US3867885A - Electrical primer - Google Patents

Electrical primer Download PDF

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Publication number
US3867885A
US3867885A US396438A US39643873A US3867885A US 3867885 A US3867885 A US 3867885A US 396438 A US396438 A US 396438A US 39643873 A US39643873 A US 39643873A US 3867885 A US3867885 A US 3867885A
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US
United States
Prior art keywords
housing
primer according
electrical primer
plated element
inner 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
Application number
US396438A
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English (en)
Inventor
Heinz Gawlick
Hellmut Bendler
Uwe 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 US3867885A publication Critical patent/US3867885A/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
    • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
    • F42C19/00—Details of fuzes
    • F42C19/08—Primers; Detonators
    • F42C19/12—Primers; Detonators electric

Definitions

  • the pole piece is accessible from the outside of the housing and is provided with a recess in the side portion facing the ignitable charge and the plated element is arranged within the recess such that the bottom surface thereof rests on the bottom of the recess of the pole piece.
  • the plated element may also have a peripheral surface portion resting against the wall portion of the recess.
  • the present invention relates to an electrical primer with an electrically conductive housing and a pole piece disposed therein and accessible from the outside, which pole piece is electrically conductively connected to the housing via a coated or plated laminated element having an ignition bridge and via an inner casing, as well as with at least one ignitable charge which is in operative connection with the ignition bridge.
  • DOS No. 2,020,016 discloses an electrical, metalcoated or plated primer having a mechanically solid in sulating body of, for example, glass or ceramic.
  • a plated primer is also disclosed in US. Pat. No. 3,682,096.
  • an ignition bridge e.g., of tantalum, tantalum nitride, or chromium, and the electrodes of the ignition bridge which are enlarged to provide sufficiently wide contact areas of, for example, nickel, palladium, palladium gold, platinum gold, etc.
  • This plated element as contrasted to the conventional electrical gap primers, has, on the one hand, an exactly defined electric resistance, so that the flawless ignition at a predetermined ignition voltage is ensured.
  • this device since this device has no parts soldered or welded thereon, it is very shockproof, as contrasted to the conventional incandescent wire primers, so that it has proven itself very well, for example, in automatic firearms having a high firing speed and consequently high shock stresses during the introduction of the ammunition into the cartridge chamber.
  • the plated element placed on the pole piece is likewise disposed in such a canted position, so that, during the application of the ignitable charge or charges by means of pressure, the plated element is pressed unilaterally against the housing and is thereby damaged in certain cases.
  • an electrical primer having an electrically conductive housing and a pole piece disposed therein and accessible from the outside.
  • the pole piece is electrically conductively connected with the housing via a plated element having ignition bridge and an inner casing or sleeve.
  • At least one ignitable charge or composition is in operative connection with the ignition bridge, by providing that the pole piece, on its side facing the at least one ignitable charge, has a cup-shaped recess wherein the plated element is arranged and rests with its bottom and peripheral surfaces against the pole piece.
  • the depth of the recess is preferably dimensioned so that the plated element is reliably supported along its entire height.
  • the recess in the pole piece in case of mass production, can also be manufactured very accurately in shape and dimensions simply by producing the pole piece with recess by a stamping or like procedure.
  • the safety attainable in this way with respect to flawless manufacture and required shockproofness is increased when the plated element more evenly contacts the bottom of the recess in the pole piece with its entire bottom surface. Therefore, in an advantageous embodiment of this invention, the provision is made that the plated element rests on the pole piece with its peripheral surface by way of a tubular extension of an insulating ring.
  • the insulating ring made of a synthetic resin, for example, also simultaneously prevents the direct electric contact between the pole piece and the inner casing.
  • the present invention furthermore provides the feature'of fashioning the inner wall of the recess and the outer wall of the extension in the manner of a tapered seat to be conical.
  • the plated element rests, with its face carrying the ignition bridge, against the inner casing, which latter has a bottom with a perforation, this bottom establishing the electrically conductive connection with one of the two electrodes of the ignition bridge.
  • the perforation is fashioned, in the zone of the ignition bridge, so that the satisfactory ignition of the charge pressed on the ignition bridge is ensured upon the flow of a current through the ignition bridge.
  • the inner casing is inserted by press fit in the housing and, during the pressure introduction of the ignitable charge or charges, is sufficiently firmly pressed with its bottom surface against one electrode of the ignition bridge.
