U.S. patent application number 16/988987 was filed with the patent office on 2020-12-03 for subsonic polymeric ammunition cartridge.
This patent application is currently assigned to TRUE VELOCITY IP HOLDINGS, LLC. The applicant listed for this patent is TRUE VELOCITY IP HOLDINGS, LLC. Invention is credited to Lonnie Burrow.
Application Number | 20200378734 16/988987 |
Document ID | / |
Family ID | 1000005005052 |
Filed Date | 2020-12-03 |
United States Patent
Application |
20200378734 |
Kind Code |
A1 |
Burrow; Lonnie |
December 3, 2020 |
SUBSONIC POLYMERIC AMMUNITION CARTRIDGE
Abstract
The present invention provides a subsonic ammunition cartridge
including a polymeric casing body comprising a generally
cylindrical hollow polymer body having a body base at a first end
thereof and a mouth at a second end to define a propellant chamber;
a propellant insert positioned in the propellant chamber to reduce
the internal volume of the propellant chamber, wherein the
propellant chamber has an internal volume that is at least 10% less
than the open internal volume of a standard casing of equivalent
caliber; and a primer insert positioned at the body base and in
communication with the propellant chamber.
Inventors: |
Burrow; Lonnie; (Carrollton,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TRUE VELOCITY IP HOLDINGS, LLC |
GARLAND |
TX |
US |
|
|
Assignee: |
TRUE VELOCITY IP HOLDINGS,
LLC
GARLAND
TX
|
Family ID: |
1000005005052 |
Appl. No.: |
16/988987 |
Filed: |
August 10, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16519608 |
Jul 23, 2019 |
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16988987 |
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14725699 |
May 29, 2015 |
10429156 |
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16519608 |
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14724240 |
May 28, 2015 |
9927219 |
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14725699 |
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14011202 |
Aug 27, 2013 |
9546849 |
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14724240 |
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13292843 |
Nov 9, 2011 |
8561543 |
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14011202 |
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61456664 |
Nov 10, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F42B 5/307 20130101 |
International
Class: |
F42B 5/307 20060101
F42B005/307 |
Claims
1. A subsonic ammunition comprising: a polymeric casing body
comprising a primer insert comprising a coupling region opposite a
bottom surface, a primer recess in the bottom surface, and a primer
flash aperture in the primer recess extending through the bottom
surface; a first end and a second end connected by a propellant
chamber, wherein the first end is molded over the coupling region
of the primer insert and into a primer flash aperture to form a
flash hole, and a second end opposite the first end and connected
by a propellant chamber, wherein the second end comprises an
aperture; propellant insert positioned in the propellant chamber to
reduce the internal volume of the propellant chamber, wherein the
propellant chamber has an internal volume that is reduced by
between 25 and 80%; a propellant disposed and confined within the
propellant chamber; a primer disposed in the primer insert in
combustible communication with the propellant; and a projectile
frictionally fitted in the mouth in combustible communication with
the propellant.
2. The subsonic ammunition of claim 1, wherein the internal volume
that is about 25.1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,
38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71,
72, 73, 74, 75, 76, 77, 78, 79, or 80% less than the open internal
volume of a standard casing of equivalent caliber.
3. The subsonic ammunition cartridge of claim 1, wherein the primer
insert is overmolded into the polymeric casing body.
4. The subsonic ammunition of claim 1, wherein the projectile does
not exceed the velocity of 1200 feet per second at sea level under
standard atmospheric conditions when fired.
5. The subsonic ammunition of claim 1, wherein the projectile does
not exceed the velocity of 1086 feet per second at standard
atmospheric conditions when fired.
6. The subsonic ammunition of claim 1, wherein the projectile is
secured to the mouth by a mechanical interference, an adhesive, an
ultrasonic welding, or a hot crimping.
7. The subsonic ammunition of claim 1, wherein the polymer body
comprises a material selected from the group consisting of
polyphenylsulfone, polycarbonate, and polyamide.
8. The subsonic ammunition of claim 1, further comprising at least
one additive selected from the group consisting of plasticizers,
lubricants, molding agents, fillers, thermo-oxidative stabilizers,
flame-retardants, coloring agents, compatibilizers, impact
modifiers, release agents, reinforcing fibers and reinforcing
agents.
9. The subsonic ammunition of claim 1, wherein the propellant
insert has a substantially cylindrical shape.
10. The subsonic ammunition of claim 1, wherein the propellant
insert has a free formed shape.
11. The subsonic ammunition of claim 1, wherein the propellant
insert has a one or more ribs extending into the propellant
chamber.
12. The subsonic ammunition of claim 1, wherein the propellant
insert has a radial cross-section selected from the group
consisting of circular, ovoid, octagonal, hexagonal, triangular,
star, ribbed, square and a combination thereof.
13. The subsonic ammunition of claim 1, wherein the radial
cross-section of the propellant chamber is irregular along its
longitudinal length.
14. The subsonic ammunition of claim 1, wherein the radial size of
the propellant chamber tapers along its longitudinal direction.
15. The subsonic ammunition of claim 1, wherein the polymeric
casing body and propellant insert are formed of different polymeric
materials.
16. The subsonic ammunition of claim 1, wherein the polymeric
casing body and propellant insert are formed of the same polymeric
materials.
17. The subsonic ammunition of claim 1, wherein the polymeric
casing body comprises a polymers selected from the group consisting
of polyurethane prepolymer, cellulose, fluoro-polymer, ethylene
inter-polymer alloy elastomer, ethylene vinyl acetate, nylon,
polyether imide, polyester elastomer, polyester sulfone, polyphenyl
amide, polypropylene, polyvinylidene fluoride or thermoset polyurea
elastomer, acrylics, homopolymers, acetates, copolymers,
acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers,
inomers, polyamides, polyamide-imides, polyacrylates,
polyatherketones, polyaryl-sulfones, polybenzimidazoles,
polycarbonates, polybutylene, terephthalates, polyether imides,
polyether sulfones, thermoplastic polyimides, thermoplastic
polyurethanes, polyphenylene sulfides, polyethylene, polypropylene,
polysulfones, polyvinylchlorides, styrene acrylonitriles,
polystyrenes, polyphenylene, ether blends, styrene maleic
anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies,
phenolics, unsaturated polyesters, bismaleimides, polyurethanes,
silicones, vinylesters, urethane hybrids, polyphenylsulfones,
copolymers of polyphenylsulfones with polyethersulfones or
polysulfones, copolymers of poly-phenylsulfones with siloxanes,
blends of polyphenylsulfones with polysiloxanes,
poly(etherimide-siloxane) copolymers, blends of polyetherimides and
polysiloxanes, and blends of polyetherimides and
poly(etherimide-siloxane) copolymers.
18. The subsonic ammunition of claim 1, wherein the propellant
insert comprises a polymers selected from the group consisting of
polyurethane prepolymer, cellulose, fluoro-polymer, ethylene
inter-polymer alloy elastomer, ethylene vinyl acetate, nylon,
polyether imide, polyester elastomer, polyester sulfone, polyphenyl
amide, polypropylene, polyvinylidene fluoride or thermoset polyurea
elastomer, acrylics, homopolymers, acetates, copolymers,
acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers,
inomers, polyamides, polyamide-imides, polyacrylates,
polyatherketones, polyaryl-sulfones, polybenzimidazoles,
polycarbonates, polybutylene, terephthalates, polyether imides,
polyether sulfones, thermoplastic polyimides, thermoplastic
polyurethanes, polyphenylene sulfides, polyethylene, polypropylene,
polysulfones, polyvinylchlorides, styrene acrylonitriles,
polystyrenes, polyphenylene, ether blends, styrene maleic
anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies,
phenolics, unsaturated polyesters, bismaleimides, polyurethanes,
silicones, vinylesters, urethane hybrids, polyphenylsulfones,
copolymers of polyphenylsulfones with polyethersulfones or
polysulfones, copolymers of poly-phenylsulfones with siloxanes,
blends of polyphenylsulfones with polysiloxanes,
poly(etherimide-siloxane) copolymers, blends of polyetherimides and
polysiloxanes, and blends of polyetherimides and
poly(etherimide-siloxane) copolymers.
19. A subsonic ammunition case comprising: a polycarbonate casing
body comprising a generally cylindrical hollow polycarbonate body
having a primer insert comprising a coupling region opposite a
bottom surface, a primer recess in the bottom surface, and a primer
flash aperture in the primer recess extending through the bottom
surface; a body base comprising a first end that extends to a
second to form a propellant chamber there between, wherein the
first end is molded over the coupling region of the primer insert
and into a primer flash aperture to form a flash hole, and the
second end comprises aperture; and a circular propellant insert
positioned in the propellant chamber to reduce the internal volume
of the propellant chamber, wherein the propellant chamber has an
internal volume that is between 25 and 80% less than the open
internal volume of a standard casing of equivalent caliber, wherein
the circular propellant insert comprises polycarbonate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S.
patent application Ser. No. 16/519,608 filed Jul. 23, 2019, which
is a Continuation application of U.S. patent application Ser. No.
