US3040660A - Electric initiator with exploding bridge wire - Google Patents
Electric initiator with exploding bridge wire Download PDFInfo
- Publication number
- US3040660A US3040660A US562517A US56251744A US3040660A US 3040660 A US3040660 A US 3040660A US 562517 A US562517 A US 562517A US 56251744 A US56251744 A US 56251744A US 3040660 A US3040660 A US 3040660A
- Authority
- US
- United States
- Prior art keywords
- wire
- electric
- bridge wire
- fuse
- detonation
- 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
-
- C—CHEMISTRY; METALLURGY
- C06—EXPLOSIVES; MATCHES
- C06C—DETONATING OR PRIMING DEVICES; FUSES; CHEMICAL LIGHTERS; PYROPHORIC COMPOSITIONS
- C06C7/00—Non-electric detonators; Blasting caps; Primers
-
- 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
-
- 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
- F42B3/128—Bridge initiators characterised by the composition of the pyrotechnic material
Definitions
- Electric detonators of the prior art generally employ a fuse wire which melts with the application of a relatively low voltage and current.
- the fuse wire is imbedded in a quantity of primer material, such as mercury fulminate, lead a-zide, or the like. Adjacent the primer material is the base charge which may be a high explosive substance, such -as pentaerythritol tetranitrate (PETN) or trimethylenetrinitramine (RDX), etc.
- PETN pentaerythritol tetranitrate
- RDX trimethylenetrinitramine
- squibs While these initiators, generally called squibs, are quite satisfactory, they possess certain disadvantages. In view of the fact that a sensitive primer material is needed they are sensitive to mechanical shocks and must be handled very carefully. Moreover, they are very sensitive to electric currents in view of the fact that only a low current is necessary to melt the wire. As a precautionary measure, the lead-in wires must be twisted and thereby shortcircuited for shipment or when the fuses are stored. This precaution is necessary to prevent chance detonation with the inadvertent application of an electric current, or a static electric charge.
- Another disadvantage in certain cases is the time delay involved between application of current and detonation. This time interval is approximately a millisecond or greater, which in special industrial applications is an undesirable time factor. In such applications, it is also desirable to have a uniform time factor for one type ofdetonator, whereby several may be synchronized to detonate at exactly the same time, preferably within microseconds of time difference.
- the object of this invention is to improve the operation of electric blasting initiators to obtain a more uniform time constant and a shorter time interval for effecting detonation.
- Another object of the invention is to improve the electrically operated squib with respect to safety in handling by making it insensitive to shocks.
- a further object of the invention is to reduce the hazard concomitant with the use of sensitive primer material together with low current and low voltage operation.
- a particular advantage of the detonator in accordance with this invention is that no primer material is required
- Another advantage of the invention is that a uniform ignition time interval can be obtained for all fuses whereby a number of detonators may be operated simultaneously at synchronized uniform time interval.
- FIGURE 1 illustrates the novel construction of an electric detonator in accordance with the invention
- FIGURE 2 is an enlarged cross sectional view of a portion thereof.
- the detonator comprises a shell, or housing 1 which may be of tubular form closed up at one end.
- the material for the housing may be metal or plastic composition or any suitable material which is easy to handle and can be stored without being affected by moisture.
- the housing is filled at one end with a high explosive substance 2, such as pentaerythritol tetranitrate or trimethylenetrinitramine, etc. loosely packed.
- a high explosive substance 2 such as pentaerythritol tetranitrate or trimethylenetrinitramine, etc. loosely packed.
- the fuse wire 3 bridged across a pair of lead-in wires 4 and 5.
- the lead-in wires are firmly held by the insulating support 6 which seals off the open end of the housing 1.
- the insulating support 6 may be a molded composition or the same plastic material as the housing.
- the lead-in wires 4 and 5 are brought out for electrical connection and may be insulated by cambrick tubing 7 extending to the support 6.
- the latter has a dividing portion 8 for additional separation and insulation of the lead-in wires.
- the fuse 'Wire is so proportioned that for a given predetermined current at a considerably high voltage the fuse material disintegrates' completely, in other words, practically explodes and thereby transmits a detonation wave of sufficient magnitude to cause sudden detonation of the high explosive charge.
- the fuse wire may be made of various metals. Platinum, tungsten, or nickel-chromium alloy are particularly well suited with different types of high explosive charges.
