 3 is afirst fuse terminal 4. The fuse terminal 4 is formed of any rigid electrically conductive material, such as copper. A second electrically conductive fuse terminal 5 is mounted in fixed position adjacent the other end (3b) of housing 3. Pursuant to the invention, this second terminal 5 is mounted in fixed position on a rigid angle support member 6. I
  • the support member 6 in the preferred embodiment of the invention is formed of flat steel plate stock into a generally L-shaped configuration.
  • the first leg portion 6a and second leg portion 6b of the L-shaped support member 6 are disposed at approximately a 90 angle to one another.
  • the supportmember 6 is mounted in fixed position on the housing 3 adjacent the second end 3b thereof, and the second electrically conductive terminal 5 is mounted in fixed position on the angle support member 6.
  • the second terminal 5 comprises a tubular connector 5a and a flat contact 5b that has a tongue 5c extending from it.
  • the connector 5 could be formed so that the flat contact portion 5b is integral with the terminalreceiving tubular portion 5a.
  • a fuse link 7 that may be formed of copper wire or other conventional vibration-resistant fuse link material is disposed at least partially within a passageway 8 that is defined by wall means 9 through the fuse body 3 from one end (30) to the other end (3b) thereof. As best seen in FIG. 3, the fuse link 7 is electrically and mechanically connected to both the. first terminal 4 and the second terminal 5 to form a fusible conductive circuit between them.
  • the fuse 1 is mounted in a conventional operating position where it is partly immersed in a body of transformer oil or other well known liquid coolant 10 within the steel housing 11 of an electric-power distribution transformer. Moreover, the first terminal 4 of the fuse 1 is staked onto one end of an elongated rod 12 that is made of copper, or other suitable material and forms an electrical circuit from the terminal 4 to a line terminal 13 mounted on the top ofa transformer bushing 14. The other terminal 5 of fuse 1 is electrically connected by conductor 15 to a primary winding (not shown) of the'transformer housed in the tank 11. Before describing the structure used to effect this connection to the primary winding of the transformer, it should be understood that the fuse housing 3 is provided with a vent hole 3' through which some of the liquid coolant 10 can enter the housing 3 and surround the fuse link 7.
  • the first leg 6a of support member 6 must be fixed rigidly in position with respect to the housing 3 of fuse 1 so that vibration is not allowed to occur between the support means 2 and the housing 3 when current is passing through the transformer in transformer housing 11.
  • a rigid mounting arrangement for the support member 6 is provided by a second wall means 16 that defines an elongated slot 16a that is adapted to receive one leg (6a) of the support member 6 therein.
  • the slot 16a in this form of the invention, is formed to extend from the outside of one side of the housing 3 around at least the center portion of the passageway 8.
  • a suitable holding means 17 is provided for retaining the leg 6a in a fixed position within the slot 16a.
  • the holding means 17 comprises an epoxy adhesive that may be of any suitable, well known type.
  • the adhesive 17 used in the preferred embodiment of the invention is thermally cured at 125 C for approximately 1 hour, when it ispositioned between a substantial portion of the leg 6a, as shown in FIG. 2, and the second wall means 16, so that it forms a rigid bond between these members and prevents movement between the support member 6 and the housing 3 of fuse 1.
  • a threaded stud 18 is mounted in fixed position on the angle support member 6 adjacent its outermost end.
  • the stud 18 is formed of copper-coated steel or other suitable electrically conductive material, and it is mounted in fixedposition on .the support member 6 by being welded thereto.
  • At least one threaded nut 19 is mounted on the stud 18 to clamp a conductor terminal 20 between it and the contact portion 5b of the second terminal 5 that is disposed adjacent the stud 18.
  • a second nut 21 is secured against it, as shown.
  • a terminal 5 tbat affords a convenient and economical means for forming a secure, vibration resistant connection between a transformer winding lead 15 and the fuse link 7 without damaging the relatively weak fuse link 7.
  • a connection is made possible with the preferred embodiment by crimping the tubular connector 5a, as shown by the detent 5d therein, so thatit secures one end 7a of fuse link 7 and the tongue 50 of contact 5b in electrically conductive relationship within the tubular connector 5a.
  • This arrangement makes it possible to utilize an air-driven wrench to drive the nut 19 against the connector 20 on primary lead 15, and contact 5b, thereby to secure them in operating position.
  • first tab 5b and a second tab 5b" (See FIG. 3) on contact 5b.
  • the tabs 5b and 5b" are bent at least partially around the leg portion 6b of'support 6, as shown in FIGS. 2 and 3. This arrangement of the tabs is effective to prevent the contact 5b from being twisted sufficiently to tear the tongue 56 when the nut 19 is driven into its clamping position.
  • only one tab e.g. the first tab 5b, would be necessary to prevent the-contact 5b from being rotated and torn during installation.
  • both tabs 5b and 5b" are used in the preferred embodiment of the invention.
  • the tabs are formed integrally with contact 5b, but it should be apparent that they may be articulated components, if desired.
  • the second terminal 5 is shown as an articulated contact 5b and tubular connector 5a in the embodiment of the invention disclosed herein, the second terminal 5 could be formed with a flatcontact portion 5 and an integral, crimpable portion 5a that could be secured to one end 7a of the fuse link 7.
  • the flat contact portion 5b of second terminal 5 may be formed -to define an aperture 22 in it that is adapted to receive the stud 18 therethrough. This aperture could either be a U-shaped channel or a circular hole in the contac portion 5b of terminal 5.
  • the support member 6 Since the support member 6 must withstand both; a torque of up to 25 inch-pounds, applied to it when a nut 19 is threaded onto the stud 18 with an air-driven wrench, and the vibration forces encountered during normal installation within a transformer, it is constructed of flat steel that is approximately one-sixteenth of an inch thick by one-half of an inch wide.
  • the slot 16a in housing 3 is formed by milling a generally rectangular-shaped groove in the walls of housing 3 such that the slot 16a snugly engages the edges of leg portion 6a of support member 6.
