US3668458A - Explosively actuated ground interrupting device - Google Patents

Explosively actuated ground interrupting device Download PDF

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Publication number
US3668458A
US3668458A US43030A US3668458DA US3668458A US 3668458 A US3668458 A US 3668458A US 43030 A US43030 A US 43030A US 3668458D A US3668458D A US 3668458DA US 3668458 A US3668458 A US 3668458A
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US
United States
Prior art keywords
resistor
cup
set forth
gap
bore
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
US43030A
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English (en)
Inventor
Kouhei Irie
Misao Kobayashi
Masaru Shimamura
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.)
Meidensha Corp
Meidensha Electric Manufacturing Co Ltd
Original Assignee
Meidensha Electric Manufacturing Co Ltd
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
Priority claimed from JP4468369A external-priority patent/JPS5119137B1/ja
Application filed by Meidensha Electric Manufacturing Co Ltd filed Critical Meidensha Electric Manufacturing Co Ltd
Application granted granted Critical
Publication of US3668458A publication Critical patent/US3668458A/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
    • H01T1/14—Means structurally associated with spark gap for protecting it against overload or for disconnecting it in case of failure

Definitions

  • An explosively actuated ground interrupting device for a lightning arrester has an explosive charge which may be detonated by a resistor having a coil-shaped portion which presents a high impedance to transient currents, thereby inhibiting false detonation of the explosive charge.
  • the present invention relates to a device for interrupting the earth or ground connection to a lightning arrester, thereby pennitting re-transmission of power after the occurrence of a grounding fault resulting from damage to the lightning arrester.
  • ground separating devices When a lightning arrester is damaged by operation beyond its working limits, re-transmission of power would be impossible due to grounding of the lightning arrester and a ground separating device is normally provided between the lightning arrester and ground. Thus, if the dynamic current is not interrupted by a defective lightning arrester, the ground connection is speedily interrupted. In recent years, ground separating devices have been required to have very high sensitivity.
  • the discharge gap of known devices is exposed to the atmosphere, and its characteristics may change with time due to corrosion, dust, or other foreign material such as rain water.
  • a first object of the present invention is to provide a ground interrupting device having a high degree of sensitivity, yet free of the-afore-described shortcomings.
  • a second object of the present invention is to provide a ground interrupting device of small size at low cost which uses its component parts to perform multiple functions.
  • a third object of the present invention is to provide a ground interrupting device in which the discharging characteristics of the discharge gap are not affected by corrosion.
  • the invention provides'an im-' provement in a device for interrupting a ground connection for a" lightning arrester in which device conductors define a discharge gap, and a sealed vessel encloses a resistor arranged in parallel circuit with the gap and in thennal contact with a body of heat-sensitive explosive.
  • theresistor has a coil-shaped portion.
  • FIG. I shows a ground interrupting device of the invention in elevational section
  • FIGS. 2a to 2f illustrate elements of the device of FIG. 1 in respective perspective views
  • FIG. 3 shows another device of the invention in elevational section
  • FIG. 4 is a perspective view of a terminal for use with devices of the invention.
  • FIG. 5 shows a modified cap for assembly with the tenninal of FIG. 4 in elevational section
  • FIG. 6 illustrates the method of inserting the cap of FIG. 5 in the terminal of FIG. 4 in elevational section
  • FIG. 7 shows the assembled cap and terminal.
  • a tubular cylinder 1 of insulating material has an annular groove 2 axially centered in its outer circumference and bevels 3 on its two outer, circular edges.
  • Two cup-shaped metal caps 4 are fitted over the two axial ends of the cylinder 1 .so that their rims spacedly face each other near the groove 2.
  • An L-shaped terminal 5 is fixed to the outer bottom face of each cap 4.
  • each cap 4 is axially notched, and alternating rim segments 4a between-adjacent notches are bent into the groove 2 to secure the cap on the cylinder 1
  • the other rim segments 4b are bent slightly outward of the groove 2 and form a discharge gap g axially coextensive with the groove 2.
  • Ring-shaped packings 6 are inserted between the inner surfaces of the caps 4 and the bevels 3 of the cylinder 1. They hold the segments 4a against the cylinder 1 and seal the axial bore 7 of the cylinder 1.