14/725,699 filed May 29, 2015, now U.S. Pat. No. 10,429,156, which
is a Continuation application of U.S. patent application Ser. No.
14/724,240 filed May 28, 2015, now U.S. Pat. No. 9,927,219, which
is a Divisional application of U.S. patent application Ser. No.
14/011,202 filed Aug. 27, 2013, now U.S. Pat. No. 9,546,849, which
is a Divisional application of U.S. patent application Ser. No.
13/292,843 filed Nov. 9, 2011, now U.S. Pat. No. 8,561,543, which
claims priority to U.S. Provisional Application Ser. No. 61/456,664
filed Nov. 10, 2010, the contents of which are all incorporated by
reference herein in their entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention generally relates to ammunition
articles, and more particularly to subsonic ammunition casings
having a propellant insert formed from polymeric materials.
STATEMENT OF FEDERALLY FUNDED RESEARCH
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIALS FILED ON COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] Without limiting the scope of the invention, its background
is described in connection with lightweight polymer subsonic
ammunition casing and more specifically to a lightweight polymer
subsonic ammunition casing having a propellant insert positioned in
the propellant chamber to reduce the internal volume of the
propellant chamber.
[0006] Generally, there are two types of ammunition: supersonic
ammunition, which fires projectiles with velocities exceeding the
speed of sound; and subsonic ammunition, which fires projectiles
with velocities less than that of the speed of sound and generally
in the range of 1,000-1,100 feet per second (fps), most commonly
given at 1,086 fps at standard atmospheric conditions. Traditional
methods of making subsonic ammunition reduce the propellant charge
(and in turn increasing the empty volume left vacant by the reduced
propellant charge) in the shell until the velocity is adequately
reduced.
[0007] Unfortunately, this empty volume can cause numerous problems
including inhibition of proper propellant burn, inconsistent
propellant positioning, reduced accuracy and propellant detonation
caused by extremely high propellant burn rates. For example, since
the propellant is free to move in the large empty volume, shooting
downward with the propellant charge away from the primer gives
different velocity results than when shooting upwards with the
propellant charge close to the primer. Finally, usage of subsonic
ammunition, and its attending lower combustion pressures,
frequently results in the inability to efficiently cycle
semi-automatic or fully automatic weapons where the propellant
charge must produce sufficient gas pressure and/or volume to
accelerate the projectile and to cycle the firing mechanism. With a
reduced quantity of propellant, subsonic ammunition generally fails
to produce sufficient pressure to properly cycle the firing
mechanism. The art has provided numerous attempts to cure these
problems, e.g., the introduction of inert fillers, expandable inner
sleeves that occupy the empty space between the propellant and the
projectile, insertion of flexible tubing, foamed inserts, stepped
down stages in the discharge end of cartridge casings, or
complicated three and more component cartridges with rupturable
walls and other complicated features. Another approach has been to
use standard cartridges in combination with non-standard
propellants. However, these result of such prior attempts to solve
the production of reliable subsonic cartridges have failed and let
to subsonic rounds that have a larger variation in velocity and
variance in accuracy potential.
[0008] In addition the use of polymer ammunition results in
additional drawbacks, e.g., the possibility of the projectile being
pushed into the cartridge casing, the bullet pull being too light
such that the bullet can fall out, the bullet pull being too
insufficient to create sufficient chamber pressure, the bullet pull
not being uniform from round to round, and portions of the
cartridge casing breaking off upon firing causing the weapon to jam
or damage or danger when subsequent rounds are fired or when the
casing portions themselves become projectiles. Accordingly, a need
exists to develop solutions that make it possible to manufacture
better and more price competitive subsonic ammunition than
previously available.
SUMMARY OF THE INVENTION
[0009] The present invention provides a subsonic ammunition
including a polymeric casing body comprising a generally
cylindrical hollow polymer body having a body base at a first end
thereof and a mouth at a second end to define a propellant chamber;
a propellant insert positioned in the propellant chamber to reduce
the internal volume of the propellant chamber, wherein the
propellant chamber has an internal volume that is at least 10% less
than the open internal volume of a standard casing of equivalent
caliber; a propellant disposed and confined within the propellant
chamber; a primer insert positioned at the body base and in
communication with the propellant chamber; a primer disposed in the
primer insert in combustible communication with the propellant; and
a projectile frictionally fitted in the mouth in combustible
communication with the propellant. The projectile does not exceed
the velocity of 1200 feet per second at sea level under standard
atmospheric conditions when fired. The projectile may be secured to
the mouth by a mechanical interference, adhesive, ultrasonic
welding, the combination of molding in place and adhesive, and hot
crimping after the act of molding. The polymer body may include a
material selected from the group consisting of polyphenylsulfone,
polycarbonate, and polyamide. The subsonic ammunition may further
include at least one additive selected from the group consisting of
plasticizers, lubricants, molding agents, fillers, thermo-oxidative
stabilizers, flame-retardants, coloring agents, compatibilizers,
impact modifiers, release agents, reinforcing fibers and
reinforcing agents. The propellant insert may have a substantially
cylindrical shape, a free formed shape, a one or more ribs
extending into the propellant chamber or a radial cross-section
selected from the group consisting of circular, ovoid, octagonal,
hexagonal, triangular, star, ribbed, square or an shape irregular
along its longitudinal length. The radial size of the propellant
chamber may taper along its longitudinal direction. The polymeric
casing body and propellant insert may be formed of the same or
different polymeric materials. The propellant chamber may be formed
of a separate propellant insert disposed within the internal cavity
of the generally cylindrical hollow polymer body.
[0010] The present invention provides a subsonic ammunition case
having a polymeric casing body comprising a generally cylindrical
hollow polymer body having an body base at a first end thereof and
a mouth at a second end to define a propellant chamber; a
propellant insert positioned in the propellant chamber to reduce
the internal volume of the propellant chamber, wherein the
propellant chamber has an internal volume that is at least 10% less
than the open internal volume of a standard casing of equivalent
caliber; a primer insert positioned at the body base and in
communication with the propellant chamber; and a primer disposed in
the primer insert in combustible communication with the
propellant.
[0011] The present invention includes a subsonic ammunition case
propellant insert which is adapted to fit in a propellant chamber
of an ammunition case to reduce an internal volume by at least 10%
that of a standard casing of equivalent caliber, wherein the
propellant insert houses a propellant and allows combustible
communication between a primer and a projectile.
[0012] The present invention includes a method of preparing a
subsonic ammunition by providing subsonic ammunition comprising a
polymeric casing body comprising a generally cylindrical hollow
polymer body having a body base at a first end thereof and a mouth
at a second end to define a propellant chamber; a propellant insert
positioned in the propellant chamber to reduce the internal volume
of the propellant chamber, wherein the propellant chamber has an
internal volume that is at least 10% less than the open internal
volume of a standard casing of equivalent caliber; connecting a
primer insert having a flash-hole to the body base to allow
communication between the propellant chamber and the flash hole;
inserting a primer disposed in the flash-hole in combustible
communication with the propellant chamber; disposing a propellant
within the propellant chamber; and inserting a projectile in the
mouth to allow combustible communication with the propellant.