  • the tubular connector 5a of second terminal 5 is brazed to the support member 6; to facilitate the brazing, a copper coating is flashed on, or otherwise affixed to, the surface of it.
  • the first terminal 4 is prevented from rotating with respect to the housing 3 by upsetting the threads on terminal 4 as shown by detents 4a and 4b, in FIG. 2.
  • the baffle member 23 comprises a substantially flat piece of insulating material, such as pressed fiberboard, and it has an aperture 24 formed in it for receiving the fuse link 7.
  • a suitable mounting means 25 which in the preferred form of the invention comprises a thermally-cured epoxy adhesive, is provided for holding the baffle member 23 in its fixed position.
  • the aperture 24 is preferably a circular aperture slightly larger than the diameter ofthe fuse link 7, so that the walls of the aperture 24 serve to restrict the movement of the fuse link when the'housing 3 is subjected to vibration.
  • baffle member 23 is not as a vibration damping means, but rather to restrict the flow of the liquid coolant 10 around the fuse link 7. It has been found that during relatively low overcurrent conditions, when the fuse link might take to seconds to interrupt, the resultant convection currents within the coolant 10 in fuse housing 3 can cause an appreciable circulation of the coolant 10, which results in an unpredictable variation in the interrupting characteristics of the fuse link 7. Therefore, the novel function of the baffle member 23 is to prevent or limit such circulation and thus avoid such a variation in the interrupting characteristics of the fuse link 7.
  • a fuse and support therefor comprising, in combination;
  • a fuse housing formed of an elongated rigid body of insulating material
  • wall means defining a passageway through said body from one end to the other end thereof
  • a second electrically conductive terminal mounted in fixed position on said angle support member and comprising a tubular connector and a flat contact having a tongue extending therefrom, and
  • a fuse link disposed at least partially within said passageway and electrically and mechanically connected to said first and second terminals to form a fusible, conductive circuit between them
  • tubular connector being crimped around said tongue and one end of said fuse link thereby to secure them in fixed, electrically conductive relationship with said tubular connector.
  • both said tubular connector and said flat contact are formed of electrically conductive copper, and wherein said angle support member is formed of steel, said tubular connector being mounted in fixed position on said angle support member by being brazed thereto.
  • a fuse and support therefor comprising, in combination;
  • a fuse housing formed of an elongated rigid body of insulating material
  • wall means defining a passageway through said body from one end to the other end thereof
  • a second electrically conductive terminal mounted in fixed position on said angle support member and comprising a tubular connector and a flat, apertured, contact portion having a tongue extending from one side thereof, and
  • a fuse link disposed at least partially within said passageway and electrically and mechanically connected to said first and second terminals to'form a fusible, conductive circuit between them
  • tubular connector being crimped around said tongue and one end of said fuse link thereby to secure them in fixed, electrically conductive relationship within said tubular connector and said stud being positioned through the aperture.
  • An invention as defined in claim 3 including a baffle member mounted on said housing around the fuse link thereby to substantially close one end of the passageway through said housing.
  • a fuse and support therefor comprising, in combination;
  • a fuse housing formed of an elongated rigid body on insulating material
  • wall means defining a passageway through said body from one end to the other end thereof
  • said second electrically conductive terminal mounted in fixed position on said angle support member, said second electrically conductive terminal being formed with a first tubular portion and a second flat contact portion including wall means defining an aperture through it, said aperture being adapted to receive said stud therethrough,
  • a fuse link disposed at least partially within said passageway and electrically and mechanically connected to said first and second terminals to form a fusible, conductive circuit between them
  • said stud being positioned throughthe aperture in said second portion, said first tubular portion being electrically connected to said fuse link.
  • a fuse and support therefor comprising; a tubular,
  • dielectric housing having wall means defining a passageway through it, a first terminal mounted in fixed position on one end of said housing, second wall means defining a slot in said housing adjacent the other end thereof, said slot being formed to extend from the outside of one side of the housing around at least the center portion of said passageway, a rigid angle support member having a first and a second leg portion, a second terminal, the first leg portion of said angle support member being positioned in said slot and the second leg portion of said support member being arranged to support the second terminal in fixed position with respect to said housing, a stud mounted on said second leg portion, said stud being adapted to have a conductor clamped in fixed position with respect thereto, thereby to hold said conductor in electrically conducting relationship with said second terminal, and a fuse link electrically connected between said first and second terminals.
  • An invention as defined in claim 6 including a baffle member of dielectric material mounted over said other end of said housing, around said fuse link, thereby to substantially seal said other end of the hous- 8.
  • said second terminal (5) comprises a contact (5b) having a first tab (Sb') thereon, said tab (Sb') being disposed at an angle to said contact and in engagement with one side of said support member (6) thereby to prevent the contact from being rotated relative to said support member.
  • said contact (5b) is generally flat and includes a second tab (5b") thereon that is disposed at an angle of approximately to the plane in which said contact (5b) is disposed, said first tab (5b') and said second tab (5b") being positioned adjacent opposite sides of said support member (6), respectively, thereby to prevent said contact (5b) from being rotated with respect to said support member (6).

