US3735705A - Filtered electro-explosive device - Google Patents

Filtered electro-explosive device Download PDF

Info

Publication number
US3735705A
US3735705A US00162863A US3735705DA US3735705A US 3735705 A US3735705 A US 3735705A US 00162863 A US00162863 A US 00162863A US 3735705D A US3735705D A US 3735705DA US 3735705 A US3735705 A US 3735705A
Authority
US
United States
Prior art keywords
filter
pin
bridging wire
metallic
charge
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
US00162863A
Other languages
English (en)
Inventor
W Hudson
W Fritz
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.)
TE Connectivity Corp
Original Assignee
AMP Inc
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 AMP Inc filed Critical AMP Inc
Application granted granted Critical
Publication of US3735705A publication Critical patent/US3735705A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B3/00—Blasting cartridges, i.e. case and explosive
    • F42B3/10—Initiators therefor
    • F42B3/18—Safety initiators resistant to premature firing by static electricity or stray currents
    • F42B3/188—Safety initiators resistant to premature firing by static electricity or stray currents having radio-frequency filters, e.g. containing ferrite cores or inductances

Definitions

  • a pyrotechnic device includes a high pass, lossy, ceramic filter on the connector pin of the device.
  • the pyrotechnic device includes a bridging wire between the connector pin and an outer metallic shield. Electrical current passing through the bridging wire detonates an explosive charge.
  • the lossy filter shunts high frequency electrical noise away from the bridging wire thereby preventing accidental detonation of the charge.
  • This invention relates to pyrotechnic devices and more particularly to a ceramic filter on the pin of the pyrotechnic device to prevent accidental detonation of the device caused by stray high frequency noise.
  • One type of commonly used pyrotechnic device includes an electrical detonator having a bridging wire which extends between a connector pin and an outer shell. An electrical voltage applied to the pin causes current to flow through the bridging wire. This explodes the bridging wire thereby igniting the explosive charge. Such devices are referred to as electroexplosive devices.
  • the bridging wire acts as an antenna which picks up stray electro-magnetic radiation for example, such noise may be caused by radio transmission in the area.
  • the filter is a compact, low cost device including an extruded tube of ferrite with deposited barium titanate forming a dielectric layer thereon.
  • a metallic plating on the filter has gaps near the extremities to electrically isolate an inner conductive surface and an outer conductive surface.
  • FIG. 1 shows the pyrotechnic device of this invention
  • FIG. 2 shows the equivalent electrical circuit of the device.
  • the pyrotechnic device includes a powder can 11 holding an explosive charge (not shown) at the bottom thereof.
  • a detonator includes an outer metallic shell 12 and a metallic connector pin 13.
  • a bridging wire 14 is connected between the outer shell 12 and the pin 13.
  • the pin 13 typically has a nickel cover and is gold plated.
  • the outer shell 12 is stainless steel.
  • the bridging wire 14 normally has a resistance of approximately 2 ohms.
  • a receptacle 15 in a socket 16 supplies DC current to the detonator.
  • the circuit is through the inner conductor of a cable, which is shown diagrammatically at 26 in FIG. 2, through the receptacle 15, the pin 13, the bridging wire 14, the outer shell 12 and the top portion of the powder can, which is electrically connected to the shell of the socket 16, and the casing on the cable which is common, or ground, potential.
  • the bridging wire 14 explodes thereby igniting the explosive charge in the can.
  • a tubular filter 17 is positioned on the pin.
  • the tubular filter is of the type including a substrate which, in a preferred embodiment, is the extruded tube of ferrite 18.
  • a dielectric layer 19 is a deposited coating of barium titanate.
  • a metal plating forms an inner conductive surface 20 and an outer conductive surface 21. Gaps in the metal plating at 22 and 23 electrically isolate the inner conductive surface 20 from the outer conductive surface 21.
  • the inner conductive surface 20 is in electrical contact with the pin 13 and the outer conductive surface 21 is in electrical contact with the outer shell 12.
  • the filter 17 shunts high frequency electrical energy to the outer shell and prevents it from appearing across the bridging wire 13 which otherwise well might detonate the charge.
  • the equivalent electrical circuit of the filtered pyrotechnic device is shown in FIG. 2.
  • a source of DC voltage represented by the battery 24 is connected through the detonator switch 25 to the cable 26, with the cable being connected through the socket 16 to pin 13 at the point 27.
  • the equivalent circuit between point 27 and the bridging wire 14 includes an inductance 28 and a resistance 29 established by the pin 13 and the ferrite tube 18.
  • the capacitors 30 and 31 represent the capacitive path between the pin and the outer conductive surface 21 of the filter.
  • the impedance of the outer conductive surface 21 has been subdivided into three different series paths including inductors 32, 33 and 34 and resistors 35, 36 and 37. Two ground return paths including the inductor 38, resistor 39, inductor'40 and resistor 41 complete the equivalent circuit.
  • FIG. 2 shows the impedances lumped into two ground return paths, actually the ground return paths are distributed along the entire length of the outer shell 12. The result is an electrical filter which very effectively shunts high frequency noise energy to ground. Only the DC current from source 24 passes through the bridging wire 14. In this manner, a very effective, compact and low cost filter for preventing accidental detonation of the pyrotechnic device is provided.
  • a pyrotechnic device comprising:
  • a detonator at the top of said can including:
  • a tubular filter including a substrate of ferrite, a dielectric layer directly on the outer surface of the substrate, and extending about said dielectric metallic plating being in contact with said shell so material, about the inner surface of said ferrite that said filter shunts high frequency electrical tube and about the ends of the filter, said metallic energy across said bridging wire without detonatplating having gaps near both extremities of said ing said charge. tube to electrically isolate the metallic plating on 5 2.
  • the pyrotechnic device recited in claim 1 wherein the outside of said filter from the plating on the said dielectric is barium titanate coated on said subinner surface of said tube, the inner metallic platstrate. ing being in contact with said pin and the outer