  • a resistor 8 which is partly coil-shaped and partly straight is enclosed in the bore 7. Its coil portion engages one cap, and the straight portion passes in direct thermal contact through an annular disc 9 of dynamite and through two soft insulating discs 10 on opposite faces of the'disc 9. The free end of the straight resistor portion is offset for contact with the lower cap 4 so that the caps 4 are connected in parallel circuit with the gap 3 by the series-connected, integral coil-shaped and straight portions of the resistor 8.
  • the high impedance of the coil-shaped portion of the resistor 8 causes the impulse to pass to ground between the terminals 5 through the gap g.
  • the impedance of the coil portion is low, and the dynamic current can flow through the resistor and heat the dynamite 9 without detonating the same if the insulation of the lightning arrester is quickly restored.
  • the resulting fault current passing through the resistor 8 heats the latter after a few cycles sufficiently to explode the dynamite 9 whereby the lower cap 4 is blown ofi and the circuit between the lightning arrester and ground is interrupted.
  • the device can withstand relatively large impulse currents while being sensitive to dynamic current. This effect can be enhanced by inserting a magnetic core, not shown, into the coil-shaped resistor portion.
  • the central, grooved segment of the cylinder 1 is relatively weak and is readily broken by the explosion.
  • the caps 4 function as sealing lids for the bore 7 and simultaneously constitute electrodes for the discharge gap 3. They also protect the cylinder 1 and the components arranged therein so that the device consists of only few and inexpensive parts and is easily assembled.
  • the modified device of the invention shown in FIG. 3 has an insulating cylinder 1 identical with that shown in FIG.'2c and enclosing a resistor 8 and dynamite charge 9 in its bore 7.
  • the rim segments 4 of two caps 4 on opposite ends of the cylinder 1 are bent into the groove 2 of the cylinder 1 to secure the caps and to compress packing rings 6. Terminals 5 are attached to the caps 4.
  • the tenninal 5 on the upper cap passes through a hole 12 in the cover 1 l.
  • the lower portion of the cover 11 spacedly surrounds the lower cap 4 and carries a projection 13 on its inner surface to form a discharge gap g with the lower cap 4.
  • the width of the gap may be set precisely by inserting a gage between the projection 13 and the lower cap 4 and thereafter suitably deforming the cover 1 l.
  • the cover 11 prevents deterioration of the discharge characteristics of the device by corrosion or by the deposition of dust or other foreign matter.
  • the width of the gap can be set after the actual assembly operation which thereby becomes extremely easy.
  • FIGS. 4 to 7 illustrate a simple manner of attaching L- shaped terminals 5 to caps 4.
  • the terminal 5 is formed with an aperture 14in one of its legs.
  • the cap 4 has an outward, cylindrical projection 15 in its bottom surfaces which constitutes an integral hollow rivet dimensioned for insertion in the aperture 14.
  • the rivet I5 is deformed between an anvil l6 shaped to be received in the cap 4 and a die 17, as is shown in FIG. 6 to lock the rivet in the aperture 14, as is seen in FIG. 7.
  • a device for interrupting a ground connection for a lightning arrester said device including conductive means defining a discharge gap, a sealed vessel, an elongated resistor mounted in said vessel in parallel circuit with said gap, and a body of heat-sensitive explosive in thermal contact with said resistor, the improvement whichcomprises a longitudinal portion of said resistor being coil-shaped.
  • said resistor having a straight longitudinal portion, said straight portion being in thermal contact with said body of explosive.
  • said vessel including a body of insulating material formed with a bore, said resistor and said body of explosive being received in said bore, said conductive means including a substantially cup-shaped member closing one end of said bore in electrical contact with one end of said resistor, a rim portion of said cup-shaped member bounding said gap.
  • said conductive means further including a substantially cup-shaped protective cover enveloping said body of insulating material in spaced relation to said rim portion and bounding said gap.
  • said vessel including a 'a part of the rim portion of one of said cup-shaped members engaging said recess and thereby axially securing said one member on said cylindrical body.
  • said cylindrical body being fonned with an annular groove in the outer circumference thereof, said groove being axially coextensive with said gap, and respective parts of said rim portions being received in said groove and thereby axially securing said cupshaped members on said cylindrical body.
  • a terminal formed with an opening therein, the bottom portion of said cup-shaped member being formed with an integral hollow rivet extending through said opening and securing said terminal to said cupshaped member.

