US2999460A - Electric blasting cap - Google Patents
Electric blasting cap Download PDFInfo
- Publication number
- US2999460A US2999460A US796350A US79635059A US2999460A US 2999460 A US2999460 A US 2999460A US 796350 A US796350 A US 796350A US 79635059 A US79635059 A US 79635059A US 2999460 A US2999460 A US 2999460A
- Authority
- US
- United States
- Prior art keywords
- ribbons
- cap
- film
- electric blasting
- plug
- 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
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
- F42B3/195—Manufacture
-
- 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
- the present invention relates to a novel electric blasting cap having an improved ignition assembly. More particularly, the present invention relates to an improved ignition assembly for regular and delay electric blasting caps involving the use of a so-called printed circuit mechanism to mechanically support and electrically heat the bridgewire of an electric blasting cap.
- novel ignition assembly of the present invention may be advantageously employed in connection with both regular electric blasting caps and delay electric blasting caps, but for reasons which will be more particularly hereinafter described, the maximum advantages of the invention are obtained in connection with delay caps, and the invention will be especially discussed in this connection.
- the foregoing objects are achieved by replacing at least the bottom terminal portion of the conventional metallic leg wires in an electric blasting cap with a printed circuit component which will convey an electric current from the lead wires to the bridgewire in order to heat the latter and initiate the ignition composition.
- the printed circuit component will consist of an electrically non-conductive strip having a Patented Sept. 12, 1961 "ice pair of separate, generally parallel metallic film sections applied to its face. Between the metallic film sections, the plastic strip is notched on its lower end to provide a gap across which the bridgewire is stretched.
- FIGURE 1 represents a cross-sectional view of a delay electric blasting cap provided with the novel ignition assembly of the present invention.
- FIGURE 2 is an exploded view of the printed circuit component of the ignition assembly and the two halves of the rubber plug between which it is supported.
- 1 represents an outer metal shell which houses the components of the blasting cap
- 2 is a base load, as for example PETN
- 3 represents a primer load, which may be lead azide or any other suitable composition that is commonly used for priming purposes in electric blasting caps.
- a delay train 13 which consists of a carrier 14, for example lead or plastic tubing, and a delay charge 15, such as an /15 barium oxide-selenium mixture or a 2/98 boron/red lead mixture.
- a plastic capsule 4 such as polyethylene or the like, is positioned within the shell above the delay train 13.
- the capsule contains a conventional ignition composition 5, such as the 2/98 boron/red lead mixture, or the like.
- a pair of leg wires 7, 7' extend through an elastomeric plug 8 which may be formed in two mating sections 8a and 8b, as shown in FIGURE 2.
- the plug 8 is secured in position within shell 1 by circumferential crimps 10 and 11.
- the leg wires 7, 7 terminate at their lower ends within the confines of .the plug 8.
- Sandwiched between the portions 8a and 8b of plug 8 is a printed circuit component which extends on its bottom end out and down from the plug a short distance.
- the printed circuit component consists of a suitable non-conducting film 20 such as glass, mica, oriented polyethylene terephthalate film of the type available commercially as Mylar polyester film, polytetrafluoroethylene or other plastic film, or the like.
- a suitable non-conducting film 20 such as glass, mica, oriented polyethylene terephthalate film of the type available commercially as Mylar polyester film, polytetrafluoroethylene or other plastic film, or the like.
- a pair of separate and distinct, generally parallel ribbons of current-conducting coating 16, 16' such as a copper coating or other suitable metal, extending at least a substantial distance along the length of the strip.
- a notch 17 is provided at the base of the film between the two coated segments 16, 16', and the film may also be chamfered, as at 18, 18', to facilitate its ultimate insertion into the plastic capsule 4 containing the ignition composition.
- leg wires 7, 7 are positioned within the plug 8 by means of the various grooves 19a, 19b, 19c, and 19d to lie directly adjacent to and in physical contact with the metallic ribbons 16, 16.
- a firm electrical contact is established between leg wires .7, 7' and metallic ribbons 16, 16'.
- a bridgewire 9 is positioned across the notch 17 and afi'ixed to both of the prongs which form the notch in firm electrical contact with the base of themetallic ribbons 16, 16.
- the end of printed circuit component supporting the bridgewire protrudes from the base of the plug 8 and is submerged in or otherwise is placed in initiating proximity to the ignition composition 5 contained within the capsule 4.
- the cap will then fire in the conventional way. However, should an exceptionally high voltage be applied to the cap, the tendency of an electric arc to develop and to sustain itself in a manner affecting the performance of the cap, as outlined above, is materially reduced.