[0013] The present invention includes a subsonic ammunition having
a substantially cylindrical hollow polymeric casing body comprising
a polymeric middle body connected to a polymeric bullet-end and a
polymeric coupling end to define a propellant chamber; a primer
insert connected to the polymeric coupling end to partially seal
the substantially cylindrical hollow polymeric casing body, wherein
the primer insert comprises a top surface opposite a bottom surface
and a substantially cylindrical coupling element that extends from
the bottom surface and couples to the polymeric coupling end, a
primer recess in the top surface that extends toward the bottom
surface, a primer flash hole positioned in the primer recess to
extend through the bottom surface, and a flange that extends
circumferentially about an outer edge of the top surface; a
propellant insert positioned in the propellant chamber to reduce
the internal volume of the propellant chamber, wherein the
propellant chamber has an internal volume that is at least 20% less
than the open internal volume of a standard casing of equivalent
caliber; a propellant disposed and confined within the propellant
chamber; a primer disposed in the primer recess in combustible
communication with the propellant through the primer flash hole;
and a projectile frictionally fitted in the mouth in combustible
communication with the propellant. The polymeric coupling end may
extend over the substantially cylindrical coupling element and
covers an circumferential surface to form the primer flash
hole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a more complete understanding of the features and
advantages of the present invention, reference is now made to the
detailed description of the invention along with the accompanying
figures and in which:
[0015] FIG. 1 depicts an exploded view of the polymeric cartridge
casing;
[0016] FIGS. 2a, 2b and 2c depict a cross-sectional view of a
polymeric cartridge case having a reduced propellant chamber volume
according to the present invention;
[0017] FIG. 3 depicts a cross-sectional view of a portion of the
polymeric cartridge case having a reduced propellant chamber volume
according to one embodiment of the present invention;
[0018] FIGS. 4a-4h depict a top view of the polymer casing having a
reduced propellant chamber volume with a substantially cylindrical
open-ended middle body component;
[0019] FIG. 5 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case displaying ribs and a reduced
propellant chamber volume according to one embodiment of the
present invention;
[0020] FIG. 6 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case having a reduced propellant chamber
volume and displaying ribs according to one embodiment of the
present invention;
[0021] FIG. 7 depicts a side, cross-sectional view of a polymeric
cartridge case having a reduced propellant chamber volume and a
diffuser according to one embodiment of the present invention;
[0022] FIG. 8 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case having a reduced propellant chamber
volume and a diffuser according to one embodiment of the present
invention;
[0023] FIGS. 9a-9h depict diffuser according to a different
embodiment of the present invention; and
[0024] FIGS. 10a and 10b depict a cross-sectional view of a
polymeric cartridge case having a reduced propellant chamber volume
according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] While the making and using of various embodiments of the
present invention are discussed in detail below, it should be
appreciated that the present invention provides many applicable
inventive concepts that can be embodied in a wide variety of
specific contexts. The specific embodiments discussed herein are
merely illustrative of specific ways to make and use the invention
and do not delimit the scope of the invention.
[0026] To facilitate the understanding of this invention, a number
of terms are defined below. Terms defined herein have meanings as
commonly understood by a person of ordinary skill in the areas
relevant to the present invention. Terms such as "a", "an" and
"the" are not intended to refer to only a singular entity, but
include the general class of which a specific example may be used
for illustration. The terminology herein is used to describe
specific embodiments of the invention, but their usage does not
delimit the invention, except as outlined in the claims.
[0027] As used herein, the term "ammunition", "ammunition article",
"munition", and "munition article" as used herein may be used
interchangeably to refer to a complete, assembled round or
cartridge of that is ready to be loaded into a firearm and fired,
including cap, casing, propellant, projectile, etc. Ammunition may
be a live round fitted with a projectile, or a blank round with no
projectile and may also be other types such as non-lethal rounds,
rounds containing rubber bullets, rounds containing multiple
projectiles (shot), and rounds containing projectiles other than
bullets such as fluid-filled canisters and capsules. Ammunition may
be any caliber of pistol or rifle ammunition, e.g., non limiting
examples include 0.22, 0.22-250, 0.223, 0.243, 0.25-06, 0.270,
0.300, 0.30-30, 0.30-40, 30.06, 0.300, 0.303, 0.308, 0.338, 0.357,
0.38, 0.380, 0.40, 0.44, 0.45, 0.45-70, 0.50 BMG, 5.45 mm, 5.56 mm,
6.5 mm, 6.8 mm, 7 mm, 7.62 mm, 8 mm, 9 mm, 10 mm, 12.7 mm, 14.5 mm,
20 mm, 25 mm, 30 mm, 40 mm and others.
[0028] As used herein, the term "subsonic ammunition" refers to
ammunition that ejects a projectile at velocities of less than the
speed of sound at standard atmospheric conditions, e.g., generally
in the range of 1,000-1,100 feet per second (fps) but may range
from 900-1,200 feet per second (fps) depending on the altitude and
atmospheric conditions. Specific examples include about 1000 fps,
1010 fps, 1020 fps, 1030 fps, 1040 fps, 1050 fps, 1060 fps, 1070
fps, 1080 fps, 1086 fps, 1090 fps, and even 1099 fps.
[0029] As used herein, the term "casing" and "case" and "body" are
used interchangeably (e.g., "cartridge casing", "cartridge case"
and "casing body") to refer to the portion of the ammunition that
remains intact after firing and includes the propellant chamber and
may include the primer insert. A cartridge casing may be one-piece,
two-piece, three piece or multi-piece design that includes a mouth
at one end and a primer insert at the other separated by a
propellant chamber.
[0030] A traditional cartridge casing generally has a deep-drawn
elongated body with a primer end and a projectile end. During use,
a weapon's cartridge chamber supports the majority of the cartridge
casing wall in the radial direction, however, in many weapons, a
portion of the cartridge base end is unsupported. During firing,
the greatest stresses are concentrated at the base end of the
cartridge, which must have great mechanical strength. This is true
for both subsonic and supersonic ammunition cartridges.
[0031] There is a need for a subsonic polymer ammunition cartridge
to reduce cost, weight and reliability. The traditional avenue to
subsonic ammunition is usage of a reduced quantity of propellant
compared to traditional supersonic ammunition. For example, a
traditional 7.62 mm ammunition uses about 45 grains of propellant
and generates projectile velocities of 2000-3000 fps, a subsonic
ammunition uses less than about 15 grains of propellant to generate
projectile velocities of less than 1100 fps. The present inventors
determined that a subsonic cartridge casing may be produced by the
design and construction of an engineered internal propellant
chamber within the overall internal volume of the casing. The
internal propellant chamber positioned within the casing may be in
the form of a propellant chamber insert that is made separately and
inserted into the chamber. Alternatively the propellant chamber
insert may be made as a part of the middle body component and the
propellant chamber by increasing the thickness of the side wall.
The propellant chamber insert will function to reduce the size of
the propellant chamber which will reduce the amount of propellant
in the propellant chamber and in turn reduce the velocity of the
projectile. In particular, the propellant chamber insert reduces
the internal volume of the propellant chamber by more than 15% or
20% compared to the equivalent supersonic casing of the same
caliber. In addition, using such a propellant chamber insert allows
the internal propellant chamber of existing ammunition cartridge
casings to be used allowing ammunition manufacturer to assemble the
cartridge casing in a rapid fashion without the need for additional
manufacturing steps or complex design parameters.
[0032] The propellant chamber insert when in the form of an
integral portion of the cartridge casing is constructed out of the
same polymer composition as the cartridge casing. When the
propellant chamber insert is a separate insert positioned within
the propellant chamber, the propellant chamber insert may be of a
similar or a different polymer composition than the cartridge
casing. It will also be recognized that in any of the embodiments
described herein, the outer wall and inner volume occupying
portions of the cartridge casing need not necessarily be of the
same polymeric material. For example, the outer wall could be made
of polymers with higher temperature resistance to resist the hot
chamber conditions, while the inner volume occupying portion could
be manufactured out of low cost polymers or be made with voids or
ribs to reduce the amount of material used. In one embodiment, the
space defined between the outer wall and the propellant chamber
includes voids or ribs. In another embodiment, the propellant
chamber comprises multiple separate internal volumes each in
combustible communication with the primer. In still yet another
such embodiment, the propellant chamber has a radial cross-section
selected from the group consisting of circular, ovoid, octagonal,
hexagonal, triangular, and square. In one embodiment, the radial
cross-section of the propellant chamber is irregular along its
longitudinal length. In another embodiment, the radial size of the
propellant chamber tapers along its longitudinal direction. In
another embodiment, the propellant chamber has a radial
cross-section selected from the group consisting of circular,
ovoid, octagonal, hexagonal, triangular, and square. In one such
embodiment, the radial cross-section of the propellant chamber is
irregular along its longitudinal length. In another such
embodiment, the radial size of the propellant chamber tapers along
its longitudinal direction.
[0033] One skilled in the art will also readily observe that
different or identical coloring of the polymers used could aid in
identification or marketing of the ammunition of the current
invention. Another embodiment of this invention would be the usage
of transparent or translucent polymers, allowing for easy
identification of the propellant level or cartridge load.
[0034] For example, a non-limiting list of suitable polymeric
materials, for both the cartridge casing and the propellant chamber
insert may be selected from any number of polymeric materials,
e.g., polyamides, polyimides, polyesters, polycarbonates,
polysulfones, polylactones, polyacetals,
acrylontrile/butadiene/styrene copolymer resins, polyphenylene
oxides, ethylene/carbon monoxide copolymers, polyphenylene
sulfides, polystyrene, styrene/acrylonitrile copolymer resins,
styrene/maleic anhydride copolymer resins, aromatic polyketones and
mixtures thereof. Preferred embodiments will be manufactured from
any polymer with a glass transition temperature of less than
250.degree. C. Particularly suitable materials include
polyphenylsulfones, polycarbonates and polyamides.
[0035] FIG. 1 depicts an exploded view of the polymeric cartridge
casing. A cartridge 10 is shown with a polymer casing 12 showing a
powder chamber 14 with a forward end opening 16 for insertion of a
projectile (not shown). Polymer casing 12 has a substantially
cylindrical open-ended polymeric bullet-end 18 extending from
forward end opening 16 rearward to opposite end 20. The bullet-end
component 18 may be formed with coupling end 22 formed on end 20.
