U.S. patent application number 13/160171 was filed with the patent office on 2012-12-20 for muzzle loader powder increment using celluloid combustible container.
This patent application is currently assigned to ALLIANT TECHSYSTEMS INC.. Invention is credited to Sandra L. Case, Benjamin R. Vaughan, William J. Worrell.
Application Number | 20120318123 13/160171 |
Document ID | / |
Family ID | 45541084 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120318123 |
Kind Code |
A1 |
Worrell; William J. ; et
al. |
December 20, 2012 |
Muzzle Loader Powder Increment using Celluloid Combustible
Container
Abstract
An encapsulated propellant charge comprised a sealed combustible
container comprised of a consumable material and having a
substantially cylindrical shape. The sealed combustible container
comprises a top wall, a bottom wall, and a side wall therebetween.
The top wall, the bottom wall and the side wall define a chamber;
which contains a propellant composition.
Inventors: |
Worrell; William J.;
(Draper, VA) ; Vaughan; Benjamin R.; (Blacksburg,
VA) ; Case; Sandra L.; (Blacksburg, VA) |
Assignee: |
ALLIANT TECHSYSTEMS INC.
Minneapolis
MN
|
Family ID: |
45541084 |
Appl. No.: |
13/160171 |
Filed: |
June 14, 2011 |
Current U.S.
Class: |
86/10 ;
102/431 |
Current CPC
Class: |
F42B 5/38 20130101; F42B
5/192 20130101; F42B 30/12 20130101; F42B 5/18 20130101; F42B 5/188
20130101 |
Class at
Publication: |
86/10 ;
102/431 |
International
Class: |
F42B 33/02 20060101
F42B033/02; F42B 5/192 20060101 F42B005/192 |
Claims
1. A propellant charge comprising a sealed combustible container
comprised of a consumable material and having a generally
cylindrical shape, the sealed combustible container comprising a
top wall, a bottom wall, and a side wall therebetween; the top
wall, the bottom wall and the side wall defining a chamber; wherein
the chamber contains a measured amount of propellant composition,
wherein the propellant composition is a different material than the
consumable material.
2. The propellant charge of claim 1, wherein the consumable
material is a foamed celluloid.
3. The propellant charge of claim 1, wherein the side wall has a
thickness of less than 0.05 inches.
4. The propellant charge of claim 1, wherein the propellant
composition is selected from the group consisting of: smokeless
propellant, single base nitrocellulose, nitrocellulose propellant,
black powder propellant, pyrotechnic propellant, non-pyrotechnic
propellant, and any combination thereof.
5. The propellant charge of claim 1, wherein the sealed combustible
container has a length that is greater than its diameter.
6. The propellant charge of claim 5, wherein the ratio of the
length of the sealed combustible container to the diameter of the
sealed combustible container is at least 2:1.
7. The propellant charge of claim 5, wherein the ratio of the
length of the sealed combustible container to the diameter of the
combustible is at least 3:1.
8. The propellant charge of claim 1, wherein the consumable
material is water resistant.
9. A muzzle-loader ammunition round comprising: a bullet held in
place with a sabot; and at least one propellant charge engaged with
the sabot, the at least one propellant charge having an outer wall
constructed from a consumable material, the outer wall defining a
chamber that is at least partially filled with at least one
propellant composition having a charge weight, wherein the
propellant composition is a different material than the consumable
material.
10. The propellant charge of claim 1, wherein the outer wall is
water resistant.
11. The propellant charge of claim 1, wherein the consumable
material is a foamed celluloid.
12. The propellant charge of claim 1, wherein the propellant
composition is selected from the group consisting of smokeless
propellant, single base nitrocellulose, nitrocellulose propellant,
black powder propellant, pyrotechnic propellant, non-pyrotechnic
propellant, and any combination thereof.
13. A method of manufacturing a propellant charge comprising:
forming a cylinder of a desired diameter from a sheet of consumable
material, the sheet having sides and ends, wherein the sides of the
sheet are adhered to each other and the cylinder has an open end;
at least partially filling a chamber defined by the cylinder with a
propellant composition; sealing the open end of the cylinder by
adhering a circular disc to the open end.