  • the plated element is advantageously subjected to a uniform pressure load.
  • annular contact disk can be provided, according to another feature of this invention, between the plated element and the inner casing.
  • the annular contact disk can either be manufactured directly from a very highly electrically conductive material, such as gold, for example, or it can also be merely provided with such a highly conductive surface, for example by gold-plating a bronze ring along its entire surface.
  • the electical contact can furthermore be addition-ally improved by forming the annular contact disk, in the not yet installed condition, to be slightly conical, and inserting the disk in the housing so that its inner rim points toward the plated element. In the finished assembled condition of the primer, the contact disk, due to the inherent stress, is then additionally pressed with its inner zone against the plated element and with its outer zone against the inner casing.
  • the inner casing which preferably is manufactured to be thin-walled of a soft material, such as copper or soft brass, is pressed so firmly against the inner wall of the housing, the contact disk and the plated element, respectively, that the flawless electrical connection is ensured even in case of high shock stresses as they occur, for example, in case of accelerations of 500,000 g.s and thereabove.
  • the inner casing is formed with a wall thickness which decreases toward the end facing away from the plated element.
  • another feature of the present invention provides for the equipping of the at least one ignitable charge accommodated in the inner casing with a cover of preferably metal.
  • the cover caries amarking which is indicative of the flawless conductance of the pressure-feeding step during the pressure feeding of the at least one ignitable charge.
  • the electrical primer of the present invention can advantageously be utilized as a cartridge primer, a detonator, a flame ignition device, or the like.
  • FIG. 1 is a partial longitudinal sectional view of an electric primer in accordance with the present invention
  • FIG. 2 is a longitudinal sectional view of another embodiment of an electrical primer in accordance with the present invention.
  • FIG. 3 is a plan view of a plated element which may be utilized in accordance with the present invention.
  • FIG. 4 is a cross-sectional view of the plated element, taken along line AA of FIG. 3.
  • a primer including a housing 1 having a pole piece 3 disposed therein and which is electrically insulated from the housing by means of insulation 2 of a synthetic resin, such as polyethylene, for example.
  • the pole piece 3 is accessible from the outside in order to connect the firing circuit, not shown, in the contact bore 4.
  • a plated element 6, which is disc-shaped, shown in an elevational view, is disposed in a recess 5 of the pole piece 3 such that the plated element rests securely with its bottom and peripheral surfaces in the recess of the pole piece 3.
  • An inner casing 7 rests with its bottom 8 having a perforation 9, against one of the electrodes, not shown, of the plated element 6.
  • the bottom 8 of the inner casing 7 is electrically insulated from the pole piece 3 by means of an insulating annular disk 10.
  • the inner casing 7 has its wall in electrical contact with the housing 1, so that the circuit is formed as follows: pole piece 3 first plated element electrode ignition bridge second plated element electrode bottom 8 inner casing 7 housing I.
  • a first ignitable charge 11, for example a mixture of initiating explosive, reducing agent and oxidizer is inserted by means of pressure into the inner casing 7.
  • the charge 11 is disposed in the zone of the perforation 9 of the bottom 8 of the inner casing, in contact with the ignition bridge, not shown, of the plated element 6, so that it is flawlessly ignited upon current flow through the ignition bridge.
  • the pressure during the pressing introduction of the charge is generally between 1 and about 1,500 kplcm preferably between about 1,000 and 1,500 kplcm The higher the selected pressing pressure, the greater is the attainable shockproofness of the primer element. In the embodiment of FIG.
  • a charge 12 is applied by a second pressing step onto the charge 11; this charge 12 can be a primer charge or also a mixture of explosives.
  • this charge 12 can be a primer charge or also a mixture of explosives.
  • the charge 11 a mixture of lead azide, calcium silicide, and potassium perchlorate
  • the charge 12 fashioned as the primer charge, a mixture of calcium silicide, potassium perchlorate, and lead dioxide or if the charge 12 involves a primer mixture a mixture of lead trinitroresorcinate, barium nitrate, and calcium silicide.
  • the purpose for which the electricalprimer is intended i.e., the type of the powder charge to be ignited thereby, the manner in which it is arranged, etc., determines conventionally which of these and the numerous other possible compositions is selected in each individual case, and whether one or more ignitable charges are utilized.
  • the inner casing 7 is held in the housing 1 by frictional connection and, in a known manner, additionally by flanging over the upper rim, not shown, of the housing 1 with respect to the corresponding rim of the inner casing 7.
  • the housing 1 and the pole piece 3 consist of a metal, e.g., brass or also a corrosion-resistant steel, such as Cr-Ni steel, for example.
