US3586914A - Overload shunt with single resistor element - Google Patents

Overload shunt with single resistor element Download PDF

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Publication number
US3586914A
US3586914A US878863A US3586914DA US3586914A US 3586914 A US3586914 A US 3586914A US 878863 A US878863 A US 878863A US 3586914D A US3586914D A US 3586914DA US 3586914 A US3586914 A US 3586914A
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US
United States
Prior art keywords
resistor element
resistor
overload
resistor elements
compression
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
Application number
US878863A
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English (en)
Inventor
Rudolf Foitzik
Klaus Reichelt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Siemens Corp
Original Assignee
Siemens Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Siemens Corp filed Critical Siemens Corp
Application granted granted Critical
Publication of US3586914A publication Critical patent/US3586914A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
    • H01T1/00—Details of spark gaps
    • H01T1/16—Series resistor structurally associated with spark gap
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
    • H01C7/12—Overvoltage protection resistors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49082—Resistor making
    • Y10T29/49087—Resistor making with envelope or housing
    • Y10T29/49089—Filling with powdered insulation
    • Y10T29/49091—Filling with powdered insulation with direct compression of powdered insulation

Definitions

  • An overload shunt includes at least one resistor element having a nonlinear resistance and comprising material compressed from at least two directions toward each other.
  • the resistor element has a width formed in the directions of compression and a length parallel to its longitudinal axis and perpendicular to the directions of compression. The length is at least as great as the width.
  • the resistor element is positioned in a manner whereby current in the overload shunt flows along the length of the resistor element perpendicularly to the directions of compression.
  • the invention relates to an overload shunt. More particularly, the invention relates to an overload shunt with a single resistor element.
  • An overload shunt or surge voltage arrestor of known type includes a plurality of resistor elements.
  • Each of the resistor elements comprises silicon carbide with added compounds.
  • the resistor element may be produced by compressing 70 percent80 percent silicon carbide powder with a porcelain compound, for example. The compressed material is then baked for about 1300 C.
  • Other types of resistor elements may be produced by the addition of a mixture of clay, prepared chalk and water glass as a banding material. The compressed material is then hardened at about 220500C.
  • resistor elements were provided in the shape of discs having axial lengths which were less than their. diameters. 'During the manufacture of such discs, the material comprising the discs was compressed in axial direction.
  • the discs are usually provided with a metal contact layer on their surfaces.
  • the contact layer may be provided, for example, by a layer of copper which is sprayed on.
  • the resistor discs are electrically charged by the voltage drop and the current which flows in the same direction as the axis of the disc. The current flow is thus in the directions of compression of the disc resistor element.
  • the principal object of the invention is to provide a new and improved resistor element for an overload shunt.
  • An object of the invention is to provide a new and improved overload shunt.
  • An object of the invention is to provide a resistor element which overcomes the disadvantages of known resistor elements.
  • An object of the invention is to provide a resistor element which has a width which is small relative to its axial length and is therefore homogenous.
  • An object of the invention is to provide a resistor element which has an axial length which is 2 to 4 times greater than its width.
  • An object of the invention is to provide an overload shunt in which a single resistor element of elongated configuration replaces a plurality of disc resistor elements.
  • An object of the invention is to provide an overload shunt which is inexpensive to manufacture due to the fewer number of resistor elements included therein.
  • an overload shunt includes at least one resistor element having a nonlinear resistance and comprising material compressed from at least two directions toward each other.
  • the resistor element has a width formed in the directions of compression and a length parallel to its longitudinal axis and perpendicular to the directions of compression. The length is at least as great as the width.
  • Positioning means positions the resistor element in a manner whereby current in the overload shunt flows along the length of the resistor element perpendicularly to the directions of compression.
  • the resistor element may have a rectangular cross-sectional area, or a prismatic cross-sectional area, or a circular crosssectional area, or other geometrical cross-sectional area.
  • the positioning means comprises a tubular member coaxially surrounding the resistor element and comprising electrically insulating material.
  • At least two resistor elements are provided, coaxially positioned one on either side of spark gap means.
