Ammunition cartridge with electric propellant ignition

Information

  • Patent Grant
  • 6332402
  • Patent Number
    6,332,402
  • Date Filed
    Wednesday, May 10, 2000
    24 years ago
  • Date Issued
    Tuesday, December 25, 2001
    23 years ago
Abstract
An ammunition cartridge with electric propellant ignition includes a case having a rearward end closed by a case bottom and a front end; a propellant powder charge contained in the case; a high-voltage electrode disposed at the case bottom and having an end situated within the case; at least three tubes composed of propellant powder and extending from the electrode end toward the front end of the case through the propellant powder charge; an electric conductor extending in each tube and having opposite first and second ends; and an electric contact arrangement situated within the case in the front end thereof. The electric contact arrangement is electrically connected to the second end of the conductors and has externally exposed contact locations connectable to an electrically conducting component externally of the case. The first end of each electric conductor is electrically connected to the electrode.
Description




CROSS REFERENCE TO RELATED APPLICATION




This application claims the priority of German Application Nos. 199 21 379.8 filed May 10, 1999 and 199 36 650.0 filed Aug. 4, 1999, which are incorporated herein by reference.




BACKGROUND OF THE INVENTION




This invention relates to an ammunition cartridge having an electrothermal ignition device for the propellant.




For igniting the propellant powder in known ammunition cartridges having an electrothermal igniting device, in the bottom region of the cartridge a wire conductor is supplied with a current of such an intensity that the wire vaporizes explosively and produces a high-energy arc which, in turn, ignites propellant powder.




It has been found to be disadvantageous in ammunition cartridges of the above-outlined type that by generating the bottom-side arc, first only a relatively small percentage of the propellant powder is ignited and, particularly in case of propellant powders which ignite only with difficulty (LOVA), frequently no reproducible combustion behavior of the propellant powder can be obtained.




SUMMARY OF THE INVENTION




It is an object of the invention to provide an ammunition cartridge of the above-outlined type in which even propellant powders which are ignitable only with difficulty and which are packed with high density have a reproducible combustion behavior without adversely affecting the performance and/or the high-voltage resistance of the cartridge.




This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the ammunition cartridge with electric propellant ignition includes a case having a rearward end closed by a case bottom and a front end; a propellant powder charge contained in the case; a high-voltage electrode disposed at the case bottom and having an end situated within the case; at least three tubes composed of propellant powder and extending from the electrode end toward the front end of the case through the propellant powder charge; an electric conductor extending in each tube and having opposite first and second ends; and an electric contact arrangement situated within the case in the front end thereof. The electric contact arrangement is electrically connected to the second end of the conductors and has externally exposed contact locations connectable to an electrically conducting component externally of the case. The first end of each electric conductor is electrically connected to the electrode.




Essentially, it is the principle of the invention to provide special, axially extending ignition channels which pass through the propellant powder which fills the case. The ignition channels are constituted by the inner passage of the propellant tubes. An electric conductor, such as a wire or an electrically conducting inner coating passes through each propellant tube and is connected with the high-voltage electrode.




Upon connecting the high-voltage electrode with a current source, the wires disposed in the propellant powder tubes or the metallized inner layer of the tubes abruptly vaporize and generate an arc plasma canal within each tube. The current then flows through the plasma canals and high energy is transmitted to the environment of the electric conductors by way of radiation. Such an energy transfer leads to a rapid ignition of the propellant tubes and results in their fragmentation. The burning fragments of the propellant tubes as well as the released arc radiation cause a rapid and uniform ignition of the propellant powder.




Advantageously, the propellant powder tubes have radial openings to enhance a rapid transfer of energy to and ignition of the surrounding powder bed.




According to an advantageous embodiment of the invention, at least three ignition channels are provided, and the high-voltage electrode forms a current distributor at its end oriented toward the inside of the case.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an axial sectional view of a preferred embodiment of the invention having three ignition channels.





FIG. 2

is an enlarged sectional view taken along line II—II of FIG.


1


.





FIG. 3

is a view similar to

FIG. 2

, illustrating a further preferred embodiment of the cartridge according to the invention.











DESCRIPTION OF THE PREFERRED EMBODIMENTS





FIG. 1

shows a large-caliber ammunition cartridge


1


, for example, a tank gun ammunition which, for igniting the propellant, is connected to an energy source


3


by means of a switch


2


. The weapon in which the ammunition cartridge is positioned is not illustrated for the sake of clarity.




The ammunition cartridge


1


includes a case


5


filled with propellant powder


4


. The case


5


is made of a combustible material and has at its rearward end a metal case bottom


6


. The combustible case is, in the region of its rearward end


7


clamped between a shaped insulating part


8


and the case bottom


6


.




