US3291943A - Time-lag fuse with ribbon fuse link folded in longitudinal and in transverse direction - Google Patents
Time-lag fuse with ribbon fuse link folded in longitudinal and in transverse direction Download PDFInfo
- Publication number
- US3291943A US3291943A US3291943DA US3291943A US 3291943 A US3291943 A US 3291943A US 3291943D A US3291943D A US 3291943DA US 3291943 A US3291943 A US 3291943A
- Authority
- US
- United States
- Prior art keywords
- pair
- fuse link
- fuse
- flanges
- casing
- 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.)
- Expired - Lifetime
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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
- H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
- H01H85/05—Component parts thereof
- H01H85/055—Fusible members
- H01H85/08—Fusible members characterised by the shape or form of the fusible member
- H01H85/10—Fusible members characterised by the shape or form of the fusible member with constriction for localised fusing
Definitions
- the invention relates to time-lag fuses, and more particularly to time-lag fuses for motor circuits.
- Another object of this invention is to provide timelag fuses for relatively small current ratings having a blowing time of about ten, or more than ten, seconds at overload currents in the order of five times the rated current of the fuse, and operating as current-limiting fuses on occurrence of currents of short-circuit current proportions.
- Still another object of this invention is to provide timelag fuses of the kind disclosed in my above referred-topatent applications, or of a similar kind, including means for reducing the heat flow in a direction longitudinally of the fuse structures, thus tending to reduce the minimum fusing current and to increase time-lag in terms of blowing time at given multiples of the rated current of the fuse structures.
- FIG. 1 is a top-plan view of an electric fuse being a first embodiment of this invention
- FIG. 2 is substantially a vertical section of the structure of FIG. 1;
- FIG. 3 is a section along 3-3 of FIG. 1;
- FIG. 4 is an isometric view of the fuse link structure forming part of the fuse shown in FIGS. 1-3;
- FIG. 5 is substantially a vertical section of another electric fuse being a second embodiment of this invention.
- FIG. 6 is a section along 6-6 of FIG. 5;
- FIG. 7 is an isometric view of a fuse link structure similar to that shown in FIGS. 5 and 6, but including a modification tending to reduce axial heat flow and to increase time-lag.
- FIGS. 1 to 4 numeral 1 has been applied to indicate a tubular casing of insulating material.
- Casing 1 is closed on both ends thereof by terminal elements in the form of caps 2 mounted on the axially outer ends of casing 1.
- Blade contacts 3 project transversely across terminal caps 2 and hollow pins 4 project transversely through casing 1 and blade contacts 3.
- Pins 4 are preferably of the type disclosed and claimed in US. Patent 2,939,935, issued June 7, 1960, and US. Patent 3,007,020,
- Reference numeral 5 has been applied to indicate pins which are driven into the ends of hollow pins 4 to expand the latter.
- Casing 1 is filled with a pulverulent arc-quenching filler 6, preferably quartz sand.
- the blade contacts 3 and the caps 2 on opposite ends of casing 1 are conductively interconnected by a ribbon fuse link of a high fusing point metal such as silver or copper.
- Reference numeral 7 has been applied to generally indicate this fuse link. Washers 8 of asbestos fibers or of a similar material are interposed between the axially outer ends of casing 1 and caps 2.
- Fuse link 7 includes an axially inner portion 7a and axially outer connector portions 7b.
- the axially inner portion is wedge-shaped and formed by a pair of flanges 7 and 7 enclosing an acute angle at.
- the axially inner portion 7a of fuse link 7 has a predetermined maximum cross-sectional area and defines serially related points of reduced cross-sectional area. Each of the three serially related points of reduced cross-sectional area is formed by a transverse line of circular perforations clearly shown in FIG. 4.
- Flanges 7' and 7" of the axially inner portion 7a of fuse link 7 support an overlay 9 of a link-severing low fusing point metal. Overlay 9 is preferably arranged in the way disclosed and claimed in my US. Patent 2,988,620, issued June 13, 1961.
- Each connector tab portion 7b is bent twice at spaced points in a direction longitudinally of fuse link 7. As a result of these two bends connector tab portions 711 form a first loop 7b toward the center of the axially inner portion 7a and form a second loop 7b" away from the center of the axially inner portion and toward one of the blade contacts 3 and terminal caps 2.
- Loops 7b and 7b greatly limit the dissipation of heat generated in the axially inner portion 7a of fuse link 7, and thus tend to limit the current-carrying capacity of the fuse structure, i.e. they require the mass of the fuse link 7 to be relatively large to obtain a predetermined minimum fusing current, and this, in turn, results in relatively long time lags, particularly in the range of five times the rated current of the fuse.