- the schematic circuit in connection with FIGURE 1 shows a condenser 10 connected to the lead-in wires 4 and through a switch 11, which in one position connects the condenser to a source of voltage, shown here by way of example, by the battery 12, and in the other position discharges the condenser 10 across the terminals of the lead-in wires.
- the condenser dis charge type of ignition is merely a preferred way insofar as it is well suited for exact timing.
- the high voltage source may be connected directly across the fuse terminals and the voltage supply may be any suitable source as long as it has the necessary voltage and current capacity.
- the enlarged cross sectional view of the squib construction shows the placement of the fuse wire 3 against the surface of the insulating support 6.
- the lead-in wires 4 and S terminate very close to the end surface of the support 6, and the wire 3 is attached to the terminals, for example by soldering, in such manner that it will rest on the flat end surface of the support 6.
- the purpose of placing the fuse wire 3 against the surface results in a definite improvement when the current discharge explodes the wire.
- the surface on which the wire rests forms a baffle or deflecting plate confining the scattering of the wire particles in the direction of the high explosive charge. The detonating efiiciency of the wire 3 is thereby increased, and less cur- 4 rent can be applied to produce the required detonating effect.
- Blasting initiators constructed as described can be used with all types of detonation charges intended to be set off.
- the time factor of the squib is not greater than a few microseconds and the uniformity of this factor in squibs of identical construction makes practical the synchronous operation of several detonators to within /2 microsecond.
- An apparatus for detonation of a high explosive in a uniform short time interval which comprises loosely packed pentaerythritol tetranitrate, a bridge wire of percent nickel and 20 percent chromium one-eighth inch long and .006 inch in diameter and means for introducing electric current of an energy in excess of one-half joule at about 500 volts to said bridge wire, whereby it is explosively distintegrated upon the application of said current with the formation of a detonation wave of sufficient magnitude to detonate the pentaerythritol tetranitrate.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Air Bags (AREA)
Description
June 26, 1962 L. H. JOHNSTON 3,040,660
ELECTRIC INITIATOR WITH EXPLODING BRIDGE WIRE Filed Nov. 8, 1944 I N V EN TOR. zurz'ence [i Jbbnwian E/ Wis/M v United States Patent 3,040,660 ELECTRIC INITIATOR yVlTH EXPLODING BRIDGE WIRE Lawrence H. Johnston, Los Angeles, Calif., assignor to the United States of America as represented by the United States Atomic Energy Commission Filed Nov. 8, 1944, Ser. No. 562,517 1 Claim. (Cl. 102-48) This invention relates to detonators and more particularly to blasting initiators of the electric ignition type.
Electric detonators of the prior art generally employ a fuse wire which melts with the application of a relatively low voltage and current. The fuse wire is imbedded in a quantity of primer material, such as mercury fulminate, lead a-zide, or the like. Adjacent the primer material is the base charge which may be a high explosive substance, such -as pentaerythritol tetranitrate (PETN) or trimethylenetrinitramine (RDX), etc. The melting of the fuse Wire by application of an electric current sets off the sensitive primer which detonates the high explosive in the shell. This explosive in turn transfers the detonation wave to the high explosivematerial to be set ofi. While these initiators, generally called squibs, are quite satisfactory, they possess certain disadvantages. In view of the fact that a sensitive primer material is needed they are sensitive to mechanical shocks and must be handled very carefully. Moreover, they are very sensitive to electric currents in view of the fact that only a low current is necessary to melt the wire. As a precautionary measure, the lead-in wires must be twisted and thereby shortcircuited for shipment or when the fuses are stored. This precaution is necessary to prevent chance detonation with the inadvertent application of an electric current, or a static electric charge.
Another disadvantage in certain cases is the time delay involved between application of current and detonation. This time interval is approximately a millisecond or greater, which in special industrial applications is an undesirable time factor. In such applications, it is also desirable to have a uniform time factor for one type ofdetonator, whereby several may be synchronized to detonate at exactly the same time, preferably within microseconds of time difference.
The object of this invention is to improve the operation of electric blasting initiators to obtain a more uniform time constant and a shorter time interval for effecting detonation.
Another object of the invention is to improve the electrically operated squib with respect to safety in handling by making it insensitive to shocks.
A further object of the invention is to reduce the hazard concomitant with the use of sensitive primer material together with low current and low voltage operation.
