US3613582A - Hollow charge having a directed explosive effect - Google Patents

Hollow charge having a directed explosive effect Download PDF

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Publication number
US3613582A
US3613582A US749067A US3613582DA US3613582A US 3613582 A US3613582 A US 3613582A US 749067 A US749067 A US 749067A US 3613582D A US3613582D A US 3613582DA US 3613582 A US3613582 A US 3613582A
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United States
Prior art keywords
charge
shells
hollow
base
cover
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Expired - Lifetime
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US749067A
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English (en)
Inventor
Reijo Levamaki
Mikko Vehvilainen
Tapani Suhonen
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    • 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
    • F42B3/08—Blasting cartridges, i.e. case and explosive with cavities in the charge, e.g. hollow-charge blasting cartridges
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
    • F42B1/00—Explosive charges characterised by form or shape but not dependent on shape of container
    • F42B1/02—Shaped or hollow charges

Definitions

  • the charge comprises an outer cone forming the shell of the charge, and a regularly shaped inner cone at the front part of the charge, enlarging towards its front end, the cones forming the cavity.
  • a cover seals the back part of the outer cone and a base closes the front part.
  • SHEET 3 (IF 3 HOLLOW CHARGE HAVING A DIRECTED EXPLOSIVE EFFECT
  • the invention relates to a hollow charge, adapted for underwater demolition and having a directed explosive effect, the charge being provided with a cavity at its front end relative to the direction of the explosion, the cavity enlarging towards the front end and having metal walls or a metal sheathing so that, on the occurrence of the explosion, a part of the metal is formed into a thin metal stream which is directed forwards at high speed.
  • the charge comprises an outer cone forming the shell of the charge, and a regularly shaped inner cone at the front part of the charge, enlarging towards its front end, the cones forming the cavity while a cover seals the back part of the outer cone and a base closes the front part.
  • a charge constructed in accordance with the invention will give the required performance using ammonium nitrate explosives (e.g. anite), dynamite or any of the other usual types of slow explosive, having a detonation wave speed of under 3,000 m./sec.
  • ammonium nitrate explosives e.g. anite
  • dynamite any of the other usual types of slow explosive, having a detonation wave speed of under 3,000 m./sec.
  • safety explosives slow civil explosives
  • rapid explosives e.g. nitroglycerine gelatine charge
  • This invention provides an effective hollow charge in which safety explosives can be used, especially appropriate for civil use, since the use of safety explosives involves no danger and the charge can, for example, be loaded on the site.
  • the manufacture of the charge in accordance with this invention is relatively cheap, not only because of the advantages gained in using safety explosives, but also because of the materials used in constructing the charge itself.
  • the outer cone, cover and base are preferably made from plastic, and the inner cone can be made from steelplate.
  • the inner cone is usually made of copper instead of steelplate, and in fact a satisfactory performance cannot be achieved using steelplate in those known hollow charges.
  • the hollow charge contains slow civil explosives, e.g. ammonium nitrate of other similar material having a detonation speed of $5,000 m./sec.
  • slow civil explosives e.g. ammonium nitrate of other similar material having a detonation speed of $5,000 m./sec.
  • the said hollow charge can be used in explosions both on land and underwater. On land, its general application is as a hole digging or frozen ground charge, but it can also be used for several other purposes.
  • FIG. I shows a partial longitudinal cross-sectional view of the outer cone
  • FIG. 2 is a cross section taken along line A--A in FIG. 1;
  • FIG. 3 shows a partial longitudinal cross-sectional ,view of the cover
  • FIG. 4 is a partial longitudinal cross-sectional view of the base
  • FIG. 5 is a partial longitudinal cross-sectionalview of an assembled charge
  • FIGS. 6a-6b, 7 and 8 are diagrammatic illustrations showing the use of the charge in underwater applications.
  • the charge in accordance with the invention is made up of an outer cone 1, an inner cone 2, a base 3 and a cover 4.
  • the space between the outer and the inner cone is filled with the explosive.
  • the outer cone, the base and the cover are preferably made of plastic material such as polyethene. In the known types of charge they are manufactured from metal plate and thus the fixing and exact tight fitting of the base and cover requires accuracy and time.
