U.S. patent application number 14/747005 was filed with the patent office on 2015-12-24 for composite handguard for a firearm.
The applicant listed for this patent is TROY INDUSTRIES, INC.. Invention is credited to Andreas Gottzmann.
Application Number | 20150369558 14/747005 |
Document ID | / |
Family ID | 54869324 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150369558 |
Kind Code |
A1 |
Gottzmann; Andreas |
December 24, 2015 |
Composite Handguard for a Firearm
Abstract
A handguard for a firearm comprising: a tubular body configured
to overlie a barrel of the firearm in spaced relationship, the
tubular body formed of a fiber reinforced plastic composite; the
tubular body including an elongated accessory mounting rail; and
the elongated accessory mounting rail includes an inner elongated
rail segment located beneath the fiber reinforced plastic composite
which extends longitudinally along a length of the mounting rail;
and the inner elongated rail segment is coupled to the a fiber
reinforced plastic composite.
Inventors: |
Gottzmann; Andreas;
(Longmeadow, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TROY INDUSTRIES, INC. |
West Springfield |
MA |
US |
|
|
Family ID: |
54869324 |
Appl. No.: |
14/747005 |
Filed: |
June 23, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62015626 |
Jun 23, 2014 |
|
|
|
Current U.S.
Class: |
42/71.01 |
Current CPC
Class: |
F41C 23/18 20130101;
F41C 23/16 20130101 |
International
Class: |
F41C 23/16 20060101
F41C023/16 |
Claims
1. A handguard for a firearm comprising: a tubular body configured
to overlie a barrel of the firearm in spaced relationship, the
tubular body formed of a fiber reinforced plastic composite; the
tubular body including an elongated accessory mounting rail; and
the elongated accessory mounting rail includes an inner elongated
rail segment located beneath the fiber reinforced plastic composite
which extends longitudinally along a length of the mounting rail;
and the inner elongated rail segment is coupled to the a fiber
reinforced plastic composite.
2. The handguard of claim 1 wherein: the fiber reinforced plastic
composite comprises a fiber reinforcement structure embedded in a
matrix composition.
3. The handguard of claim 2 wherein: the fiber reinforcement
structure comprises at least one tubular reinforcement member.
4. The handguard of claim 3 wherein: the at least one tubular
reinforcement member is formed to a preformed shape of the tubular
body before the tubular reinforcement member is embedded in the
matrix composition.
5. The handguard of claim 3 wherein: the at least one tubular
reinforcement member is provided without a terminating edge or a
seam extending along a longitudinal direction of the tubular
reinforcement member.
6. The handguard of claim 3 wherein: the at least one tubular
reinforcement member is a tubular sleeve.
7. The handguard of claim 6 wherein: the tubular sleeve comprises
at least one of a woven sleeve and a braided sleeve.
8. The handguard of claim 7 wherein: the tubular sleeve comprises a
tubular braided sleeve with a biaxial braid.
9. The handguard of claim 8 wherein: the tubular braided sleeve
comprises fiber bundles which are not arranged parallel to a
longitudinal axis of the tubular body.
10. The handguard of claim 3 wherein: the at least one tubular
reinforcement member comprises a plurality of tubular reinforcement
members; and at least a one of the tubular reinforcement members is
formed of carbon fiber; and at least a one of the tubular
reinforcement members is formed of glass fiber.
11. The handguard of claim 2 wherein: the matrix composition
comprises a thermoset polymer.
12. The handguard of claim 8 wherein: the thermoset polymer
comprises at least one of an epoxy, a polyester, a vinyl ester, a
methacrylate and a phenolic.
13. The handguard of claim 1 wherein: an upper portion of the
elongated accessory mounting rail comprises a plurality of
alternating ribs and slots extending transverse to a longitudinal
axis if the tubular body.
14. The handguard of claim 1 wherein: the rail comprises an upper
elongated rail segment coupled with the tubular body; and the upper
elongated rail segment extends longitudinally along a length of the
rail.
15. The handguard of claim 14 wherein: the upper elongated rail
segment is at least one of mechanically coupled and adhesively
coupled with the tubular body.
16. The handguard of claim 14 wherein: the upper elongated rail
segment forms an upper portion of the rail; and the tubular body
forms a lower portion of the rail.
