Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42D—BLASTING
  • F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
  • F42D1/02—Arranging blasting cartridges to form an assembly
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42D—BLASTING
  • F42D3/00—Particular applications of blasting techniques
  • F42D3/04—Particular applications of blasting techniques for rock blasting

Definitions

• the invention concerns an explosive cartridge including a substantially cylindrical sleeve having an end wall sealing a first end of the sleeve, an end unit inserted in the sleeve to a certain depth in a second end of the sleeve, said end unit having an inner side facing the interior of the sleeve and an outer side on the opposite side of the end unit, a chamber in the sleeve between said end wall and said inner side, said chamber being filled with a blasting agent, a channel extending through the end unit between an outer mouth and an inner mouth, said channel comprising a seat for a priming cartridge and a priming cartridge accommodated in the seat, said priming cartridge containing a detonating explosive for the firing of the blasting agent in said chamber.
• blasting agent also includes all kinds of gunpowder, or explosives as they also may be called.
• SE 519 883 discloses an explosive cartridge with a priming cartridge provided for indirect detonation via a firing pin, which is triggered by a chock wave.
• the priming cartridge is of the rim- fire type.
• At least one spacing member protruding in the axial direction, is provided on the outer side of the end wall in the first end of the explosive cartridge and/or on the end unit in the second end of the explosive cartridge, such that an intermediate space is formed between the outer side of a first, lower explosive cartridge and the under side of the end wall of a second, upper explosive cartridge resting on the first explosive cartridge, when the two cartridges are entered into a drill hole in order to be detonated, and that at least one passage in the radial direction is provided, beyond said spacing member, allowing communication between said intermediate space and the surrounding space in the drill hole, such that a shock wave or shock pulse, that is generated in a liquid or gel state fluid surrounding the explosive cartridge in the drill hole, can be transmitted through said at least one passage beyond said spacing member to said intermediate space for the firing of the priming cartridge.
• Fig. 1 is a side elevation of an explosive cartridge according to a first embodiment of the invention
• Fig. 2 shows an end view of the same explosive cartridge along the line II- II in Fig. 1,
• Fig. 3 shows an axial section through the same explosive cartridge
• Fig. 4 shows three explosive cartridges according to the invention, stacked on top of one another in a drill hole, prepared to be fired,
• Fig. 5 shows a detail of Fig. 4 at a larger scale
• Fig. 6 is a side elevation of a modified embodiment of the explosive cartridge according to Figs. 1-3
• Fig. 7 shows another embodiment of an explosive cartridge according to the invention, in an axial section thereof.
• an explosive cartridge according to a first embodiment of the invention is generally designated 1. Its main parts consist of a substantially cylindrical plastic sleeve 2 having an end wall 6, sealing a first end of the sleeve, and an end unit 3 inserted in the sleeve to a certain depth thereof in the opposite, second end of the cartridge.
• the end unit 3 is made of a single piece of a comparatively stiff plastic material.
• an end unit 3 consisting of a plurality of components, which together form an integrated end unit, may also be conceived. The end unit 3 is pressed into the sleeve, such that it seals against the inner side of the sleeve.
• the end unit 3 has an inner side 4 facing the interior of the sleeve and an outer side on the opposite side of the end unit.
• a chamber in the sleeve 2 between said end wall 6 and said inner side 4 of the end unit is designated 7.
• the chamber 7 occupies the main part of the volume of the sleeve 2 and is filled with a blasting agent 8.
• gunpowder is a suitable blasting agent, e.g. nitrocellulose powder, so called NC-powder.
• dynamite, nitrolite, trinitrotoluene, and several other blasting agents may be conceived, at least for certain other applications than rock cracking.
• a central channel 10 extends trough the end unit 3 between an outer mouth 11 and an inner mouth 12.
• a seat 13 for a priming cartridge 14 is provided in an inner portion of the channel 10.