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Bags (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
  • Manufacturing Of Electrical Connectors (AREA)
US00162863A 1971-07-15 1971-07-15 Filtered electro-explosive device Expired - Lifetime US3735705A (en)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US16286371A 1971-07-15 1971-07-15
NL7301372A NL7301372A (de) 1971-07-15 1973-01-31
GB491773A GB1368223A (en) 1971-07-15 1973-01-31 Electrical detonator
AU51659/73A AU465861B2 (en) 1971-07-15 1973-02-01 Pyrotechnic device
DE2304952A DE2304952A1 (de) 1971-07-15 1973-02-01 Pyrotechnische vorrichtung mit sicherung gegen ungewolltes detonieren
FR7303840A FR2216545B1 (de) 1971-07-15 1973-02-02

Publications (1)

Publication Number Publication Date
US3735705A true US3735705A (en) 1973-05-29

Family

ID=27542741

Family Applications (1)

Application Number Title Priority Date Filing Date
US00162863A Expired - Lifetime US3735705A (en) 1971-07-15 1971-07-15 Filtered electro-explosive device

Country Status (6)

Country Link
US (1) US3735705A (de)
AU (1) AU465861B2 (de)
DE (1) DE2304952A1 (de)
FR (1) FR2216545B1 (de)
GB (1) GB1368223A (de)
NL (1) NL7301372A (de)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2429993A1 (fr) * 1978-07-01 1980-01-25 Nissan Motor Structure de couplage pour allumeur pyrotechnique
EP0029672A1 (de) * 1979-11-20 1981-06-03 Ici Americas Inc. Elektrischer Sicherheits-Initialzünder
EP0648997A1 (de) * 1993-10-13 1995-04-19 Thomson Brandt Armements Hoch-energetische Zünder
ES2083902A2 (es) * 1992-05-08 1996-04-16 Hughes Aircraft Comapany Conectador de seguridad frente a descargas electrostaticas para dispositivos electroexplosivos.
US5847309A (en) * 1995-08-24 1998-12-08 Auburn University Radio frequency and electrostatic discharge insensitive electro-explosive devices having non-linear resistances
EP0942256A1 (de) * 1998-03-09 1999-09-15 Hirtenberger Präzisionstechnik GmbH Elektrisch auslösbarer Zünder zum Anschiessen einer Treibladung
EP1008208A1 (de) * 1997-08-29 2000-06-14 Talley Defence Systems, Incorporated Einzelner anschlussstiftkoaxialstecker, halter und stercker und betriebsverfahren
US6082264A (en) * 1996-12-19 2000-07-04 Sasol Mining Initiators (Proprietary) Limited Connectors for wired networks for detonators
US6105503A (en) * 1998-03-16 2000-08-22 Auburn University Electro-explosive device with shaped primary charge
US6219218B1 (en) * 1997-01-31 2001-04-17 The United States Of America As Represented By The Secretary Of The Navy Magnetic flux suppression system
US6389972B2 (en) * 1997-03-07 2002-05-21 Livbag S.N.C. Electro-pyrotechnic initiator built around a complete printed circuit