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US00278030A 1972-08-04 1972-08-04 Expulsion fuse and support means Expired - Lifetime US3781746A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US27803072A 1972-08-04 1972-08-04

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5936507A (en) * 1998-06-15 1999-08-10 Cooper Industries, Inc. Bayonet-type fuse housing assembly having a vent tube
US6624736B1 (en) * 2000-05-19 2003-09-23 Abb Inc. Fuse housing with rate release control plug
US20190259556A1 (en) * 2016-11-15 2019-08-22 Littelfuse, Inc. Ventilated fuse housing

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2170698A (en) * 1939-01-11 1939-08-22 Gen Electric Fuse support
US2188792A (en) * 1935-12-03 1940-01-30 Gen Electric Protective means for electric circuit
US2606954A (en) * 1948-03-22 1952-08-12 S & C Electric Co Universal single insulator mounting for high-voltage electrical devices
US3244838A (en) * 1963-09-12 1966-04-05 Westinghouse Electric Corp Current limiting fuse device and corona free protective link for use therein
US3365616A (en) * 1965-04-01 1968-01-23 Gen Electric Overvoltage protection system for electrical apparatus with current limiting fuse and removable oil fuse in series on line side
US3684995A (en) * 1970-12-09 1972-08-15 Westinghouse Electric Corp Electrical bushing assembly

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2188792A (en) * 1935-12-03 1940-01-30 Gen Electric Protective means for electric circuit
US2170698A (en) * 1939-01-11 1939-08-22 Gen Electric Fuse support
US2606954A (en) * 1948-03-22 1952-08-12 S & C Electric Co Universal single insulator mounting for high-voltage electrical devices
US3244838A (en) * 1963-09-12 1966-04-05 Westinghouse Electric Corp Current limiting fuse device and corona free protective link for use therein
US3365616A (en) * 1965-04-01 1968-01-23 Gen Electric Overvoltage protection system for electrical apparatus with current limiting fuse and removable oil fuse in series on line side
US3684995A (en) * 1970-12-09 1972-08-15 Westinghouse Electric Corp Electrical bushing assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5936507A (en) * 1998-06-15 1999-08-10 Cooper Industries, Inc. Bayonet-type fuse housing assembly having a vent tube
US6624736B1 (en) * 2000-05-19 2003-09-23 Abb Inc. Fuse housing with rate release control plug
US20190259556A1 (en) * 2016-11-15 2019-08-22 Littelfuse, Inc. Ventilated fuse housing
US10930463B2 (en) * 2016-11-15 2021-02-23 Littelfuse, Inc. Ventilated fuse housing

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Publication number Publication date
JPS4980550A (Direct) 1974-08-03

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