U.S. patent application number 17/336581 was filed with the patent office on 2022-01-20 for apparatus and method for tensioning a gun barrel liner.
This patent application is currently assigned to Global Metallix Canada Inc.. The applicant listed for this patent is Global Metallix Canada Inc.. Invention is credited to Jack J. MASSARELLO, Robert A. SOTELO, Brian E. SPENCER, Zachary B. SPENCER.
Application Number | 20220018622 17/336581 |
Document ID | / |
Family ID | 1000005942125 |
Filed Date | 2022-01-20 |
United States Patent
Application |
20220018622 |
Kind Code |
A1 |
MASSARELLO; Jack J. ; et
al. |
January 20, 2022 |
Apparatus and Method for Tensioning a Gun Barrel Liner
Abstract
Tensioned gun barrel liners, and methods and apparatus for
tensioning gun barrel liners are disclosed. Tensioned gun barrels
have been shown to have superior performance. The apparatus allows
for axial strain to be imparted into the gun barrel using
mechanical means while other embodiments utilize thermal expansion
of the material such as metal that is used for the gun barrel liner
to introduce the strain and maintain it using other mechanical
means or applied material such as composites.
Inventors: |
MASSARELLO; Jack J.;
(Ottawa, CA) ; SOTELO; Robert A.; (Folsom, CA)
; SPENCER; Zachary B.; (Sacramento, CA) ; SPENCER;
Brian E.; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Global Metallix Canada Inc. |
Vancouver |
|
CA |
|
|
Assignee: |
Global Metallix Canada Inc.
Vancouver
CA
|
Family ID: |
1000005942125 |
Appl. No.: |
17/336581 |
Filed: |
June 2, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63033883 |
Jun 3, 2020 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F41A 21/04 20130101 |
International
Class: |
F41A 21/04 20060101
F41A021/04 |
Claims
1. A method of tensioning a barrel liner, the method comprising: a)
stretching the barrel liner along a longitudinal axial direction
from at least one of a distal end and a proximal end of the barrel
liner, to place the barrel liner under axial strain in a tensioned
state; and b) restraining the barrel liner in the tensioned state
such that the barrel liner remains under said axial strain.
2. The method of claim 1, wherein said restraining comprises one or
more restraining elements.
3. The method of claim 1, wherein said restraining comprises
applying external material.
4. The method of claim 3, wherein said external material comprises
one or more of: composite material, advanced composite material and
carbon composite material.
5. The method of claim 1, wherein said stretching is achieved by
thermal expansion.
6. The method of claim 5, comprising: a) heating the barrel liner
to cause said stretching; b) applying a restraining element to the
heated barrel liner in said tensioned state; c) cooling the heated
barrel liner; wherein upon said cooling, the barrel liner remains
in said tensioned state restrained by the restraining element from
contracting, thereby resulting in said axial strain.
7. The method of claim 6, wherein said cooling comprises applying
external material to the heated barrel liner.
8. The method of claim 6, wherein said restraining element
comprises external material applied to the heated barrel liner and
then subsequently cooled.
9. An apparatus for tensioning a barrel liner, the apparatus
comprising: an implement for engaging the barrel liner; and
securing elements for securing the implement to the barrel liner,
wherein the implement is operable to engage the barrel liner to
cause axial strain in the barrel liner along a central axis of the
barrel liner, the securing elements are operable to secure the
barrel liner to the implement, to prevent displacement a portion of
the implement relative to the barrel liner, such that movement of
the said portion of the implement causes said axial strain.
10. The apparatus of claim 9, wherein the implement is a rod; and
the securing elements comprise: a stop for placement at a proximal
end of the barrel liner to stop the rod disposed within the barrel
liner; and a cap for capping a distal end of the barrel liner, the
cap having an opening for allowing the rod therethrough, wherein as
the rod is introduced through the distal end of the barrel liner
and progresses longitudinally along the central axis, the stop and
the cap prevent further longitudinal displacement of the rod
relative to the barrel liner, and instead causes said axial strain
in the barrel liner.
11. The apparatus of claim 10, wherein the rod is a threaded rod
and the opening is threaded.
12. A gun barrel produced by a process comprising: a) providing
barrel liner and a structural external feature; b) placing the
barrel liner under axial strain; and c) applying the external
feature while the barrel liner is under said axial strain.
13. The gun barrel of claim 12, wherein the barrel liner comprises
one or more of steel, carbon steel, steel alloy, ceramic and
composite material.
14. The gun barrel of claim 12, wherein the barrel liner is steel
or stainless steel.
15. The gun barrel of claim 12, wherein the barrel liner is
ceramic.
16. The gun barrel of claim 12, wherein the external feature is a
composite material.