14. The method of claim 12, wherein the consumable material is a
foamed celluloid.
15. The method of claim 12, wherein the propellant composition is
selected from the group consisting of: smokeless propellant, single
base nitrocellulose, nitrocellulose propellant, black powder
propellant, pyrotechnic propellant, non-pyrotechnic propellant, and
any combination thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable
BACKGROUND OF THE INVENTION
[0003] The present invention generally relates to ammunition for
muzzle-loader firearms, and more particularly to propellant charges
having a consumable cartridge case. Some embodiments are directed
to the manufacture and methods of use of such devices.
[0004] In muzzle-loader firearms, multiple ammunition components
are loaded from the open end of the barrel. These multiple
components include at least a propellant charge and projectile. The
propellant charges comprise an amount of black powder, black powder
substitutes, and smokeless gunpowder. The projectile typically
comprises a bullet and a sabot. In some instances, the projectile
and the propellant charge are inserted into the barrel as a unitary
structure. Alternatively, the propellant charge is loaded
separately from the projectile. In such instances, the propellant
charge is loaded first into the barrel, followed by the sabot and
the bullet.
[0005] The propellant charges are loaded into the barrel either in
a granular form or in a compacted or consolidated pellet. The
pellet allows for a simple, accurate and precise measurement of the
propellant. U.S. Pat. Nos. 5,726,378 and 6,688,232, incorporated by
reference in their entireties herein, describe exemplary pellets.
In either the granular form or the pellet, the propellant is
susceptible to moisture absorption and other environmental effects
that can result in undesirable ballistic variation and corrosion of
the firearm barrel and chamber.
[0006] The art referred to and/or described above is not intended
to constitute an admission that any patent, publication or other
information referred to herein is "prior art" with respect to this
invention. In addition, this section should not be construed to
mean that a search has been made or that no other pertinent
information as defined in 37 C.F.R. .sctn.1.56(a) exists. All U.S.
patents and applications and all other published documents
mentioned anywhere in this application are incorporated herein by
reference in their entirety.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention prevents exposure of the propellant to
moisture and other environmental effects with enhanced ignition and
ballistic reproducibility capabilities. A propellant charge
comprises a sealed combustible container comprised of a consumable
material and having a substantially cylindrically shape. The sealed
combustible container comprises a top wall, a bottom wall, and a
side wall therebetween. The top wall, the bottom wall and the side
wall define a chamber; wherein the chamber contains a propellant
composition. In at least one embodiment, the consumable material is
a foamed celluloid. In at least one embodiment, the propellant
composition is selected from the group consisting of: smokeless
propellant, single base nitrocellulose, nitrocellulose propellant,
black powder propellant, pyrotechnic propellant, non-pyrotechnic
propellant, and any combination thereof.
[0008] In at least one embodiment, an ammunition round for a
muzzle-loader is provided. The ammunition round comprises a bullet
and at least one propellant charge having an outer wall constructed
from a consumable material. The outer wall defines a chamber that
is at least partially filled with at least one propellant
composition having a charge weight.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0009] FIG. 1 is a cross-sectional view of the muzzle of a
muzzle-loader firearm with ammunition using the encapsulated
propellant charge of the present invention.
[0010] FIG. 2 is a cross-sectional view of the encapsulated
propellant charge shown in FIG. 1.
[0011] FIG. 3 shows an embodiment of the encapsulated propellant
charge.
[0012] FIG. 4 shows an embodiment of the encapsulated propellant
charge.
[0013] FIGS. 5A-5F show an embodiment of the manufacturing process
of the propellant charge.
DETAILED DESCRIPTION OF THE INVENTION
[0014] This invention contemplates a number of embodiments where
any one, any combination of some, or all of the embodiments can be
incorporated into ammunition. In addition, this invention
contemplates a number of embodiments where any one, any combination
of some, or all of the embodiments can be incorporated into a
method of using such ammunition.