17. The handguard of claim 1 wherein: the inner elongated rail
segment is at least one of mechanically coupled and adhesively
coupled to the a fiber reinforced plastic composite.
18. The handguard of claim 17 wherein: the inner elongated rail
segment is adhesively coupled with the fiber reinforced plastic
composite during forming of the tubular body.
19. The handguard of claim 18 wherein: the inner elongated rail
segment is adhesively coupled with the fiber reinforced plastic
composite by the matrix composition.
20. The handguard of claim 1 further comprising: an attachment
member to attach the handguard to the firearm; and the attachment
member is coupled with the tubular body.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application No. 62/015,626, filed Jun. 23, 2014, the entire content
of which is incorporated herein by reference.
FIELD
[0002] The present disclosure relates to relates to firearms, and
more particularly relates to a handguard for a firearm.
BACKGROUND
[0003] Certain firearms, such as certain semi-automatic and
automatic firearms in the family of AR-15/M16 firearms, may include
a tubular handguard which surrounds at least a portion of the
length of the barrel.
[0004] Among other functions, the handguard may protect the firearm
operator's hand from a heated barrel after the firearm is fired,
particularly by inhibiting the operator's hand from contacting the
barrel directly and subsequently suffering a burn or other injury.
The handguard may also protect the barrel and other parts of the
firearm contained therein from being damaged during use of the
firearm.
[0005] The handguard may be made of metal, particularly aluminum.
However, in response to extreme use of the firearm, a metal
handguard may be understood to heat-up due to the high thermal
conductivity of the metal, and thus defeat the objective of
protecting the firearm operator's hand from heat associated with
the barrel after the firearm is fired.
[0006] In order to address the problems associated with the heating
of metal handguards, injection molded thermoplastic polymer
handguards have been developed. However, while addressing the
problems associated with the heating of metal handguards, the
injection molded thermoplastic polymer may not offer adequate
strength or other physical properties, such as impact resistance or
heat resistance.
[0007] In order to increase either the impact resistance and/or
heat resistance of an injection molded thermoplastic polymer, fiber
reinforcement may be added to the injection molded thermoplastic
polymer to provide a fiber-reinforced thermoplastic handguard.
[0008] However, a fiber-reinforced thermoplastic polymer, while
possibly offering an increase in impact resistance and heat
resistance as compared to an unreinforced thermoplastic polymer,
still may suffer from impact resistance and heat resistance
limitations as the fiber length of injection molded fiber
reinforced thermoplastic polymers is generally less than 10 mm, and
more commonly less than about 3 mm, due to the screw of the
injection molding machine tending to break the fibers as they are
processed within the barrel. Furthermore, fiber loading levels may
generally be limited to about 20-30% by weight.
FIGURES
[0009] The features of this disclosure, and the manner of attaining
them, will become more apparent and better understood by reference
to the following description of embodiments described herein taken
in conjunction with the accompanying drawings, wherein:
[0010] FIG. 1 is a side view of a firearm which includes a
handguard according to the present disclosure;
[0011] FIG. 2 is a front perspective view of the firearm of FIG.
1;
[0012] FIG. 3 is an enlarged side view of the portion of the
handguard of the firearm of FIG. 1 bounded by rectangle 3;
[0013] FIG. 4 is a cross-sectional side view of the handguard of
the firearm of FIG. 1 taken along line 4-4 of FIG. 1;
[0014] FIG. 5 is an enlarged cross-sectional view of the portion of
the handguard of FIG. 4 bounded by circle 5;
[0015] FIG. 6 is an enlarged side view of an another embodiment of
the handguard of the firearm of FIG. 1 according to the present
disclosure;
[0016] FIG. 7 is a cross-sectional view of an elongated insert for
another embodiment of the handguard of the firearm of FIG. 1
according to the present disclosure;
[0017] FIG. 8 is a cross-sectional side view of another embodiment
of the handguard of the firearm of FIG. 1 taken along line 4-4 of
FIG. 1 including the insert of FIG. 7; and
[0018] FIG. 9 is a perspective view of an attachment member which
may be provided with a handguard according to the present
disclosure to attach the handguard to the firearm.