17. The gun barrel of claim 16, wherein the composite material
comprises one or more of carbon, glass, Kevlar.TM. and fibrous
reinforcing material.
18. The gun barrel of claim 16, wherein the composite material
comprises any one of epoxy, or any matrix polymer.
19. The gun barrel of claim 12, wherein the external feature
comprises a metal matrix.
20. The gun barrel of claim 12, wherein the external feature
comprises wire.
21. The gun barrel of claim 16, wherein the composite is applied
via filament winding.
22. The gun barrel of claim 16, wherein the composite is applied
through roll wrapping.
23. The gun barrel of claim 16, wherein the composite is applied
through braiding.
24. The gun barrel of claim 20, wherein the wire is applied through
a winding process.
25. The gun barrel of claim 12, wherein the barrel liner is
tensioned by a torqued threaded rod positioned in the center of the
barrel.
26. The gun barrel of claim 12, tensioned by thermal expansion.
27. The gun barrel of claim 12, made from an existing barrel that
is machined to a smaller diameter.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to firearm
components, and more specifically to an apparatus and a method for
tensioning a gun barrel liner.
BACKGROUND
[0002] Many different types of firearms are known. Firearms inflict
damage on targets by launching projectiles driven by a propellant
towards the target. The purpose is to accelerate a projectile to
very high speeds so that it can hit a target at a distance with
sufficient force to make a desired impact.
[0003] The mechanism that generates force to expel the projectile
is typically a controlled explosion that is initiated when the
trigger is pulled. A spring-loaded metal piece is arranged to
strike a volatile substance that ignites when struck called a
primer. The primer causes a spark inside the casing where gunpowder
is held, creating a controlled explosion. The controlled expansion
of burning propellant or gunpowder generates force or pressure,
applied to the base of the projectile such as a bullet, which in
turn is equivalent to inner diameter of the barrel. A projectile
traveling through a barrel is characterized by increasing
acceleration as the expanding gases push on it.
[0004] Barrels greatly affect the acceleration and other kinetic
characteristics of the projectile. A barrel is thus a very
important element of a firearm.
[0005] It has been shown that tensioned barrels have been proven to
be more accurate than conventional untensioned barrels, many
firearms still utilize untensioned barrels or components.
[0006] It is thus desirable to have improved methods and apparatus
to impart the required tension into a gun barrel.
SUMMARY OF INVENTION
[0007] In accordance with one aspect of the present invention,
there is provided a method of tensioning barrel liner comprising:
stretching the barrel liner along a longitudinal axial direction
from at least one of a distal end and a proximal end of the barrel
liner, such that the barrel liner is under axial strain in a
tensioned state; and restraining the barrel liner in its tensioned
state such that the barrel liner remains under said axial
strain.
[0008] In accordance with one aspect of the present invention,
there is provided an apparatus for tensioning a barrel liner. The
apparatus includes a implement which may be a threaded rod for
insertion along the central axis of the barrel liner; and securing
elements securing the implement to the liner. The implement is
operable to engage the barrel liner to cause axial strain in the
barrel liner along a central axis of the barrel liner, the securing
elements are operable to secure the barrel liner to the implement,
to prevent displacement a portion of the implement relative to the
barrel liner, such that movement of the said portion of the
implement causes said axial strain. The securing elements may be in
the form of a stop for placement at a proximal end of the barrel
liner to stop the implement or rod which may be disposed within the
barrel liner; and a cap for capping a distal end of the barrel
liner, the cap having an opening for allowing the rod therethrough,
wherein as the rod is introduced to the distal end of the barrel
liner and progresses longitudinally along the central axis, the
stop and the cap preventing further longitudinal displacement of
the rod relative to the barrel liner, and instead causing axial
strain in the barrel liner, such that the barrel liner remains
under axial strain.
[0009] In accordance with another aspect of the present invention,
there is provided a gun barrel produced by a process comprising:
providing barrel liner and a structural external feature; placing
the barrel liner under axial strain; and applying the external
feature while the barrel liner is under said axial strain.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the accompanying drawings, which illustrate one or more
embodiments:
[0011] FIG. 1 is a side elevational view of a conventional
untensioned gun barrel liner;
[0012] FIG. 2 is a longitudinal sectional view of the barrel liner
of FIG. 1, disposed in a barrel tensioning apparatus; and
[0013] FIG. 3 is a side elevational view of a tensioned gun barrel
liner exemplary of an embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENT
[0014] Tensioned gun barrel liners, and methods and apparatus for
tensioning gun barrel liners are disclosed. Tensioned gun barrels
have been shown to have superior performance including increased
rigidity, reduced vibration and increased accuracy. Some of the
exemplary apparatuses and methods provided in this disclosure allow
for axial strain to be imparted into the gun barrel using
mechanical means. Other embodiments utilize thermal expansion of
the material used for the gun barrel liner to introduce the strain
and maintain it using other mechanical means.
