US2075969A - Blasting explosive cartridge and borehole charge - Google Patents

Blasting explosive cartridge and borehole charge Download PDF

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Publication number
US2075969A
US2075969A US736752A US73675234A US2075969A US 2075969 A US2075969 A US 2075969A US 736752 A US736752 A US 736752A US 73675234 A US73675234 A US 73675234A US 2075969 A US2075969 A US 2075969A
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US
United States
Prior art keywords
explosive
charge
gunpowder
cartridge
borehole
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
US736752A
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English (en)
Inventor
White Albert Greville
Jones Elwyn
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 US2075969A publication Critical patent/US2075969A/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
    • 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
    • F42B3/28—Cartridge cases characterised by the material used, e.g. coatings

Definitions

  • 'Ihis invention relates to blasting explosive cartridges and borehole charges of the type in which a core of explosive is provided with a jacket of one or more cooling substances capable of cooling 5 or blanketing the hot products of combustion, either by evolving non-infiammable gases and/ or by decomposition or change of state with corresariding absorption of heat.
  • the charge of explosive may be in granular form, or in the form of a compressed pellet which may have a longitudinal channel for the introduction of an igniter, or an inner core of explosive of sensitiveness and rate of burning relatively higher than the remainder of the explosive charge.
  • the 'I'he jacketing material may be applied to the explosive charge' in several ways.
  • it may be cast or pressed into the form of a tube or cup into which the charge of gunpowder may be introduced either loose or in the form of a compressed pellet.
  • the cartridge may be held together by a wrapping of waxed or unwaxed paper or the like.
  • the charge of gunpowder may be introduced into the central space of a double-walled annulus of paper or the like containing loose jacketing material.
  • the jacketing material and gunpowder- may be suitably arranged in a. container, preferably of' ⁇ metal such as tinned iron sheet, which is loaded into the borehole, or the gunpowder may be placed in the borehole in the form of a lpellet and the jacketing material placed around it.
  • the jacketing material may also be formed aroun'd a pellet by pressure in a suitable mould, or the granular explosive and jacketing material. may be placed in the desired relative positions in a mould and pressed into shape simultaneously.
  • the two last mentioned methods have the advantage that the cooling material is firmly adherent to the explosive core and cannot readily be separated from it.
  • the requisite thickness of the sheath will depend to some extent'upon its composition, but in most cases we ilnd that a thickness of 4 mm. is sucient to render the cartridge safe for use in fiery and dusty mines. l
  • Figure 1 is a sectional elevation of an apparatus suitable ior producing a sheathed cartridge of gunpowder or the like as an integral unit.
  • FIGS 3 to 6 are diagrammatic representations of a sheathed cartridge produced in accordance with the invention and provided with a longitudinal channel for the insertion of an4 an annular piston C to t inside the cylinder A and over the pin B, and a thin sheet metal cylinderV E, which is used as a temporary separator between the blackpowder charge and the sheathing material. All the components are preferably made of non-ferrous metal.
  • the operation of making a pressed sheathed pellet is carried out as follows.
  • the cylinder A is placed in position on the base D and the pin B is inserted in position.
  • 'Ihe thin walled cylinder E which is preferably provided with lateral prongs or the like to ensure its central position in the device, is placed as shown in the diagram.
  • a suitable charge of blackpowder for a single pellet is poured into the space formed between 40 the annular cylinder E and the pin B, and powdered borax is poured into the annular space between the annular cylinder E and Vthe outside cylinder A until the levels of the'powders inside and outside the cylinder E are equal.
  • a previously formed pellet of blackpowder and of suitable dimensions may be inserted within the cylinder E.
  • Cylinder E is then withdrawn with as little disturbance of the charge as possible, and the annular piston C is placed over the pin B so that it rests lon the powder in the mould
  • the whole assembly is then transferred to a suitable press and subjected to a heavy pressure until the materials are thoroughly compacted together.
  • a pressure of 2 tons weight for 2 minutes is usually sumcient to produce a very compact pellet which can be handled without risk of damage.
  • the assembly is taken apart by removing the ⁇ base D and pressing out the central pin B which carries the compressed pellet with it. The pellet is then easily withdrawn from the pin.
  • the central pin.B is replaced by a 6 ilat circular disc.
  • Automatic weighing and charging devices may be employed to supply the blackpowder and sheathing materials respectively to the mold.
  • the proportion of sheathing material to explosive core is conveniently regulated by selecting an annular separatingv cylinder of appropriate diameter. v
  • the materials may be used dry, or containing up to 5% moisture. Pellets which have been pressed from blackpowder containing appreciable quantities of moisture are caused to set hard by drying them after the pressing operation.
  • 'I'he present invention is particularly applicable to the production of safety explosive cartridges comprising gunpowder as the explosive ingredient, for example a gunpowder consisting of approximately 75%-potassium nitrate, 15% charcoal and 10% sulphur.
  • gunpowder consisting of approximately 75%-potassium nitrate, 15% charcoal and 10% sulphur.
  • the proportion of these ingredients may, of course, be varied as is known in the art.
  • Example 1 A cylinder of thin sheet -metal having an internal diameter of 1% inches is arranged to stand concentrically in a vertical cylindrical mould ot internal diameter 11"; inches, which' is furnished with a central pin M1" in diameter.
  • Example 2 2 ozs. of gunpowder are loaded into the central space of the mould used in Example 1, on top oi. a layer of borax containing 30% borlc acid, and the annular space is then iilled as before with a mixture of powdered borax containing 30% borlc acid. The partition is then withdrawn and the pressing operation carried out as before.
  • Example 4 2 ozs. of a mixture of 1 part by weight of potassium chloride with 2 parts by weight 0I Empowder are loaded into the central space ofthe press l used in Example4 1 on top of a layer of borax. The annularspace is filled with borax to the level of the gunpowder mixture. The separator is then withdrawn and a layer of borax is added to cover the gunpowder. The pressing operation is then carried out as before. The total quantity of borax used is V2 oz.
  • a safety explosive cartridge or borehole charge comprising a. core of black powder and a sheath comprising a borate.
  • a safety explosive cartridge or borehole charge comprising a core of black powder and a sheath comprising borax.
  • a safety explosive cartridge or ⁇ borehole charge comprising a central core consisting of a compressed pellet of black powder and a sheath comprising a borate.
  • a safety explosive cartridge or borehole charge comprising a central core of black powder provided with a longitudinal channel'adapted to accommodate an igniter and a, sheath for the said core comprising a borate.
  • a method of forming a safety explosive cartridge which includes the step of feeding a sheathv l ing material into an annular space around a quantity of slow burning explosive and compressing the explosive and the sheathing material to form an integral unit.
  • a method of forming a safety explosive cartridge which includes the step of feeding a sheathing material into an annular space around an already formed pellet of slow burning explosive and compressing the explosive and the sheathing material to form an integral unit.
  • a method of forming a safety explosive cartridge which includes the steps of feeding a sheathing material into an annular space around a quantity of slow burning explosive, compressing the explosive and the sheathing material to form an integral unit and dryingvthe compressed unit to form a hard compact mass.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Glass Compositions (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
US736752A 1933-07-24 1934-07-24 Blasting explosive cartridge and borehole charge Expired - Lifetime US2075969A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB20801/33A GB423040A (en) 1933-07-24 1933-07-24 Improved blasting explosive cartridges and borehole charges