Coupling end 22 is shown as a female element, but may also be
configured as a male element in alternate embodiments of the
invention. The forward end of bullet-end component 18 has a
shoulder 24 forming chamber neck 26. Polymer casing 12 has a
substantially cylindrical opposite end 20. Coupling end 22 is shown
as a female element, but may also be configured as a male element
in alternate embodiments of the invention. The middle body
component (not shown) is connected to a substantially cylindrical
coupling element 30 of the substantially cylindrical insert 32.
Coupling element 30, as shown may be configured as a male element,
however, all combinations of male and female configurations is
acceptable for coupling elements 30 and coupling end 22 in
alternate embodiments of the invention. Coupling end 22 fits about
and engages coupling element 30 of a substantially cylindrical
insert 32. The substantially cylindrical insert 32 includes a
substantially cylindrical coupling element 30 extending from a
bottom surface 34 that is opposite a top surface 36. When contacted
the coupling end 22 interlocks with the substantially cylindrical
coupling element 30, through the coupling element 30 that extends
with a taper to a smaller diameter at the tip 44 to form a physical
interlock between substantially cylindrical insert 32 and middle
body component 28. The substantially cylindrical insert 32 also has
a flange 46 cut therein and a primer recess 38 and primer flash
aperture formed therein for ease of insertion of the primer (not
shown). A primer flash hole aperture 42 is located in the primer
recess 38 and extends through the bottom surface 34 into the
propellant chamber 14 to combust the propellant in the propellant
chamber 14. When molded the coupling end 22 extends the polymer
through the primer flash hole aperture 42 to form the primer flash
hole 40 while retaining a passage from the top surface 36 through
the bottom surface 34 and into the propellant chamber 14 to provide
support and protection about the primer flash hole aperture 42.
[0036] The polymeric and composite casing components may be
injection molded. Polymeric materials for the bullet-end and middle
body components must have propellant compatibility and resistance
to gun cleaning solvents and grease, as well as resistance to
chemical, biological and radiological agents. The polymeric
materials must have a temperature resistance higher than the
cook-off temperature of the propellant, typically about 320.degree.
F. The polymeric materials must have elongation-to-break values
that to resist deformation under interior ballistic pressure as
high as 60,000 psi in all environments (temperatures from about -65
to about 320.degree. F. and humidity from 0 to 100% RH). According
to one embodiment, the middle body component is either molded onto
or snap-fit to the casing head-end component after which the
bullet-end component is snap-fit or interference fit to the middle
body component. The components may be formed from high-strength
polymer, composite or ceramic.
[0037] Examples of suitable high strength polymers include
composite polymer material including a tungsten metal powder, nylon
6/6, nylon 6, and glass fibers; and a specific gravity in a range
of 3-10. The tungsten metal powder may be 50%-96% of a weight of
the bullet body. The polymer material also includes about 0.5-15%,
preferably about 1-12%, and most preferably about 2-9% by weight,
of nylon 6/6, about 0.5-15%, preferably about 1-12%, and most
preferably about 2-9% by weight, of nylon 6, and about 0.5-15%,
preferably about 1-12%, and most preferably about 2-9% by weight,
of glass fibers. It is most suitable that each of these ingredients
be included in amounts less than 10% by weight. The cartridge
casing body may be made of a modified ZYTEL.RTM. resin, available
from E.I. DuPont De Nemours Co., a modified 612 nylon resin,
modified to increase elastic response.
[0038] Commercially available polymers suitable for use in the
present invention thus include polyphenylsulfones; copolymers of
polyphenylsulfones with polyether-sulfones or polysulfones;
copolymers and blends of polyphenylsulfones with polysiloxanes;
poly(etherimide-siloxane); copolymers and blends of polyetherimides
and polysiloxanes, and blends of polyetherimides and
poly(etherimide-siloxane) copolymers; and the like. Particularly
preferred are polyphenylsulfones and their copolymers with
poly-sulfones or polysiloxane that have high tensile strength and
elongation-to-break to sustain the deformation under high interior
ballistic pressure. Such polymers are commercially available, for
example, RADEL.RTM. R5800 polyphenylesulfone from Solvay Advanced
Polymers. The polymer can be formulated with up to about 10 wt % of
one or more additives selected from internal mold release agents,
heat stabilizers, anti-static agents, colorants, impact modifiers
and UV stabilizers.
[0039] Examples of suitable polymers include polyurethane
prepolymer, cellulose, fluoro-polymer, ethylene inter-polymer alloy
elastomer, ethylene vinyl acetate, nylon, polyether imide,
polyester elastomer, polyester sulfone, polyphenyl amide,
polypropylene, polyvinylidene fluoride or thermoset polyurea
elastomer, acrylics, homopolymers, acetates, copolymers,
acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers,
inomers, polyamides, polyamide-imides, polyacrylates,
polyatherketones, polyaryl-sulfones, polybenzimidazoles,
polycarbonates, polybutylene, terephthalates, polyether imides,
polyether sulfones, thermoplastic polyimides, thermoplastic
polyurethanes, polyphenylene sulfides, polyethylene, polypropylene,
polysulfones, polyvinylchlorides, styrene acrylonitriles,
polystyrenes, polyphenylene, ether blends, styrene maleic
anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies,
phenolics, unsaturated polyesters, bismaleimides, polyurethanes,
silicones, vinylesters, or urethane hybrids. Examples of suitable
polymers also include aliphatic or aromatic polyamide,
polyeitherimide, polysulfone, polyphenylsulfone, poly-phenylene
oxide, liquid crystalline polymer and polyketone. Examples of
suitable composites include polymers such as polyphenylsulfone
reinforced with between about 30 and about 70 wt %, and preferably
up to about 65 wt % of one or more reinforcing materials selected
from glass fiber, ceramic fiber, carbon fiber, mineral fillers,
organo nanoclay, or carbon nanotube. Preferred reinforcing
materials, such as chopped surface-treated E-glass fibers provide
flow characteristics at the above-described loadings comparable to
unfilled polymers to provide a desirable combination of strength
and flow characteristics that permit the molding of head-end
components. Composite components can be formed by machining or
injection molding. Finally, the cartridge case must retain
sufficient joint strength at cook-off temperatures. More
specifically, polymers suitable for molding of the projectile-end
component have one or more of the following properties: Yield or
tensile strength at -65.degree. F.>10,000 psi
Elongation-to-break at -65.degree. F.>15% Yield or tensile
strength at 73.degree. F.>8,000 psi Elongation-to-break at
73.degree. F.>50% Yield or tensile strength at 320.degree.
F.>4,000 psi Elongation-to-break at 320.degree. F.>80%.
Polymers suitable for molding of the middle-body component have one
or more of the following properties: Yield or tensile strength at
-65.degree. F.>10,000 psi Yield or tensile strength at
73.degree. F.>8,000 psi Yield or tensile strength at 320.degree.
F.>4,000 psi.
[0040] In one embodiment, the polymeric material additionally
includes at least one additive selected from plasticizers,
lubricants, molding agents, fillers, thermo-oxidative stabilizers,
flame-retardants, coloring agents, compatibilizers, impact
modifiers, release agents, reinforcing fibers. In still another
such embodiment, the polymeric material comprises a material
selected from the group consisting of polyphenylsulfone,
polycarbonate, and polyamide. In such an embodiment, the polymeric
material may include a translucent or transparent polymer. In
another such embodiment, the polymeric material may include a
polymeric material possessing a glass transition temperature of
less than 250.degree. C.
[0041] The polymers of the present invention can also be used for
conventional two-piece metal-plastic hybrid cartridge case designs
and conventional shotgun shell designs. One example of such a
design is an ammunition cartridge with a one-piece substantially
cylindrical polymeric cartridge casing body with an open
projectile-end and an end opposing the projectile-end with a male
or female coupling element; and a cylindrical metal cartridge
casing head-end component with an essentially closed base end with
a primer hole opposite an open end having a coupling element that
is a mate for the coupling element on the opposing end of the
polymeric cartridge casing body joining the open end of the
head-end component to the opposing end of the polymeric cartridge
casing body. The high polymer ductility permits the casing to
resist breakage.
[0042] FIGS. 2a, 2b and 2c depict a cross-sectional view of a
polymeric cartridge case according to one embodiment of the present
invention. The present invention is not limited to the described
caliber and is believed to be applicable to other calibers as well.
This includes various small and medium caliber munitions, including
5.56 mm, 7.62 mm and .50 caliber ammunition cartridges, as well as
medium/small caliber ammunition such as 380 caliber, 38 caliber, 9
mm, 10 mm, 20 mm, 25 mm, 30 mm, 40 mm, 45 caliber and the like. The
cartridges, therefore, are of a caliber between about 0.05 and
about 5 inches. Thus, the present invention is applicable to the
military industry as well as the sporting goods industry for use by
hunters and target shooters.