A particular advantage of the detonator in accordance with this invention is that no primer material is required,
which increases stability to shocks as well as reduces the.
ignition time delay.
Another advantage of the invention is that a uniform ignition time interval can be obtained for all fuses whereby a number of detonators may be operated simultaneously at synchronized uniform time interval.
Other objects and advantages will be apparent from the following description of the invention, pointed out in particularity in the appended claims and taken in connection with the accompanying drawing, in which:
FIGURE 1 illustrates the novel construction of an electric detonator in accordance with the invention, and
FIGURE 2 is an enlarged cross sectional view of a portion thereof.
The detonator comprises a shell, or housing 1 which may be of tubular form closed up at one end. The material for the housing may be metal or plastic composition or any suitable material which is easy to handle and can be stored without being affected by moisture. The housing is filled at one end with a high explosive substance 2, such as pentaerythritol tetranitrate or trimethylenetrinitramine, etc. loosely packed. In contact with the explosive material is the fuse wire 3 bridged across a pair of lead-in wires 4 and 5. The lead-in wires are firmly held by the insulating support 6 which seals off the open end of the housing 1. The insulating support 6 may be a molded composition or the same plastic material as the housing. Other materials having suitable insulating properties may be used as long as they form a solid support for the lead-in wires, and at the same time prevent the falling out of the loose charge from the shell. The lead-in wires 4 and 5 are brought out for electrical connection and may be insulated by cambrick tubing 7 extending to the support 6. The latter has a dividing portion 8 for additional separation and insulation of the lead-in wires. I p w It is to be noted that in the construction of the fuse the customary primer material is omitted and the high explosive charge is in direct contact with the current reactive element; that is, the fuse wire 3. The high explosive material is insensitive to shocks normally encountered in'handling and the hazard of explosion due to inadvertent use is practically eliminated.
Another and far more important advantage results from the use of a detonating, e.g. high explosive material in place of a deflagrating primer material. This advantage is the reduction in the time delay from milliseconds to microseconds. The sensitivity of the primer has always been a potential hazard and introduced also a time delay in the operation. -In view of the fact that the initiation of the explosion depends upon the comparatively slow burning or deflagrating material of the primer charge to transfer the detonation wave to the high explosive, a considerable delay is unavoidable. Aside from this time delay which in certain materials may amount to several thousandths of a second, there is also a considerable variation of time factor between a number of squibs of the same type and construction. .In certain industrial applications it is extremely important that the detonation of a number of squibs should be effected at exactly the same time in order to obtain exact synchronization.
Employing a high explosive substance free from defiagrating material necessitates certain changes in the electric fuse. The detonation is not to be achieved by the slow melting of a fuse Wire, instead a sudden and large thermal impact must be produced by the applied current. In accordance with the invention the fuse 'Wire is so proportioned that for a given predetermined current at a considerably high voltage the fuse material disintegrates' completely, in other words, practically explodes and thereby transmits a detonation wave of sufficient magnitude to cause sudden detonation of the high explosive charge. The fuse wire may be made of various metals. Platinum, tungsten, or nickel-chromium alloy are particularly well suited with different types of high explosive charges. In practice it was found that a tungsten wire about .001 in. in diameter and /s of an inch long produces very good results. The electric energy necessary for its disintegration was approximately /2 joule. This can be accomplished for example, by a high voltage discharge of a condenser. A condenser of 2 microfarads charged to about 1500 volts produced sufficient energy to explode the tungsten wire. Equal results can be obtained with a #34 Nichrome wire of the same length at a 500 volt discharge of a large condenser, about Patented, June 26, 1962" a 50 microfarads. The number 34 Nichrome wire used was a Brown and Sharpe gauge and had a diameter of .006 inch.
For the purpose of illustrating the preferred method of electrical ignition, the schematic circuit in connection with FIGURE 1 shows a condenser 10 connected to the lead-in wires 4 and through a switch 11, which in one position connects the condenser to a source of voltage, shown here by way of example, by the battery 12, and in the other position discharges the condenser 10 across the terminals of the lead-in wires. The condenser dis charge type of ignition is merely a preferred way insofar as it is well suited for exact timing. The high voltage source may be connected directly across the fuse terminals and the voltage supply may be any suitable source as long as it has the necessary voltage and current capacity.