FR2823841A1 (fr) * 2001-04-20 2002-10-25 Dassault Aviat Dispositif electro-pyrotechnique
US6477957B2 (en) * 2000-06-02 2002-11-12 Hirschmann Austria Gmbh Ignition device for a safety system
US20030000411A1 (en) * 2001-06-29 2003-01-02 Cernocky Edward Paul Method and apparatus for detonating an explosive charge
US6772692B2 (en) 2000-05-24 2004-08-10 Lifesparc, Inc. Electro-explosive device with laminate bridge
FR2856139A1 (fr) * 2003-06-11 2004-12-17 Schott Glas Procede de revetement de la surface de paroi interieure d'un corps creux et corps creux ainsi revetu
US20050121195A1 (en) * 2003-01-09 2005-06-09 Bell Matthew R.G. Casing conveyed well perforating apparatus and method
US20080250963A1 (en) * 2003-03-03 2008-10-16 Schott Ag Metal fixing material bushing and method for producing a base plate of a metal fixing material bushing
US8733250B2 (en) 2006-01-27 2014-05-27 Schott Ag Metal-sealing material-feedthrough and utilization of the metal-sealing material feedthrough with an airbag, a belt tensioning device, and an ignition device
US9423218B2 (en) 2010-09-17 2016-08-23 Schott Ag Method for producing a ring-shaped or plate-like element
US10684102B2 (en) 2010-09-17 2020-06-16 Schott Ag Method for producing a ring-shaped or plate-like element

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE378139B (de) * 1973-11-27 1975-08-18 Bofors Ab
SE445489B (sv) * 1978-04-03 1986-06-23 Thiokol Corp Elektriskt aktiverbar sprengkapsel
GB2397365B (en) * 1978-09-01 2004-11-10 Emi Ltd RF protection device
ATE3588T1 (de) * 1979-01-15 1983-06-15 Ici Ltd Steuerschaltung fuer einen wahlweise ausloesbaren elektrischen zuender und zuender mit solcher schaltung.
SE431486B (sv) * 1979-09-03 1984-02-06 Bofors Ab Elektrisk tendare
FR2557689B1 (fr) * 1983-12-28 1987-06-12 Poudres & Explosifs Ste Nale Initiateur pyrotechnique utilisant une prise coaxiale
DE3643301A1 (de) * 1986-12-18 1988-06-30 Diehl Gmbh & Co Elektrisches anzuendstueck
IL82508A (en) * 1987-05-13 1991-06-10 Israel Defence Electric igniter assembly
DE3812958A1 (de) * 1988-04-19 1989-11-02 Diehl Gmbh & Co Elektrisches anzuendmittel
US5200574A (en) * 1991-04-05 1993-04-06 Morton International, Inc. Universal squib connector

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351012A (en) * 1966-06-30 1967-11-07 Robert E Wilson Explosive bridgewire initiators
US3572247A (en) * 1968-08-29 1971-03-23 Theodore Warshall Protective rf attenuator plug for wire-bridge detonators

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3351012A (en) * 1966-06-30 1967-11-07 Robert E Wilson Explosive bridgewire initiators
US3572247A (en) * 1968-08-29 1971-03-23 Theodore Warshall Protective rf attenuator plug for wire-bridge detonators