- the exposed components of the ignition assembly contain an insufficient amount of metallic material to vaporize, ionize, and sustain an are for any extended period. Then too, the very thin metallic ribbons of the printed circuit will often act as a fuse by melting away if the current becomes too high and will interrupt further current flow.
- the plastic support itself is not conductive and is preferably made of a substance such as an oriented polyethylene terephthalate film which does not carbonize and support current flow.
- the electrically-resistant heating means may be either a bridgewire as indicated at 9 in the attached drawing, or a portion of metallic ribbon, similar to the ribbons 16, 16' or any other suitable electrically-resistant heating means.
- the printed circuit component of the ignition assembly is shown as terminating within the confines-of the plug member 8 and the conducting ribbons 16, 16' are in electrical contact with a pair of conventional leg wires 7, 7' entering the plug from the top.
- blasting caps in which the printed circuit component extends up and out of the plug 8 for some distance (even for direct connection to the power source) are within the scope of the invention.
- the exposed metallic ribbons 16, 16' exterior of the plug 8 would have to be covered, for example, by a separate non-conducting film or coating applied to the surface of film 20 which carries the ribbons 16, 16'.
- that portion of the ribbons 16, 16' above the point of contact of the ribbons with the bridgewire 9, or at least that portion of the ribbons which extends up from the plug member 8 and out of the shell, may be positioned between a pair of laminated films which encase the ribbons.
- the critical feature of the invention is the presence of the printed circuit component within the confines of the blasting cap as part of the ignition assembly, and the precise mode by which this component is electrically connected to the source of power is not too significant.
- the printed circuit component 6 of the present invention may be prepared by any suitable technique which is commonly used today in the manufacture of printed circuits" for a variety of electrical machines and appliances.
- the metallic ribbons may be applied to the plastic support by vapor deposition of the metal onto one entire side of the plastic in a vacuum chamber in the well-known way.
- the surplus metal may be removed by chemical or mechanical means to leave two separate and distinct strips which serve as two individual conductive ribbons.
- the plastic may be masked prior to vapor deposition of the metal ribbons such that the latter deposit on the desired areas only.
- the bridgewire may then be affixed at both ends across the notch 17 to the conductive metal ribbons 16, 16' by any suitable technique.
- the bridgewire may be soldered into position by a spray soldering technique, or it may be mechanically embedded into the plastic and then connected electrically to the copper strip by further deposition of metal after suitably masking the remainder of the circuit with a soluble masking material which may thereafter be removed with a suitable solvent.
- a spray soldering technique or it may be mechanically embedded into the plastic and then connected electrically to the copper strip by further deposition of metal after suitably masking the remainder of the circuit with a soluble masking material which may thereafter be removed with a suitable solvent.
- novel ignition assembly of the present invention may be advantageously used in connection with either delay electric blasting caps or regular electric blasting caps. Since the arcing problem is particularly serious with delay caps, the invention may find its greatest utility in that connection. However, the invention is definitely applicable to regular blasting caps too, and the latter are contemplated as falling within the scope of the invention.
- An electric blasting cap comprising a shell containing a detonation composition and an ignition composition in initiating proximity thereto, a plug member formed in two one-piece mating sections above said ignition composition, a single, thin non-conducting film supported between the mating sections of the plug and projecting out and down therefrom, a notch in the lower end of said film which protrudes out from the bottom of the plug, a pair of separate and distinct conducting ribbons afiixed along the surface of said film, each ribbon terminating at one end along one side of said notch, a bridgewire in initiating proximity to the ignition composition stretching across the mouth of the notch and secured at either end in electrical contact with one of the two separate conducting ribbons, each of said ribbons also being in electrical contact with one of a pair of leg wires entering the cap at the end remote from the detonating composition and mounted between the mating sections of the plug member.
- an improved ignition assembly at least partially embedded in said ignition composition comprising a single thin non-conducting film having a notch at its lower end, a pair of separate and distinct conducting ribbons aflixed along the surface of said film, each ribbon terminating at one side of said notch, an electrical-resistant heating means in initiating proximity to the ignition composition stretching across the mouth of the notch and secured at either end in electrical contact with one of the two separate conducting ribbons, and means for connecting said conducting ribbons to a source of electrical power.
- an improved ignition assembly at least partially embedded in said ignition composition comprising a single, thin, nonconducting film having a notch at its lower end, a pair of separate and distinct conducting ribbons affixed along the surface of said film, each ribbon terminating at one end along one side of said notch, an electrical-resistant heating means, in initiating proximity to the ignition composition stretching across the mouth of the notch and secured at either end in electrical contact with one of the two separate conducting ribbons, and means for connecting said conducting ribbons to a source of electrical power.