• the priming cartridge 14 is arranged with moisture proof fit in the seat 13.
• the inner end extends a distance beyond the inner side 4 of the end unit, into the blasting agent 8 in the chamber 7.
• the priming cartridge 14 contains a detonating explosive for the ignition of the gunpowder 8. More specifically, the priming cartridge is of a type, which is detonated through centre firing. For the firing, no firing pin is needed. Instead, the priming cartridge 14 can be fired by a shock wave, a feature that is utilised according to the invention, as will be explained in the following.
• priming cartridges of the type that are used in shotgun shells may be employed.
• the seat 13 has a shape which is adapted to the shape of the collar shaped, rear portion 15 of the priming cartridge.
• the rest of the inner portion 9 of the channel 10 has a cylindrical shape, matching the shape of the main portion of the priming cartridge 14, providing said moisture proof fit between the priming cartridge 14 and the end unit 3.
• the outermost portion 19 of the end unit 3 has a larger diameter than the main part of the end unit, which is inserted into the sleeve 2.
• a peripheral portion of said outermost portion 19 abuts on the second end of the sleeve 3 and determines the entrance depth of the end unit 3 into the sleeve.
• the explosive cartridge 1 is provided with three spacing members 20 protruding in the axial direction on the end unit 3 in the second end of the explosive cartridge.
• the spacing members 20 have the shape of substantially cylindrical bodies with a height, which approximately corresponds to the thickness of the outermost portion 19 of the end unit 3.
• the three spacing members 20 are arranged peripherally and symmetrically on the outer side of the end unit 3, outside the channel 10 with reference to the radial direction, which channel contains the priming cartridge 14, such that three equally large openings, in the following also called passages, are established between the spacing members 20.
• Fig. 4 shows three explosive cartridges 1 arranged on top of one another in a drill hole 24 in an object 25 that shall be cracked, e.g. a major piece of rock.
• the drill hole 24 has a slightly - about 10 mm - larger diameter than the explosive cartridge 1.
• the drill hole 24 is filled up with a liquid or possibly a gel state fluid 26, preferably water, which surrounds the explosive cartridges 1.
• the fluid fills up the space 27 between the explosive cartridges 1 and the wall of the drill hole 24, as well as an intermediate space 28 that is established by means of the spacing members 20 between the outer side 5 of the end unit 3 of a first, lower explosive cartridge and the under side of the end wall 6 of a second, upper explosive cartridge that rests on the first explosive cartridge, when the two cartridges have been brought into the drill hole 24 in order to be detonated.
• the fluid 26 also fills up the outer portion 17 of the channel 10 between said intermediate space 28 and the priming cartridge 14.
• the openings 21 between the spacing members 20, form passages between the gap between on one hand the explosive cartridges 1 and the drill hole wall 23 and on the other hand said intermediate space 28, allowing communication in the radial direction between the space that surrounds the explosive cartridges and said intermediate space, and hence also communication with the liquid column 29 in the outer portion 17 of the channel 10, so that a shock wave or shock pulse that is generated in the fluid 26 can be transmitted via said passages 21 and pass the spacing members 20, reaching the intermediate space 28 and thence also reach the liquid column 29 for the firing of the priming cartridge 14.
• all the explosive cartridges 1, which are accommodated in the drill hole 24 beneath an uppermost explosive cartridge 1, are detonated simultaneously with the uppermost, explosive cartridge.
• a device 31 which is shown only schematically, is provided in the upper end of the drill hole for the generation of a necessary pressure pulse in the fluid.
• the device 31 preferably consists of a body having a substantial mass, e.g. 20 kg, containing a starter cartridge, which is directed downwards into the drill hole 24 and can be fired at a distance by means of wire release.
• the device 31 is appropriately covered by a not shown blasting mat.
• Fig. 6 shows a modification of the explosive cartridge 1 that has been described with reference to Figs. 1-3.