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US43030A 1969-06-09 1970-06-03 Explosively actuated ground interrupting device Expired - Lifetime US3668458A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP4468369A JPS5119137B1 (enrdf_load_stackoverflow) 1969-06-09 1969-06-09
JP4468569 1969-06-09
JP3991670 1970-04-24

Publications (1)

Publication Number Publication Date
US3668458A true US3668458A (en) 1972-06-06

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ID=27290306

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Application Number Title Priority Date Filing Date
US43030A Expired - Lifetime US3668458A (en) 1969-06-09 1970-06-03 Explosively actuated ground interrupting device

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US (1) US3668458A (enrdf_load_stackoverflow)
SE (1) SE377740B (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4566401A (en) * 1983-04-04 1986-01-28 Kinki Denki Co., Ltd. Dynamic current interruption-type indicators and method therefor
US4920446A (en) * 1986-04-18 1990-04-24 G & W Electric Co. Pyrotechnically-assisted current interrupter
US5057810A (en) * 1991-02-14 1991-10-15 Hubbell Incorporated Arrester isolator-disconnector
US5113167A (en) * 1991-02-15 1992-05-12 Hubbell Incorporated Lightning arrester isolator
US5215478A (en) * 1992-05-29 1993-06-01 Amphenol Corporation Spark gap device
CN101277666B (zh) * 2005-10-03 2012-09-26 金伯利-克拉克环球有限公司 紧凑折叠的吸收性制品
EP3373401A1 (en) * 2017-03-06 2018-09-12 Tyco Electronics (Uk) Ltd Disconnector arrangement and fabrication method

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU153501A1 (enrdf_load_stackoverflow) *
US2411325A (en) * 1943-07-09 1946-11-19 Rca Corp Control of electrical arcs
US2629765A (en) * 1951-03-13 1953-02-24 Cougnard Jerome Double-acting lightning protector for electric installations
US3328632A (en) * 1965-08-16 1967-06-27 English Electric Co Ltd Vacuum-protective spark gap with trigger electrode
US3501667A (en) * 1968-11-25 1970-03-17 Gen Electric Surge protector for secondary voltage circuits

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU153501A1 (enrdf_load_stackoverflow) *
US2411325A (en) * 1943-07-09 1946-11-19 Rca Corp Control of electrical arcs
US2629765A (en) * 1951-03-13 1953-02-24 Cougnard Jerome Double-acting lightning protector for electric installations
US3328632A (en) * 1965-08-16 1967-06-27 English Electric Co Ltd Vacuum-protective spark gap with trigger electrode
US3501667A (en) * 1968-11-25 1970-03-17 Gen Electric Surge protector for secondary voltage circuits

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4566401A (en) * 1983-04-04 1986-01-28 Kinki Denki Co., Ltd. Dynamic current interruption-type indicators and method therefor
US4920446A (en) * 1986-04-18 1990-04-24 G & W Electric Co. Pyrotechnically-assisted current interrupter
US5057810A (en) * 1991-02-14 1991-10-15 Hubbell Incorporated Arrester isolator-disconnector
US5113167A (en) * 1991-02-15 1992-05-12 Hubbell Incorporated Lightning arrester isolator
US5215478A (en) * 1992-05-29 1993-06-01 Amphenol Corporation Spark gap device
CN101277666B (zh) * 2005-10-03 2012-09-26 金伯利-克拉克环球有限公司 紧凑折叠的吸收性制品
EP3373401A1 (en) * 2017-03-06 2018-09-12 Tyco Electronics (Uk) Ltd Disconnector arrangement and fabrication method
WO2018162388A1 (en) * 2017-03-06 2018-09-13 Tyco Electronics Uk Ltd Disconnector arrangement and fabrication method

Also Published As

Publication number Publication date
SE377740B (enrdf_load_stackoverflow) 1975-07-21

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