[0015] Directional terms such as "top," "bottom," "upwards,"
"downwards," "left," "right," "vertically," and "laterally" are
used in the following description for the purpose of providing
relative reference only, and are not intended to suggest any
limitations on how any article is to be positioned during use, or
to be mounted in an assembly or relative to an environment. The use
of the word "a" or "an" when used herein in conjunction with the
term "comprising" may mean "one," but it is also consistent with
the meaning of "one or more," "at least one" and "one or more than
one." Any element expressed in the singular form also encompasses
its plural form. Any element expressed in the plural form also
encompasses its singular form. The term "plurality" as used herein
means more than one; for example, the term "plurality includes two
or more, three or more, four or more, or the like.
[0016] In this disclosure, the terms "comprising", "having",
"including", and "containing", and grammatical variations thereof,
are inclusive or open-ended and do not exclude additional,
un-recited elements and/or method steps. The term "consisting
essentially of" when used herein in connection with a composition,
use or method, denotes that additional elements, method steps or
both additional elements and method steps may be present, but that
these additions do not materially affect the manner in which the
recited composition, method, or use functions. The term "consisting
of" when used herein in connection with a composition, use, or
method, excludes the presence of additional elements and/or method
steps.
[0017] In this disclosure, the term "firearm" refers to a rifle, a
pistol, or any other portable gun, which utilizes a propellant to
propel a projectile towards a target.
[0018] In this disclosure, the terms "barrel", "firearm barrel" and
"gun barrel" refer to a straight tube, which forms part of a
firearm, and through which a contained rapid expansion of
high-pressure gas is introduced behind a projectile in order to
propel it out of the front end of the barrel at a high
velocity.
[0019] In this disclosure, the terms "barrel liner", "gun barrel
liner", and "firearm barrel liner" refer to the inner component of
a firearm barrel. The barrel liner may include the fluted section
of a barrel.
[0020] FIG. 1 depicts an schematic diagram of a barrel liner 100.
Barrel liner 100 has an elongate cylindrical body 104 defined by a
central longitudinal axis 108 with a neck 102 near the proximal
end.
[0021] Barrel liner 100 is typically made of metal or another
appropriate material. Materials such as steel, carbon steel, other
steel alloys, ceramic and composite materials can also be used in
alternative embodiments. As may be appreciated, although the
depicted embodiment in FIG. 1 has a cylindrical body 104 having a
circular cross-section, in other embodiments, the cross-section of
the barrel body may have an elliptical, polygonal or other
shapes.
[0022] The barrel liner 100 provides a wear surface for a
projectile. To tension the barrel liner 100 of FIG. 1 to a desired
axial strain, in accordance with an embodiment of the present
invention, a tensioning apparatus such as that shown in FIG. 2 is
used.
Mechanical Embodiment
[0023] As shown in FIG. 2, an exemplary tensioning apparatus 200
includes an implement such as a threaded rod 202 disposed along, in
parallel or through central axis 108 of barrel liner 100. Securing
elements such as a stop 204 and a cap 206 are used to secure the
barrel liner 100 to the apparatus 200. Components of barrel liner
100 are the same as those shown in FIG. 1 and will not be further
described.
[0024] In operation, using apparatus 200, axial strain is applied
using the threaded rod 202. Stop 204 and cap 206 secure the barrel
liner 100 in place while the threaded rod 202 progresses
longitudinally relative to the barrel liner 100 along the direction
of central axis 108. The securing elements in the form of stop 204
and cap 206 are used to prevent relative displacement of the
implement in the form of rod 202 so that further movement of the
threaded rod 202 causes tension or axial strain instead.
[0025] Once the barrel liner 100 is tensioned, a restraining
element is introduced to keep the barrel liner 100 tensioned or
under axial strain. The restraining element may be an external
structural material applied to the barrel liner 100.
[0026] In one embodiment, the restraining element is a composite
material, such as carbon composite material that is applied to the
tensioned barrel liner 100. In other embodiments using advanced
composite resin applied to the tensioned barrel liner 100. The
advanced composite resin may be cured to a hardened state through
heat, to keep the liner 100 restrained or tensioned.
[0027] Once the composite is cured the threaded rod 202 is removed
from the barrel line 100, the cured composite prevents the barrel
liner 100 from returning to its natural state resulting in a
residual axial strain. Due to Poisson's ratio v which measures the
expansion or contraction of a material in directions perpendicular
to the direction of loading, there may be a resultant hoop strain
as well.
[0028] The barrel liner 100 may have stops or features to provide a
mechanical lock other than just bonding that would occur between a
composite (not illustrated) and barrel liner 100.