• the modified explosive cartridge 1 ' has three spacing members 20, which are arranged symmetrically, protruding in the axial direction on the outer side of the end wall 6 in the first end of the explosive cartridge, while the second end of the explosive cartridge is void of any spacing members.
• the explosive cartridge 1 ' is identical with the explosive cartridge 1 according to the embodiment according to Figs. 1-3 and it also functions in the same mode as that one. Therefore, as far as the design of the interior of the explosive cartridge 1' is concerned, reference is made to the foregoing description of the explosive cartridge 1.
• Fig. 7 illustrates the principle of the invention applied on an explosive cartridge 1 " having a priming cartridge 14" of the rim- fire type and a firing pin 40.
• the explosive cartridge 1 " is provided with three spacing members 20 of the same design and arranged in the same mode as according to the embodiment according to Figs. 1-3, i.e. protruding in the axial direction on the end unit 3" of the explosive cartridge 1 ".
• the explosive cartridge 1 " is designed as is described in SE-C-519 883, the disclosure of which is incorporated into the present description through reference.
• the intermediate spaces which communicate with the surrounding fluid in the drill hole, in which the explosive cartridges are accommodated, are established between explosive cartridges that are stacked on top of one another, wherein a pressure pulse or a shock wave that is generated in the fluid is transmitted to said intermediate spaces via the passages between the spacing members 20.
• This provides the power which is required for breaking the safety provision of the firing pin in the weakened, fracture promoting region 41, allowing the firing pin to be propulsed forwards to fire the priming cartridge 14".
• the design of the interior of the explosive cartridge 1 " which is known through said SE-C-519 883, does not form part of the present invention. Therefore, these prior art parts are not described in any detail.
• the explosive cartridge 1 ' ' can be modified in the same way as the explosive cartridge 1 ' has been modified in comparison with the explosive cartridge 1 , namely by providing the spacing members 20 on the end wall in the first end of the explosive cartridge instead of locating them on the outer side of the end unit 3 " in the second end of the explosive cartridge 1".
• the number of spacing members and/or passages for the fluid between the space surrounding the explosive cartridge and said intermediate space between adjacent cartridges in a drill hole may be fewer or more than three.
• the passages for the fluid, and thence for the shock waves consist of openings in a continuous spacing member having the shape of a rim, which protrudes in the axial direction in the first and/or in the second end of the explosive cartridge.
• the spacing members may consist of tongues, formed of end portions of the sleeve 2, protruding in the axial direction, like a crenelation. In this case, the end unit is provided with recesses for said tongues. It is also possible to provide spacing members in both ends of the explosive cartridge. It should be understood that these modifications exemplify just a few of those modifications which may be conceived within the conceptual idea of the invention.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Drilling And Exploitation, And Mining Machines And Methods (AREA)
• Portable Nailing Machines And Staplers (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
• Air Bags (AREA)

Applications Claiming Priority (2)

Publications (2)

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• 2004
  • 2004-03-18 SE SE0400682A patent/SE526830C2/sv not_active IP Right Cessation
• 2005
  • 2005-03-02 CA CA002559935A patent/CA2559935A1/en not_active Abandoned
  • 2005-03-02 AT AT05711154T patent/ATE520956T1/de not_active IP Right Cessation
  • 2005-03-02 WO PCT/SE2005/000296 patent/WO2005088236A1/en active Application Filing
  • 2005-03-02 EP EP05711154A patent/EP1725827B1/de not_active Expired - Lifetime
  • 2005-03-02 AU AU2005220576A patent/AU2005220576A1/en not_active Abandoned
  • 2005-03-02 RU RU2006133117/03A patent/RU2006133117A/ru unknown
  • 2005-03-02 US US10/592,033 patent/US20070193467A1/en not_active Abandoned
  • 2005-03-02 CN CNB2005800085795A patent/CN100504280C/zh not_active Expired - Fee Related
• 2006
  • 2006-10-18 NO NO20064707A patent/NO20064707L/no not_active Application Discontinuation

Non-Patent Citations (1)

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