Referring to FIGURE 2 the enlarged cross sectional view of the squib construction shows the placement of the fuse wire 3 against the surface of the insulating support 6. The lead-in wires 4 and S terminate very close to the end surface of the support 6, and the wire 3 is attached to the terminals, for example by soldering, in such manner that it will rest on the flat end surface of the support 6. The purpose of placing the fuse wire 3 against the surface results in a definite improvement when the current discharge explodes the wire. The surface on which the wire rests forms a baffle or deflecting plate confining the scattering of the wire particles in the direction of the high explosive charge. The detonating efiiciency of the wire 3 is thereby increased, and less cur- 4 rent can be applied to produce the required detonating effect.
Blasting initiators constructed as described can be used with all types of detonation charges intended to be set off. The time factor of the squib is not greater than a few microseconds and the uniformity of this factor in squibs of identical construction makes practical the synchronous operation of several detonators to within /2 microsecond.
What is claimed is:
An apparatus for detonation of a high explosive in a uniform short time interval which comprises loosely packed pentaerythritol tetranitrate, a bridge wire of percent nickel and 20 percent chromium one-eighth inch long and .006 inch in diameter and means for introducing electric current of an energy in excess of one-half joule at about 500 volts to said bridge wire, whereby it is explosively distintegrated upon the application of said current with the formation of a detonation wave of sufficient magnitude to detonate the pentaerythritol tetranitrate.
References Cited in the file of this patent UNITED STATES PATENTS 173,681 Smith Feb. 15, 1876 394,192 Macbeth Dec. 11, 1888 2,086,531 Burrows et a1. July 13, 1937 2,153,171 Burrows et a1. Apr. 4, 1939 2,320,880 Nash June 1, 1943 2,331,058 Stick Oct. 5, 1943 2,350,172 Lawrence May 30, 1944
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US562517A US3040660A (en) | 1944-11-08 | 1944-11-08 | Electric initiator with exploding bridge wire |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US562517A US3040660A (en) | 1944-11-08 | 1944-11-08 | Electric initiator with exploding bridge wire |
Publications (1)
Publication Number | Publication Date |
---|---|
US3040660A true US3040660A (en) | 1962-06-26 |
Family
ID=24246601
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US562517A Expired - Lifetime US3040660A (en) | 1944-11-08 | 1944-11-08 | Electric initiator with exploding bridge wire |
Country Status (1)
Country | Link |
---|---|
US (1) | US3040660A (en) |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3111594A (en) * | 1961-05-10 | 1963-11-19 | Stolte Fred | Method and apparatus for generating electrical pulses |
US3117519A (en) * | 1962-01-31 | 1964-01-14 | Charles R Hamilton | Electric initiators for explosives, pyrotechnics and propellants |
US3134329A (en) * | 1962-05-10 | 1964-05-26 | Thiokol Chemical Corp | Exploding bridgewire coating |
US3149372A (en) * | 1960-07-21 | 1964-09-22 | Du Pont | Electromagnetic apparatus |
US3156186A (en) * | 1961-03-17 | 1964-11-10 | Gen Precision Inc | Ammonium nitrate-aluminum explosive |
US3157120A (en) * | 1962-01-12 | 1964-11-17 | William C Morgan | Solid dielectric exploding bridgewire series safety element |
US3158098A (en) * | 1963-08-09 | 1964-11-24 | Robert J Reithel | Low voltage detonator system |
US3159103A (en) * | 1962-04-05 | 1964-12-01 | Beckman & Whitley Inc | Detonator to igniter adapter for initiating propellant mixes |
US3160097A (en) * | 1961-07-17 | 1964-12-08 | Gen Precision Inc | Molybdenum trioxide-aluminum explosive and exploding bridgewire detonator therefor |
US3175492A (en) * | 1961-06-13 | 1965-03-30 | Schlumberger Prospection | Electrical safety detonator |
