US2506229A - Electric fuse - Google Patents
Electric fuse Download PDFInfo
- Publication number
- US2506229A US2506229A US83504A US8350449A US2506229A US 2506229 A US2506229 A US 2506229A US 83504 A US83504 A US 83504A US 8350449 A US8350449 A US 8350449A US 2506229 A US2506229 A US 2506229A
- Authority
- US
- United States
- Prior art keywords
- fuse
- blasting
- charge
- pressure
- gas
- 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
- F42B3/103—Mounting initiator heads in initiators; 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
- F42B3/125—Bridge initiators characterised by the configuration of the bridge initiator case
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49107—Fuse making
Definitions
- the present invention relates to improvements in electric blasting fuses of the kind especially adapted for shot-firing in a blasting cartridge wherein a gas that does not support combustion is confined under pressure along with a combustible gas-producing heating charge within a pressure resisting container by a sealing device adapted to yield when a predetermined pressure has been built up.
- a pressure-resistant container leading to a vented discharge head with an interposed seal adapted to yield when a predetermined pressure has been built up by the gases produced by the charge in the container which consists essentially of an ignitable heater charge comprising a mixture of an oxidising agent and one or more organic combustibles, and a charge of carbon dioxide liquefied by loading it under pressure.
- an ignitable heater charge comprising a mixture of an oxidising agent and one or more organic combustibles, and a charge of carbon dioxide liquefied by loading it under pressure.
- pressure On ignition of the heater charge, pressure is built up very rapidly under the confinement until the seal yields, whereupon the partly gaseous products of the reaction stream through the discharge head and produce a blasting eifect in the borehole.
- the heater charge usually comprises a compact mixture of an inorganic perchlorate and an organic fuel which when ignited in the absence of the liquid carbon dioxide undergoes a strongly exothermic reaction with the production of flame.
- this igniting composition consisting of a mixture of an oxidiser and sodium or potassium salicylate, which may if desired contain an endothermic salt in a proportion that renders the composition non selfbuming in air but capable of initiating combustion of the gas-producing charge when under pressure in a cartridge.
- a matchhead for ignitin combustible gas-producing charges of the kind described comprises an electrical resistance wire embedded in a consolidated mixture of 68% potassium perchlorate, 17% sodium or potassium salicylate and 15% ammonium oxalate.
- the object of the present invention is to provide an electric blasting fuse adapted to ignite a heating charge or combustible gas-producing mixture confined under the pressure under which the carbon dioxide or equivalent gas is loaded in a blasting cartridge as aforesaid but which will not fire under atmospheric pressure conditions when an electric current is passed through its resistance bridgewire, and wherein the combustible composition will be free from the corrosive effects associated with the presence of ammonium salts on base metal parts, and espressure would become more pecially brass or other copper metal parts. of the structure in contact with which it is consolidated, whereby its adhesion thereto on long storage is rendered safe.
- an electric blasting fuse of the kind especially adapted for shot-firing in a blasting cartridge wherein a gas that does not support combustion is under pressure along with a combustible gasproducing heating charge within a pressure resisting container by a sealing device adapted to yield when a predetermined pressure has been built up comprised a resistance bridge wire of not more than about 1 millimetre length and not more'than 0.025 millimetre thickness and preferably having a specific resistance of at least lOO micro-ohms wholly embedded in an ignitable composition consisting essentially of a mixture of potassium perchlorate and-dinitroso-pentamethylene-tetramine.
- Dinitroso pentamethylene tetramine as is known, may be prepared by a reaction between hexamethylene tetramine and nitrous acid in presence of aqueous nitric acid.
- compositions employed in the construction of the electric blasting fuses according to the invention are capable of ignition under atmospheric pressure conditions when they are sumciently strongly heated, the heat energy that it is permissable to develop in the resistance bridge wire by the passage of an electric current-from the exploder, even if the current used is willcient to fuse it, is limited. For this reason it is essential that the resistance wire should not have a diameter exceeding 0.025 millimetre or a length exceeding about 1 millimetre.
- An alloy based on nickel and chromium may be used for the resistance bridge-wire.
- the fusehead-of the electric blasting fuse may conveniently be of the kind in which the pole pieces to which ends of the resistance bridge wire are attached are made of brass foil cemented to an insulating layer, but other forms of construction may be employed e. g. the resistance bridge wire may be attached to the air spaced ends of tinned copper wires kept in parallel relation by means of a plug of insulating material.
- the composition is conveniently applied in the form of a dope made up with a solution of nitrocellulose or other cement in a volatile solvent from which a bead is built up in known manner.
