US3744416A - Electronic safety bridge primer - Google Patents

Electronic safety bridge primer Download PDF

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Publication number
US3744416A
US3744416A US00006783A US678370A US3744416A US 3744416 A US3744416 A US 3744416A US 00006783 A US00006783 A US 00006783A US 678370 A US678370 A US 678370A US 3744416 A US3744416 A US 3744416A
Authority
US
United States
Prior art keywords
semiconductor
resistance
ignition
electrodes
primer
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
US00006783A
Other languages
English (en)
Inventor
H Bendler
H Rudolph
U Brede
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.)
Dynamit Nobel AG
Original Assignee
Dynamit Nobel AG
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 Dynamit Nobel AG filed Critical Dynamit Nobel AG
Application granted granted Critical
Publication of US3744416A publication Critical patent/US3744416A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F42B3/185—Safety initiators resistant to premature firing by static electricity or stray currents having semi-conductive means, e.g. sealing plugs
    • 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
    • F42B3/12—Bridge initiators
    • F42B3/124—Bridge initiators characterised by the configuration or material of the bridge

Definitions

  • ABSTRACT A detonator element of the bridge-type adapted for electrical ignition having two electrodes supported in mutually spaced relationship by an electrically nonconductive support member, a bridging conductor connected across the ends of the electrodes and capable of incandescence or explosive evaporation, and an ignitible charge in contact with the bridging conductor, and.
  • the semiconductor further including a mechanically solid semiconductor exhibiting a resistance which is variable depending upon the voltage applied thereto, the semi-conductor being disposed electrically in series with one of said electrodes and/or in parallel with the electrodes, the semiconductor additionally or alternatively serving as the means for connecting the bridging conductor across the ends of the electrodes.
  • the present invention relates to a detonator element for electrical ignition or priming, and more particularly to a simplified electronic safety bridge primer.
  • the primer element in the known arrangement disclosed in the aforementioned copending application can be protected against unintended ignition due to: (a) stray voltages, surface leakage currents, etc., by providing that the primer element responds only when a correspondingly high-adjusted minimum ignition voltage is reached; (b) electrostatic discharges, by providing that the primer element responds only up to a correspondingly lowadjusted maximum ignition voltage; or (c) both of the foregoing effects (a) and (b), by providing that the voltage causing the ignition of the element is limited in a specific manner with respect to its minimum as well as its maximum.
  • a primer element for electric ignition formed by two electrodes arranged on an electrically non-conductive support member with a bridging conductor connecting these two electrodes with each other in an electrically conductive manner, which conductor is capable of incandescence or of explosive evaporation, as well as with an ignitable charge which is in effective connection with the conductor to be ignited thereby.
  • a mechanically stable semiconductor with a voltage-dependent resistance electrically connected in parallel and/or in series with the bridging conductor.
  • the constructional design of the primer element with a semiconductor connected in parallel with the bridging conductor becomes particularly simple by providing, according to a further feature of this invention, that the conductor is directly connected to the two metallic coatings of the semiconductor arranged on the support, for example by soldering.
  • the two ignition electrodes 5 are passed through the support member 1, which latter is made, for example, of organic plastic material: At points A and B, thes ignition electrodes 5 are electrically connected with the electrodes 3a and 3b of the semiconductor 2, which may be conventionally formed by metallic coatings 3a and 3b on opposite faces of a suitable semiconductor material having a voltage dependent impedance characteristic.
  • the semiconductor 2, contacting the support 1, carries on the side facing away from the support 1 the bridging conductor 4, which is also electrically connected to the metallic coatings 3a and 3b and is capable of incandescence or of explosive evaporation in response to an applied current.
  • the conductor 4 is surrounded by the ignitable charge 6, indicated by dotdash lines.
  • an additional semiconductor 7 can optionally be inserted in series with one of the ignition electrodes 5 and the ignition generator.
  • the detonator according to the present invention With its capabilities of limiting and/or braching the current, it is possible to secure the detonator composition against voltages which are excessive as well as against those which are lower than a predetermined level, depending upon whether the semiconductors employed are of the type wherein the resistance decreases with increasing voltage and, conversely, increases with decreasing voltage, or vice versa.
  • a minimum threhold of effective voltage values can be established by selecting a semiconductor 2 which provides an increase in resistance with increase in voltage, since initial low values of resistance in parallel with the bridging conductor would prevent sufiicient current flow therethrough to effect ignition, while subsequent increase in this shunt resistance with increase in applied voltage will divert more current through the bridging conductor 4 until ignition occurs.
  • a primer element for electrical ignition of an ignitable charge comprising a pair of electrodes supported in spaced relationship by an insulating support member, an ignitable bridge conductor electrically connected across said electrodes, said ignitable charge being in connection with said bridge conductor, and semiconductor means providing a resistance which varies in response to variation of the voltage applied thereto being disposed in circuit with said electrodes so as to control the threshold level of voltage for ignition, said semiconductor means supporting said bridging conductor and including at least a first semiconductor element connected in parallel with said bridging conductor and having metallic coatings on opposite surfaces thereof, said bridging conductor being connected to said pair of electrodes via said metallic coatings on said first semiconductor element.
  • a primer element as defined in claim l wherein said semiconductor means includes a second semic0n-' ductor element connected in series with said bridge conductor.
  • a primer element as defined in claim 43 wherein said first and second semiconductor elements each provide a resistance which decreases with increase in voltage applied thereto.
  • a primer element as defined in claim ll wherein said first semiconductor element is physically supported on said insulating support member, said pair of electrodes portruding through said support member being soldered to respective metallic coatings adjacent said support member and said bridging conductor being connected between said coatings at the other end of said first semiconductor element.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Bags (AREA)
  • Agricultural Chemicals And Associated Chemicals (AREA)
  • Spark Plugs (AREA)
US00006783A 1969-03-03 1970-01-29 Electronic safety bridge primer Expired - Lifetime US3744416A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691910665 DE1910665A1 (de) 1969-03-03 1969-03-03 Zuendelement