[0015] Referring now to FIG. 1, there is shown an embodiment of the
invention featuring a muzzle-loaded ammunition round 100 having a
bullet 102, a sabot 104, and at least one encapsulated propellant
charge 106 loaded into a barrel 108 of a firearm. The bullet 102 is
held in place at one end by sabot 104, which in turn is engaged
with an encapsulated propellant charge 106. For purposes of this
application, the definition of the term "bullet" is a projectile
fired by a firearm intended and designed for the purpose of
striking a target. Bullets include saboted bullets, full bore
non-saboted bullets, and shotgun shot. Bullets do not include
sabot, wads, propellant, cartridge cases, compressed gas, or any
other material ejected from the barrel of a fired firearm other
than the projectile missile intended and designed to strike a
target.
[0016] Depending on the propellant requirements for a given
muzzle-loaded firearm, the ammunition round can include one or more
than one encapsulated propellant charge 106. In the embodiment
shown in FIG. 1, the ammunition round 100 includes two encapsulated
propellant charges 106a and 106b. As shown in FIG. 1, each
propellant charge 106 has a capsule 110 having a wall 112 that
defines a chamber 114 containing a propellant 116. In at least one
embodiment, the capsule 110 is cylindrical. In at least one
embodiment, the capsule 110 has a rigid construction. In at least
one embodiment, the wall 112 of capsule 110 is formed from a
consumable material having sufficient energy or burning rate for
muzzle loader applications. In at least one embodiment, the
consumable material is a foamed celluloid. In at least one
embodiment, the consumable material is a felted nitrocellulose. In
some embodiments, the consumable material is selected from the
group consisting of molded energetic thermoplastic elastomers and
non-energetic thermoplastics filed with an energetic solid, such as
nitramines and other energetic solids. In at least one embodiment,
the consumable material is different than the propellant 116. In at
least one embodiment, the consumable material is water
resistant.
[0017] The propellant 116 is selected from the group consisting of
smokeless propellant, single base nitrocellulose, nitrocellulose
propellant, black powder propellant, pyrotechnic propellant,
non-pyrotechnic propellant, and any combination thereof. In at
least one embodiment, the chamber 114 is substantially filled with
the propellant 116.
[0018] In at least one embodiment, the ammunition round 100 is
constructed and arranged with its rear portion positioned facing a
breech block part of the muzzle loading firearm when loaded into a
firearm. In some embodiments (such as the embodiment shown in FIG.
1), when loaded into the firearm, at least one encapsulated
propellant charge 106 is engaged with the sabot 104 and at least
one encapsulated propellant charge 106 is engaged with a portion of
the breech block of the firearm. As shown in FIG. 1, when loaded
into the firearm, the first encapsulated propellant charge 106a is
engaged with the sabot 104 and the second encapsulated propellant
charge 106b is engaged with the first encapsulated propellant
charge 106a.
[0019] In at least one embodiment, the ammunition round is
constructed and arranged to be used in combination with a primer or
igniter separately positioned within a firearm barrel. When the
firearm is triggered, a hammer strikes the primer material which
ignites the primer material, resulting in an expulsion of a high
temperature energetic jet of combustion products that penetrates
the end of the capsule to ignite the encapsulated propellant
charge. In other embodiments of the invention, the breech block
penetrates an end of the capsule 110 of the encapsulated propellant
charge 106 with a probe 120 or bayonet having a sharp point that
forms a hole which allows hot materials from the ignited primer to
enter the chamber 114 and ignite the propellant 116. The probe 120
can be tubular with a conical tip, can be conical, can be serrated,
or can be any combination thereof, or can be of any shape known in
the art. The ignition of the first encapsulated propellant charge
106a will ignite the second encapsulated propellant charge 106b.
Ignition of the encapsulated propellant charges 106 provides the
energy that propels the bullet 102 at a target. The capsule 110,
which in at least one embodiment comprises a consumable material,
is entirely consumed following ignition such that no portion of the
capsule 110 remains.