  • the inner casing 7 is manufactured of a softer material, such as copper or soft brass.
  • the plated element 6 rests with its peripheral surface against the wall of the recess 5 of the pole piece 3 by way of the tubular extension 14 of an insulating ring 13.
  • the insulating ring 13 is made, for example, of polyethylene.
  • the extension 14, as well as the wall of recess 5', is of a conical configuration.
  • a contact disk is provided between the bottom 8 of the inner casing 7' and the plated element 6 for aiding in establishing a good electrically conductive path therebetween.
  • the contact disk 15 in the uninstalled condition has a slight conical shape and is inserted in the housing with the inner rim thereof pointing in the direction of the plated element.
  • the two ignitable charges 11 and 12 are covered by a cover or seal 16 of, for example, tin-plated lead foil; during the pressing of the charge or charges and a marking 17 is embossed into this seal 16.
  • the marking 17, here fashioned as a toroid, indicates by its more or less pronounced profile whether the pressing step has been satisfactorily accomplished and thus the functionality of the primer is ensured.
  • the primer is equipped in the zone of the cover 16 conventionally with a cover layer, not shown, of nitrocellulose lacquer, for example.
  • the illustrated arrangement of the primer with the end 18 of the inner casing 7 extending out of the housing 1 is specifically intended for use in cartridge ammunition wherein the end 18 takes over the support on the bottom of the chamber provided for the primer and optionally compensates for axial or longitudinal tolerances by compression.
  • the inner casing 7' is formed with a wall thickness which decreases toward the end 18 which faces away from the plated element which aids in the compressibility of the casing in the axial or longitudinal direction.
  • the plated element which may be of the type disclosed in U.S. Pat. No. 3,682,096, as shown in FIGS. 3 and 4 includes a circular-disc-shaped carrier element 21 in the form of an insulating body of, for example, glass or ceramic.
  • the top side is provided with a radially eXtending metallic web of a small thickness and width, forming the glow or incandescent bridge 22, which is enlarged at the outer end thereof into an annular contact surface 23 and whose inner end is extended through a central bore 24 to the circular-disc-shaped contact surface 25 formed on the bottom side of the carrier element 21.
  • connection between the inwardly disposed end of the heater or incandescent bridge 22 and the lower contact surface 25 can thereby be either self-constructed that the entire cross-section of the bore 241 is filled out, in that part sample, a solid rivet is inserted into the bore 24, or -as indicated in dashed lines in that this connection is limited only to a thin layer along the wall of the bore, which can, for example, be applied simultaneously with other metallic surfaces by galvanic means.
  • An electrical primer comprising an electrically conductive housing, a pole piece disposed within said housing and accessible from outside of said housing, plated element means disposed within said housing and having an ignition bridge on one surface thereof, an inner casing means disposed within said housing, said plated element means and said inner casing means being arranged in said housing such that said pole piece is electrically conductively connected to said housing via said plated element means and said inner casing means, and at least one ignitable charge being disposed within said housing in operative relation with said ignition bridge for ignition thereby, said pole piece including cup-shaped recess means in the end portion thereof facing said at least one ignitable charge, said plated element means being arranged in said recess means such that at least a bottom surface of said plated element means rests on and is in electrically conductive contact with said pole piece.
  • said plated element means includes first and second oppositely facing surface portions and a peripheral surface portion therebetween, said ignition bridge being provided on the first surface portion and the bottom surface of said plated element means being the second surface portion thereof.
  • tubular extension of said insulating member has an inner cylindrical surface portion arranged forcooperatio n with the peripheral surface portion of said plated element means.
  • annular contact disk means is provided with a slight conical shape prior to being disposed in said housing and is disposed in said housing with the inner rim thereof facing in the direction of said plated element means.
  • said inner casing means includes a tubular wall portion adjoining the bottom portion thereof, said tubular wall portion having a wall thickness which decreases in the direction facing away from said plated W element means.
  • An electrical primer according to claim 16 further comprisng sealing means covering the at least one ignitable charge disposed within said housing, and marking means provided on said sealing means for indicating the flawless conducting of the pressing operation for the pressure introduction of the at least one ignitable charge within said housing.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Spark Plugs (AREA)
  • Air Bags (AREA)
US396438A 1972-09-15 1973-09-12 Electrical primer Expired - Lifetime US3867885A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2245308A DE2245308C3 (de) 1972-09-15 1972-09-15 Elektrisches Brückenzündmittel