- An electric blasting cap comprising a shell containing a detonation composition and an ignition composition in initiating proximity thereto, a plug member formed in two one-piece mating sections above said ignition composition, a single, thin non-conducting film supported between the mating sections of the plug and projecting out and down therefrom, a notch in the lower end of said film which protrudes out from the bottom of the plug,
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Air Bags (AREA)
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
- Organic Insulating Materials (AREA)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DENDAT1163210D DE1163210B (de) | 1959-03-02 | Elektrischer Sicherheits-Brueckenzuender | |
US796350A US2999460A (en) | 1959-03-02 | 1959-03-02 | Electric blasting cap |
GB7414/60A GB891972A (en) | 1959-03-02 | 1960-03-02 | New electric blasting caps and initiators therefor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US796350A US2999460A (en) | 1959-03-02 | 1959-03-02 | Electric blasting cap |
Publications (1)
Publication Number | Publication Date |
---|---|
US2999460A true US2999460A (en) | 1961-09-12 |
Family
ID=25167991
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US796350A Expired - Lifetime US2999460A (en) | 1959-03-02 | 1959-03-02 | Electric blasting cap |
Country Status (3)
Country | Link |
---|---|
US (1) | US2999460A (de) |
DE (1) | DE1163210B (de) |
GB (1) | GB891972A (de) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3277766A (en) * | 1964-08-04 | 1966-10-11 | Francis B Burkdoll | Explosively releasable bolt |
DE2829050A1 (de) * | 1977-07-04 | 1979-01-25 | Asahi Chemical Ind | Fuer statische elektrizitaet unempfindlicher elektrischer zuender |
US4335652A (en) * | 1979-02-26 | 1982-06-22 | E. I. Du Pont De Nemours & Company | Non-electric delay detonator |
US4369708A (en) * | 1979-09-21 | 1983-01-25 | E. I. Du Pont De Nemours And Company | Delay blasting cap |
US4429632A (en) | 1981-04-27 | 1984-02-07 | E. I. Du Pont De Nemours & Co. | Delay detonator |
US4696231A (en) * | 1986-02-25 | 1987-09-29 | E. I. Du Pont De Nemours And Company | Shock-resistant delay detonator |
US4996922A (en) * | 1989-11-15 | 1991-03-05 | The United States Of America As Represented By The United States Department Of Energy | Low profile thermite igniter |
EP0942256A1 (de) * | 1998-03-09 | 1999-09-15 | Hirtenberger Präzisionstechnik GmbH | Elektrisch auslösbarer Zünder zum Anschiessen einer Treibladung |
US20050258159A1 (en) * | 2004-05-20 | 2005-11-24 | Alexza Molecular Delivery Corporation | Stable initiator compositions and igniters |
WO2005118510A1 (en) * | 2004-05-20 | 2005-12-15 | Alexza Pharmaceuticals, Inc. | Stable initiator compositions and igniters |
US7581540B2 (en) | 2004-08-12 | 2009-09-01 | Alexza Pharmaceuticals, Inc. | Aerosol drug delivery device incorporating percussively activated heat packages |
US8387612B2 (en) | 2003-05-21 | 2013-03-05 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
CN103148746A (zh) * | 2013-04-07 | 2013-06-12 | 安徽理工大学 | 一种特殊起爆药装药结构的电*** |
WO2017041830A1 (en) * | 2015-09-07 | 2017-03-16 | Abb Schweiz Ag | An assembly feeder and a method for automated assembly of a primer device and a detonator unit |
EP3163249A1 (de) * | 2015-10-29 | 2017-05-03 | Nexter Munitions | Zündungseinheit für triebwerk |
US20220349692A1 (en) * | 2019-10-23 | 2022-11-03 | Orica International Pte Ltd | Automated systems and apparatuses for storing, transporting, dispensing, and tracking wireless initiation device components configurable for initiating explosive material compositions |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1935495A (en) * | 1931-01-22 | 1933-11-14 | Atlas Powder Co | Slow match composition |
US2331007A (en) * | 1939-03-03 | 1943-10-05 | Ici Ltd | Manufacture of electric detonators |
US2506229A (en) * | 1948-04-30 | 1950-05-02 | Ici Ltd | Electric fuse |
US2762302A (en) * | 1951-11-16 | 1956-09-11 | Norman A Macleod | Electric detonator |
US2878752A (en) * | 1956-12-05 | 1959-03-24 | Du Pont | Blasting initiator |