[0020] FIG. 2 shows a cross-section of the encapsulated propellant
charge 106 with capsule 110 having wall 112 that defines chamber
114. The wall 112 comprises a top wall 122, a bottom wall 124, and
a side wall 126 that define the chamber 114. The chamber 114
contains propellant 116. In at least one embodiment, the chamber
114 contains a measured amount of propellant, sometimes referred to
as a propellant charge with a charge weight. In an exemplary
embodiment, where the propellant charge 106 is used in a
.50-caliber muzzle-loader firearm, the chamber contains propellant
with a charge weight between about 30 and 100 grains, preferably
between about 30 and 50 grains. In other embodiments, the chamber
114 contains an appropriate amount of propellant depending on the
caliber of the weapon and other factors. In at least one
embodiment, the chamber 114 is substantially filled with propellant
116. In at least one embodiment, the chamber 114 is partially
filled with propellant 116. The encapsulated propellant charge 106
is therefore provided in an easy to load and handle form, with in
some embodiments a known amount of propellant, while protecting the
propellant from moisture absorption and being a fully consumable
charge.
[0021] In at least one embodiment, the capsule 110 has an axial
length L that is greater than its diameter D. In at least one
embodiment, the axial length L is twice the diameter D. In at least
one embodiment, the axial length is at least three times the
diameter D. In some embodiments, the wall thickness is dependent
upon the caliber of the firearm being used. In some embodiments,
the side wall 126 is thin-walled. In at least one embodiment, the
thin-walled side wall 126 has a thickness of less than 0.05 inches
(1.27 mm). In at least one embodiment, the side wall 126 has a
thickness of between about 0.01 inches (0.254 mm) and 0.03 inches
(0.762 mm). In at least one embodiment, the top wall 122 has a
thickness of less than 0.05 inches (1.27 mm). In at least one
embodiment, the top wall 122 has a thickness of between about 0.01
inches (0.254 mm) and 0.03 inches (0.762 mm). In at least one
embodiment, the bottom wall 124 has a thickness of less than 0.05
inches (1.27 mm). In at least one embodiment, the bottom wall 124
has a thickness of between about 0.01 inches (0.254 mm) and 0.03
inches (0.762 mm).
[0022] In at least one embodiment, the diameter of the capsule is
constant along the length of the capsule. In other embodiments, the
diameter of the capsule tapers from a first end to a second end of
the capsule. In one embodiment, the bottom wall 124 has an outer
diameter that is tapered, as shown in FIG. 2. In other embodiments,
the bottom wall 124 has a constant diameter.
[0023] In at least one embodiment, the capsule has flat ends formed
by the top wall and the bottom wall. In other embodiments, the
capsule can have an arcuate surface at one end of the capsule. In
another embodiment, the capsule can have an arcuate surface at each
end of the capsule. FIGS. 3 & 4 show exemplary embodiments with
arcuate surfaces forming either or both of the top wall 122 and the
bottom wall 124. The embodiments shown in FIGS. 3 & 4 also have
a two part construction, where a cap 129 forms at least one of
either the top wall 122 or the bottom wall 124.
[0024] To manufacture the encapsulated propellant charge 106, in
one embodiment, the capsule 110 is made using a thermoforming
process. In at least one embodiment shown in FIG. 5A, a sheet 130
of the consumable material having sides 132 and ends 134 is heated
to a predetermined softening temperature. In at least one
embodiment, the consumable material is a foamed celluloid material.
This material forms a hard, plastic capsule when thermoformed.
[0025] As shown in FIG. 5B, the sheet 130 is then stretched about a
cylindrical form 140 (such as a die or a mandrel) of the desired
diameter using a vacuum to form at least the side wall 126. In at
least one embodiment, the ends 134 of the sheet have a length that
is shorter than the sides 132 of the sheet. In some embodiments,
vacuum pressure is then used to pull the softened sheet of
consumable material into the desired cylindrical shape. In at least
one embodiment, after the vacuum pressure has been applied, a
second die can be used to finalize the cylinder into the desired
cylindrical shape.
[0026] In some embodiments, the sides of the sheet are fastened
together in the cylindrical shape with an adhesive 150 forming the
side wall 126, as shown in FIG. 5C. In at least one embodiment, the
adhesive is cyanoacrylate, but other suitable adhesives may be
used. In another embodiment, the sides are welded together using
sonic welding, solvent welding, or other appropriate welding
processes.
