US2863392A - Delay electric initiators - Google Patents

Delay electric initiators Download PDF

Info

Publication number
US2863392A
US2863392A US598584A US59858456A US2863392A US 2863392 A US2863392 A US 2863392A US 598584 A US598584 A US 598584A US 59858456 A US59858456 A US 59858456A US 2863392 A US2863392 A US 2863392A
Authority
US
United States
Prior art keywords
delay
composition
metal tube
detonator
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
US598584A
Other languages
English (en)
Inventor
Hill Royston Arthur Walter
Moody Robert Walter
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.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial Chemical Industries Ltd
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 Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Application granted granted Critical
Publication of US2863392A publication Critical patent/US2863392A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • F42B3/16—Pyrotechnic delay initiators

Definitions

  • a ventless delay electric deto-nator l comprising a casing of copper, zinc, copper alloy or zinc alloy containing therein a base charge of a secondary explosive composition and a superimposed charge of a primary explosive composition and having a delay element consisting of a metal tube containing therein a delay fuse composition and interposed between the primary explosive composition and an electric fusehead is characterised in that the lower end of the metal tube is closed and contains a small charge of a primary explosive composition between the closed end thereof and the lower end of the column of delay fuse composition and in that said delay element is so secured in the casing that it is retained on the firing of the detonator.
  • Said metal tube of the delay element may be of copper alloy or of mild steel but not of aluminium and it must not be deformed to any substantial degree during the loading of the delay composition therein and must not disintegrate on the tiring of the detonator.
  • the delay element is retained in the casing on explosion of the detonator by for example crimping the casing to the metal tube of the delay element or preferably by having an intervening metal tube of for instance copper, copper alloy, mild steel, zinc or zinc alloy between the delay element and the casing and crimped to the casing.
  • This intervening metal tube is preferably provided with a small aperture in its lbase of smaller diameter than the inner diameter of the metal tube of the delay element.
  • the metal tube of the delay element should preferably t tightly in this intervening metal tube.
  • the diameter, nature and amount of the delay fuse composition in the metal tube of the delay element can be those normally characteristic for delay elements in delay electric detonators.
  • the diameter of the delay fuse composition in the metal tube of the delay element may be 3.3 mm.
  • the length of the column of the delay composition may vary for example between 3 and 30 mm.
  • the delay fuse composition may be for instance a substantially gasless mixture of oxidising agents and reducing agents for example one consisting of lead dioxide and silicon or potassium permanganate and antimony.
  • the del-ay element should preferably be in contact with the upper surface of the primary explosive composition in the casing so that the shock wave for-med on the detonation of the primary explosive composition in the metal tube of the delay element is transmitted through the bottom of this metal tube and readily initiates the explosion of the primary explosive composition in the casing.
  • the metal tube of the delay element does not disintegrate but remains intact on the firing of the detonator no hot particles of slag from the delay composition or from the fusehead are ejected on the firing of the detonator and so the danger of ignition of inllammable methane/'air mixtures is removed.
  • 1 is a copper tube
  • 2 is a base charge
  • 3 is a superimposed primary charge
  • 4 is a copper tube which contacts the charge 3 and is provided with a hole
  • 6 is a-mild steel tube having its lower end closed and containing an initiating charge 7 on top of which is a column 8 of delay fuse composition
  • 9 is an electric fusehead
  • 10 is a neoprene plug to which the tubes 1 and 4 are crimped and through which pass the leading wires 11 for the electric fusehead 9.
  • Example 1 Form a delay detonator of mean delay time of 266 milliseconds copper tube 1 is of an external diameter 7.14 mm. and a length of 65 mm.
  • base charge 2 is 0.25 gram tetryl
  • primary explosive charge 3 is 0.35 gram of an aluminium/lead azide/lead styphnate composition
  • copper tube 4 is of an external diameter 6.52 mm. and a length 52 mm.
  • hole 5 is of a diameter 1.90 mm.
  • mild steel tube 6 is of an external diameter 6.02 mm. and internal diameter 3.30 mm., a length 21.5 mm. and a base thickness 0.76 mm.
  • the initiating charge 7 consists of 0.03 gram lead azide
  • the delay fuse composition 8 consists of lead dioxide/silicon (S0/50) pressed at 18 tons per square inch.
  • each detonator is suspended in a 9% (by volume) methane/methane air mixture and is tired by a single shot exploder and it is found that not a single detonator ignites the methane air mixture.
  • Each of for instance 30 of these detonators is also tired to determine scatter and it is found that the scatter is 3l milliseconds.
  • Example 2 Fora delay detonator of mean delay time of 2.26 seconds the dimensions and compositions are the same asin Example. l .except that metal ⁇ tube 6' is .of a. length 13.0 mm. and the delay fuse composition 8 consists of potassium permanganate/antimony (36/ 36).
  • Example 3 For a delay detonator of mean delay time of 27 milliseconds the dimensions and compositions are the same as in Example l except that ythe metal tube 6 is of a length mm.
  • each detonator is suspended in a 9% (by Volume) methane/methane air mixture and is fired by a single shot exploder and it is found. that not a single detonator ignites the methane air mixture.
  • Each of for instance 25 of these detonators is also tired to determine scatter and it is found that theV scatter is 8 milliseconds.
  • a ventless delay electric detonator comprising 'a metallic casing containing therein a fusehead, a base charge of a secondary explosive composition and a superimposed vcharge of a primary explosive composition and having a delay element including a metal tube containing therein a delay fuse composition, said delay element be- Y ing interposed between said primary explosive composition and said fusehead, said delay fuse composition beingv of the gasless type and said 'metaltube having its lower end nonrupturably sealed against the reaction of its contents and secured so as to be retained in the detonator casing on firing of the detonator, and a small charge of primary explosive composition being disposed within said metal tube between the gasless delay composition and the .closed end of the tube.
  • a ventless electric delay detonator comprising a metallic casing, a base charge of a secondary explosive, a superimposed charge of a primary explosive composition and a fusehead in said casing, a delay element in said casing comprising a metal tube containing therein a delay fuse composition and interposed between said primary explosive composition and said fusehead, said delay composition being of the gasless type and said metal tube having its lower end nonrupturably sealed against the reaction of its contained constituents, a small quantity of a primary explosive composition disposed ⁇ Within said tube between lthe delay composition yand the closed end of said tube and an intervening second metal tube between said casing and said delay element tube, said second tube being assembled to retain the delay element tube Within the detonator-casing upon firing of the detonator.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Bags (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
  • Fuses (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Compositions Of Oxide Ceramics (AREA)
US598584A 1955-08-15 1956-07-18 Delay electric initiators Expired - Lifetime US2863392A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB23417/55A GB776854A (en) 1955-08-15 1955-08-15 Improvements in or relating to delay electric initiators