DETAILED DESCRIPTION
[0019] It may be appreciated that the present disclosure is not
limited in its application to the details of construction and the
arrangement of components set forth in the following description or
illustrated in the drawings. The invention(s) herein may be capable
of other embodiments and of being practiced or being carried out in
various ways. Also, it may be appreciated that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting as such may be understood by one
of skill in the art.
[0020] Referring now to FIGS. 1-2, there is shown a firearm 10
according to the present disclosure. As shown, the firearm 10 may
comprise a gas-operated semi-automatic or full-automatic firearm.
The gas operated system may be a direct gas impingement system, or
a gas operated piston system. The direct gas impingement system
directs hot propellant combustion gas from a fired cartridge
directly to a bolt carrier to cycle the action of the firearm. More
particularly, the gas pressure of the combustion gas pushes the
bolt carrier rearward against the bias of a buffer spring, during
which time the fired cartridge case is extracted from the chamber
of the barrel and ejected from the firearm. As the gas pressure
dissipates, the compressed buffer spring then decompresses and
pushes the bolt carrier forward, during which time an unfired
cartridge is removed from the magazine and loaded into the chamber
of the barrel. In contrast to a direct gas impingement system, with
a gas operated piston system, the gas forces a piston rod of a
piston and the bolt carrier rearward to handle the extraction and
ejection process, and thereafter the bolt carrier is forced forward
by a decompression of the buffer spring to the closed position just
as with direct impingement.
[0021] Even more particularly, firearm 10 may be a member of the
family of AR-15/M16 firearms, which may include the AR-10, AR-15,
M16, M16A1, M16A2, M16A3, M16A4, M4, M4A1, CAR-15, etc. Firearm 10
may also include a submachine gun, a compact assault rifle or a
machine pistol. Firearm 10 may be configured to fire rifle
cartridges (e.g. the 5.56x 45 mm NATO military cartridge, 5.56/.223
Remington, 300 Blackout, 0.308 Win/7.62x51, 5.45x39, 7.62x39, 458
SOCOM, and 0.50 Beowulf) as well as pistol cartridges (9 mm).
Firearm 10 may be categorized as a rifle, a carbine, a mid-length
or a pistol, particularly depending on barrel length.
[0022] As shown, firearm 10 includes a receiver 12 comprising a
lower receiver 14 and mating upper receiver 16. Upper receiver 16
includes bolt carrier 30 including a firing pin, as well as a
cartridge loading and unloading mechanism. A barrel 40 is affixed
to the front end of upper receiver 16 and a butt stock 50 is
affixed to the rear end of lower receiver 14. A trigger portion of
upper receiver 16 fits into an access opening in lower receiver 14
and is integrated with the internal mechanism of upper receiver 16
and lower receiver 14. A pistol grip 60 is attached to lower
receiver 14. A detachable (removable) box magazine as known in the
art (not shown) may be inserted into a magazine receptacle 18
having a downwardly oriented access opening in lower receiver 14
for feeding cartridges to the cartridge insertion and ejection
mechanism within upper receiver 16. The detachable magazine is
capable of being loaded and unloaded while detached from firearm
10, and holds the cartridges side-by-side in one or more
columns/rows, which may be staggered. In certain embodiments, the
detachable magazine may also comprise a drum magazine in which the
cartridges are positioned and fed in an unwinding spiral.
[0023] A handguard 80 is affixed at the front end of upper receiver
16, either to the upper receiver 16 or the barrel 40. Handguard 80
includes an elongated tubular body 82. FIG. 3 shows an enlarged
view of the portion of tubular body 82 bounded by the area of
rectangle 3 of FIG. 1, while FIG. 4 shows a cross section of the
tubular body 82 taken along line 4-4 of FIG. 1.
[0024] As shown by FIG, 4, the tubular body 82 may have a
substantially octagonal (i.e. having 8 sides) shaped cross-section.
