U.S. patent application number 09/783014 was filed with the patent office on 2002-08-15 for cartridge actuated ordnance filter.
Invention is credited to DeLeon, J. David, Kaloterakis, Nickolas, Kang, Thomas K., Nial, John A..
Application Number | 20020108523 09/783014 |
Document ID | / |
Family ID | 25127917 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020108523 |
Kind Code |
A1 |
Nial, John A. ; et
al. |
August 15, 2002 |
Cartridge actuated ordnance filter
Abstract
The present invention comprises a capacitor, of sufficient area
to cover the glass seal of a cartridge actuated ordnance device,
comprising a low pass filter. This capacitor connects to the leads
of the cartridge actuated ordnance device in a fashion that covers
the glass seal of the cartridge. Although the capacitor is not
directly contacting the glass seal, it is located proximately so
that very few frequencies of EMR can enter the seal, wherein a safe
level of EMR is achieved. The capacitor also filters both EMR and
ESD that come through the leads of the cartridge.
Inventors: |
Nial, John A.; (Park Hall,
MD) ; DeLeon, J. David; (Bel Alton, MD) ;
Kaloterakis, Nickolas; (Washington, DC) ; Kang,
Thomas K.; (Burke, VA) |
Correspondence
Address: |
Office of Counsel Code OC4
Naval Surface Warfare Center
Indian Head Division
101 Strauss Ave., Bldg. D-326
Indian Head
MD
20640-5035
US
|
Family ID: |
25127917 |
Appl. No.: |
09/783014 |
Filed: |
February 9, 2001 |
Current U.S.
Class: |
102/202.2 |
Current CPC
Class: |
F42B 3/188 20130101 |
Class at
Publication: |
102/202.2 |
International
Class: |
F42B 003/18 |
Goverment Interests
[0001] The invention described herein may be manufactured and used
by or for the Government of the United States of America for
governmental purposes without payment of any royalties thereon or
therefor.
Claims
What is claimed is:
1. A filtering device that provides electromagnetic radiation and
electrostatic discharge protection for cartridge actuated ordnance
wherein the cartridge has a glass seal and a plurality of leads,
comprising: a capacitor, having an area sufficient to cover the
glass seal, comprising a low pass filter, connected to the leads
and substantially covering the glass seal wherein the capacitor
substantially blocks electromagnetic radiation from entering the
glass seal and provides filtering for both electromagnetic
radiation and electrostatic discharge.
2. The filtering device of claim 1, wherein the capacitor comprises
a discoidal capacitor.
3. The filtering device of claim 2, wherein the capacitor further
comprises a faraday cage to substantially cover the glass seal.
4. The filtering device of claim 3, wherein the capacitor comprises
a capacitance from about 0.4 microfarads to about 1.1
microfarads.
5. The filtering device of claim 4, wherein the capacitor comprises
a capacitance of about 0.5 microfarads.
6. The filtering device of claim 5, further comprising a plurality
of holes formed within the capacitor wherein the plurality of leads
fit through the holes.
7. The filtering device of claim 6, comprising two holes formed
within the capacitor.
8. A method of blocking electromagnetic radiation and filtering
electromagnetic radiation and electrostatic discharge from
cartridge actuated ordnance wherein the cartridge has a glass seal
and a plurality of leads, comprising the step of: providing a
filtering device comprising a capacitor, being discoidal and having
an area sufficient to cover the glass seal, comprising a
capacitance of approximately 0.5 microfarads, connected to the
leads and substantially covering the glass seal wherein the
capacitor substantially blocks electromagnetic radiation from
entering the glass seal and provides filtering for both
electromagnetic radiation and electrostatic discharge.
Description
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to an improvement to
cartridge actuated ordnance. More particularly, the present
invention adds or improves the following safety feature to such
devices: shielding from electromagnetic radiation (EMR); filtering
to eliminate EMR conducted along the firing leads of the device;
and, increased protection against human borne electrostatic
discharge (ESD) when handling the devices. The present invention
accomplishes these tasks by incorporating a low-pass filter into
the design of current devices.
SUMMARY OF THE INVENTION
[0004] The present invention comprises a capacitor, of sufficient
area to cover the glass seal of a cartridge actuated ordnance
device, having a capacitance value of from about 0.4 microfarads to
about 1.1 microfarads. This capacitor connects to the leads of the
cartridge actuated ordnance device in a fashion that covers the
glass seal of the cartridge. Although the capacitor is not directly
contacting the glass seal, it is located proximately so that very
few frequencies of EMR can enter the seal, wherein a safe level of
EMR is achieved. The capacitor also filters both EMR and ESD that
comes through the leads of the cartridge.
