US3587466A - Relay charge with a fuse of weakened explosive power - Google Patents

Relay charge with a fuse of weakened explosive power Download PDF

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Publication number
US3587466A
US3587466A US749879A US3587466DA US3587466A US 3587466 A US3587466 A US 3587466A US 749879 A US749879 A US 749879A US 3587466D A US3587466D A US 3587466DA US 3587466 A US3587466 A US 3587466A
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US
United States
Prior art keywords
charge
delay
fuse
relay
explosives
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
US749879A
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English (en)
Inventor
Josef Prior
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
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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 US3587466A publication Critical patent/US3587466A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42D—BLASTING
    • F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
    • F42D1/04—Arrangements for ignition

Definitions

  • Pendegrass Attorney-Craig and Antonelli ABSTRACT A relay charge for use with fuses in the initiation of insensitive explosives which comprises two parts preferably detachably connected with each other; one of the two parts contains secondary explosives within a structurally rigid case, open at one end while the other part forms a delay element which is connected with the open end of the case and serves for the accommodation of the fuse and of the delay charge.
  • the delay element includes a shock-sensitive primer composition, a delay charge and a base charge, appropriately encapsuled within a casing.
  • the present invention relates to a relay or magazine charge, and more particularly to a relay or primer charge which can be used in vertical blast-holes.
  • fuses are employed which are incapable by themselves of initiating or setting off the main charge, i.e., without the means of booster charges or priming cartridges. It is required of these booster charges that they can be initiated or set ofl by the fuse either instantaneously or with a delay.
  • the primer or relay charge essentially consists of the priming cartridge, properly speaking, which is constituted by a metallic container filled with explosives and of sufiicient strength to withstand with certainty the pressure of the explosive column resting thereon, and of the delay part. 7
  • the explosive filling for the priming cartridge there may be used conventional secondary explosives or explosive mixtures, such as cyclonite (RDX, hexogen) or pentaerythritol tetranitrate (PETN), dipentahexanitrate, nitromannite (mannitol hexanitrate), nitroglycerin, and nitroglycol explosives.
  • RDX cyclonite
  • PETN pentaerythritol tetranitrate
  • dipentahexanitrate dipentahexanitrate
  • nitromannite mannitol hexanitrate
  • nitroglycerin nitroglycerin
  • the delay part essentially consists of an external sleeve or casing, open on both sides, which encompasses a capsule having a strong-walled bottom in such a manner that an empty or hollow space is produced at one end this outer casing and that the end of the fuse can be introduced into this empty or hollow space and can be tightly clamped therein.
  • the capsule with the strong-walled bottom contains, adjoining the bottom, a
  • shock-sensitive primer or detonator composition for example, in the form of a percussion cap, a small empty tube retaining this composition or percussion cap, a delay body or delay element, charged witha delay composition, a firing charge in this delay element, and finally a powder train charge.
  • the capsule is sealed off in a watertight manner by means of a metallic or plastic foil, or by means of an impregnated paper foil.
  • the delay element and the relay or primer charge, properly speaking, are connected with each other, at the latest shortly before use, with the aid of appropriate, conventional means, for instance, by means of a threaded part or an adapter with a bayonet-type connection.
  • Another object of the present invention resides in a primer and relay charge which increases the safety of operation, especially when used in vertical blast-holes.
  • a further object of the present invention resides in a relay charge of the type described above which is able to withstand the explosive charge, properly speaking, that rests on the same, and at the same time minimizes the danger of excessive sensitivity to shocks and impacts. 7
  • the single F IGURE is an axial cross-sectional view through one embodiment of a relaycharge in accordance with the present invention.
  • the starting detonation of the fuse l of any known, conventional construction acts through the reinforced bottom 2' of the internal capsule 2, on the shock-sensitive primer charge 3; the latter produces a flame which ignites the delay charge 5 across the empty tube 4.
  • the delay charge 5 burns up and ignites the firing charge 6 which, depending on the flame sensitivity of the powder charge, may be made of an especially strongly flame-spraying firing charge.
  • the firing charge 6 ignites the base charge 7, and owing to the secure connection'8 of the delay element with the relay charge 9, the latter is detonated.
  • an additional booster charge 10 for example, in the form of a primer or percussion cap, which is directed toward the end of the fuse 1 and which increases a possibly inadequate percussion of the fuse.
  • the shock-sensitive primer charge 3 and/or 10 may consist of a conventional mixture of potassium chlorate and of an explosive from the class of the solid nitric acid esters, such as penthrite (PETN, pentaerythritol tetranitrate), nitromannite, or nitrostarch (starch nitrate), or also of any desired, known primer cap composition.
  • PTN penthrite
  • pentaerythritol tetranitrate nitromannite
  • nitrostarch starch nitrate
  • the delay charge 5 may consist, depending on the desired period of delay, of conventional thermite (Thermit )mixtures, e.g., minimum/silicon; minium/boron;, potassium permanganate/antimony, and the like.
  • a firing charge 6 for the ignition of a compressible base powder charge for example, of a mixture of minium/silicon, nitrocellulose or black powder, which firing charge 6 is made of a flame-spraying thermite composition, such as, for example, zirconium/minium.
  • Suitable charges 9 for the primer cartridge are explosives which are more sensitive with. respect to initiation than tetryl, i.e., cyclonite, penthrite, and other solid nitric acid esters, but also plastic mixtures on the basis of nitroglycerin or nitroglycol.
  • a relay charge for delayed blasting operations initiated by means of a fuse for detonating explosives from the bottom of a blast hole comprising a unilaterally closed structurally rigid case filled with a secondary explosive and delay means including a delay charge detachably connected between said rigid case and said fuse, said delay means being provided as an open cylindrical casing including a capsule having one end open and the other end closed by a thickened bottom wall, a shock-sensitive primer cap positioned on the inner bottom wall of said capsule, said delay charge being spaced from said primer cap to form a delay space therebetween, a flameproducing composition in contact with said delay charge at the open end of said capsule, and a base charge positioned ad jacent said flame-producing composition at the other end of said casing detachably connected to, said rigid case and spaced from said secondary explosive, the other end of said casing including a bayonet-type connection for receiving and holding said fuse.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Catching Or Destruction (AREA)
  • Fuses (AREA)
US749879A 1967-08-02 1968-08-02 Relay charge with a fuse of weakened explosive power Expired - Lifetime US3587466A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED0053738 1967-08-02