It will of course be understood that the cross-sectional profile
could be oval, square, rectangular, or any cylindrical
configuration which is hollow so as to surround at least a portion
of the barrel 40 of firearm 10 without coming in contact therewith
along the length of the barrel 40 that is surrounded. The length of
tubular body 82 of handguard 80 may particularly be such that, when
mounted on firearm 10, it extends from the front surface of the
upper receiver 16 of the firearm 10 to a distance short of the end
of the barrel 30 for easy and convenient gripping by the firearm
operator and for protection of the operator's hand from the barrel
40. Handguard 80, and more particularly the tubular body 82, may
also serve as a platform to mount accessories to the fore-end of
the firearm 10, such as by providing one or more accessory mounting
rails as discussed herein. As shown, the tubular body 82 of the
handguard 80 may be provided by as a single piece tubular
member.
[0025] As shown, tubular body 82 defines an elongated center
passage 84 to contain the barrel 40, as well as certain other
components (e.g. the combustion gas return tube or other
accessories/features that may be incorporated at some future time)
depending on the type of firearm 10. Tubular body 82 has an outer
surface 86 and an inner surface 88, and may include a plurality of
rows of apertures 90 formed therein, particularly to vent heat away
from the barrel 40. While the apertures 90 are shown as having a
circular shape, the apertures 90 may have any geometric shape
including oval, ellipse, triangle, square, rhombus, diamond,
rectangle, pentagon, hexagon, heptagon, octagon, etc. The apertures
90 may be formed in the tubular body 82 after the handguard 80 is
molded as discussed in greater detail below.
[0026] The top side 92 of the handguard 80, and the tubular body
82, may include an elongated accessory (mounting) rail 94, which
provides a mounting platform for accessories (e.g. scope). As shown
by FIG. 4, elongated rail 94 has a T-shaped cross-sectional profile
(transverse to the longitudinal axis LA of the handguard 80.
Elongated rail 94 may more particularly be a Weaver rail or a
Picatinny rail, comprising a plurality of alternating equally
spaced parallel ribs 96 and slots 98 extending transverse to the
longitudinal axis LA of the handguard 80
[0027] Referring now to FIG. 5, handguard 80, and more particularly
wall 83 forming tubular body 82, may be formed of a composite
material comprising a plurality of constituent components. More
particularly, the composite material may be a fiber reinforced
plastic composite material, in which a reinforcement structure 100
in fiber form is embedded in a matrix (binder) composition 110
which comprises at least one polymer. The reinforcement structure
100 may also be referred to as the discontinuous phase while the
matrix composition 110 may be referred to as the continuous phase.
The composite material of the present disclosure may provide a
handguard 80 formed of a thermal (non-conductive) insulator which
provides high heat resistance, high impact strength and protects
the operator's hand from the heat of the barrel 40, as well as
inhibits the rail 94 as disclosed herein from heating, possibly
adversely effecting the operation of any accessories mounted
thereon.
[0028] The matrix composition 110 may be a thermoset matrix
composition formed of at least one thermoset polymer. Exemplary
thermoset polymers may include polyester, epoxy, viny ester, methyl
methacrylate and phenolic.
[0029] The reinforcement structure 100 may particularly comprise at
least one pre-manufactured fiber reinforcement layer 102, which is
embedded in the matrix composition 110. A pre-manufactured fiber
reinforcement layer may be understood as a fiber reinforcement
layer which is first formed into a reinforcement layer separate
from the matrix 110. Such would not include, for example, loose,
random fibers which are packaged as such.
[0030] More particularly, the at least one fiber reinforcement
layer 102 may comprise a plurality of fiber reinforcement layers
102, 104, 106 and 108. As shown by FIG. 5, fiber reinforcement
layer 102 is shown to be an outer reinforcement layer,
reinforcement layer 104 is shown to be an inner reinforcement layer
and reinforcement layers 106, 108 are shown to be intermediate
reinforcement layers between outer reinforcement layer 102 and
inner reinforcement layer 104.
[0031] Any one or all of the fiber reinforcement layers 102, 104,
106 and 108 may be provided by a tubular fiber reinforcement
member, which is particularly provided without a terminating edge
or a seam extending in the longitudinal direction of the tubular
reinforcement member (which may be understood to be in the same as
the longitudinal axis LA of the handguard 80). More particularly,
any one or all of the reinforcement layers 102, 104, 106 and 108
may be provided by a tubular braided and/or woven fabric sleeve.