US3181463A (en) * | 1961-03-17 | 1965-05-04 | Gen Precision Inc | Explosive device containing charge of elongated crystals and an exploding bridgewire |
US3181464A (en) * | 1961-06-21 | 1965-05-04 | Gen Precision Inc | Low conductance exploding bridge |
US3208379A (en) * | 1961-02-21 | 1965-09-28 | Special Devices Inc | Squib arrangement initiated by exploding wire |
US3208380A (en) * | 1965-01-19 | 1965-09-28 | Hercules Powder Co Ltd | Electric blasting cap assembly |
US3225695A (en) * | 1961-08-04 | 1965-12-28 | Space Recovery Systems Inc | Pyrotechnic bridge detonating circuit with zener diode circuit controlling switching of scr |
US3340808A (en) * | 1963-10-18 | 1967-09-12 | Howard S Leopold | One component detonator requiring low firing energy |
DE1258771B (en) * | 1965-03-09 | 1968-01-11 | Montage Technik Anstalt F | Process for firing propellant charges for powder-powered bolt setting tools and propellant charge for this |
US3457859A (en) * | 1967-11-24 | 1969-07-29 | Hercules Inc | Method and system for initiating explosive composition |
US4782911A (en) * | 1981-06-01 | 1988-11-08 | Imperial Chemical Industries Plc | Seismic recording |
US5070789A (en) * | 1990-06-27 | 1991-12-10 | Cxa Ltd./Cxa Ltee | Electric exploding bridge wire initiators |
AU2010299288B2 (en) * | 2009-09-28 | 2014-06-26 | Hitachi Zosen Corporation | Blasting cartridge, demolition device, and demolition method |
US20150308796A1 (en) * | 2013-04-26 | 2015-10-29 | Dana Raymond Allen | Method and device for micro blasting with reusable blasting rods and electrically ignited cartridges |
US11201027B2 (en) * | 2017-02-01 | 2021-12-14 | Dehn Se + Co Kg | Triggered fuse for low-voltage applications |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US173681A (en) * | 1876-02-15 | Improvement in electric fuses | ||
US394192A (en) * | 1888-12-11 | Electrical fuse | ||
US2086531A (en) * | 1935-10-30 | 1937-07-13 | Du Pont | Electric blasting initiator |
US2153171A (en) * | 1936-11-19 | 1939-04-04 | Du Pont | Electric blasting cap |
US2320880A (en) * | 1940-05-25 | 1943-06-01 | Hercules Powder Co Ltd | Bridge plug assembly |
US2331058A (en) * | 1942-08-14 | 1943-10-05 | Lane Wells Co | Firing apparatus for gun perforators |
US2350172A (en) * | 1940-05-17 | 1944-05-30 | Hercules Powder Co Ltd | Electric blasting cap |
-
1944
- 1944-11-08 US US562517A patent/US3040660A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US173681A (en) * | 1876-02-15 | Improvement in electric fuses | ||
US394192A (en) * | 1888-12-11 | Electrical fuse | ||
US2086531A (en) * | 1935-10-30 | 1937-07-13 | Du Pont | Electric blasting initiator |
US2153171A (en) * | 1936-11-19 | 1939-04-04 | Du Pont | Electric blasting cap |
US2350172A (en) * | 1940-05-17 | 1944-05-30 | Hercules Powder Co Ltd | Electric blasting cap |
US2320880A (en) * | 1940-05-25 | 1943-06-01 | Hercules Powder Co Ltd | Bridge plug assembly |
US2331058A (en) * | 1942-08-14 | 1943-10-05 | Lane Wells Co | Firing apparatus for gun perforators |
Cited By (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3149372A (en) * | 1960-07-21 | 1964-09-22 | Du Pont | Electromagnetic apparatus |
US3208379A (en) * | 1961-02-21 | 1965-09-28 | Special Devices Inc | Squib arrangement initiated by exploding wire |
US3156186A (en) * | 1961-03-17 | 1964-11-10 | Gen Precision Inc | Ammonium nitrate-aluminum explosive |
US3181463A (en) * | 1961-03-17 | 1965-05-04 | Gen Precision Inc | Explosive device containing charge of elongated crystals and an exploding bridgewire |
US3111594A (en) * | 1961-05-10 | 1963-11-19 | Stolte Fred | Method and apparatus for generating electrical pulses |
US3175492A (en) * | 1961-06-13 | 1965-03-30 | Schlumberger Prospection | Electrical safety detonator |
US3181464A (en) * | 1961-06-21 | 1965-05-04 | Gen Precision Inc | Low conductance exploding bridge |
US3160097A (en) * | 1961-07-17 | 1964-12-08 | Gen Precision Inc | Molybdenum trioxide-aluminum explosive and exploding bridgewire detonator therefor |