US2880671A (en) * | 1954-10-05 | 1959-04-07 | Sylvania Electric Prod | Initiator primer |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE278357C (de) * | ||||
DE1049756B (de) * | ||||
US2235009A (en) * | 1937-05-18 | 1941-03-18 | Ici Ltd | Manufacture of fuseheads |
BE546106A (de) * | 1955-03-15 |
-
0
- DE DENDAT1163210D patent/DE1163210B/de active Pending
-
1959
- 1959-03-02 US US796350A patent/US2999460A/en not_active Expired - Lifetime
-
1960
- 1960-03-02 GB GB7414/60A patent/GB891972A/en not_active Expired
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1935495A (en) * | 1931-01-22 | 1933-11-14 | Atlas Powder Co | Slow match composition |
US2331007A (en) * | 1939-03-03 | 1943-10-05 | Ici Ltd | Manufacture of electric detonators |
US2506229A (en) * | 1948-04-30 | 1950-05-02 | Ici Ltd | Electric fuse |
US2762302A (en) * | 1951-11-16 | 1956-09-11 | Norman A Macleod | Electric detonator |
US2880671A (en) * | 1954-10-05 | 1959-04-07 | Sylvania Electric Prod | Initiator primer |
US2878752A (en) * | 1956-12-05 | 1959-03-24 | Du Pont | Blasting initiator |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3277766A (en) * | 1964-08-04 | 1966-10-11 | Francis B Burkdoll | Explosively releasable bolt |
DE2829050A1 (de) * | 1977-07-04 | 1979-01-25 | Asahi Chemical Ind | Fuer statische elektrizitaet unempfindlicher elektrischer zuender |
US4220088A (en) * | 1977-07-04 | 1980-09-02 | Asahi Kasei Kogyo Kabushiki Kaisha | Static-resistant electric initiator |
US4335652A (en) * | 1979-02-26 | 1982-06-22 | E. I. Du Pont De Nemours & Company | Non-electric delay detonator |
US4369708A (en) * | 1979-09-21 | 1983-01-25 | E. I. Du Pont De Nemours And Company | Delay blasting cap |
US4429632A (en) | 1981-04-27 | 1984-02-07 | E. I. Du Pont De Nemours & Co. | Delay detonator |
US4696231A (en) * | 1986-02-25 | 1987-09-29 | E. I. Du Pont De Nemours And Company | Shock-resistant delay detonator |
US4996922A (en) * | 1989-11-15 | 1991-03-05 | The United States Of America As Represented By The United States Department Of Energy | Low profile thermite igniter |
EP0942256A1 (de) * | 1998-03-09 | 1999-09-15 | Hirtenberger Präzisionstechnik GmbH | Elektrisch auslösbarer Zünder zum Anschiessen einer Treibladung |
US8387612B2 (en) | 2003-05-21 | 2013-03-05 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
US9370629B2 (en) | 2003-05-21 | 2016-06-21 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
US8991387B2 (en) | 2003-05-21 | 2015-03-31 | Alexza Pharmaceuticals, Inc. | Self-contained heating unit and drug-supply unit employing same |
WO2005118510A1 (en) * | 2004-05-20 | 2005-12-15 | Alexza Pharmaceuticals, Inc. | Stable initiator compositions and igniters |
US7923662B2 (en) | 2004-05-20 | 2011-04-12 | Alexza Pharmaceuticals, Inc. | Stable initiator compositions and igniters |
US7402777B2 (en) | 2004-05-20 | 2008-07-22 | Alexza Pharmaceuticals, Inc. | Stable initiator compositions and igniters |
US20050258159A1 (en) * | 2004-05-20 | 2005-11-24 | Alexza Molecular Delivery Corporation | Stable initiator compositions and igniters |
US7581540B2 (en) | 2004-08-12 | 2009-09-01 | Alexza Pharmaceuticals, Inc. | Aerosol drug delivery device incorporating percussively activated heat packages |
CN103148746A (zh) * | 2013-04-07 | 2013-06-12 | 安徽理工大学 | 一种特殊起爆药装药结构的电*** |
WO2017041830A1 (en) * | 2015-09-07 | 2017-03-16 | Abb Schweiz Ag | An assembly feeder and a method for automated assembly of a primer device and a detonator unit |
EP3163249A1 (de) * | 2015-10-29 | 2017-05-03 | Nexter Munitions | Zündungseinheit für triebwerk |
FR3043191A1 (fr) * | 2015-10-29 | 2017-05-05 | Nexter Munitions | Allumeur pour propulseur |
US10180311B2 (en) | 2015-10-29 | 2019-01-15 | Nexter Munitions | Igniter for propulsion unit |
US20220349692A1 (en) * | 2019-10-23 | 2022-11-03 | Orica International Pte Ltd | Automated systems and apparatuses for storing, transporting, dispensing, and tracking wireless initiation device components configurable for initiating explosive material compositions |
Also Published As
Publication number | Publication date |
---|---|
DE1163210B (de) | 1964-02-13 |
GB891972A (en) | 1962-03-21 |
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