For example, any or all of the fiber reinforcement layers 102, 104,
106 and 108 may comprise a braided fiber sleeve where the fibers
(continuous) are arranged (woven) in a multi-directional (biaxial)
braid such that the braided fiber bundles (braid yarns or strands)
are arranged off-axis, i.e. at an angle of +/-45 degrees) relative
to the longitudinal axis LA of the tubular sleeve. Stated another
way, the fibers are not arranged parallel to a longitudinal axis LA
of the tubular body 82. In such a manner, the fiber orientation may
provide for balanced control of torsional and longitudinal loads
placed on the handguard 80. Also, while the tubular braided sleeve
may be manufactured with the fiber bundles at +/-45 degrees, the
actual orientation in the molded tubular body 82 may be broader
(due to stretching or other shaping of the tubular braided sleeve),
such as within a range of in a range of +/-30 degrees to +/-60
degrees.
[0032] Any one or all of the reinforcement layers 102, 104, 106 and
108 may also comprise a woven fiber sleeve where the fibers
(continuous) are arranged (woven) such that the fiber bundles
(braid yarns or strands) are arranged multi-directionally,
particularly longitudinally (0 degrees) and transversely (90
degrees), relative to the longitudinal axis LA of the tubular
sleeve. Stated another way, the fibers are arranged parallel and
perpendicular to a longitudinal axis LA of the tubular body 82.
[0033] Any one or all of the fiber reinforcement layers 102, 104,
106 and 108 may also be provided by a fiber mat, which may be a
continuous strand mat or a chopped strand mat.
[0034] While it may be preferred that each of the fiber
reinforcement layers 102, 104, 106 and 108 are provided by
independent (discrete) members, fiber reinforcement layers 102,
104, 106 and 108 may also formed by a single mat which is wrapped
in a coil to provide the fiber reinforcement layers 102, 104, 106
and 108 is overlying/underlying relationship.
[0035] Any one or all of the reinforcement layers 102, 104, 106 and
108 may be made of glass fibers, carbon fibers or a combination
thereof. In a particular embodiment, reinforcement layers 104, 106
and 108 may be made of carbon fiber, while reinforcement layer 102
is made of glass fiber. In another embodiment, reinforcement layers
102, 104 and 108 may be made of carbon fiber, while reinforcement
layer 106 made of glass fiber. The weight/area and the diameter of
the layers 102, 104, 106, 108 may vary depending on the particular
application of the handguard 80 and the type of firearm 10.
[0036] With regards to fiber loading, the tubular body 82, may have
a fiber content in a range of 30% to 60% by weight of the tubular
body 82, and more particularly have a fiber content in a range of
35% to 55% by weight of the tubular body 82. The fibers may
comprise 80-95% by weight carbon fibers and 5%-20% by weight glass
fibers. The tubular body may have a thickness in a range of 0.5 mm
to 10 mm, and more particularly have a thickness in a range of 2 mm
to 5 mm.
[0037] The handguard 80, and more particularly the tubular body 82,
may be formed by a closed mold (i.e. two-sided) molding process,
such as resin infusion molding process where the matrix composition
(e.g. polymer resin) is introduced into a mold containing the
preplaced/preloaded reinforcement structure 100. More particularly,
the resin infusion molding process may be a resin transfer molding
process, which may be vacuum (i.e. less than atmospheric pressure)
or pressure (i.e. greater than atmospheric pressure) assisted, to
obtain a tubular body 82 with low void content and high fiber
loading.
[0038] As part of the process, a mold may be provided which has at
least one molding cavity to form the tubular body 82, with the
molding cavity being defined by opposing mold halves which may be
referred to as the core half and cavity half. The molding process
may begin by opening the mold and placing the inner reinforcement
layer 104 over an elongated core half of a mold, which may be
referred to as the mandrel. The intermediate layer 108 may then be
placed over the inner layer 104, followed by intermediate layer 106
and the outer layer 102 placed over the intermediate layer 106 to
form a four layer reinforcement structure 100. The mold may then be
closed and clamped.
[0039] In alternative embodiments the reinforcement layers 102,
104, 106 and 108 may be formed to a preformed shape of the tubular
body 82 before being placed in the mold, such as being formed over
a performing mandrel and then sprayed with a stiffening agent such
as starch. The reinforcement layers 102, 104, 106 and 108 may then
all be introduced to the molding cavity simultaneously.