Publications (1)

Publication Number Publication Date
US3867885A true US3867885A (en) 1975-02-25

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ID=5856438

Family Applications (1)

Application Number Title Priority Date Filing Date
US396438A Expired - Lifetime US3867885A (en) 1972-09-15 1973-09-12 Electrical primer

Country Status (8)

Country Link
US (1) US3867885A (fr)
BE (1) BE804857A (fr)
CH (1) CH555529A (fr)
DE (1) DE2245308C3 (fr)
FR (1) FR2200501B1 (fr)
GB (1) GB1401576A (fr)
IT (1) IT994251B (fr)
SE (1) SE408964B (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4014264A (en) * 1974-09-13 1977-03-29 Dynamit Nobel Aktiengesellschaft Combined igniter cap
US4261263A (en) * 1979-06-18 1981-04-14 Special Devices, Inc. RF-insensitive squib
US4267567A (en) * 1977-04-19 1981-05-12 Aktiebolaget Bofors Electric igniter
US4644863A (en) * 1983-11-09 1987-02-24 Dynamit Nobel Aktiengesellschaft Electric detonator
US4686903A (en) * 1984-05-21 1987-08-18 Ems-Inventia AG Method of manufacturing a pole body for an electric fuse, pole body for an electric fuse and method of using the pole body
US4715280A (en) * 1984-05-24 1987-12-29 Ems-Inventa Ag Pole body for an electric fuze, method of manufacturing and method of using the pole body
US4821646A (en) * 1987-06-29 1989-04-18 Cxa Ltd./Cxa Ltee Delay initiator for blasting
US5113764A (en) * 1989-09-25 1992-05-19 Olin Corporation Semiconductor bridge (SCB) packaging system
US5293821A (en) * 1990-06-22 1994-03-15 Ici Canada Inc. Delay initiator for blasting
US5454320A (en) * 1992-10-23 1995-10-03 Quantic Industries, Inc. Air bag initiator
US5647924A (en) * 1993-10-20 1997-07-15 Quantic Industries, Inc. Electrical initiator
US5648634A (en) * 1993-10-20 1997-07-15 Quantic Industries, Inc. Electrical initiator
US20160169651A1 (en) * 2013-08-05 2016-06-16 Ruag Ammotec Gmbh Electromechanical Primer Cap
US10415944B2 (en) 2013-08-05 2019-09-17 Ruag Ammotec Gmbh Electronic primer cap for small-caliber ammunition

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2654087C3 (de) * 1976-11-29 1981-07-16 Dynamit Nobel Ag, 5210 Troisdorf Elektrisches Zündmittel
DE3222765C2 (de) * 1982-06-18 1986-01-02 Comet GmbH Pyrotechnik - Apparatebau, 2850 Bremerhaven Behälter zur Lagerung und Abschuß - aus der Hand - einer Signalrakete
DE3245187A1 (de) * 1982-12-07 1984-06-07 Dynamit Nobel Ag, 5210 Troisdorf Kontaktierung von traegerelementen in elektrischen zuendmitteln
US5044278A (en) * 1989-07-03 1991-09-03 James E. Meagher Electrically ignitible cartridge system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3018732A (en) * 1954-09-30 1962-01-30 Bendix Corp Ignition means for ammunition primer or the like
US3295446A (en) * 1964-03-12 1967-01-03 Rheinmetall Gmbh Electric primer
US3308758A (en) * 1964-07-02 1967-03-14 Dynamit Nobel Ag Ignition device
US3682096A (en) * 1968-07-25 1972-08-08 Dynamit Nobel Ag Electric detonator element