- the flange 7' of axially inner portion 7a is arranged in the plane defined by blade contacts 3, as is clearly apparent from FIG. 2, and thus the hottest portion of the fuse link 7 is positioned close to the longitudinal axis of the fuse tube or casing 1, and relatively evenly spaced from the latter.
- each connector tab 7b i.e. the loop 7b" thereof, encloses an obtuse angle with one of blade contacts 3.
- the axially inner portion 7a of fuse link 7 can be arranged close to the longitudinal axis of casing 1, as mentioned above.
- axially inner portion 7a of fuse link 7 includes two flanges 7 and 7" which enclose the acute angle 04.
- the axially inner portion 7a of fuse link 7 has a predetermined maximum cross-sectional area and defines three serially related points of reduced cross-sectional area which determine the fusing i -t of the fuse link structure. These points of reduced cross-sectional area are formed by transverse lines of circular perforations.
- Flanges 7 and 7" support a link-severing overlay 9 of a soft low fusing point metal such as, for instance, tin, or an appropriate alloy thereof.
- Fuse link 7 further includes the connector tab portions 7b.
- Each connector tab portion 7b is bent twice in a direction longitudinally of fuse link 7 and includes an axially inner loop portion 7b and an axially outer loop portion 7b.
- the axially inner loop portion 7b and the axially outer loop portion 712" shown to the left of FIGS. 5 and 7 are formed by an extension of flange 7 of axially inner portion 7a and the axially inner loop portion 7b and the axially outer loop portion 7b" shown to the right of FIGS. 5 and 7 are formed by an extension of flange 7 of the axially inner portion 7a.
- the zig-zag or loop geometry of connector tabs 7b tends likewise to minimize heat exchange between the axially inner portion 7a of fuse link 7 and its surroundings, particularly terminal caps 2.
- the connector tabs 7b have a cross-sectional area progressively decreasing toward one of the terminal elements, i.e. toward one of caps 2.
- Each connector tab 7b tapers axially outwardly and has a minimum cross-sectional area at the axially outer end thereof, i.e. the end thereof adjacent one of terminal caps 2. The cross-sectional area of this point of minimum crosssectional area of each connector tab 7b exceeds the crosssectional area of any point of reduced cross-sectional area of flange portions 7' and 7".
- flanges 7 and 7 form juxtaposed areas of the fuse link 7 which establish parallel current paths and that flanges 7' and 7" define an edge at the intersection of the planes thereof which extends in a direction substantially longitudinally of casing 1.
- Flanges 7 and 7" are portions of the fuse link 7 mutually heating each other.
- a time-lag fuse comprising:
- a time-lag fuse as specified in claim 1 comprising a pair of terminal caps and a pair of blade contacts each projecting transversely through one of said pair of terminal caps wherein one of said pair of flanges is arranged in a plane defined by said pair of blade contacts and wherein the axially outer end of each of said pair of connector tabs encloses an obtuse angle with one of said pair of blade contacts.
- a time-lag fuse as specified in claim 1 wherein one of said pair of connector tabs forms an axial extension of one of said pair of flanges of said axially inner fuse link portion and wherein the other of said pair of connector tabs forms an axial extension of the other of said pair of flanges of said axially inner fuse link portion.
- each of said pair of connector tabs has a cross-sectional area progressively decreasing from said pair of flanges toward said pair of terminal elements, each of said pair of connector tabs having a minimum cross-sectional area at the end thereof adjacent one of said pair of terminal elements, and said minimum cross-sectional area being larger than said points of reduced cross-sectional area of said pair of flanges.