  • a first plurality of resistor elements are positioned on one side of the spark gap means and a second plurality of the resistor elements are positioned coaxially with the-first plurality of resistor elements on the other side of the spark gap means.
  • a tubular member of electrically insulating material is coaxially positioned around the first and second pluralities of resistor elements and the spark gap means.
  • the resistor elements of the first plurality of resistor elements are electrically connected in parallel with each other and the resistor elements of the second plurality of resistor elements are electrically connected in parallel with each other.
  • the resistor elements Prior to our invention, the resistor elements have been utilized only in series arrangement, since a parallel arrangement of disc resistor elements tends to be unstable due to the negative temperature coefficient thereof. It has therefore beennecessary to manufacture disc resistor elements of various 1 types and sizes for overload shunts of different values.
  • the resistor element of our invention is electrically charged perpendicularly to the directions of compression and has a considerably higher specific energy capacity than the resistor element discs of the prior art.
  • the resistor elements of our invention may therefore be arranged in parallel with each other, without difficulty. It is therefore possible to manufacture only one type of resistor element for a relatively small electrical charge and stock it for the overload shunts rated for higher charges by utilizing two or more of such resistor elements, electrically connected in parallel, in an overload shunt.
  • the resistor element of the present invention having a prismatic cross-sectional area isyof substantially square crosssectional area having a slight taper.
  • Such a resistor element has an additional advantage that it may be centered in a simple manner along its edges by the surrounding tube of electrically insulating material.
  • FIG. I is an axial sectional view of an embodiment of the overload shunt of the invention.
  • FIG. 2 is a cross-sectional view, taken along the lines II-II of FIG. 1;
  • FIG. 3 is a longitudinal sectional view, taken along the lines III-III of FIG. 4, of a compression die utilized to manufacture a resistor element of the invention having a square cross-sectional area; 1
  • FIG. 4 is a top view of the die of FIG. 3;
  • FIG. 5 is a cross-sectional view, taken along the lines V-V of FIG. 4, of the compression die of FIG. 4;
  • FIG. 6 is a cross-sectional view of a compression die for manufacturing a resistor element of the invention having a prismatic cross-sectional area
  • FIG. 7 is a cross-sectional view of a compression die for manufacturing a resistor element of the invention having a circular or oval crosssectional area;
  • FIG. 8 is a cross-sectional view of a compression die for manufacturing a resistor element of the invention having an octagonal cross-sectional area
  • FIG. 9 is a cross-sectional view of a compression die for manufacturing a resistor element of the invention having a hexagonal cross-sectional area
  • FIG. 10 is an axial sectional view of another embodiment of the overload shunt of the invention.
  • FIG. 11 is a cross-sectional view, taken along the lines Xl-XI of FIG. 10.
  • an outer ribbed housing 1 comprises electrically insulating material such as, for example, porcelain.
  • the insulating housing 1 is of generally hollow cylindrical configuration and is closed at its top base by a metal cap 2 via a sealing gasket 3 which is cemented to said housing by any suitable adhesive such as, for example, cement 4.
  • the insulating housing 1 is closed at its bottom base by a metal cap 5 and a sealing gasket 6.
  • a deflection disc 7 coaxially surrounds the bottom metal cap 5'of the insulating housing 1 and is affixed to a diaphragm 8, which is interposed between said cap and said disc.
  • the deflection disc 7 supports a ground wire or cable 9. Upon the failure of the overload shunt, the diaphragm 8 is destroyed by the resulting high pressure and the deflection disc 7 and the ground wire 9 are thrown off.
  • the overload shunt includes a stack 10 of spark gaps, coaxially positioned in the insulating housing 1, as shown in FIG. 1.
  • the stack 10 of spark gaps is coaxially positioned in an annular or hollow cylindrical control resistor 11.
  • a first resistor element 12, of square cross-sectional area is positioned in the insulating housing 1 above the stack 10 of spark gaps.
  • a second resistor element 12', of square cross-sectional area is positioned below the stack 10 of spark gaps.
  • the first resistor element 12 has an electrically conductive metal layer on its top surface 12a and an electrically conductive metal layer on its bottom surface 12a in order to improve its electrical connection with the other elements of the overload shunt.
  • the metal layers on the top and bottom surfaces may comprise copper which may be sprayed on.
  • the second resistor element 12 is provided with top and bottom electrically conductive metal layers, not shown in FIG. 1.
  • a top metal spacer 13 is coaxially positioned in the insulating housing 1 in electrical contact with the top surface metal coating 12a of the first resistor element 12.
  • a bottom metal spacer 14 is coaxially positioned in the insulating housing 1 in electrical contact with the bottom surface metal layer of the second resistor element 12'.