[0040] The matrix composition 110 may then introduced into the
molding cavity (e.g. pumped in under pressure greater than
gravity), such as while in the form of a catalyzed low viscosity
polymer resin. The matrix composition 110 flows through the molding
cavity and the interstices of the reinforcement layers 102, 104,
106 and 108 while displacing air from the molding cavity. Air may
be displaced from the molding cavity through one or more molding
cavity vents formed in the mold, or a vacuum may be drawn on the
molding cavity to remove air from the molding cavity as well as
assist helping the matrix composition 110 flow through the molding
cavity and reinforcement layers 102, 104, 106 and 108 located
therein.
[0041] After the matrix composition 110 has filled the mold and
undergone a suitable cure time, the mold may be opened and the
handguard 80 comprising the tubular body 82 removed from the mold.
The tubular body 82 may then be trimmed and apertures 90 formed
(cut) therein. Alternatively the apertures 90 may be formed therein
during molding.
[0042] As an alternative to resin transfer molding, other resin
infusion molding processes which may be used to manufacture the
handguard 80 of the present disclosure may include structural
reaction injection molding, which may particularly make use of a
thermoset polymer such as a polyurethane which is processed through
a reaction injection molding mixhead.
[0043] Another closed mold (i.e. two-sided) molding process which
may be used to produce handguard 80, particularly tubular body 82,
may be compression prepreg process in which a reinforcement
structure is saturated with a matrix composition 110 (a/k/a
pre-impregnation), which is then compression molded with heat and
pressure to form the molded article.
[0044] In the foregoing embodiment of the handguard 80, the ribs 96
and slots 98 forming the elongated rail 94 may be formed in the
tubular body 82 during molding. Alternatively, the ribs 96 and
slots 98 may be formed after molding the tubular body 82 by milling
otherwise cutting the slots 98 into the tubular body 82, thereby
forming the ribs there between.
[0045] In another embodiment of the handguard 80 of the present
disclosure, as shown in FIG. 6, a lower elongated rail segment 120
may be formed by the tubular body 82 which has a planar upper
surface 122, and an upper elongated rail segment 130 may be formed
separately from the tubular body 80 (i.e. preformed before
manufacture of the tubular body 80), with the separately formed
upper elongated rail segment 130 having a planar lower surface 132,
as well as preformed ribs 96 and slots 98. The separately formed
upper elongated rail segment 130 may be formed of metal (e.g.
aluminum, steel, titanium), or a plastic (e.g. a composite as
disclosed herein, or injection molded from a thermoplastic
composition).
[0046] The planar lower surface 132 of the upper elongated rail
segment 130 may be coupled to the planar upper surface 122 of the
lower elongated rail segment 120 particularly by adhesive bonding
with a separate bonding agent located there between. Alternatively,
adhesive bonding the upper elongated rail segment 130 to the lower
elongated rail segment 120 may be accomplished using the matrix
composition 110.
[0047] Such may be accomplished by placing the upper elongated rail
segment 130 in the forming mold for the tubular body 82, such as by
positioning the upper elongated rail segment 130 on the cavity half
of the mold, prior to introducing the matrix composition 110.
Thereafter, when the matrix composition 110 is introduced into the
molding cavity and the lower elongated rail segment 120/tubular
body 82 is formed, the upper elongated rail segment 130 becomes a
molded-in insert, which may also be referred to as inserted molded,
during molding of the tubular body 82 which is bonded directly to
the matrix composition 110 during molding. Alternatively, such may
also be accomplished after tubular body 82 and the lower elongated
rail segment 120 are formed by removing the tubular body 82 from
the mold before the matrix composition 110 of the tubular body 82
has reach full cure, in which case the upper elongated rail segment
130 may be pressed onto the lower elongated rail segment 120 and
bonded thereto while the matrix composition 110 of the tubular body
82 is still curing.
[0048] Alternatively, the separately formed upper elongated rail
segment 130 may be mechanically coupled, rather than adhesively
coupled, to the lower elongated rail segment 120 with a detachable
mechanical fastener (e.g. a threaded fattener such as a screw) or a
non-detachable mechanical fastener (e.g. a rivet).