Cited By (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2429993A1 (fr) * 1978-07-01 1980-01-25 Nissan Motor Structure de couplage pour allumeur pyrotechnique
US4271453A (en) * 1978-07-01 1981-06-02 Nissan Motor Company, Limited Igniter with coupling structure
EP0029672A1 (de) * 1979-11-20 1981-06-03 Ici Americas Inc. Elektrischer Sicherheits-Initialzünder
ES2083902A2 (es) * 1992-05-08 1996-04-16 Hughes Aircraft Comapany Conectador de seguridad frente a descargas electrostaticas para dispositivos electroexplosivos.
EP0648997A1 (de) * 1993-10-13 1995-04-19 Thomson Brandt Armements Hoch-energetische Zünder
FR2711237A1 (fr) * 1993-10-13 1995-04-21 Thomson Brandt Armements Dispositif de mise à feu à haute énergie.
US5847309A (en) * 1995-08-24 1998-12-08 Auburn University Radio frequency and electrostatic discharge insensitive electro-explosive devices having non-linear resistances
US5905226A (en) * 1995-08-24 1999-05-18 Auburn University Radio frequency and electrostatic discharge insensitive electro-explosive devices having non-linear resistances
US6272965B1 (en) * 1995-08-24 2001-08-14 Auburn University Method of forming radio frequency and electrostatic discharge insensitive electro-explosive devices
US6082264A (en) * 1996-12-19 2000-07-04 Sasol Mining Initiators (Proprietary) Limited Connectors for wired networks for detonators
US6219218B1 (en) * 1997-01-31 2001-04-17 The United States Of America As Represented By The Secretary Of The Navy Magnetic flux suppression system
US6389972B2 (en) * 1997-03-07 2002-05-21 Livbag S.N.C. Electro-pyrotechnic initiator built around a complete printed circuit
US6539875B2 (en) * 1997-03-07 2003-04-01 Livbag S.N.C. Electro-pyrotechnic initiator built around a complete printed circuit
EP1008208A4 (de) * 1997-08-29 2000-08-23 Talley Defence Systems Inc Einzelner anschlussstiftkoaxialstecker, halter und stercker und betriebsverfahren
EP1008208A1 (de) * 1997-08-29 2000-06-14 Talley Defence Systems, Incorporated Einzelner anschlussstiftkoaxialstecker, halter und stercker und betriebsverfahren
EP0942256A1 (de) * 1998-03-09 1999-09-15 Hirtenberger Präzisionstechnik GmbH Elektrisch auslösbarer Zünder zum Anschiessen einer Treibladung
US6105503A (en) * 1998-03-16 2000-08-22 Auburn University Electro-explosive device with shaped primary charge
US6772692B2 (en) 2000-05-24 2004-08-10 Lifesparc, Inc. Electro-explosive device with laminate bridge
US6925938B2 (en) 2000-05-24 2005-08-09 Quantic Industries, Inc. Electro-explosive device with laminate bridge
US20050115435A1 (en) * 2000-05-24 2005-06-02 Baginski Thomas A. Electro-explosive device with laminate bridge
US6477957B2 (en) * 2000-06-02 2002-11-12 Hirschmann Austria Gmbh Ignition device for a safety system
FR2823841A1 (fr) * 2001-04-20 2002-10-25 Dassault Aviat Dispositif electro-pyrotechnique
US20030000411A1 (en) * 2001-06-29 2003-01-02 Cernocky Edward Paul Method and apparatus for detonating an explosive charge
US7284601B2 (en) 2003-01-09 2007-10-23 Shell Oil Company Casing conveyed well perforating apparatus and method
US20060000613A1 (en) * 2003-01-09 2006-01-05 Bell Matthew R G Casing conveyed well perforating apparatus and method
US20060060355A1 (en) * 2003-01-09 2006-03-23 Bell Matthew R G Perforating apparatus, firing assembly, and method
US20060196693A1 (en) * 2003-01-09 2006-09-07 Bell Matthew R G Perforating apparatus, firing assembly, and method
US20050121195A1 (en) * 2003-01-09 2005-06-09 Bell Matthew R.G. Casing conveyed well perforating apparatus and method
US7284489B2 (en) 2003-01-09 2007-10-23 Shell Oil Company Casing conveyed well perforating apparatus and method
US7461580B2 (en) 2003-01-09 2008-12-09 Shell Oil Company Casing conveyed well perforating apparatus and method
US7975592B2 (en) 2003-01-09 2011-07-12 Shell Oil Company Perforating apparatus, firing assembly, and method
US8327765B2 (en) 2003-03-03 2012-12-11 Schott Ag Metal fixing material bushing and method for producing a base plate of a metal fixing material bushing
US20080250963A1 (en) * 2003-03-03 2008-10-16 Schott Ag Metal fixing material bushing and method for producing a base plate of a metal fixing material bushing
US20100229616A1 (en) * 2003-03-03 2010-09-16 Schott Ag Metal fixing material bushing and method for producing a base plate of a metal fixing material bushing
US8276514B2 (en) 2003-03-03 2012-10-02 Schott Ag Metal fixing material bushing and method for producing a base plate of a metal fixing material bushing
FR2856139A1 (fr) * 2003-06-11 2004-12-17 Schott Glas Procede de revetement de la surface de paroi interieure d'un corps creux et corps creux ainsi revetu
US8733250B2 (en) 2006-01-27 2014-05-27 Schott Ag Metal-sealing material-feedthrough and utilization of the metal-sealing material feedthrough with an airbag, a belt tensioning device, and an ignition device
US9423218B2 (en) 2010-09-17 2016-08-23 Schott Ag Method for producing a ring-shaped or plate-like element
US9651345B2 (en) 2010-09-17 2017-05-16 Schott Ag Method for producing a ring-shaped or plate-like element
US10684102B2 (en) 2010-09-17 2020-06-16 Schott Ag Method for producing a ring-shaped or plate-like element

