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
  • F42B3/10—Initiators therefor
  • F42B3/12—Bridge initiators
  • F42B3/121—Initiators with incorporated integrated circuit

Definitions

• the present invention relates to pyrotechnic detonators, and more particularly, to a standalone ignition subassembly designed for incorporation into detonators.
• timed detonation can be accomplished by detonators that use pyrotechnic delays, sequential-type blasting machines, and electronically programmable detonators.
• detonators that use pyrotechnic delays, sequential-type blasting machines, and electronically programmable detonators.
• time-delayed detonators are described in U.S. Patent Nos. 6,173,651, 6,085,659, 6,079,332, 5,602,360, 5,460,093, 5,435,248, 4,869,170, 4,819,560, 4,730,558, and 4,712,477, the disclosures of which are hereby incorporated by reference herein .
• Such detonators are, however, generally tailored to a specific application, thus precluding the use of interchangeable detona t ors for a number of applications. Hitherto, it is believed that it has not been conceived to use an in t erchangeable, standalone ignition subassembly to initiate a variety of detonators.
• An object of the present invention is to provide a standalone ignition subassemDly that can be readily incorporated into a variety of detonator shells.
• a separate object of the present invention is to provide an ignition subassembly that is protected against vibration and the environment, so as to permit convenient handling and transportation of the subassembly.
• FIG. 1 is a side sectional view of an embodiment of the present invention
• FIG. 2 s a top sectional view of an alternate embodiment of the present invention.
• Fig. 3 is an exploded side and sectional view showing how an embodiment of the present invention such as that shown in Figs. 1 or 2 fits into a loaded detonator shell.
• Fxg 4 is a side view of an alternate embodiment of the present invention having an alternate outer surface to that of the embodiment shown in F g. 3.
• FIG. 5 is a side sectional view of an alternate embodiment of the present invention incorporating an off-the- shelf capacitor, witn this embodiment inserted in a loaded shell snd crimped m place with a plug
• Fig 6 is a side sectional view of another alternate embodiment similar to that shown in Fig 5, w th the off-the- shelf capacitor m a different con iguration.
• an ignition subassembly 8 of an embodiment of the present invention, and an alternate embodiment 8' are shown.
• a subassembly is placed inside of a shell 40 that may contain a primary charge 36 and a base charge 38 loaded into its closed end.
• a detonator shell is typically a metal cylinder 6 to 8 mm. in diameter and from 60-100 mm. in length
• Subassembly 8 can then be secured in place in the shell 40, such as by placing an elastomeric plug or the like (see elastomeric plug 46 and crimp 47 in Figs. 5 and 6) in the open end of the shell and crimping the shell 40 to the plug, or other suitable method.
• Subassembly 8 may have a body portion 32 formed of an elastomeric plug or the like (see elastomeric plug 46 and crimp 47 in Figs. 5 and 6) in the open end of the shell and crimping the shell 40 to the plug, or other suitable method.
• the material for encapsulation 31 is preferably chosen to afiord economical material and manu acturing costs, desirable electrical isolation and vibration and environmental protection for the encapsulated circuitry (including desirable modulus of elasticity, et cetera, as general] y taught in U.S. Patent No 6,079,332), adequate physical integrity and holding and securing of the subassembly' s components, and a lack of chemical volatility with other materials comprising the detonator.
• the oreferred encapsula ion materials for use in the RIM technique are poyurethane-based materials.
• a standalone ignition subassembly may include any kind of suitable ignition element (e.g., atchhead-type) as long as it is hermetically sealed and protected from the environment, a header-based, or automotive airbag initia or-s yle, ignition element 28 is employed in the preferred embodiments shown in the Figures As will be appreciated, such an ignition element lends itself to hermetic sealing because it includes an integral, rigid charge can and header that hermetically seals the charge in an enclosure.
• a header assembly '/if a sealed electrical feedthrough cs ⁇ 'pns ⁇ rg a- eye--.ee 10 (preferably stainless steel), insulator glass 14 (preferably a glass such a s a sodasilicate, e.g., 9010, that is chosen to for ⁇ a compression seal xth the eyelet and center pm, or less preferably a T.atched seal), a center pin 18 (preferaoly an iron nickel alloy), a grouno p: n 20, and an igniter wire 12 (preferably a low energy igniter wire with a diameter of 10 to 20 m-icrons).