Publications (1)

Publication Number Publication Date
US3587466A true US3587466A (en) 1971-06-28

Family

ID=7055217

Family Applications (1)

Application Number Title Priority Date Filing Date
US749879A Expired - Lifetime US3587466A (en) 1967-08-02 1968-08-02 Relay charge with a fuse of weakened explosive power

Country Status (4)

Country Link
US (1) US3587466A (enrdf_load_stackoverflow)
BE (1) BE718843A (enrdf_load_stackoverflow)
FR (1) FR1584062A (enrdf_load_stackoverflow)
GB (1) GB1232443A (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3776135A (en) * 1972-06-29 1973-12-04 Hercules Inc Non-electric blasting cap assembly
US3945322A (en) * 1974-04-05 1976-03-23 The United States Of America As Represented By The Secretary Of The Navy Through-bulkhead explosion initiation
US4314508A (en) * 1978-03-17 1982-02-09 Ici Australia Limited Device with incendiary fusecord ignited by detonation
US4335652A (en) * 1979-02-26 1982-06-22 E. I. Du Pont De Nemours & Company Non-electric delay detonator
US4727808A (en) * 1984-08-23 1988-03-01 China Metallurgical Import & Export Corporation Non-primary explosive detonator

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU4078885A (en) * 1984-04-27 1985-10-31 Jet Research Center Inc. Oil well perforating gun

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3776135A (en) * 1972-06-29 1973-12-04 Hercules Inc Non-electric blasting cap assembly
US3945322A (en) * 1974-04-05 1976-03-23 The United States Of America As Represented By The Secretary Of The Navy Through-bulkhead explosion initiation
US4314508A (en) * 1978-03-17 1982-02-09 Ici Australia Limited Device with incendiary fusecord ignited by detonation
US4335652A (en) * 1979-02-26 1982-06-22 E. I. Du Pont De Nemours & Company Non-electric delay detonator
US4727808A (en) * 1984-08-23 1988-03-01 China Metallurgical Import & Export Corporation Non-primary explosive detonator

Also Published As

Publication number Publication date
FR1584062A (enrdf_load_stackoverflow) 1969-12-12
BE718843A (enrdf_load_stackoverflow) 1968-12-31
GB1232443A (enrdf_load_stackoverflow) 1971-05-19

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