- a time-lag fuse comprising:
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- Fuses (AREA)
Description
Claims (1)
Publications (1)
Publication Number | Publication Date |
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US3291943A true US3291943A (en) | 1966-12-13 |
Family
ID=3458867
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US3291943D Expired - Lifetime US3291943A (en) | Time-lag fuse with ribbon fuse link folded in longitudinal and in transverse direction |
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US (1) | US3291943A (en) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3611238A (en) * | 1970-07-28 | 1971-10-05 | Chase Shawmut Co | High-voltage fuse having high speed ratio |
US4166267A (en) * | 1978-01-27 | 1979-08-28 | Gould Inc. | Electric fuse having heat retaining means |
DE2931832A1 (en) * | 1978-08-08 | 1980-02-21 | Gould Inc | MELT LADDER FOR ELECTRICAL FUSES, THEIR PRODUCTION AND USE |
US4219795A (en) * | 1978-10-18 | 1980-08-26 | Gould Inc. | Fusible element for time-lag fuses having current-limiting action |
US4228417A (en) * | 1979-07-30 | 1980-10-14 | Gould Inc. | Electric fuse and method of manufacturing the same |
US4611192A (en) * | 1985-01-25 | 1986-09-09 | Eagle Electric Mfg. Co., Inc. | Heavy-duty time-delay fuse |
WO1989003117A1 (en) * | 1987-09-30 | 1989-04-06 | Cooper Industries, Inc. | Cable fuse |
US5900798A (en) * | 1997-03-28 | 1999-05-04 | Yazaki Corporation | Current limiting fuse having a non-directional fusing characteristic |
US20150371803A1 (en) * | 2013-02-05 | 2015-12-24 | Pacific Engineering Corporation | Fuse element |
WO2019060874A1 (en) * | 2017-09-25 | 2019-03-28 | Littelfuse, Inc. | Multiple element fuse |
US20230162939A1 (en) * | 2021-11-23 | 2023-05-25 | Littelfuse, Inc. | Protection device including multi-plane fusible element |
-
0
- US US3291943D patent/US3291943A/en not_active Expired - Lifetime
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3611238A (en) * | 1970-07-28 | 1971-10-05 | Chase Shawmut Co | High-voltage fuse having high speed ratio |
US4166267A (en) * | 1978-01-27 | 1979-08-28 | Gould Inc. | Electric fuse having heat retaining means |
DE2931832A1 (en) * | 1978-08-08 | 1980-02-21 | Gould Inc | MELT LADDER FOR ELECTRICAL FUSES, THEIR PRODUCTION AND USE |
FR2435802A1 (en) * | 1978-08-08 | 1980-04-04 | Gould Inc | DELAYED ACTION FUSE ELEMENT AND MANUFACTURING METHOD THEREOF |
US4219795A (en) * | 1978-10-18 | 1980-08-26 | Gould Inc. | Fusible element for time-lag fuses having current-limiting action |
US4228417A (en) * | 1979-07-30 | 1980-10-14 | Gould Inc. | Electric fuse and method of manufacturing the same |
US4611192A (en) * | 1985-01-25 | 1986-09-09 | Eagle Electric Mfg. Co., Inc. | Heavy-duty time-delay fuse |
US4831353A (en) * | 1987-09-30 | 1989-05-16 | Cooper Industries, Inc. | Cable fuse |
WO1989003117A1 (en) * | 1987-09-30 | 1989-04-06 | Cooper Industries, Inc. | Cable fuse |
GB2230660A (en) * | 1987-09-30 | 1990-10-24 | Cooper Ind Inc | Cable fuse |
GB2230660B (en) * | 1987-09-30 | 1992-01-02 | Cooper Ind Inc | Cable fuse |
US5900798A (en) * | 1997-03-28 | 1999-05-04 | Yazaki Corporation | Current limiting fuse having a non-directional fusing characteristic |
US20150371803A1 (en) * | 2013-02-05 | 2015-12-24 | Pacific Engineering Corporation | Fuse element |
US10297410B2 (en) * | 2013-02-05 | 2019-05-21 | Pacific Engineering Corporation | Fuse element |
WO2019060874A1 (en) * | 2017-09-25 | 2019-03-28 | Littelfuse, Inc. | Multiple element fuse |
US10325745B2 (en) | 2017-09-25 | 2019-06-18 | Littelfuse, Inc. | Multiple element fuse |
CN111201583A (en) * | 2017-09-25 | 2020-05-26 | 力特保险丝公司 | Multi-element fuse |
US20230162939A1 (en) * | 2021-11-23 | 2023-05-25 | Littelfuse, Inc. | Protection device including multi-plane fusible element |
US11875962B2 (en) * | 2021-11-23 | 2024-01-16 | Littelfuse, Inc. | Protection device including multi-plane fusible element |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: GOULD INC Free format text: MERGER;ASSIGNOR:I-T-E IMPERIAL CORPORATION;REEL/FRAME:004167/0705 Effective date: 19830607 Owner name: GOLUD INC 10 GOULD CENTER ROLLING MEADOWS IL 60008 Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:I-T-E IMPERIAL CORPORATION;REEL/FRAME:004167/0716 Effective date: 19821227 Owner name: I-T-E IMPERIAL CORPORATION A DE CORP Free format text: MERGER;ASSIGNORS:AIRMATIC - BECKETT HARCUM INC - THE CHASE SHAWMUT COMPANY COMPONETROL INC - DATAMETRICS INC - EFCO DIE CASTING CORPORATION - GENRE REALTY INC - IMPERIAL EASTMAN CORPORATION - INDUSTRIAL DESIGN INC - RUNDEL COMP;ONENTS INC - TERAC CONTROLS INC;REEL/FRAME:004167/0712 Effective date: 19761130 |