  • the components in the housing 1 are supported by a base member 15 which rests upon the diaphragm 8.
  • the components of the overload shunt are coax ially positioned in a tubular member 16 of electrically insulating material.
  • the tubular member 16 is coaxially positioned in the electrically insulating housing 1.
  • the tubular member 16 may comprise, for example, stiff paper.
  • the longitudinal edges of the second resistor element 12, and, as not shown in the. F 105., the longitudinal edges of the first resistor element 12, abut against the inside surface of the tubular member 16.
  • Air spaces 17 (FIGS. 1 and 2) between the resistor elements 12 and 12' and the tube member 16 function to equalize pressure
  • each of the resistor elements 12 and 12 is the length in the direction of arrows 19, is at least as great as the width of said resistor elements, in the directions of compression.
  • the axial length of each of the resistor elements 12 and 12' is several times greater than the width thereof in the directions of compression, and is approximately 2 5; times as great.
  • FIGS. 3, 4 and 5 show a compression die for producing resistor elements of the invention having a square cross-sectional area.
  • the compression die comprises a massive frame 20a, 20b having an opening 21 formed therein.
  • a pair of compression pistons 22 and 23 are positioned in the opening 21 of the die 20a, 20b in a manner whereby they are movable relative to each other and toward each other.
  • the material 24, of silicon carbide and a binding agent, to be compressed, is placed in the opening 21.
  • the compressing force is applied in the direction of arrows and 25 and may comprise about 100 to 1000 kp per cm?, and is preferably 750 kp per cm.
  • the compression forces are perpendicular to the axial or longitudinal direction of the material 24 to be compressed, so that the compression pistons 22 and 23 move only a small distance. In this manner, inhomogeneity of the compressed material, due to friction, is prevented to a large extent.
  • the resistor element comprising the compressed material 24 is electrically charged along its longitudinal or axial length, as shown in FIG. 1.
  • the compression die as shown in FIG. 6, may be formed so that the compressed material 24 has a slightly tapered, essentially rectangular, cross-sectional area.
  • the cross-sectional area of the resistor element is thus substantially prismatic and is removable from the compression die with considerable facility. 7
  • FIG. 7 illustrates a compression die for manufacturing a resistor element 24 having a circular or oval cross-sectional area.
  • FIG. 8 illustrates a compression die for manufacturing a resistor element 24" having an octagonal cross-sectional area.
  • FIG. 9 illustrates a compression die for manufacturing a resistor element 24"" having a hexagonal cross-sectional area.
  • the embodiment of the overload shunt of FIGS. 10 and 11 is generally similar to that of FIGS. 1 and 2.
  • the overload shunt of FIGS. 10 and 11 includes a stack 30 of spark gaps.
  • resistor elements 31a, 31b, 31c, 31d, 31e, 31f, 31g and 31h of the invention, as hereinbefore described, are included in the overload shunt.
  • Each of the resistor elements 31a to 31h is identical with the resistor element 12 or 12 of the embodiment of FIGS. 1 and 2.
  • resistor elements 31a, 31b, 31c and 31f are positioned in the tubular member 34, in the insulating housing, above the stack 30 of spark gaps.
  • the resistor elements 31a, 31b, 31c and 31f are electrically connected to each other in parallel and are commonly electrically connected by an electrically conductive metal plate 32 covering the bottom surfaces thereof.
  • the metal plate 32 electrically contacts the top of the stack 30 of spark gaps.
  • the four resistor elements 31a, 31b, 31c and 31f are positioned by the tubular member 34.
  • resistor elements 31c, 31d, 31g and 31h are positioned in the tubular member 34, in the insulating housing, below the stack 30 of spark gaps.
  • the resistor elements 31c, 31d, 31g and 31h are electrically connected to each other in parallel and commonly electrically connected by an electrically conductive metal plate 33 covering the top surfaces thereof.
  • the metal plate 33 electrically contacts the bottom of the stack 30 of spark gaps.
  • the four resistorelements 31c, 31d, 31g and 31h are positioned by the tubular member 34.
  • An overload shunt including:
  • At least one resistor element having a nonlinear resistance and comprising material compressed at least two directions toward each other, said resistor element having a width formed in the directions of compression and a length parallel to its longitudinal axis and perpendicular to the directions of compression, said length being at least as great as said width;
  • positioning means positioning said resistor element in a manner whereby current in said overload shunt flows along the length of the resistor element perpendicularly to said directions of compression.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Thermistors And Varistors (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Tires In General (AREA)
US878863A 1968-11-26 1969-11-21 Overload shunt with single resistor element Expired - Lifetime US3586914A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1812253A DE1812253B2 (de) 1968-11-26 1968-11-26 Überspannungsableiter mit einem oder mehreren, durch Pressen hergestellten Widerstandskörpern