  • the base 3, which is made of flexible polyethene has a rim of U-shape, the upward rising edge of which has a shoulder 5, which engages a groove 6, in the front part'of the outer cone, the front edges of the inner and outer cones thus becoming locked in the said U-shaped rim.
  • the cover 4 which is also manufactured from flexible polyethene, has a central part in the form of a detonation cylinder 7 which is directed downwards, and a rim forming a vertical flange 8, the edgeof which is bent outwards to form a collar 9.
  • An inward by turned edge 10 of the upper part of the outer cone is flttcd under the collar 9.
  • the inner cone should be seamless. However, in the charge in accordance with the invention it can have an open seam without any effect on its operation. This significantly decreases the manufacturing costs.
  • the seam of the inner cone need only be sealed with, for example, electrical tape or similar material. A hole can even be left in the top of the inner cone provided that it is closed, for example with a polyethene plug 11.
  • the thickness of the material of the inner cone 2 depends on the amount of explosive. The greater the amount of explosive the greater should be the thickness. For example, when using lkg. of explosive the thickness is l.5 mm. and with l.5 kg. it is 2.0 mm.
  • the drawing show a charge having l.kg. of explosive.
  • the dimensions are as follows: Inner cone: cone angle 60, height 107 mm., thickness of material l.5 mm.
  • the wall of the outer cone forms an angle of 30 with the vertical.
  • the detonation wave is directed towards the outer walls of the inner cone, causing the cone to be compressed from the back to the front, and approximately 60 percent, by weight, of the inner wall to melt to a temperature of 50,000" C.
  • the molted metal nozzle then begins to move straight along the central axis, the initial value of the speed being approximately 8,000 m./sec. when using ammonium nitrate as an explosive.
  • the penetration ability of the nozzle, when using I kg. of explosive is:
  • the diver When carrying out underwater blasting the procedure is that the diver locates the charge on the surface of the object to be blasted (on the top, at the side or below) so that the noule is directed in its most effective manner.
  • the best possible result when breaking stones for example, is to place the charge under a stone, so that the nozzle penetrating the stone, together with the pressure wave transmitted by the water breaks a far larger stone than is possible in free air.
  • a charge is first exploded beside the stone with the nozzle directed beneath the stone so that all the loose material will be cleared away. The charge can then be located beneath the stone. Location of the charge under the stone by drilling is impossible. The deeper the explosion occurs the more effective it is.
  • the size and number of the charges naturally depends upon the size and shape of the object.
  • FIGS. tin-6b, 7 and 8 illustrate the explosion of underwater objects.
  • a hollow is first blasted under the stone [2, using charge 13.
  • the actual blasting operation is then carried out with charge 15, located in the hollow l4, and charge 16 placed on the opposite side.
  • the explosion shown in FIG, 7 is carried out using charges 17 and 18.
  • three charges, 19, 20 and 21 are used.
  • Stone, rock, bedrock and other objects can be blasted using the method in accordance with the invention. It has proved to be an extremely effective and rapid method of blasting in channel-clearing operations.
  • a hollow charge having a directed explosive effect comprising a hollow body with a front and back, said body including an outer shell of frustoconical shape and an inner metal shell of conical shape, the shells both diverging toward the front of the body, a base of flexible plastic material including a U-shaped rim joining said shells at the front ends thereof and flexed to cover the front of said body, a cover of flexible plastic material on said outer shell at the back of the body defining a closed space between the shells, an explosive charge contained in said closed space, and detonation means carried by said cover and extending forwardly into said space between the shells for detonating the explosive charge in said space to cause the inner metal shell to be melted and a part thereof formed into a thin metal jet which is propelled through the front of the body thereof to produce vaporization of surrounding water when the charge is submerged during underwater demolition work.
  • a hollow charge as claimed in claim 1 comprising means on said cover for press fitting the same on said outer shell.
  • a hollow charge as claimed in claim 3 comprising a plastic plug in said inner conical shell at the apex thereof, said plug closing said inner shell.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
US749067A 1967-10-19 1968-07-31 Hollow charge having a directed explosive effect Expired - Lifetime US3613582A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FI2812/67A FI42288B (no) 1967-10-19 1967-10-19