• insulator glass 14 preferably a glass such a s a sodasilicate, e.g., 9010, that is chosen to for ⁇ a compression seal xth the eyelet and center pm, or less preferably a T.atched seal
• a center pin 18 preferaoly an iron nickel alloy
• the ignition element 28 further preferably includes a charge can 26 that is preferably metallic and hermetically sealed to the eyelet at circumferential through-weld 16, with an ignition charge contained between the can 26 and upper surface of the header, in tight contact with igniter wire 12.
• An insulator cup 27 may preferably be attached around the can 26 so that, except for female connectors 52 that protrude from the input end of the subassembly, the entire outer surface of ignition subassembly 8 consists of insulating naterial, thus providing electrical isolation and vibration and environmental protection to the components within. Pins are inserted and crimped within female connectors 52.
• a circuit board 24 and electronic components 25 may be provided within ignition subassembly 8, to provide a means of triggering ignition of the gnition element based on the processing of an electrical gnition signal received by connectors 52, which are ⁇ ir-ctrically connected to a blasting machine or the like that .o . ⁇ rs the cietorator Sue.
• electronic comconents are well-known and preferably include means for imparting a programmable perio ⁇ of delay to the ignition, mea ns for ESD and RF protection, et cetera.
• Circuit board 24 a; ⁇ electronic components 25 are preferably encapsulated together in encapsulation 31, and connected to pins 18 and 20 at contacts 22 through soldering or other suitable connection.
• retention of tho ignition element 28 to the encapsulation 31 may be enhanced by providing a lip 17 at the bottom of the eyelet 10' .
• the insulator cup 27' may also be held within the encapsulation 31 to facilitate its retention as well, and the can may also have a lip (not shown) as another retention feature.
• Figs. 5 and 6 illustrate two alternate configurations for the electronics encapsulated within the alternate ignition subassemblies 8a and 8b.
• an off-the- shelf cylindrical capacitor 42 is contained within the encapsulation 31, either between the input leads 48 and circuit board 24a as shown in Fig. 5, or between the circuit board 24a and the ignition element 28 as shown in Fig. 6.
• Fig. 5 illustrates two alternate configurations for the electronics encapsulated within the alternate ignition subassemblies 8a and 8b.
• an off-the- shelf cylindrical capacitor 42 is contained within the encapsulation 31, either between the input leads 48 and circuit board 24a as shown in Fig. 5, or between the circuit board 24a and the ignition element 28 as shown in Fig. 6.
• Fig. 5 and 6 illustrate two alternate configurations for the electronics encapsulated within the alternate ignition subassemblies 8a and 8b.
• an off-the- shelf cylindrical capacitor 42 is contained within the encapsulation 31, either between the input leads 48 and circuit board 24a as shown in
• thin, flat flexible jumpers 44 can be provided, end the a/as of the capacitor 42 slj-ghtly offset from the a ⁇ s of the subassembly 8a. Similarl s shown in Fig 6, flexible jumper 60 can traverse the length of capacitor 42, and the leads to capacitor 42 can be soldered LO the circuit board 24 at through-mounts (as can one or bot ⁇ o tne ends of flexible jumper 60) .
• a nickel/chromium alloy, 13 micron diameter, 0.7mm long igniter wire, and a 50 g ignition charge of zirconium potassium perchlorate having a neight of 1.0mm and a diameter of 4.8mm is capable of reliably detonating all commonly used primary charges.
• a minimum suitable charge is approximately 30 mg for a configuration of this size, as a smaller charge may result in an insufficient charge thickness.
• a preferred all-fire voltage is 6 volts, and in this embodiment, may be delivered with a 100 ( ⁇ icrofarad capacitor included in the electronic components 25.

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• 2002
  • 2002-05-29 US US10/158,529 patent/US20030221577A1/en not_active Abandoned
• 2003
  • 2003-05-28 AU AU2003232382A patent/AU2003232382A1/en not_active Abandoned
  • 2003-05-28 EP EP03755251A patent/EP1509743A1/de not_active Withdrawn
  • 2003-05-28 WO PCT/IB2003/002057 patent/WO2003100344A1/en not_active Application Discontinuation
• 2004
  • 2004-11-26 ZA ZA200409576A patent/ZA200409576B/en unknown

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