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1084745A (en) * 1913-09-08 1914-01-20 Union Metallic Cartridge Co Electric primer.
DE882970C (de) * 1942-12-29 1953-07-13 Dynamit Nobel Ag Elektrisch zuendbare Sprengkapseln
US2972951A (en) * 1952-05-06 1961-02-28 Richard H Stresau Electric initiator for fuze
SE339185B (fr) * 1970-01-26 1971-09-27 Philips Svenska Ab
DE2020016C3 (de) * 1970-04-24 1974-12-12 Dynamit Nobel Ag, 5210 Troisdorf Metallschichtzündmittel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3018732A (en) * 1954-09-30 1962-01-30 Bendix Corp Ignition means for ammunition primer or the like
US3295446A (en) * 1964-03-12 1967-01-03 Rheinmetall Gmbh Electric primer
US3308758A (en) * 1964-07-02 1967-03-14 Dynamit Nobel Ag Ignition device
US3682096A (en) * 1968-07-25 1972-08-08 Dynamit Nobel Ag Electric detonator element

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4014264A (en) * 1974-09-13 1977-03-29 Dynamit Nobel Aktiengesellschaft Combined igniter cap
US4267567A (en) * 1977-04-19 1981-05-12 Aktiebolaget Bofors Electric igniter
US4261263A (en) * 1979-06-18 1981-04-14 Special Devices, Inc. RF-insensitive squib
US4644863A (en) * 1983-11-09 1987-02-24 Dynamit Nobel Aktiengesellschaft Electric detonator
US4686903A (en) * 1984-05-21 1987-08-18 Ems-Inventia AG Method of manufacturing a pole body for an electric fuse, pole body for an electric fuse and method of using the pole body
US4715280A (en) * 1984-05-24 1987-12-29 Ems-Inventa Ag Pole body for an electric fuze, method of manufacturing and method of using the pole body
US4821646A (en) * 1987-06-29 1989-04-18 Cxa Ltd./Cxa Ltee Delay initiator for blasting
US5113764A (en) * 1989-09-25 1992-05-19 Olin Corporation Semiconductor bridge (SCB) packaging system
US5293821A (en) * 1990-06-22 1994-03-15 Ici Canada Inc. Delay initiator for blasting
US5454320A (en) * 1992-10-23 1995-10-03 Quantic Industries, Inc. Air bag initiator
US5647924A (en) * 1993-10-20 1997-07-15 Quantic Industries, Inc. Electrical initiator
US5648634A (en) * 1993-10-20 1997-07-15 Quantic Industries, Inc. Electrical initiator
US5711531A (en) * 1993-10-20 1998-01-27 Quantic Industries, Inc. Electrical initiator seal
US5728964A (en) * 1993-10-20 1998-03-17 Quantic Industries, Inc. Electrical initiator
US5763814A (en) * 1993-10-20 1998-06-09 Quanti Industries, Inc. Electrical initiator
US20160169651A1 (en) * 2013-08-05 2016-06-16 Ruag Ammotec Gmbh Electromechanical Primer Cap
US10215545B2 (en) * 2013-08-05 2019-02-26 Ruag Ammotec Gmbh Electromechanical primer cap
US10415944B2 (en) 2013-08-05 2019-09-17 Ruag Ammotec Gmbh Electronic primer cap for small-caliber ammunition

Also Published As

Publication number Publication date
FR2200501B1 (fr) 1978-01-06
IT994251B (it) 1975-10-20
FR2200501A1 (fr) 1974-04-19
DE2245308C3 (de) 1981-05-07
BE804857A (fr) 1974-01-02
DE2245308A1 (de) 1974-03-21
DE2245308B2 (de) 1980-07-31
CH555529A (de) 1974-10-31
GB1401576A (en) 1975-07-16
SE408964B (sv) 1979-07-16

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