[0027] A first circular disc 160 of the consumable material having
a desired diameter is then adhered at one end 134 of the cylinder
to form either the top wall 122 or the bottom wall 124, as shown in
FIG. 5D. The circular disc 160 can either have a diameter that is
equivalent to the inner diameter of the cylindrical side wall 126
or the outer diameter of the cylindrical side wall 126. Where the
diameter of the circular disc is equivalent to the inner diameter
of the side wall, the circular disc 160 is inserted into a lumen
162 formed by the side wall 126 such that an outer surface of the
circular disc is flush with the end of the side wall 126. Where the
diameter of the circular disc 160 is equivalent to the outer
diameter of the side wall 126, the inner surface of the circular
disc is engaged with the end of the side wall 126 and adhered
thereto. The circular disc 160 is adhered to the side wall 126
using an adhesive 150 such as cyanoacrylate and other suitable
adhesives. In another embodiment, the circular disc 160 is welded
to the side wall 126 using sonic welding, solvent welding, or other
appropriate welding processes.
[0028] As shown in FIG. 5E, the chamber 114 partially formed by the
side wall 126 and the first circular disc 160 is then filled with
the desired charge weight of propellant 116. In at least one
embodiment, plate loader technology and other standard techniques
in the industry can be used to fill the chambers of multiple
cylinders simultaneously with a volumetrically measured propellant
charge.
[0029] As shown in FIG. 5F, a second circular disc 164 of the
consumable material is adhered at the opposite end of the side wall
126 from the first circular disc 160 to seal the propellant 116 in
chamber 114. Again, the second circular disc 164 can either have a
diameter that is equivalent to the inner diameter of the side wall
126 or the outer diameter of the side wall 126. Where the diameter
of the second circular disc 164 is equivalent to the inner diameter
of the side wall, the second circular disc is inserted into the
lumen of the side wall such that an outer surface of the circular
disc is flush with the end of the side wall 126. Where the diameter
of the circular disc is equivalent to the outer diameter of the
side wall 126, the inner surface of the circular disc is engaged
with the end of the side wall 126 and adhered thereto. The circular
disc is adhered to the side wall 126 using an adhesive 150 such as
cyanoacrylate and other suitable adhesives. In another embodiment,
the circular disc is welded to the side wall using sonic welding,
solvent welding, or other appropriate welding processes.
[0030] In some embodiments, the solid circular discs 160, 164 can
be replaced by caps that have a cavity that fits over the ends of
the side wall 126. In at least one embodiment, the caps have an
outer diameter that is greater than the diameter of the side wall
126. These caps are adhered to the side wall 126 using an adhesive
such as cyanoacrylate and other suitable adhesives. In another
embodiment, the caps are welded to the side wall using sonic
welding, solvent welding, or other appropriate welding
processes.
[0031] In another embodiment, the encapsulated propellant charge
106 is formed by vacuum thermoforming two portions of a cylinder
each with one end enclosed by the mold design. After filling at
least a portion of one of the cylindrical portions with the
propellant, the two portions are adhered to one another with an
adhesive such as cyanoacrylate or could be welded to together sonic
welding, solvent welding, or other appropriate welding
processes.
[0032] In some embodiments, a cylindrical tube of the consumable
material can be extruded in relatively long tubes using a
thermoplastic extrusion process, examples of which include a screw
extruder or batch press with an associated annular extrusion die.
The extruded cylindrical tube can then be cut to an appropriate
length and closed on both ends using small end caps produced with a
stamping operation. The small end caps are attached to the ends of
the extruded cylinder using a mechanical fit, an adhesive, sonic
welding, solvent welding, and other appropriate attachment
processes In some embodiments, a first end cap can be attached to a
first end of a cylindrical tube, the chamber can then be filled,
and then a second small end cap would then be attached to a second
end of the cylindrical tube to finished the sealed propellant
charge. In at least one embodiment, as discussed above, a plate
loader and/or other standard techniques in the industry can be used
to fill the chambers of multiple cylinders simultaneously with a
volumetrically measured amount of propellant. In one embodiment,
the plate loader can also be used to fit the second small end cap
on the second end of cylindrical tube. The second small end cap can
then be adhered to the second end of the cylindrical tube to seal
the propellant charge at a final sealing station with the adhesive
or welding process.