Publications (1)

Publication Number Publication Date
US3586914A true US3586914A (en) 1971-06-22

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ID=5714993

Family Applications (1)

Application Number Title Priority Date Filing Date
US878863A Expired - Lifetime US3586914A (en) 1968-11-26 1969-11-21 Overload shunt with single resistor element

Country Status (9)

Country Link
US (1) US3586914A (enrdf_load_html_response)
BE (1) BE742232A (enrdf_load_html_response)
BR (1) BR6914422D0 (enrdf_load_html_response)
CH (1) CH509682A (enrdf_load_html_response)
DE (1) DE1812253B2 (enrdf_load_html_response)
FR (1) FR2024269A1 (enrdf_load_html_response)
GB (1) GB1263597A (enrdf_load_html_response)
NO (1) NO127078B (enrdf_load_html_response)
SE (1) SE350160B (enrdf_load_html_response)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4298900A (en) * 1980-01-02 1981-11-03 Avdeenko Boris K Overvoltage protective device
US5128824A (en) * 1991-02-20 1992-07-07 Amerace Corporation Directionally vented underground distribution surge arrester
EP2565899A1 (en) * 2011-08-30 2013-03-06 Siemens Aktiengesellschaft Pressure resistant housing for an electric component

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2627769C3 (de) * 1976-06-18 1979-04-26 Siemens Ag, 1000 Berlin Und 8000 Muenchen Widerstandsanordnung für Hochspannungsgeräte
US4100588A (en) * 1977-03-16 1978-07-11 General Electric Company Electrical overvoltage surge arrester with varistor heat transfer and sinking means

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE438592A (enrdf_load_html_response) *
US2305577A (en) * 1940-08-04 1942-12-15 Line Material Co Resistor
US2331852A (en) * 1940-09-09 1943-10-12 Line Material Co Lightning arrester
US2376815A (en) * 1942-09-15 1945-05-22 Westinghouse Electric & Mfg Co Molded lightning-arrester block
AT206502B (de) * 1957-10-15 1959-12-10 Elin Union Ag Überspannungsableiter für Hochspannung mit verringerter Bauhöhe

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4298900A (en) * 1980-01-02 1981-11-03 Avdeenko Boris K Overvoltage protective device
US5128824A (en) * 1991-02-20 1992-07-07 Amerace Corporation Directionally vented underground distribution surge arrester
EP2565899A1 (en) * 2011-08-30 2013-03-06 Siemens Aktiengesellschaft Pressure resistant housing for an electric component
WO2013029916A3 (en) * 2011-08-30 2013-04-25 Siemens Aktiengesellschaft Pressure resistant housing for an electric component
CN103765543A (zh) * 2011-08-30 2014-04-30 西门子公司 用于电气组件的压力抵抗壳
CN103765543B (zh) * 2011-08-30 2016-11-02 西门子公司 用于电气组件的压力抵抗壳
US9648762B2 (en) 2011-08-30 2017-05-09 Siemens Aktiengesellschaft Pressure resistant housing for an electric component

Also Published As

Publication number Publication date
BR6914422D0 (pt) 1973-04-19
BE742232A (enrdf_load_html_response) 1970-05-14
FR2024269A1 (enrdf_load_html_response) 1970-08-28
DE1812253A1 (de) 1970-06-04
SE350160B (enrdf_load_html_response) 1972-10-16
NO127078B (enrdf_load_html_response) 1973-04-30
CH509682A (de) 1971-06-30
DE1812253B2 (de) 1978-05-03
GB1263597A (en) 1972-02-09

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