Publications (1)

Publication Number Publication Date
US3744416A true US3744416A (en) 1973-07-10

Family

ID=5726928

Family Applications (1)

Application Number Title Priority Date Filing Date
US00006783A Expired - Lifetime US3744416A (en) 1969-03-03 1970-01-29 Electronic safety bridge primer

Country Status (9)

Country Link
US (1) US3744416A (de)
JP (1) JPS496644B1 (de)
AT (1) AT292531B (de)
BE (1) BE746559A (de)
CH (1) CH498367A (de)
DE (1) DE1910665A1 (de)
FR (1) FR2037487A6 (de)
GB (1) GB1281444A (de)
NO (1) NO122174B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4484523A (en) * 1983-03-28 1984-11-27 The United States Of America As Represented By The Secretary Of The Navy Detonator, solid state type I film bridge

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3537821A1 (de) * 1985-10-24 1987-04-30 Dynamit Nobel Ag Elektrisches zuendelement
SE517704C2 (sv) 1999-05-10 2002-07-09 Tzn Forschung & Entwicklung Patron med elektrotermisk tändanordning
DE19936650C2 (de) * 1999-05-10 2002-10-24 Rheinmetall W & M Gmbh Patrone

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4484523A (en) * 1983-03-28 1984-11-27 The United States Of America As Represented By The Secretary Of The Navy Detonator, solid state type I film bridge

Also Published As

Publication number Publication date
FR2037487A6 (de) 1970-12-31
CH498367A (de) 1970-10-31
GB1281444A (en) 1972-07-12
DE1910665A1 (de) 1970-09-17
JPS496644B1 (de) 1974-02-15
AT292531B (de) 1971-08-25
NO122174B (de) 1971-05-24
BE746559A (fr) 1970-07-31

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