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US3613582A true US3613582A (en) 1971-10-19

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FI (1) FI42288B (no)
NO (1) NO120512B (no)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3777663A (en) * 1972-06-22 1973-12-11 Jet Research Center Shaped charge enclosure apparatus
US3831522A (en) * 1973-03-02 1974-08-27 R Romney Explosive booster and container therefor
US4114537A (en) * 1976-10-01 1978-09-19 Andrew James Brown Explosive device
US4759886A (en) * 1987-01-28 1988-07-26 Olin Corporation Method of assembling shaped charge projectiles which employ fluted liners
US6305289B1 (en) * 1998-09-30 2001-10-23 Western Atlas International, Inc. Shaped charge for large diameter perforations
US7600476B1 (en) * 2006-03-24 2009-10-13 The United States Of America As Represented By The Secretary Of The Army Geometric/mechanical apparatus to improve well perforator performance
US9188413B2 (en) * 2009-11-25 2015-11-17 The Secretary Of State For Defense Shaped charge casing

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL441724A1 (pl) * 2022-07-13 2024-01-15 Wojskowy Instytut Techniczny Uzbrojenia Kierunkowe urządzenie wybuchowe

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2494256A (en) * 1945-09-11 1950-01-10 Gulf Research Development Co Apparatus for perforating well casings and well walls
US2932251A (en) * 1956-04-23 1960-04-12 Olin Mathieson Ammonium nitrate explosive
US2938460A (en) * 1956-09-12 1960-05-31 Energa Finned projectile
US3119178A (en) * 1959-09-17 1964-01-28 Harrold D Owen Method of making liners for shaped charges
US3183836A (en) * 1963-08-21 1965-05-18 Trojan Powder Co Canister for cast primer
US3431848A (en) * 1967-04-28 1969-03-11 Hercules Inc Explosive cartridge assemblies
US3437036A (en) * 1966-04-20 1969-04-08 Diehl Hollow charge for land mines

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2494256A (en) * 1945-09-11 1950-01-10 Gulf Research Development Co Apparatus for perforating well casings and well walls
US2932251A (en) * 1956-04-23 1960-04-12 Olin Mathieson Ammonium nitrate explosive
US2938460A (en) * 1956-09-12 1960-05-31 Energa Finned projectile
US3119178A (en) * 1959-09-17 1964-01-28 Harrold D Owen Method of making liners for shaped charges
US3183836A (en) * 1963-08-21 1965-05-18 Trojan Powder Co Canister for cast primer
US3437036A (en) * 1966-04-20 1969-04-08 Diehl Hollow charge for land mines
US3431848A (en) * 1967-04-28 1969-03-11 Hercules Inc Explosive cartridge assemblies

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3777663A (en) * 1972-06-22 1973-12-11 Jet Research Center Shaped charge enclosure apparatus
US3831522A (en) * 1973-03-02 1974-08-27 R Romney Explosive booster and container therefor
US3955504A (en) * 1973-03-02 1976-05-11 Romney Russell H Explosive booster casing
US4114537A (en) * 1976-10-01 1978-09-19 Andrew James Brown Explosive device
US4759886A (en) * 1987-01-28 1988-07-26 Olin Corporation Method of assembling shaped charge projectiles which employ fluted liners
US6305289B1 (en) * 1998-09-30 2001-10-23 Western Atlas International, Inc. Shaped charge for large diameter perforations
US7600476B1 (en) * 2006-03-24 2009-10-13 The United States Of America As Represented By The Secretary Of The Army Geometric/mechanical apparatus to improve well perforator performance
US9188413B2 (en) * 2009-11-25 2015-11-17 The Secretary Of State For Defense Shaped charge casing

Also Published As

Publication number Publication date
FI42288B (no) 1970-03-02
NO120512B (no) 1970-10-26

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