Thermal Embodiment
[0029] The axial strain may be produced using thermal means. In an
alternate embodiment, barrel liner 100 may be heated or otherwise
subjected to a higher temperate so as to cause its expansion.
Thereafter, the expanded barrel liner is restrained using an
external feature such as a composite applied to the heated barrel
liner. The combination of the heated liner and the applied material
or external feature is then cooled. As the barrel liner tends to
contract further under cooling than the applied material, the
cooling step causes axial strain in the barrel liner 100.
[0030] As would be appreciated, the coefficient of thermal
expansion of the barrel liner (CTE.sub.b) is typically higher than
for the applied material (CTE.sub.a) causing axial strain in the
barrel liner 100 upon cooling.
[0031] FIG. 3 depicts a schematic diagram of a barrel liner 100a
under axial strain. Barrel liner 100a is essentially the same as
barrel liner 100 of FIG. 1 except for the presence of axial strain
leading to slightly larger dimensions. Like parts in FIG. 3 and
FIG. 1 are labeled with like reference numerals, with a prime
symbol (') or a letter suffix (e.g., `a`) used to distinguish the
elements of FIG. 3 from their counterparts in FIG. 1. Barrel liner
100a therefore also has an elongate cylindrical body 104a defined
by a central longitudinal axis 108 with a neck 102a at near the
proximal end.
Alternate Embodiments
[0032] Alternate embodiments of the present invention include a
method of tensioning barrel liner comprising: stretching the barrel
liner along a longitudinal axial direction from at least one of a
distal end and a proximal end of the barrel liner, such that the
barrel liner is under axial strain; and securing the barrel liner
in its expanded state such that the barrel liner remains under said
axial strain.
[0033] In another embodiment of the above method, securing the
barrel liner includes restraining the barrel liner in place while
under said axial strain using restraining elements, features or
composites.
[0034] In some embodiments, thermal expansion is exploited to
stretch or expand the elongate barrel liner. This may involve
heating the barrel liner so as to cause expansion; restraining the
heated barrel liner using a restraining element; and cooling the
heated barrel liner; wherein upon said cooling, the barrel liner is
restrained by the external feature from contracting, thereby
resulting in axial strain. The restraining or cooling may include
applying external material to the heated barrel liner.
[0035] In another embodiment of the present invention, an apparatus
for tensioning a barrel liner having a central axis is provided.
The apparatus comprises: a implement such as a rod which may be
threaded, for insertion or disposition along the central axis of
the barrel liner; and securing elements in the form of a stop and a
cap. The stop is for placement at a proximal end of the barrel
liner to stop the rod disposed within the barrel liner; and the cap
is for capping a distal end of the barrel liner. Where the
implement is a rod, the cap may have an opening for allowing the
rod therethrough, wherein as the rod is introduced to the distal
end of the barrel liner and progresses longitudinally along the
central axis, the stop and the cap prevent further longitudinal
displacement of the rod relative to the barrel liner and instead
cause axial strain in the barrel liner. Thereafter, other means of
tensioning such as applying materials may be used so that barrel
liner remains under axial strain even after the securing elements
are disengaged from the barrel liner or the implement. The
implement may be a threaded rod.
[0036] In other embodiments of the apparatus, different elements or
fixtures other than stop 204 and cap 206 may be used to secure a
barrel liner in place. Implements other than threaded rod 202 may
be used to cause axial strain in the liner, along the direction of
central axis 108. The implement need not necessarily be inserted in
the liner in all embodiments and operations, but need only cause
axial strain.
[0037] In another embodiment of the present invention, a process
for tensioning a gun barrel or liner is provided. The process
comprises: providing barrel liner and a structural external
feature; placing the barrel liner under axial strain; and applying
the external feature while the barrel liner is under said axial
strain.
[0038] In some embodiments, the barrel liner is made up of one or
more of steel, carbon steel, steel alloy, ceramic and composite
material. In other embodiments, the gun barrel liner is steel or
stainless steel or ceramic. The external feature may be a composite
material including one or more of carbon, glass, Kevlar.TM. and
fibrous reinforcing material and the composite material comprises
any one of epoxy or any matrix polymer.
[0039] In some embodiments of the gun barrel the external feature
comprises a metal matrix. In others it comprises wire and the wire
may be applied through a winding process.
[0040] The composite may be applied via filament winding or through
roll wrapping or through braiding.
[0041] In some embodiments, the barrel liner could be tensioned by
a torqued threaded rod positioned in the center of the barrel. The
barrel liner may be made from an existing barrel that is machined
to a smaller diameter.
[0042] The above-described embodiments are intended to be examples
of the present disclosure and alterations and modifications may be
effected thereto, by those of skill in the art, without departing
from the scope of the invention, which is defined solely by the
claims appended hereto.
* * * * *