US3225695A (en) * | 1961-08-04 | 1965-12-28 | Space Recovery Systems Inc | Pyrotechnic bridge detonating circuit with zener diode circuit controlling switching of scr |
US3157120A (en) * | 1962-01-12 | 1964-11-17 | William C Morgan | Solid dielectric exploding bridgewire series safety element |
US3117519A (en) * | 1962-01-31 | 1964-01-14 | Charles R Hamilton | Electric initiators for explosives, pyrotechnics and propellants |
US3159103A (en) * | 1962-04-05 | 1964-12-01 | Beckman & Whitley Inc | Detonator to igniter adapter for initiating propellant mixes |
US3134329A (en) * | 1962-05-10 | 1964-05-26 | Thiokol Chemical Corp | Exploding bridgewire coating |
US3158098A (en) * | 1963-08-09 | 1964-11-24 | Robert J Reithel | Low voltage detonator system |
US3340808A (en) * | 1963-10-18 | 1967-09-12 | Howard S Leopold | One component detonator requiring low firing energy |
US3208380A (en) * | 1965-01-19 | 1965-09-28 | Hercules Powder Co Ltd | Electric blasting cap assembly |
DE1258771B (en) * | 1965-03-09 | 1968-01-11 | Montage Technik Anstalt F | Process for firing propellant charges for powder-powered bolt setting tools and propellant charge for this |
US3457859A (en) * | 1967-11-24 | 1969-07-29 | Hercules Inc | Method and system for initiating explosive composition |
US4782911A (en) * | 1981-06-01 | 1988-11-08 | Imperial Chemical Industries Plc | Seismic recording |
GB2245690A (en) * | 1990-06-27 | 1992-01-08 | Cxa Ltd | Electric exploding bridge wire initiators. |
US5070789A (en) * | 1990-06-27 | 1991-12-10 | Cxa Ltd./Cxa Ltee | Electric exploding bridge wire initiators |
AU2010299288B2 (en) * | 2009-09-28 | 2014-06-26 | Hitachi Zosen Corporation | Blasting cartridge, demolition device, and demolition method |
US8904938B2 (en) | 2009-09-28 | 2014-12-09 | Hitachi Zosen Corporation | Blasting cartridge, blasting apparatus, and blasting method |
US20150308796A1 (en) * | 2013-04-26 | 2015-10-29 | Dana Raymond Allen | Method and device for micro blasting with reusable blasting rods and electrically ignited cartridges |
US10801818B2 (en) * | 2013-04-26 | 2020-10-13 | Dana Raymond Allen | Method and device for micro blasting with reusable blasting rods and electrically ignited cartridges |
US11201027B2 (en) * | 2017-02-01 | 2021-12-14 | Dehn Se + Co Kg | Triggered fuse for low-voltage applications |
US11764025B2 (en) | 2017-02-01 | 2023-09-19 | Dehn Se | Triggered fuse for low-voltage applications |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3040660A (en) | Electric initiator with exploding bridge wire | |
US3366055A (en) | Semiconductive explosive igniter | |
US3726217A (en) | Detonating devices | |
US5027707A (en) | Electric primer with reduced RF and ESD hazard | |
US3062143A (en) | Detonator | |
US2475875A (en) | Explosive assembly | |
US4994125A (en) | Electric primer with intrinsic conductive mix | |
US2981186A (en) | Electric detonator | |
US3332350A (en) | Electric blasting cap having heatshrinkable plastic-covered match assembly | |
US4070970A (en) | Electro-explosive igniters | |
US3351012A (en) | Explosive bridgewire initiators | |
US2086548A (en) | Electric initiator | |
US3021786A (en) | Blasting device | |
US3589294A (en) | System for multiple point simultaneous initiation of explosive charges | |
US3117519A (en) | Electric initiators for explosives, pyrotechnics and propellants | |
US3361064A (en) | Electric detonating apparatus | |
US3158098A (en) | Low voltage detonator system | |
US2960933A (en) | Detonator | |
US3288065A (en) | Booster and method of detonating explosive | |
US3286628A (en) | Electric detonator ignition systems | |
GB752724A (en) | Improvements in or relating to electrical pellet primers | |
US3159103A (en) | Detonator to igniter adapter for initiating propellant mixes | |
US2963971A (en) | Initiator assembly | |
US3390636A (en) | Electro-initiating device | |
US3371607A (en) | Arrangement for increasing the safety against unintentional initiation of socalled low energy detonating cord assemblies |