- the resulting electric blasting fuses will not become ignited if an electric current is passed through the resistance bridge wire, e. g. as a result of stray currents, which minimises the hazards of manufacture, handling and storage, but under the high pressure at which the cartridge is charged e. g. atmospheres and over even in the presence of liquid carbon dioxide it becomes ignited and effectively ignites heating charges or combustible gas-producing mixtures such as are used in "Gordon" blasting 4 e. g. those made in accordance with British specification No. 480,330.
- the invention is further illustrated in the diagrammatic drawing accompanying the speciflcation, which represents a vertical axial section of electric blasting fuse in accordance with the invention.
- i is a pressboard sheet
- 2 and 2 are brass foils cemented to the press-board sheet I, the foil 2 and a portion of the thickness of the press-board sheet I being cut away at 3 to provide a step bridged by the resistance wire I which is soldered to the foils 2 and 2 at I and 5 8 is a bead of a composition built up by drying of successive coats of a paste of a mixture of potassium perchlorate and dinitroso-pentamethylene-tetramine in the proportions 3:1 by weight in a 5% solution of nitrocellulose in an amyl acetate/amyl alcohol mixture, and subsequently drying of two coats of collodion Ii for waterproofing purposes.
- I and I are insulated leading wires of which the bated ends are soldered to the foils 2 and 2 at 8 and 8 9 is a paper tube and I0 is a cast sulphur filling from which the bead protrudes, when a current sufllcient to fuse the resistance wire 4 is applied through the loading wires I and 1* while the fuse is exposed at atmospheric pressure, the head 6 falls to ignite, but in a Cardox blasting apparatus in contact with a gas-producing mixture as described in British specification No. 480,330 and charged with carbon dioxide at a pressure of 55 atmospheres the passage of a current even below that recognised to fuse the resistance wire 4 causes the bead l to ignite, and this in turn ignites the gas-producing charge.
- resistance bridge wire has a specific. resistance of at least micro-ohms.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Fuses (AREA)
- Air Bags (AREA)
- Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1187648A GB636450A (en) | 1970-03-16 | 1948-04-30 | Improvements in or relating to electric blasting fuses |
GB02550/70A GB1277682A (en) | 1948-04-30 | 1970-03-16 | Improvements relating to fuseheads |
Publications (1)
Publication Number | Publication Date |
---|---|
US2506229A true US2506229A (en) | 1950-05-02 |
Family
ID=32232422
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US83504A Expired - Lifetime US2506229A (en) | 1948-04-30 | 1949-03-25 | Electric fuse |
US495994A Expired - Lifetime US3332350A (en) | 1948-04-30 | 1965-10-14 | Electric blasting cap having heatshrinkable plastic-covered match assembly |
US00124761A Expired - Lifetime US3717096A (en) | 1948-04-30 | 1971-03-16 | Fuseheads |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US495994A Expired - Lifetime US3332350A (en) | 1948-04-30 | 1965-10-14 | Electric blasting cap having heatshrinkable plastic-covered match assembly |
US00124761A Expired - Lifetime US3717096A (en) | 1948-04-30 | 1971-03-16 | Fuseheads |
Country Status (5)
Country | Link |
---|---|
US (3) | US2506229A (xx) |
BE (2) | BE764347A (xx) |
DE (1) | DE2112387A1 (xx) |
FR (2) | FR984258A (xx) |
GB (1) | GB1277682A (xx) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2999460A (en) * | 1959-03-02 | 1961-09-12 | Du Pont | Electric blasting cap |
US3332350A (en) * | 1948-04-30 | 1967-07-25 | Atlas Chem Ind | Electric blasting cap having heatshrinkable plastic-covered match assembly |
US3353262A (en) * | 1963-05-09 | 1967-11-21 | Davey Bickford Smith Cie | Manufacture of electric ignitors for detonators |
US3763783A (en) * | 1970-02-04 | 1973-10-09 | A Thomas | Manufacture of fuze heads |
US3910188A (en) * | 1974-04-04 | 1975-10-07 | Us Army | One watt/one amp no-fire match type initiator |
US6363853B1 (en) * | 1999-09-17 | 2002-04-02 | Apti, Inc. | Electrically initiated distributed igniter |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3415189A (en) * | 1967-03-24 | 1968-12-10 | Atlas Chem Ind | Water destructible electric match |