Publications (1)

Publication Number Publication Date
US2075969A true US2075969A (en) 1937-04-06

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US736752A Expired - Lifetime US2075969A (en) 1933-07-24 1934-07-24 Blasting explosive cartridge and borehole charge

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US (1) US2075969A (en(2012))
BE (1) BE404344A (en(2012))
GB (1) GB423040A (en(2012))

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2419949A (en) * 1944-02-07 1947-05-06 Edwin J Hottinger Device for securing a propellent charge to an artillery primer
US2513531A (en) * 1944-11-15 1950-07-04 Ici Ltd Safety sheathed blasting explosive cartridge
US2541334A (en) * 1944-05-20 1951-02-13 Atlas Powder Co Explosive assembly and method of making it
US2563491A (en) * 1946-07-26 1951-08-07 Blasting assembly
US3046829A (en) * 1959-06-22 1962-07-31 Olin Mathieson Composite propellent grains
US3661047A (en) * 1968-11-18 1972-05-09 Us Navy Apparatus for casting thin walled hollow cylindrical inserts
US20110232466A1 (en) * 2010-03-23 2011-09-29 Bruce Van Stratum Modular hand grenade

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8810691D0 (en) * 1988-05-06 1988-06-08 Ici Plc Explosive systems & process & apparatus for preparing same

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2419949A (en) * 1944-02-07 1947-05-06 Edwin J Hottinger Device for securing a propellent charge to an artillery primer
US2541334A (en) * 1944-05-20 1951-02-13 Atlas Powder Co Explosive assembly and method of making it
US2513531A (en) * 1944-11-15 1950-07-04 Ici Ltd Safety sheathed blasting explosive cartridge
US2563491A (en) * 1946-07-26 1951-08-07 Blasting assembly
US3046829A (en) * 1959-06-22 1962-07-31 Olin Mathieson Composite propellent grains
US3661047A (en) * 1968-11-18 1972-05-09 Us Navy Apparatus for casting thin walled hollow cylindrical inserts
US20110232466A1 (en) * 2010-03-23 2011-09-29 Bruce Van Stratum Modular hand grenade
US8136437B2 (en) * 2010-03-23 2012-03-20 Martin Electronics, Inc. Modular hand grenade

Also Published As

Publication number Publication date
BE404344A (en(2012))
GB423040A (en) 1935-01-24

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