[0005] This present invention is specifically designed to protect
cartridge actuated ordnance from high power EMR resulting from two
bodies that are in proximity, or, are intermittently making
contact. This environment is commonly known as Hazards of
Electromagnetic Radiation to Ordnance (HERO). HERO tests are
conducted at a broad range of frequencies using continuous wave and
pulsed power modulations. The interaction between the two bodies,
such as between a cartridge actuated ordnance device and a person's
body loading such a device, causes arcing at various frequencies.
The present invention also provides protection against ESD through
ionization and filtering.
[0006] The present invention was developed in order to provide
sufficient EMR protection to meet Military Standard 464 for HERO.
Prior to this invention, cartridge actuated ordnance often failed
to meet this standard. Although a single capacitor is used in order
to accomplish this and other objectives, the configuration and
placement of the capacitor would not lead one skilled in the art to
deduce that sufficient HERO protection would result.
[0007] Accordingly, it is the object of this invention to provide a
device that shields a cartridge actuated ordnance from EMR.
[0008] It is a further object of this invention to provide a device
that filters EMR and ESD from a cartridge actuated ordnance.
[0009] This invention accomplishes these objectives and other needs
related to protecting cartridge actuated ordnance devices from EMR
and ESD.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention, and, together with the description, serve to explain
the principles of the invention.
[0011] FIG. 1 is a cross-sectional view of a cartridge
incorporating an embodiment of the present invention.
[0012] FIG. 2 is a top view of the present invention of the
embodiment shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] The invention, as embodied herein, comprises a filtering
device that provides electromagnetic radiation and electrostatic
discharge protection for cartridge actuated ordnance. The cartridge
portion of a cartridge actuated ordnance normally comprises a glass
seal that provides a vacuum within the cartridge in order to
function properly in actuating ordnance. In most configurations,
the cartridge also comprises two leads that extend past the glass
seal in order to attach the cartridge to the ordnance for
actuation. The present invention comprises a capacitor that has an
area sufficient to substantially cover the glass seal. The
capacitor also comprises a low pass filter. The capacitor is
connected to the cartridge leads so that it substantially covers
the glass seal as noted above, but does not actually contact the
seal. This configuration provides protection from electromagnetic
radiation (EMR) and electrostatic discharge (ESD) through two
different methods. First, by covering the glass seal, EMR is
physically blocked from entering the cartridge by capacitor.
Second, the capacitor filters high frequency EMR and ESD attempting
to enter the device through the leads.
[0014] Referring to FIG. 1, the cartridge 100 comprises two leads
102 that extend from the sides of a glass seal 104. The glass seal
104 is a standard feature on most cartridges 100 used for actuating
ordnance. The glass seal is placed on the cartridge in order to
form a vacuum for the initiator portion of the cartridge 100. The
present invention comprises a capacitor 106 that has an area
sufficient to substantially cover the glass seal 104. This enables
the capacitor 106 material itself to substantially block EMR from
entering the cartridge 100 through the glass seal 104. In one
embodiment of the invention, the capacitor 106 comprises a
discoidal capacitor. In another embodiment of the invention, the
capacitor 106 comprises a faraday cage to substantially cover the
glass seal 104. The capacitor 106 also comprises a low pass filter.
More preferably, the capacitor comprises a capacitance of about 0.4
microfarads to about 1.1 microfarads, and comprises a most
preferred capacitance of approximately 0.5 microfarads. The
capacitor 106 comprises a low pass filter in order to filter out
EMR and ESD passing through the leads 102. The capacitor 106 is
able to perform both of these functions due to its proximity to the
entry point of the EMR and ESD, the leads 102.
[0015] The capacitor 106 is connected to the cartridge 100 by the
two leads 102 so that it substantially covers the glass seal 104 as
noted above, but does not actually contact the glass seal 104. In
the embodiment of the invention shown in FIG. 2, the capacitor 106
comprises holes 210 formed within the capacitor wherein leads 102
fit through the holes. Most standard cartridges 100 comprise two
leads 102, so, therefore, the preferred capacitor 106 comprises two
holes 210.
[0016] The present invention also comprises a method of blocking
electromagnetic radiation and filtering electromagnetic radiation
and electrostatic discharge from cartridge actuated ordnance. This
method comprises providing the filtering device disclosed
above.
[0017] What is described are specific examples of many possible
variations on the same invention and are not intended in a limiting
sense. The claimed invention can be practiced using other
variations not specifically described above.
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