[0043] A cartridge casing 10 suitable for use with high velocity
rifles is shown manufactured with a casing 12 showing a propellant
chamber 14 with a projectile (not shown) inserted into the forward
end opening 16. The cartridge casing 12 has a substantially
cylindrical open-ended bullet-end component 18 extending from the
forward end opening 16 rearward to the opposite end 20. The forward
end of bullet-end component 18 has a shoulder 24 forming a chamber
neck 26. The bullet-end component 18 may be formed with coupling
end 22 formed on substantially cylindrical opposite end 20 or
formed as a separate component. These and other suitable methods
for securing individual pieces of a two-piece or multi-piece
cartridge casing are useful in the practice of the present
invention. Coupling end 22 is shown as a female element, but may
also be configured as a male element in alternate embodiments of
the invention. The forward end of bullet-end component 18 has a
shoulder 24 forming chamber neck 26. The bullet-end component
typically has a wall thickness between about 0.003 and about 0.200
inches and more preferably between about 0.005 and more preferably
between about 0.150 inches about 0.010 and about 0.050 inches.
[0044] The middle body component 28 is substantially cylindrical
and connects the forward end of bullet-end component 18 to the
substantially cylindrical opposite end 20 and forms the propellant
chamber 14. The substantially cylindrical opposite end 20 includes
a substantially cylindrical insert 32 that partially seals the
propellant chamber 14. The substantially cylindrical insert 32
includes a bottom surface 34 located in the propellant chamber 14
that is opposite a top surface 36. The substantially cylindrical
insert 32 includes a primer recess 38 positioned in the top surface
36 extending toward the bottom surface 34 with a primer flash hole
aperture 42 is located in the primer recess 38 and extends through
the bottom surface 34 into the propellant chamber 14 to combust the
propellant in the propellant chamber 14. A primer (not shown) is
located in the primer recess 38 and extends through the bottom
surface 34 into the propellant chamber 14. When molded the coupling
end 22 extends the polymer through the primer flash hole aperture
42 to form the primer flash hole 40 while retaining a passage from
the top surface 36 through the bottom surface 34 and into the
propellant chamber 14 to provide support and protection about the
primer flash hole aperture 42. The bullet-end 18, middle body 28
and bottom surface 34 define the interior of propellant chamber 14
in which the powder charge (not shown) is contained. The interior
volume of propellant chamber 14 may be varied to provide the volume
necessary for complete filling of the propellant chamber 14 by the
propellant chosen so that a simplified volumetric measure of
propellant can be utilized when loading the cartridge. The
propellant chamber 14 includes a propellant chamber insert 66 that
extends from the bottom surface 34 to the shoulder 24. The
thickness of the propellant chamber insert 66 may be defined as the
distance from the propellant chamber 14 to the interior of the
middle body component 28 and may be varied as necessary to achieve
the desired velocity depending on the propellant used. The
propellant chamber 14 includes a propellant chamber insert 66 that
extends from the bottom surface 34 to the shoulder 24 at a
graduated distance from the propellant chamber 14 to the interior
of the middle body component 28. For example, FIG. 2b shows a
propellant chamber insert 66 that is thicker in the bottom of the
propellant chamber 14 and thinner at the near the bullet-end 18.
FIG. 2c shows a propellant chamber insert 66 that is thicker in the
bottom of the propellant chamber 14 extending about half of the
middle body component 28 and thinner at the near the bullet-end
component 18 with the propellant chamber insert 66 tapering from
towards the bullet-end 18. The propellant chamber insert 66 may be
made of the same material as the casing or a different material.
The propellant chamber insert 66 may be formed by extending the
casing wall or may be made by separately forming a insert (not
shown) that is inserted into the propellant chamber 14 during
assembly.
[0045] The middle body component 28 is connected to a substantially
cylindrical coupling element 30 of the substantially cylindrical
insert 32. Coupling element 30, as shown may be configured as a
male element, however, all combinations of male and female
configurations is acceptable for coupling elements 30 and coupling
end 22 in alternate embodiments of the invention. Coupling end 22
of bullet-end component 18 fits about and engages coupling element
30 of a substantially cylindrical insert 32. The substantially
cylindrical insert 32 includes a substantially cylindrical coupling
element 30 extending from a bottom surface 34 that is opposite a
top surface 36. Located in the top surface 36 is a primer recess 38
that extends toward the bottom surface 34. A primer flash hole 40
extends through the bottom surface 34 into the propellant chamber
14. The coupling end 22 extends the polymer through the primer
flash hole aperture 42 to form an primer flash hole 40 while
retaining a passage from the top surface 36 through the bottom
surface 34 and into the propellant chamber 14 to provide support
and protection about the primer flash hole 40. When contacted the
coupling end 22 interlocks with the substantially cylindrical
coupling element 30, through the coupling element 30 that extends
with a taper to a smaller diameter at the tip 44 to form a physical
interlock between substantially cylindrical insert 32 and middle
body component 28. Polymer casing 12 also has a substantially
cylindrical open-ended middle body component 28. The middle body
component extends from a forward end opening 16 to coupling element
22. The middle body component typically has a wall thickness
between about 0.003 and about 0.200 inches and more preferably
between about 0.005 and more preferably between about 0.150 inches
about 0.010 and about 0.050 inches.
[0046] The substantially cylindrical insert 32 also has a flange 46
cut therein and a primer recess 38 formed therein for ease of
insertion of the primer (not shown). The primer recess 38 is sized
so as to receive the primer (not shown) in an friction fit during
assembly. The cartridge casing 12 may be molded from a polymer
composition with the middle body component 28 being over-molded
onto the substantially cylindrical insert 32. When over-molded the
coupling end 22 extends the polymer through the primer flash hole
aperture 42 to form the primer flash hole 40 while retaining a
passage from the top surface 36 through the bottom surface 34 and
into the propellant chamber 14 to provide support and protection
about the primer flash hole aperture 42. The primer flash hole 40
communicates through the bottom surface 34 of substantially
cylindrical insert 32 into the propellant chamber 14 so that upon
detonation of primer (not shown) the propellant (not shown) in
propellant chamber 14 will be ignited. The bullet-end component 18
and middle body component 28 can be welded or bonded together using
solvent, adhesive, spin-welding, vibration-welding,
ultrasonic-welding or laser-welding techniques. Other possible
securing methods include, but are not limited to, mechanical
interlocking methods such as over molding, press-in, ribs and
threads, adhesives, molding in place, heat crimping, ultrasonic
welding, friction welding etc.
[0047] FIG. 3 depicts cross-sectional view of a portion of the
polymeric cartridge case according to one embodiment of the present
invention. A portion of a cartridge suitable for use with high
velocity rifles is shown with a polymer casing 12 showing a
propellant chamber 14. The polymer casing 12 has a substantially
cylindrical opposite end 20. The bullet-end component 18 may be
formed with coupling end 22 formed on end 20. Coupling end 22 is
shown as a female element, but may also be configured as a male
element in alternate embodiments of the invention. The middle body
component (not shown) is connected to a substantially cylindrical
coupling element 30 of the substantially cylindrical insert 32.
Coupling element 30, as shown may be configured as a male element;
however, all combinations of male and female configurations is
acceptable for coupling elements 30 and coupling end 22 in
alternate embodiments of the invention. Coupling end 22 fits about
and engages coupling element 30 of a substantially cylindrical
insert 32. The substantially cylindrical insert 32 includes a
substantially cylindrical coupling element 30 extending from a
bottom surface 34 that is opposite a top surface 36. The propellant
chamber 14 includes a propellant chamber insert 66 that extends
from the bottom surface 34 to the shoulder 24. The thickness of the
propellant chamber insert 66 may be defined as the distance from
the propellant chamber 14 to the interior of the middle body
component 28 and may be varied as necessary to achieve the desired
volume to produce the desired velocity depending on the propellant
used. The propellant chamber insert 66 may be made of the same
material as the casing or a different material. The propellant
chamber insert 66 may be formed by extending the casing wall or may
be made by forming a separate insert that is formed and then
inserted into the propellant chamber 14 during assembly. Located in
the top surface 36 is a primer recess 38 that extends toward the
bottom surface 34. A primer flash hole 40 is located in the primer
recess 38 and extends through the bottom surface 34 into the
propellant chamber 14. The coupling end 22 extends the polymer
through the flash hole aperture 42 to form a primer flash hole 40
while retaining a passage from the top surface 36 through the
bottom surface 34 and into the propellant chamber 14 to provide
support and protection about the primer flash hole 40. When
contacted the coupling end 22 interlocks with the substantially
cylindrical coupling element 30, through the coupling element 30
that extends with a taper to a smaller diameter at the tip 44 to
form a physical interlock between substantially cylindrical insert
32 and middle body component 28. Polymer casing 12 also has a
substantially cylindrical open-ended middle body component 28.
