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US2583802A - Explosive booster - Google Patents

Explosive booster Download PDF

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Publication number
US2583802A
US2583802A US65558A US6555848A US2583802A US 2583802 A US2583802 A US 2583802A US 65558 A US65558 A US 65558A US 6555848 A US6555848 A US 6555848A US 2583802 A US2583802 A US 2583802A
Authority
US
United States
Prior art keywords
explosive
charge
booster
detonator
pellet
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
US65558A
Other languages
English (en)
Inventor
Wright Harold Reginald
Martyn Roger William
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 US2583802A publication Critical patent/US2583802A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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

Definitions

  • FIG 2 Inventors HAROLD REGINALD WRIGHT ROGER WILLIAM MARTYN Attorneys Patented Jan. 29, 1952 EXPLOSIVE BOOSTER Harold Reginald Wright, West Kilbride, and
  • the present invention is concerned with a new or improved form of explosive booster, and has-for an object to provide a detonating explosive booster adapted for use under conditions of high hydrostatic pressure; as in deep well blasting.
  • each explosive charge at its upper end with a booster comprising an explosive of the same order of sensitiveness as the customary explosive pellet boosters consisting of cyclonite, pentaerythritol tetra-nitrate, tetryl or the like, furnished with a detonator; but under high hydrostatic pressures the tubular container of an ordinary detonator is liable to be distorted with the result that the liquid can gain entry into and phlegmatise its explosive charges.
  • a booster of readiJy assembled construction suitable for use under conditions of considerable hydrostatic pressure comprises two threaded rigid cups of pressure-resisting wall construction screwed together to form a liquid-tight capsule wherein is contained a pellet charge of a solid high velocity detonating explosive channelled from end to end, and, occupying the channel with its closed end supported against the base of one of the cups and its open end pressed into a lining of resilient material at the closed end of the other cup, a detonator capable when itself exploded of initiating the detonation of said pellet charge and comprising a thin walled tube loaded under pressure with two superposed detonating explosive charges, whereof that at its closed end is the more sensitive to initiation by shock, the end wall of the rigid cup in contact with the closed end of the said thin walled tube being locally weakened so that although rigid under the prevailing hydrostatic pressure the weakened portion will be easily ruptured from without by the detonation of an explosive charge in its proximity.
  • the external contour of the end wall of the cup-like member is recessed at the weakened portion.
  • the channelled pellet charge and the less sensitive of the charges of the detonator should be based on an explosive of melting point exceeding C., for instance cyclonite, if desired with a binder.
  • the more sensitive explosive charge at the closed end of the detonator is preferably one comprising a heavy metal azide, e. g. lead azide. To assist the binding properties of the lead azide or to increase in 'sensitiveness to initiation alead salt of a polynitro-phenolic compound e. g.
  • lead styphnate may be admixed with the heavy metal azide.
  • the less sensitive charge of the detonator and the pellet charge might consist essentially of pentaerythritol tetranitrate (melting point 139 C.) or even tetryl (melting point 128 C.).
  • the thin walled tube of the detonator should be slightly longer than the pellet charge, which advantageously is held between the end of the cup with the weakened wall and the resilient lining at the end of the other cup, so that when the cups are screwed together the open end of the detonator tube will bite into the resilient linin but the pellet will not be crushed.
  • the detonator tube may be an easy sliding fit within the channel through the pellet.
  • the hydrostatic pressure liable to be encountered may be of the order of 5 tons per square inch, and the cups are preferably made of steel. They may be provided externally with projections or flattened locally to assist their being threaded tightly together.
  • the detonators will be stored separately from the channelled pellet charges for reasons of safety.
  • the weakened portions of the end wall of the cup of the booster contiguous to the closed end of the detonator tube has a recessed exterior contour the risk of any premature explosion taking place while a blasting explosive charge and the booster in contact with its upper end are being lowered into the wellhole is minimised, since the thicker portions of the metal bounding this recess tend to prevent any large stones that may fall down from striking the weakened portion of the end wall.
  • I is a thick walled rigid cup of pressure resisting metal with an internally plane end wall having a thin portion 12 around its axis opposite a recess formed in the exterior of the end wall, and having a longitudinal wall terminating in an internally threaded portion 2; 3 is a thick walled rigid cup made of pressure resisting metal whose longitudinal wall terminates in an externally threaded portion 4.
  • 6 is a pellet primer composed essentially of a high melting explosive, such as cyclonite, made 'by compressing the explosive and having a longitudinal axial channel in which the detonator tube 1 is an easy sliding fit.
  • 8 is a rubber disc and 9 is a gasket washer.
  • Ill is a charge of a mixture of lead azide, lead styphnate and aluminium compressed into the closed end of the thin walled aluminium detonator tube 1 and II is a charge of cyclonite compressed over the more sensitive charge ID.
  • the curved Wall of the cup I is locally flattened and there are projections 13 on the wall of the cup 3 to assist the threaded ends 2 and 3 being screwed together tightly enough to prevent any leakage of fluid into the booster under the conditions of its use, as well as ensuring that the pellet 6 is in contact with the rubber disc 8 and the slightly longer tube V bites into said disc and is thus held firmly in position.
  • a booster comprising two threaded rigid cups of pressure-resisting wall construction screwed together to form a liquid tight capsule, a lining of resilient material in the bottom of one of said cups, a pellet charge of a solid high velocity detonating explosive channelled from end to end and located within said capsule, and a detonator capable when exploded of initiating the detonation of said pellet and comprising a thin walled tube loaded under pressure with two superposed detonating explosive charges, said detonator occupying the channel with its open end pressed into said lining in the bottom of one of said cups and its closed end supported against the base or the other cup which is locally weakened so that although rigid under the prevailing hydrostatic pressure it will be easily ruptured from without by the detonation 01' an explosive charge in its proximity.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Air Bags (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)
  • Portable Nailing Machines And Staplers (AREA)
US65558A 1948-03-01 1948-12-16 Explosive booster Expired - Lifetime US2583802A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB6423/48A GB634005A (en) 1948-03-01 1948-03-01 Improvements in or relating to explosive boosters