An electrically insulated high-voltage electrode


9


passes through the case bottom


6


and the insulating part


8


and is connected with a metal current distributor disk


10


.




Also referring to

FIG. 2

, three electric wires


11


,


12


and


13


secured to the current distributor


10


, pass axially through tubes


14


,


15


and


16


and are, in the region of the case lid


17


of the propellant case


5


, connected with an annular contact part


18


. The tubes


14


,


15


and


16


are composed of propellant powder. The contact part


18


, in turn, is grounded by contacting the inner wall of the non-illustrated weapon barrel.




The propellant powder tubes


14


,


15


and


16


are each provided with a plurality of radial apertures


19


which are axially and circumferentially distributed.




For firing the cartridge


1


the switch


2


is closed and the energy source delivering a voltage of up to 40 kV and containing a series of charged condensers is abruptly discharged. The resulting discharging current causes an electric explosion of the wires


11


,


12


and


13


, resulting in arc discharges within the propellant tubes


14


,


15


and


16


. The tubes are ignited by the arcs and are caused to burst. The burning and flying fragments of the tubes


14


,


15


and


16


as well as the released arc radiation cause a rapid and uniform ignition and combustion of the propellant powder


4


, together with the case


5


accommodating the propellant powder


4


.





FIG. 3

shows an embodiment of the invention in which, instead of the wires


11


-


13


of the earlier described embodiment, electrically conducting layers


20


,


21


and


22


are provided on the inside face of the respective propellant powder tubes


14


′,


15


′ and


16


′. The layers


20


,


21


and


22


are connected with the current distributor


10


and, by means of wires, with the contact portion


18


.




It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.



Claims
  • 1. An ammunition cartridge with electric propellant ignition comprising(a) a case having a rearward end closed by a case bottom and a front end; (b) a propellant powder charge contained in said case; (c) a high-voltage electrode disposed at said case bottom and having an end situated within said case; (d) at least three tubes composed of propellant powder and extending from said end of said electrode toward said front end of said case through said propellant powder charge; (e) an electric conductor extending in each said tube and having opposite first and second ends; (f) an electric contact arrangement situated within said case in said front end thereof; said electric contact arrangement being electrically connected to said second end of said conductors and having externally exposed contact locations being connectable to an electrically conducting component externally of said case; and (g) means for electrically connecting said first end of each said electric conductor to said electrode.
  • 2. The ammunition cartridge as defined in claim 1, wherein at least some of the electric conductors are conductor wires passing through respective said tubes.
  • 3. The ammunition cartridge as defined in claim 1, wherein at least some of the electric conductors are constituted by an electrically conducting coating carried on an inside surface of respective said tubes; each said coating having a first end electrically connected to said electrode and an opposite, second end electrically connected to said electric contact arrangement.
  • 4. The ammunition cartridge as defined in claim 1, wherein said tubes are supported on said electrode.
  • 5. The ammunition cartridge as defined in claim 1, wherein each tube has a length and a circumference; further wherein each tube has a plurality of apertures distributed circumferentially and along the tube lengths.
  • 6. The ammunition cartridge as defined in claim 1, wherein said end of said electrode comprises a current distributor.
  • 7. The ammunition cartridge as defined in claim 6, wherein said current distributor comprises a metal disk.
  • 8. The ammunition cartridge as defined in claim 1, further comprising a lid closing said front end of said case and further wherein said contact arrangement is situated in a region of said lid.
  • 9. The ammunition cartridge as defined in claim 1, wherein said contact arrangement comprises a contact ring.
  • 10. The ammunition cartridge as defined in claim 1, wherein said case is combustible.
Priority Claims (2)
Number Date Country Kind
199 21 379 May 1999 DE
199 36 650 Aug 1999 DE
US Referenced Citations (13)
Number Name Date Kind
319628 Russell Jun 1885
5044278 Campbell Sep 1991
5227577 Eich et al. Jul 1993
5231242 Chryssomallis et al. Jul 1993
5235129 Corney Aug 1993
5241909 Eches et al. Sep 1993
5355764 Marinos et al. Oct 1994
5503081 Lindblom et al. Apr 1996
5549046 Widner et al. Aug 1996
5945623 Goldstein et al. Aug 1999
6186040 Weise et al. Feb 2001
6247411 Vornfett Jun 2001
6247412 Vornfett Jun 2001
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Number Date Country
1 910 665 Sep 1970 DE
26 44 568 Apr 1978 DE
34 41 117 May 1986 DE
36 06 364 Sep 1987 DE
37 31 074 Mar 1990 DE
2 326 701 Dec 1998 GB
2 343 500 May 2000 GB