[0048] FIGS. 4a-4h depict a top view of the polymer casing 12 with
a substantially cylindrical open-ended middle body component 28.
The polymer casing 12 includes a propellant chamber insert 66
positioned in the powder (propellant) chamber 14. The propellant
chamber insert 66 may be molded as part of the outer wall of the
polymer casing 12 or may be formed (e.g., molded, milled, etc.) as
a separate insert that is formed and positioned separately in the
powder (propellant) chamber 14. Visible is the primer flash hole 40
which extends through the bottom surface 34 to connect the primer
(not shown) to the propellant chamber 14. The propellant chamber
insert 66 may be of any shape or profile to occupy the necessary
volume in the powder (propellant) chamber 14. In addition having
any profile, the present invention may have a varied profile
throughout the casing which allows the shoulder region to have a
greater volume than the base region or to have a multistage
propellant load. In addition, the propellant chamber insert 66 may
have separate profiles in separate regions to achieve a specific
burn and specific ignition.
[0049] FIG. 5 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case displaying ribs according to one
embodiment of the present invention. The polymer casing 12 has a
substantially cylindrical opposite end 20. The bullet-end component
18 may be formed with coupling end 22 formed on substantially
cylindrical opposite end 20. Coupling end 22 is shown as a female
element, but may also be configured as a male element in alternate
embodiments of the invention. The middle body component (not shown)
is connected to a substantially cylindrical coupling element 30 of
the substantially cylindrical insert 32. The substantially
cylindrical insert 32 may be integrated into the polymer casing 12
by over-molded of the polymer, this process is known to the skilled
artisan. The substantially cylindrical insert 32 may also be
pressed into an insert aperture in the polymer casing 12. The
substantially cylindrical insert 32 may be affixed to the insert
aperture using solvent, adhesive, spin-welding, vibration-welding,
ultrasonic-welding or laser-welding techniques. Coupling element
30, as shown may be configured as a male element, however, all
combinations of male and female configurations is acceptable for
coupling elements 30 and coupling end 22 in alternate embodiments
of the invention. Coupling end 22 fits about and engages coupling
element 30 of a substantially cylindrical insert 32. The
substantially cylindrical insert 32 includes a substantially
cylindrical coupling element 30, extending from a bottom surface 34
that is opposite a top surface 36. Located in the top surface 36 is
a primer recess 38 that extends toward the bottom surface 34. A
flash hole aperture 42 extends through the bottom surface 34 into
the propellant chamber 14. The coupling end 22 extends the polymer
through the flash hole aperture 42 to form a primer flash hole 40
while retaining a passage from the top surface 36 through the
bottom surface 34 and into the propellant chamber 14 to provide
support and protection about the primer flash hole 40. The
propellant chamber 14 includes a propellant chamber insert 66 that
extends from the bottom surface 34 to the shoulder 24. The
thickness of the propellant chamber insert 66 may be defined as the
distance from the propellant chamber 14 to the interior of the
middle body component 28 and may be varied as necessary to achieve
the desired volume in the propellant camber 66 to achieve the
desired velocity depending on the propellant used. The propellant
chamber insert 66 may be made of the same material as the casing or
a different material. The propellant chamber insert 66 may be
formed by extending the casing wall or may be made by forming a
separate insert that is formed and then inserted into the
propellant chamber 14 during assembly. When contacted the coupling
end 22 interlocks with the substantially cylindrical coupling
element 30, through the coupling element 30 that extends with a
taper to a smaller diameter at the tip 44 to form a physical
interlock between substantially cylindrical insert 32 and middle
body component 28. Polymer casing 12 also has a substantially
cylindrical open-ended middle body component 28. The substantially
cylindrical opposite end 20 or anywhere within the propellant
chamber 14 may include one or more ribs 48 on the surface. The
number of ribs 48 will depend on the specific application and
desire of the manufacture but may include 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, or more ribs. In the counter bore, the polymer was having
difficulty filling this area due to the fact that the polymer used
has fillers in it, and needed to be reblended during molding. One
embodiment includes six ribs 48 to create turbulence in the flow of
the polymer, thus allowing the material to fill the counter
bore.
[0050] FIG. 6 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case displaying ribs according to one
embodiment of the present invention. One embodiment that reduces
bellowing of the insert includes a shortened insert and angled
coupling element 30 inside of the insert. In addition, the raised
portion of the polymer at the primer flash hole 40 was removed, the
internal polymer wall was lowered and angled to match the insert
and the internal ribs were lengthened. The polymer casing 12 has a
substantially cylindrical opposite end 20. The bullet-end component
18 may be formed with coupling end 22 formed on end 20. Coupling
end 22 is shown as a female element, but may also be configured as
a male element in alternate embodiments of the invention. The
middle body component (not shown) is connected to a substantially
cylindrical coupling element 30 of the substantially cylindrical
insert 32. Coupling element 30, as shown may be configured as a
male element, however, all combinations of male and female
configurations is acceptable for coupling elements 30 and coupling
end 22 in alternate embodiments of the invention. Coupling end 22
fits about and engages coupling element 30 of a substantially
cylindrical insert 32. The substantially cylindrical insert 32
includes a substantially cylindrical coupling element 30 extending
from a bottom surface 34 that is opposite a top surface 36. Located
in the top surface 36 is a primer recess 38 that extends toward the
bottom surface 34. A flash hole aperture 42 extends through the
bottom surface 34 into the propellant chamber 14. The coupling end
22 extends the polymer through the primer flash hole 40 to form an
aperture coating 42 while retaining a passage from the top surface
36 through the bottom surface 34 and into the propellant chamber 14
to provide support and protection about the primer flash hole 40.
The propellant chamber 14 includes a propellant chamber insert 66
that extends from the bottom surface 34 to the shoulder 24. The
thickness of the propellant chamber insert 66 may be defined as the
distance from the propellant chamber 14 to the interior of the
middle body component 28 and may be varied as necessary to achieve
the desired velocity depending on the propellant used. The
propellant chamber insert 66 may be made of the same material as
the casing or a different material. The propellant chamber insert
66 may be formed by extending the casing wall or may be made by
forming a separate insert that is formed and then inserted into the
propellant chamber 14 during assembly. When contacted the coupling
end 22 interlocks with the substantially cylindrical coupling
element 30, through the coupling element 30 that extends with a
taper to a smaller diameter at the tip 44 to form a physical
interlock between substantially cylindrical insert 32 and middle
body component 28. Polymer casing 12 also has a substantially
cylindrical open-ended middle body component 28. The substantially
cylindrical opposite end 20 or anywhere within the propellant
chamber 14 may include one or more ribs 48 on the surface. The
number of ribs 48 will depend on the specific application and
desire of the manufacture but may include 1, 2, 3, 4, 5, 6, 7, 8,
9, 10, or more ribs. In the counter bore, the polymer was having
difficulty filling this area due to the fact that the polymer used
has fillers in it, and needed to be reblended during molding. One
embodiment includes six ribs 48 to create turbulence in the flow of
the polymer, thus allowing the material to fill the counter bore.
Another embodiment of the instant invention is a shortened insert
and angled coupling element 30 inside of the insert. In addition,
raised portions of the polymer at the flash hole 40, lowered and
angled the internal polymer wall to match the insert and lengthened
the internal ribs.
[0051] FIG. 7 depicts a side, cross-sectional view of a polymeric
cartridge case having a diffuser according to one embodiment of the
present invention. The diffuser 50 is a device that is used to
divert the affects of the primer off of the polymer and directing
it to the flash hole 40. The affects being the impact from igniting
the primer as far as pressure and heat. A cartridge 10 suitable for
use with high velocity rifles is shown manufactured with a polymer
casing 12 showing a propellant chamber 14 with projectile (not
shown) inserted into the forward end opening 16. Polymer casing 12
has a substantially cylindrical open-ended polymeric bullet-end
component 18 extending from forward end opening 16 rearward to the
opposite end 20. The bullet-end component 18 may be formed with
coupling end 22 formed on end 20. Coupling end 22 is shown as a
female element, but may also be configured as a male element in
alternate embodiments of the invention. The forward end of
bullet-end component 18 has a shoulder 24 forming chamber neck
26.