Publications (1)

Publication Number Publication Date
US2583802A true US2583802A (en) 1952-01-29

Family

ID=9814225

Family Applications (1)

Application Number Title Priority Date Filing Date
US65558A Expired - Lifetime US2583802A (en) 1948-03-01 1948-12-16 Explosive booster

Country Status (5)

Country Link
US (1) US2583802A (xx)
ES (1) ES186607A1 (xx)
FR (1) FR982240A (xx)
GB (1) GB634005A (xx)
NL (2) NL73399C (xx)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2774304A (en) * 1953-03-12 1956-12-18 John L Worzel Bottom firing detonator
US2785633A (en) * 1953-03-12 1957-03-19 Us Navy Apparatus for detonating explosive charges
US2794396A (en) * 1953-11-02 1957-06-04 Ici Ltd Blasting devices
US3015275A (en) * 1957-09-03 1962-01-02 Peyton Stanley Victor Explosive initiators
US3048103A (en) * 1956-11-13 1962-08-07 Hercules Powder Co Ltd Blasting assembly
US3688702A (en) * 1969-08-12 1972-09-05 Dynamit Nobel Ag Detonator device for explosive charge exhibiting detonating effect capable of bridging gap between spaced charges
US3850104A (en) * 1972-04-14 1974-11-26 Bofors Ab Holder for pyrotechnical delay composition

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB191424305A (en) * 1914-12-18 1915-12-02 Reginald Hugh Spencer Bacon Improvements in Fuzes for Projectiles.
US1297499A (en) * 1918-06-15 1919-03-18 Samuel W Rushmore Explosive shell.
US2464650A (en) * 1944-07-03 1949-03-15 Onondaga Pottery Company Fuse

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB191424305A (en) * 1914-12-18 1915-12-02 Reginald Hugh Spencer Bacon Improvements in Fuzes for Projectiles.
US1297499A (en) * 1918-06-15 1919-03-18 Samuel W Rushmore Explosive shell.
US2464650A (en) * 1944-07-03 1949-03-15 Onondaga Pottery Company Fuse

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2774304A (en) * 1953-03-12 1956-12-18 John L Worzel Bottom firing detonator
US2785633A (en) * 1953-03-12 1957-03-19 Us Navy Apparatus for detonating explosive charges
US2794396A (en) * 1953-11-02 1957-06-04 Ici Ltd Blasting devices
US3048103A (en) * 1956-11-13 1962-08-07 Hercules Powder Co Ltd Blasting assembly
US3015275A (en) * 1957-09-03 1962-01-02 Peyton Stanley Victor Explosive initiators
US3688702A (en) * 1969-08-12 1972-09-05 Dynamit Nobel Ag Detonator device for explosive charge exhibiting detonating effect capable of bridging gap between spaced charges
US3850104A (en) * 1972-04-14 1974-11-26 Bofors Ab Holder for pyrotechnical delay composition

Also Published As

Publication number Publication date
ES186607A1 (es) 1949-03-01
NL144453B (nl)
NL73399C (xx)
FR982240A (fr) 1951-06-07
GB634005A (en) 1950-03-15

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