[0049] In another embodiment of the handguard 80 of the present
disclosure, as shown in FIG. 7, elongated rail 94 may include an
inner elongated rail segment 140 which, similar to upper elongated
rail segment 130, may be separately formed from the tubular body 80
(i.e. preformed before manufacture of the tubular body 80). The
separately formed inner elongated rail segment 140 may be formed of
metal (e.g. aluminum, steel, titanium), or a plastic (e.g. profile
extruded from a thermoplastic composition).
[0050] The inner elongated rail segment 140 may be used to
eliminate any need for a separately formed upper elongated rail
segment 130, as will become more evident from the disclosure
herein. Similar to the first embodiment of the disclosure, the ribs
96 and slots 98 forming the elongated rail 94 may be formed in the
tubular body 82 during molding without need for the separately
formed upper elongated rail segment 130. Alternatively, the ribs 96
and slots 98 may be formed after molding the tubular body 82 by
milling otherwise cutting the slots 98 into the tubular body 82,
thereby forming the ribs there between. However, it should be
recognized that the present disclosure does not preclude the upper
elongated rail segment 130 from being used in conjunction with the
preformed inner elongated rail segment 140. It should be understood
that when the rail 94 is formed of a lower elongated rail segment
120 and a separate molded-in or attached upper elongated rail
segment 130, the inner elongated rail segment 140 will be part of
the lower elongated rail segment 120.
[0051] Referring briefly to FIG. 4, as shown the elongated rail 94
may have a thicker cross-sectional profile, to increase stiffness,
than the remainder of the tubular body 82 of the handguard 80. As a
result, depending on the loft and weight of the reinforcement
structure, the reinforcement structure 100 may be further from the
outer surface 86 of the rail 94 than for the remaining thinner
portion of the tubular body 82, resulting in an outer portion of
the rail thickness being formed predominately of the matrix
composition 110 with little or no reinforcement structure 100.
[0052] In order to overcome the foregoing difficulty and
geometrical challenges of the used materials, inner elongated rail
segment 140 may be placed in the mold, such as by positioning the
inner elongated rail segment 140 on the core half of the mold,
prior to introducing the reinforcement structure 100. This will, in
effect, decrease the thickness of the molding cavity used to form
rail 94. Thereafter, when the reinforcement structure 100 is placed
on the core half of the mold, the reinforcement structure 100 will
overlie the inner elongated rail segment 140, which will force the
reinforcement structure 100 closer to the outer surface 86 of the
handguard 80. Thereafter, when the matrix composition 110 is
introduced into the molding cavity and the tubular body 82 is
formed, the inner elongated rail segment 140 becomes a molded-in
insert during molding of the tubular body 82 which is bonded
directly to the matrix composition 110 during molding. In addition
to the inner elongated rail segment 140 positioning the
reinforcement structure 100 closer to the outer surface 86 of the
handguard 80, in such fashion the inner elongated rail segment 140
will be enclosed and protected towards the inside of the rail 94 by
the reinforcement structure 100, as well as increase the stiffness
of the rail 94.
[0053] In another embodiment of the handguard 80 of the present
disclosure, as shown in FIG. 9, the handguard 80 may include
attachment member 150 configured to attached the handguard 80 to
the upper receiver 16 or the barrel 40 of firearm 10. The
attachment member 150 may be formed of metal (e.g. aluminum, steel,
titanium), or a plastic (e.g. a thermoset composite as disclosed
herein, or injection molded from a thermoplastic composition). The
attachment member 150 and the handguard 80 may attach to the upper
receiver 16 or barrel 40 of firearm 10 in a manner as disclosed in
U.S. Pat. No. 8,037,633 entitled "Handguard System For Firearms"
and U.S. Pat. No. 8,464,457 entitled "Firearm Handguard System",
both assigned to the assignee of the present disclosure and both
hereby incorporated by reference in their entirety.
[0054] As shown, attachment member 150 may have an outer profile
152 which substantially conforms to the inner profile 89 (FIG. 8)
of the tubular body 82. The attachment member 150 may be coupled to
the handguard 80 by being located within the elongated center
passage 84 and interference (press-fit) against tubular body 82.