[0052] The middle body component 28 is connected to a substantially
cylindrical coupling element 30 of the substantially cylindrical
insert 32. Coupling element 30, as shown may be configured as a
male element, however, all combinations of male and female
configurations is acceptable for coupling elements 30 and coupling
end 22 in alternate embodiments of the invention. Coupling end 22
of bullet-end component 18 fits about and engages coupling element
30 of a substantially cylindrical insert 32. The substantially
cylindrical insert 32 includes a substantially cylindrical coupling
element 30 extending from a bottom surface 34 that is opposite a
top surface 36. Located in the top surface 36 is a primer recess 38
that extends toward the bottom surface 34. A flash hole aperture 42
extends through the bottom surface 34 into the propellant chamber
14. The coupling end 22 extends the polymer through the primer
flash hole 40 to form an aperture coating 42 while retaining a
passage from the top surface 36 through the bottom surface 34 and
into the propellant chamber 14 to provides support and protection
about the primer flash hole 40. The propellant chamber 14 includes
a propellant chamber insert 66 that extends from the bottom surface
34 to the shoulder 24. The thickness of the propellant chamber
insert 66 may be defined as the distance from the propellant
chamber 14 to the interior of the middle body component 28 and may
be varied as necessary to achieve the desired velocity depending on
the propellant used. The propellant chamber insert 66 may be made
of the same material as the casing or a different material. The
propellant chamber insert 66 may be formed by extending the casing
wall or may be made by forming a separate insert that is formed and
then inserted into the propellant chamber 14 during assembly. When
contacted the coupling end 22 interlocks with the substantially
cylindrical coupling element 30, through the coupling element 30
that extends with a taper to a smaller diameter at the tip 44 to
form a physical interlock between substantially cylindrical insert
32 and middle body component 28. Polymer casing 12 also has a
substantially cylindrical open-ended middle body component 28. The
middle body component extends from a forward end opening 16 to
coupling element 22. Located in the top surface 36 is a primer
recess 38 that extends toward the bottom surface 34 with a diffuser
50 positioned in the primer recess 38. The diffuser 50 includes a
diffuser aperture 52 that aligns with the primer flash hole 40. The
diffuser 50 is a device that is used to divert the affects of the
primer (not shown) off of the polymer. The affects being the impact
from igniting the primer as far as pressure and heat to divert the
energy of the primer off of the polymer and directing it to the
flash hole.
[0053] FIG. 8 depicts a side, cross-sectional view of a portion of
the polymeric cartridge case having a diffuser 50 according to one
embodiment of the present invention. A portion of a cartridge
suitable for use with high velocity rifles is shown manufactured
with a polymer casing 12 showing a propellant chamber 14. Polymer
casing 12 has a substantially cylindrical opposite end 20. The
bullet-end component 18 may be formed with coupling end 22 formed
on end 20. Coupling end 22 is shown as a female element, but may
also be configured as a male element in alternate embodiments of
the invention. The middle body component (not shown) is connected
to a substantially cylindrical coupling element 30 of the
substantially cylindrical insert 32. Coupling element 30, as shown
may be configured as a male element, however, all combinations of
male and female configurations is acceptable for coupling elements
30 and coupling end 22 in alternate embodiments of the invention.
Coupling end 22 fits about and engages coupling element 30 of a
substantially cylindrical insert 32. The substantially cylindrical
insert 32 includes a substantially cylindrical coupling element 30
extending from a bottom surface 34 that is opposite a top surface
36. Located in the top surface 36 is a primer recess 38 that
extends toward the bottom surface 34. A flash hole aperture 42
extends through the bottom surface 34 into the propellant chamber
14. The propellant chamber 14 includes a propellant chamber insert
66 that extends from the bottom surface 34 to the shoulder 24. The
thickness of the propellant chamber insert 66 may be defined as the
distance from the propellant chamber 14 to the interior of the
middle body component 28 and may be varied as necessary to achieve
the desired velocity depending on the propellant used. The
propellant chamber insert 66 may be made of the same material as
the casing or a different material. The propellant chamber insert
66 may be formed by extending the casing wall or may be made by
forming a separate insert that is formed and then inserted into the
propellant chamber 14 during assembly. The coupling end 22 extends
the polymer through the primer flash hole aperture 42 to form a
primer flash hole 40 while retaining a passage from the top surface
36 through the bottom surface 34 and into the propellant chamber 14
to provides support and protection about the primer flash hole 40.
When contacted the coupling end 22 interlocks with the
substantially cylindrical coupling element 30, through the coupling
element 30 that extends with a taper to a smaller diameter at the
tip 44 to form a physical interlock between substantially
cylindrical insert 32 and middle body component 28. Polymer casing
12 also has a substantially cylindrical open-ended middle body
component 28. Located in the top surface 36 is a primer recess 38
that extends toward the bottom surface 34 with a diffuser 50
positioned in the primer recess 38. The diffuser 50 includes a
diffuser aperture 52 and a diffuser aperture extension 54 that
aligns with the primer flash hole 40. The diffuser 50 is a device
that is used to divert the affects of the primer (not shown) off of
the polymer. The affects being the impact from igniting the primer
as far as pressure and heat to divert the energy of the primer off
of the polymer and directing it to the flash hole 40. The diffuser
50 can be between 0.004 to 0.010 inches in thickness and made from
half hard brass. For example, the diffuser 50 can be between 0.005
inches thick for a 5.56 diffuser 50. The OD of the diffuser for a
5.56 or 223 case is 0.173 and the ID is 0.080. The diffuser could
be made of any material that can withstand the energy from the
ignition of the primer. This would include steel, stainless,
cooper, aluminum or even an engineered resin that was injection
molded or stamped. The diffuser can be produce in T shape by
drawing the material with a stamping and draw die. In the T shape
diffuser the center ring can be 0.005 to 0.010 tall and the OD is
0.090 and the ID 0.080.
[0054] FIGS. 9a-9h depict different embodiment of the diffuser of
the present invention.
[0055] FIGS. 10a and 10b depict a cross-sectional view of a
polymeric cartridge case having a reduced propellant chamber volume
according to one embodiment of the present invention. A cartridge
casing 10 shows a casing 12 showing a propellant chamber 14 with a
projectile (not shown) inserted into the forward end opening 16.
The cartridge casing 12 has a substantially cylindrical open-ended
bullet-end component 18 extending from the forward end opening 16
rearward to the opposite end 20. The forward end of bullet-end
component 18 has a shoulder 24 forming a chamber neck 26. The
bullet-end component 18 may be formed with coupling end 22 formed
on substantially cylindrical opposite end 20 or formed as a
separate component. The bullet-end, middle body component 28,
bullet (not shown) and other casing components can then be welded
or bonded together using solvent, adhesive, spin-welding,
vibration-welding, ultrasonic-welding or laser-welding techniques.
The welding or bonding increases the joint strength so the casing
can be extracted from the hot gun after firing at the cook-off
temperature. Other possible securing methods include, but are not
limited to, mechanical interlocking methods such as ribs and
threads, adhesives, molding in place, heat crimping, ultrasonic
welding, friction welding etc. These and other suitable methods for
securing individual pieces of a two-piece or multi-piece cartridge
casing are useful in the practice of the present invention.
Coupling end 22 is shown as a female element, but may also be
configured as a male element in alternate embodiments of the
invention. The forward end of bullet-end component 18 has a
shoulder 24 forming chamber neck 26. The bullet-end component
typically has a wall thickness between about 0.003 and about 0.200
inches and more preferably between about 0.005 and about 0.150
inches and more preferably between about 0.010 and about 0.050
inches. The middle body component 28 is substantially cylindrical
and connects the forward end of bullet-end component 18 to the
substantially cylindrical opposite end 20 and forms the propellant
chamber 14. The substantially cylindrical opposite end 20 includes
a substantially cylindrical insert 32 that partially seals the
propellant chamber 14. The substantially cylindrical insert 32
includes a bottom surface 34 located in the propellant chamber 14
that is opposite a top surface 36. The substantially cylindrical
insert 32 includes a primer recess 38 positioned in the top surface
36 extending toward the bottom surface 34 with a primer flash hole
aperture 42 is located in the primer recess 38 and extends through
the bottom surface 34 into the propellant chamber 14 to combust the
propellant in the propellant chamber 14. A primer (not shown) is
located in the primer recess 38 and extends through the bottom
surface 34 into the propellant chamber 14. When molded the coupling
end 22 extends the polymer through the primer flash hole aperture
42 to form the primer flash hole 40 while retaining a passage from
the top surface 36 through the bottom surface 34 and into the
propellant chamber 14 to provide support and protection about the
primer flash hole aperture 42. The bullet-end 18, middle body 28
and bottom surface 34 define the interior of propellant chamber 14
in which the powder charge (not shown) is contained. The interior
volume of propellant chamber 14 may be varied to provide the volume
necessary for complete filling of the propellant chamber 14 by the
propellant chosen so that a simplified volumetric measure of
propellant can be utilized when loading the cartridge. The
propellant chamber 14 includes a propellant chamber insert 66 that
extends from the bottom surface 34 to the shoulder 24. The
thickness of the propellant chamber insert 66 may be defined as the
distance from the propellant chamber 14 to the interior of the
middle body component 28 and may be varied as necessary to achieve
the desired velocity depending on the propellant used. The
propellant chamber 14 includes a propellant chamber insert 66 that
extends from the bottom surface 34 to the shoulder 24 at a
graduated distance from the propellant chamber 14 to the interior
of the middle body component 28. For example, FIG. 10a shows a
propellant chamber insert 66 extends from the bottom of the
polymeric cartridge case 12 toward the shoulder 24. This includes
an extended primer flash hole 40 that connects the primer recess 38
and the propellant chamber 14. The propellant chamber insert 66 may
include a burn tube extension 70 that sits above the propellant
chamber bottom 72 of the propellant chamber 14. FIG. 10b shows a
polymeric cartridge case having a 2 piece insert. The propellant
chamber 14 has a first propellant chamber insert 66a that extends
from the polymeric cartridge case 12 toward the shoulder 24 ending
at any point between the primer recess 38 and the shoulder 24. The
first propellant chamber insert 66a extends about half way the
polymeric cartridge case 12 to form the propellant chamber bottom
72 of the propellant chamber 14. A second propellant chamber insert
66b extends from the propellant chamber bottom 72 toward the
shoulder 24. The first propellant chamber insert 66a and the second
propellant chamber insert 66b may be of similar or different
materials and have similar or different thicknesses to form
propellant chamber 14 of different volumes. The propellant chamber
insert 66 may be formed by extending the casing wall or may be made
by forming a separate insert (not shown) that is formed and then
inserted into the propellant chamber 14 during assembly.