Also Published As

Publication number Publication date
GB1368223A (en) 1974-09-25
FR2216545B1 (de) 1977-02-04
AU5165973A (en) 1974-08-01
AU465861B2 (en) 1975-09-18
FR2216545A1 (de) 1974-08-30
DE2304952A1 (de) 1974-08-08
NL7301372A (de) 1974-08-02

Similar Documents

Publication Publication Date Title
US3735705A (en) Filtered electro-explosive device
US3572247A (en) Protective rf attenuator plug for wire-bridge detonators
US5036768A (en) Attenuator for dissipating electromagnetic and electrostatic energy
EP0029672B1 (de) Elektrischer Sicherheits-Initialzünder
EP0029671B1 (de) Elektrostatisches Sicherheitselement für einen elektrischen Initialzünder
US3264989A (en) Ignition assembly resistant to actuation by radio frequency and electrostatic energies
US3002162A (en) Multiple terminal filter connector
US2821139A (en) Shielded initiator
US5905226A (en) Radio frequency and electrostatic discharge insensitive electro-explosive devices having non-linear resistances
CA1206805A (en) Electric initiator resistant to actuation by radio frequency and electrostatic energies
EP0455496B1 (de) Mehrschichtige scheibenförmige Kondensatoren
US2818020A (en) Safeguarded electric firing initiating devices
US3329911A (en) Low transfer impedance capacitor with resistive electrode
JP2003502615A (ja) 電圧防護型半導体ブリッジ点火要素
US4374605A (en) An assembly of an electrical connector and pyrotechnic igniter
KR20000058078A (ko) 점화 신뢰성이 향상된 일렉트로파이로테크닉 점화기
US3447104A (en) Electrical connector filter comprising at least one electrically conductive coated dielectric disc and a ferromagnetic disc
US4690056A (en) Electric detonator device
US3597711A (en) Removable electrical connector filter
EP0123457A1 (de) Steckverbinder mit eingebautem Filter
US3804018A (en) Initiator and blasting cap
US3425004A (en) Radio frequency energy attenuator
US5701665A (en) Pi signal frequency filter method of manufacture
US4380958A (en) Electrostatic safe electric match
SE445489B (sv) Elektriskt aktiverbar sprengkapsel