Alternatively, the outer profile 152 of the attachment member 150
and/or the inner profile 89 of the tubular body 82 may be coated
with a bonding agent to form an adhesive bond therebetween.
Alternatively, adhesive bonding the attachment member 150 to the
tubular body 82 of the handguard 80 may be accomplished using the
matrix composition 110.
[0055] Such may be accomplished by placing the attachment member
150 in the forming mold for the tubular body 82, such as by
positioning the attachment member 150 on the core half of the mold,
prior to introducing the matrix composition 110. Thereafter, when
the matrix composition 110 is introduced into the molding cavity
and the tubular body 82 is formed, the attachment member 150
becomes a molded-in insert during molding of the tubular body 82
which is bonded directly to the matrix composition 110 during
molding. Alternatively, adhesive bonding the attachment member 150
to the tubular body 82 of the handguard 80 may be accomplished
using the matrix composition 110 as a coating which is applied to
the tubular body 82 after molding, which may be brushed on. The
attachment member 150 may then be placed in overlying relationship
to the coating had held with pressure thereto until the matrix
composition 110 has suitably cured.
[0056] While embodiments of the present invention have been
described and illustrated herein, those of ordinary skill in the
art will readily envision a variety of other means and/or
structures for performing the functions and/or obtaining the
results and/or one or more of the advantages described herein, and
each of such variations and/or modifications is deemed to be within
the scope of the present invention. More generally, those skilled
in the art will readily appreciate that all parameters, dimensions,
materials, and configurations described herein are meant to be
exemplary and that the actual parameters, dimensions, materials,
and/or configurations will depend upon the specific application or
applications for which the teachings of the present invention
is/are used. Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. It is, therefore, to be understood that the foregoing
embodiments are presented by way of example only and that, within
the scope of the appended claims and equivalents thereto, the
invention may be practiced otherwise than as specifically described
and claimed. The present invention is directed to each individual
feature, system, article, material, kit, and/or method described
herein. In addition, any combination of two or more such features,
systems, articles, materials, kits, and/or methods, if such
features, systems, articles, materials, kits, and/or methods are
not mutually inconsistent, is included within the scope of the
present invention.
[0057] All definitions, as defined and used herein, should be
understood to control over dictionary definitions, definitions in
documents incorporated by reference, and/or ordinary meanings of
the defined terms.
[0058] The indefinite articles "a" and "an," as used herein in the
specification and in the claims, unless clearly indicated to the
contrary, should be understood to mean "at least one."
[0059] The phrase "and/or," as used herein in the specification and
in the claims, should be understood to mean "either or both" of the
elements so conjoined, i.e., elements that are conjunctively
present in some cases and disjunctively present in other cases.
Other elements may optionally be present other than the elements
specifically identified by the "and/or" clause, whether related or
unrelated to those elements specifically identified, unless clearly
indicated to the contrary.
LISTING OF REFERENCE CHARACTERS
[0060] 10 firearm
[0061] 12 receiver
[0062] 14 lower receiver
[0063] 16 upper receiver
[0064] 18 magazine receptacle
[0065] 30 bolt carrier
[0066] 40 barrel
[0067] 50 butt stock
[0068] 60 pistol grip
[0069] 80 handguard
[0070] 82 tubular body
[0071] 83 wall of tubular body
[0072] 84 center passage
[0073] 86 tubular body outer surface
[0074] 88 tubular body inner surface
[0075] 89 inner profile
[0076] 90 apertures
[0077] 92 top side of handguard
[0078] 94 accessory rail
[0079] 96 rail ribs
[0080] 98 rail slots
[0081] 100 rail reinforcement structure
[0082] 102 reinforcement layer
[0083] 104 reinforcement layer
[0084] 106 reinforcement layer
[0085] 108 reinforcement layer
[0086] 110 matrix composition
[0087] 120 lower elongated rail segment
[0088] 122 planar upper surface
[0089] 130 upper elongated rail segment
[0090] 132 planar lower surface
[0091] 140 inner elongated rail segment
[0092] 150 attachment member
[0093] 152 outer profile
[0094] LA longitudinal axis
* * * * *