GB1456281A (en) * | 1974-04-22 | 1976-11-24 | Ici Ltd | Detonating fuse-cord |
US3968724A (en) * | 1974-10-03 | 1976-07-13 | The United States Of America As Represented By The Secretary Of The Army | Method for accurately varying the density of a powder or powder charge, and shrink tubes for use therewith |
US4152988A (en) * | 1977-09-19 | 1979-05-08 | The United States Of America As Represented By The Secretary Of The Navy | Electric match with epoxy coated fluorocarbon containing pyrotechnic composition |
FR2412051A1 (fr) * | 1977-12-13 | 1979-07-13 | Davey Bickford Ets D Bickford | Inflammateur electrique a tete d'amorce isolee |
US4299168A (en) * | 1980-03-20 | 1981-11-10 | The United States Of America As Represented By The United States Department Of Energy | Resistance after firing protected electric match |
US4380958A (en) * | 1980-12-17 | 1983-04-26 | The United States Of America As Represented By The Secretary Of The Army | Electrostatic safe electric match |
US4530269A (en) * | 1983-05-12 | 1985-07-23 | Burroughs Corp. | Remotely initiated separation latch assembly |
GB2141528B (en) * | 1983-05-19 | 1987-06-03 | Haley & Weller Ltd | Firework |
GB2191566A (en) * | 1986-06-09 | 1987-12-16 | Royal Ordnance Plc | Electrical igniter |
US5780765A (en) * | 1997-02-18 | 1998-07-14 | Dyben; Jerry F. | Pyrogen compound kit for an electrical model rocket ignitor |
FR2760525B1 (fr) * | 1997-03-07 | 1999-04-16 | Livbag Snc | Initiateur electro-pyrotechnique constitue autour d'un circuit imprime complet |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2341263A (en) * | 1940-07-12 | 1944-02-08 | Remington Arms Co Inc | Ammunition priming mixture |
US2429490A (en) * | 1945-10-12 | 1947-10-21 | Hercules Powder Co Ltd | Detonator |
US2473405A (en) * | 1945-01-24 | 1949-06-14 | Hercules Powder Co Ltd | Delay electric initiator |
US2481696A (en) * | 1946-09-11 | 1949-09-13 | Olin Ind Inc | Electric firing device |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2350172A (en) * | 1940-05-17 | 1944-05-30 | Hercules Powder Co Ltd | Electric blasting cap |
US2549533A (en) * | 1945-06-27 | 1951-04-17 | Atlas Powder Co | Electric match and explosion initiator containing the same |
BE488616A (xx) * | 1948-04-30 |
-
0
- BE BE488616D patent/BE488616A/xx unknown
-
1949
- 1949-03-25 US US83504A patent/US2506229A/en not_active Expired - Lifetime
- 1949-04-06 FR FR984258D patent/FR984258A/fr not_active Expired
-
1965
- 1965-10-14 US US495994A patent/US3332350A/en not_active Expired - Lifetime
-
1970
- 1970-03-16 GB GB02550/70A patent/GB1277682A/en not_active Expired
-
1971
- 1971-03-15 FR FR7108906A patent/FR2084616A5/fr not_active Expired
- 1971-03-15 DE DE19712112387 patent/DE2112387A1/de active Pending
- 1971-03-16 BE BE764347A patent/BE764347A/xx unknown
- 1971-03-16 US US00124761A patent/US3717096A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2341263A (en) * | 1940-07-12 | 1944-02-08 | Remington Arms Co Inc | Ammunition priming mixture |
US2473405A (en) * | 1945-01-24 | 1949-06-14 | Hercules Powder Co Ltd | Delay electric initiator |
US2429490A (en) * | 1945-10-12 | 1947-10-21 | Hercules Powder Co Ltd | Detonator |
US2481696A (en) * | 1946-09-11 | 1949-09-13 | Olin Ind Inc | Electric firing device |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3332350A (en) * | 1948-04-30 | 1967-07-25 | Atlas Chem Ind | Electric blasting cap having heatshrinkable plastic-covered match assembly |
US3717096A (en) * | 1948-04-30 | 1973-02-20 | British Aircraft Corp Ltd | Fuseheads |
US2999460A (en) * | 1959-03-02 | 1961-09-12 | Du Pont | Electric blasting cap |
US3353262A (en) * | 1963-05-09 | 1967-11-21 | Davey Bickford Smith Cie | Manufacture of electric ignitors for detonators |
US3763783A (en) * | 1970-02-04 | 1973-10-09 | A Thomas | Manufacture of fuze heads |
US3910188A (en) * | 1974-04-04 | 1975-10-07 | Us Army | One watt/one amp no-fire match type initiator |
US6363853B1 (en) * | 1999-09-17 | 2002-04-02 | Apti, Inc. | Electrically initiated distributed igniter |
Also Published As
Publication number | Publication date |
---|---|
DE2112387A1 (de) | 1971-10-14 |
FR984258A (fr) | 1951-07-04 |
GB1277682A (en) | 1972-06-14 |
BE488616A (xx) | |
BE764347A (fr) | 1971-09-16 |
FR2084616A5 (xx) | 1971-12-17 |
US3717096A (en) | 1973-02-20 |
US3332350A (en) | 1967-07-25 |
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