[0056] The substantially cylindrical insert 32 also has a flange 46
cut therein and a primer recess 38 formed therein for ease of
insertion of the primer (not shown). The primer recess 38 is sized
so as to receive the primer (not shown) in an interference fit
during assembly. The cartridge casing 12 may be molded from a
polymer composition with the middle body component 28 being
over-molded onto the substantially cylindrical insert 32. When
over-molded the coupling end 22 extends the polymer through the
primer flash hole aperture 42 to form the primer flash hole 40
while retaining a passage from the top surface 36 through the
bottom surface 34 and into the propellant chamber 14 to provide
support and protection about the primer flash hole aperture 42. The
primer flash hole 40 communicates through the bottom surface 34 of
substantially cylindrical insert 32 into the propellant chamber 14
so that upon detonation of primer (not shown) the propellant (not
shown) in propellant chamber 14 will be ignited. The bullet-end
component 18 and middle body component 28 can be welded or bonded
together using solvent, adhesive, spin-welding, vibration-welding,
ultrasonic-welding or laser-welding techniques.
[0057] The middle body component 28 is connected to a substantially
cylindrical coupling element 30 of the substantially cylindrical
insert 32. Coupling element 30, as shown may be configured as a
male element, however, all combinations of male and female
configurations is acceptable for coupling elements 30 and coupling
end 22 in alternate embodiments of the invention. Coupling end 22
of bullet-end component 18 fits about and engages coupling element
30 of a substantially cylindrical insert 32. The substantially
cylindrical insert 32 includes a substantially cylindrical coupling
element 30 extending from a bottom surface 34 that is opposite a
top surface 36. Located in the top surface 36 is a primer recess 38
that extends toward the bottom surface 34. A primer flash hole 40
extends through the bottom surface 34 into the propellant chamber
14. The coupling end 22 extends the polymer through the flash hole
aperture 42 to form a primer flash hole 40 while retaining a
passage from the top surface 36 through the bottom surface 34 and
into the propellant chamber 14. When contacted the coupling end 22
interlocks with the substantially cylindrical coupling element 30,
through the coupling element 30 that extends with a taper to a
smaller diameter at the tip 44 to form a physical interlock between
substantially cylindrical insert 32 and middle body component 28.
Polymer casing 12 also has a substantially cylindrical open-ended
middle body component 28. The middle body component extends from a
forward end opening 16 to coupling element 22. The middle body
component typically has a wall thickness between about 0.003 and
about 0.200 inches and more preferably between about 0.005 and more
preferably between about 0.150 inches about 0.010 and about 0.050
inches.
[0058] It is understood that the propellant chamber insert 66 can
be of any geometry and profile to reduce the propellant chamber
volume. The propellant chamber insert 66 may be uniformed in the
geometry and profile or may vary in geometry, profile or both to
achieve the desired burn and propellant chamber volume. In
addition, the propellant chamber insert can be formed
simultaneously with the case by over-molding or machining or can be
prepared separate from the case and assembled sequentially. The
propellant chamber insert 66 can be bonded, welded or otherwise
affixed to the case.
[0059] One embodiment includes a 2 cavity mold having an upper
portion and a base portion for a 5.56 case having a metal insert
over-molded with a Nylon 6 (polymer) based material. In this
embodiment, the polymer in the base forms a lip or flange to
extract the case from the weapon. One 2-cavity mold to produce the
upper portion of the 5.56 case can be made using a stripper plate
tool using an Osco hot spur and two subgates per cavity. Another
embodiment includes a subsonic version, the difference from the
standard and the subsonic version is the walls are thicker thus
requiring less powder to decrease the velocity of the bullet
creating a subsonic round.
[0060] The extracting inserts is used to give the polymer case a
tough enough ridge and groove for the weapons extractor to grab and
pull the case out the chamber of the gun. The extracting insert is
made of 17-4 SS that is hardened to 42-45 rc. The insert may be
made of aluminum, brass, cooper, steel or even an engineered resin
with enough tensile strength.
[0061] The insert is over molded in an injection molded process
using a nano clay particle filled Nylon material. The inserts can
be machined or stamped. In addition, an engineered resin able to
withstand the demand on the insert allows injection molded and/or
even transfer molded.
[0062] One of ordinary skill in the art will know that many
propellant types and weights can be used to prepare workable
ammunition and that such loads may be determined by a careful trial
including initial low quantity loading of a given propellant and
the well known stepwise increasing of a given propellant loading
until a maximum acceptable load is achieved. Extreme care and
caution is advised in evaluating new loads. The propellants
available have various burn rates and must be carefully chosen so
that a safe load is devised.
[0063] It will be understood that particular embodiments described
herein are shown by way of illustration and not as limitations of
the invention. The principal features of this invention can be
employed in various embodiments without departing from the scope of
the invention. Those skilled in the art will recognize, or be able
to ascertain using no more than routine experimentation, numerous
equivalents to the specific procedures described herein. Such
equivalents are considered to be within the scope of this invention
and are covered by the claims.
[0064] All publications and patent applications mentioned in the
specification are indicative of the level of skill of those skilled
in the art to which this invention pertains. All publications and
patent applications are herein incorporated by reference to the
same extent as if each individual publication or patent application
was specifically and individually indicated to be incorporated by
reference.
[0065] The use of the word "a" or "an" when used in conjunction
with the term "comprising" in the claims and/or the specification
may mean "one," but it is also consistent with the meaning of "one
or more," "at least one," and "one or more than one." The use of
the term "or" in the claims is used to mean "and/or" unless
explicitly indicated to refer to alternatives only or the
alternatives are mutually exclusive, although the disclosure
supports a definition that refers to only alternatives and
"and/or." Throughout this application, the term "about" is used to
indicate that a value includes the inherent variation of error for
the device, the method being employed to determine the value, or
the variation that exists among the study subjects.
[0066] As used in this specification and claim(s), the words
"comprising" (and any form of comprising, such as "comprise" and
"comprises"), "having" (and any form of having, such as "have" and
"has"), "including" (and any form of including, such as "includes"
and "include") or "containing" (and any form of containing, such as
"contains" and "contain") are inclusive or open-ended and do not
exclude additional, unrecited elements or method steps.
[0067] The term "or combinations thereof" as used herein refers to
all permutations and combinations of the listed items preceding the
term. For example, "A, B, C, or combinations thereof" is intended
to include at least one of: A, B, C, AB, AC, BC, or ABC, and if
order is important in a particular context, also BA, CA, CB, CBA,
BCA, ACB, BAC, or CAB. Continuing with this example, expressly
included are combinations that contain repeats of one or more item
or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so
forth. The skilled artisan will understand that typically there is
no limit on the number of items or terms in any combination, unless
otherwise apparent from the context.
[0068] All of the compositions and/or methods disclosed and claimed
herein can be made and executed without undue experimentation in
light of the present disclosure. While the compositions and methods
of this invention have been described in terms of preferred
embodiments, it will be apparent to those of skill in the art that
variations may be applied to the compositions and/or methods and in
the steps or in the sequence of steps of the method described
herein without departing from the concept, spirit and scope of the
invention. All such similar substitutes and modifications apparent
to those skilled in the art are deemed to be within the spirit,
scope and concept of the invention as defined by the appended
claims.
* * * * *