Publications (1)

Publication Number Publication Date
US2863392A true US2863392A (en) 1958-12-09

Family

ID=10195271

Family Applications (1)

Application Number Title Priority Date Filing Date
US598584A Expired - Lifetime US2863392A (en) 1955-08-15 1956-07-18 Delay electric initiators

Country Status (5)

Country Link
US (1) US2863392A (no)
BE (1) BE550304A (no)
DE (1) DE1024415B (no)
FR (1) FR1161090A (no)
GB (1) GB776854A (no)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100447A (en) * 1960-08-31 1963-08-13 Robert E Betts Igniter squib
US3173366A (en) * 1961-01-13 1965-03-16 Lissements Davey Bickford Smit Electric, delay-type detonator assembly
US4727808A (en) * 1984-08-23 1988-03-01 China Metallurgical Import & Export Corporation Non-primary explosive detonator
EP0339847A2 (en) * 1988-04-29 1989-11-02 Aeci Limited A detonator

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5522318A (en) * 1990-11-05 1996-06-04 The Ensign-Bickford Company Cushion element for detonators and the like; apparatus and method of assembly

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE516956A (no) * 1952-03-01
AT132566B (de) * 1925-10-13 1933-03-25 Konrad Schaffler Elektrischer Zünder mit Verzögerungspatrone.
US2133119A (en) * 1935-04-05 1938-10-11 Western Cartridge Co Delay detonator
US2604044A (en) * 1948-06-23 1952-07-22 Atlas Powder Co Blasting cap

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE918493C (de) * 1952-03-01 1954-09-27 Dynamit Nobel Ag Schlagwettersicherer Zeitzuender

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT132566B (de) * 1925-10-13 1933-03-25 Konrad Schaffler Elektrischer Zünder mit Verzögerungspatrone.
US2133119A (en) * 1935-04-05 1938-10-11 Western Cartridge Co Delay detonator
US2604044A (en) * 1948-06-23 1952-07-22 Atlas Powder Co Blasting cap
BE516956A (no) * 1952-03-01

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100447A (en) * 1960-08-31 1963-08-13 Robert E Betts Igniter squib
US3173366A (en) * 1961-01-13 1965-03-16 Lissements Davey Bickford Smit Electric, delay-type detonator assembly
US4727808A (en) * 1984-08-23 1988-03-01 China Metallurgical Import & Export Corporation Non-primary explosive detonator
EP0339847A2 (en) * 1988-04-29 1989-11-02 Aeci Limited A detonator
EP0339847A3 (en) * 1988-04-29 1990-09-05 Aeci Limited A detonator

Also Published As

Publication number Publication date
FR1161090A (fr) 1958-08-20
BE550304A (no)
DE1024415B (de) 1958-02-13
GB776854A (en) 1957-06-12

Similar Documents

Publication Publication Date Title
FI82678B (fi) Taendelement foer en icke-primaer spraengaemnesdetonator samt spraengaemnesdetonator.
US3106892A (en) Initiator
US4335652A (en) Non-electric delay detonator
US3306201A (en) Explosive composition and waterhammer-resistant delay device containing same
JPS6041638B2 (ja) 遅発雷管
CZ292045B6 (cs) Pyrotechnická nálož pro rozbušky
US2913982A (en) Priming device
US4374686A (en) Delay composition for detonators
US3499386A (en) Primer
US3727552A (en) Bidirectional delay connector
US2429490A (en) Detonator
US2652775A (en) Percussion initiated detonator
US2980019A (en) Electric initiator
JPS6235039B2 (no)
US2863392A (en) Delay electric initiators
US2123691A (en) Electric initiator
US2402235A (en) Blasting initiator
US2068516A (en) Stratified primer charge
US2773447A (en) Ventless delay electric initiators
CN1055053A (zh) 低能量信管
US3286628A (en) Electric detonator ignition systems
US4821646A (en) Delay initiator for blasting
US2525397A (en) Blasting initiator
US2991714A (en) Delay composition
US1928208A (en) Safety detonator