[0033] In some embodiments, a sheet of the consumable material can
be heated and wrapped around a mandrel to form a relatively long
cylindrical tube, which can be cut to an appropriate length and
closed on both ends using the small end caps discussed above. In at
least one embodiment, multiple sheets of the consumable material
can be wrapped around the mandrel in a spiral wrap to create a
multi-layered cylinder that can be closed with the end caps
discussed above.
[0034] In some embodiments, the encapsulated propellant charge 106
can be manufactured by injection molding at least a portion of the
capsule into the desired shape.
[0035] In at least one embodiment, such as those embodiments shown
in FIGS. 3 & 4, at least one cap 129 can be attached to a first
end of a molded cylindrical tube having a closed second end, after
the chamber has been filled with the desired amount of propellant.
In at least the embodiment shown, the second closed end has an
arcuate shape. In some embodiments, the cap 129 can be adhered to
the cylindrical tube with an adhesive such as cyanoacrylate or
welded to together sonic welding, solvent welding, or other
appropriate welding processes.
[0036] In embodiments where the consumable material used in the
propellant charge is a foamed celluloid, the aforementioned methods
of manufacture assume that the foaming operation has been completed
before shaping, and thus the sheets used to manufacture the
encapsulated propellant charge comprise a foamed celluloid. In at
least one embodiment, the sheets can comprise an unfoamed celluloid
material with a foaming agent in the material and the foaming
reaction can take place during the thermoforming or other shaping
process where heat and pressure are applied. In an exemplary
embodiment, the unfoamed celluloid material can be extruded into
the long cylindrical tube and the foaming process would take place
within the annular extrusion die under heat and pressure. The
annular extrusion die would provide the necessary confinement of
the material to control wall thickness, pore size, and density of
the foamed celluloid material. In other embodiments, the unfoamed
celluloid material is injected into a two part mold with cavities
in the desired shape of the encapsulated propellant charge with the
vacuum capability to expand the foam once it was pressed into the
mold cavities.
[0037] Ballistic performance tests were conducted using standard
market rifles equipped with pressure transducers and fired in a
location equipped to measure muzzle velocity. The ballistic
performance of the encapsulated propellant charge as described
herein and a non-encapsulated charge is given in table 1 below:
TABLE-US-00001 TABLE 1 Average Breech Average Pressure, Velocity,
Projectile Propellant N/mm.sup.2 m/s Sabot, 260 Black powder
substitute, 51.39 456.6 grain 54.6 grain wt., with capsule Sabot,
260 Black powder substitute, 87.65 524.3 grain 66.2 grain wt., with
capsule Sabot, 260 Black powder substitute, 104.5 486.2 grain 54
grain wt., no capsule Sabot, 260 Black powder substitute, 115.8
530.0 grain 66 grain wt., no capsule
[0038] As shown in the data presented above, the addition of the
capsule had little effect on the average velocity of the projectile
as compared to similar propellant charges that were not
encapsulated.
[0039] Although the above disclosure describes the use of the
encapsulated propellant charges in muzzle-loaded firearms, it is
within the scope of the invention that appropriately sized
encapsulated propellant charges as described herein may also be
applicable to other ammunition such as tank rounds and caseless
ammunition.
[0040] The above disclosure is intended to be illustrative and not
exhaustive. This description will suggest many variations and
alternatives to one of ordinary skill in this art. The various
elements shown in the individual figures and described above may be
combined or modified for combination as desired. Those skilled in
the art may recognize other equivalents to the embodiments
described herein, the equivalents of which are intended to be
encompassed by the claims attached hereto. All these alternatives
and variations are intended to be included within the scope of the
claims where the term "comprising" means "including, but not
limited to."
* * * * *