U.S. patent number RE39,465 [Application Number 10/811,794] was granted by the patent office on 2007-01-16 for modular sleeve yoke.
Invention is credited to Richard E. Swan.
United States Patent |
RE39,465 |
Swan |
January 16, 2007 |
**Please see images for:
( Reexamination Certificate ) ** |
Modular sleeve yoke
Abstract
A Swan universal receiver sleeve attached to the top of a
firearm upper receiver and extended forward above the firearm
barrel to a position just short of the firearm front sight. The
underside of the rear portion of the sleeve is fixedly attached to
the receiver top. The underside of the forward portion of the
sleeve has an upper handguard piece attached thereto. A bottom
handguard piece is fitted about the bottom of the gun barrel and is
attached to the upper handguard piece. The handguard pieces are not
physically connected in any way to the gun barrel. The sleeve is
self supported by the connection of the rear portion underside to
the receiver top. A special yoke is inserted about the barrel nut
of the firearm to which the modular sleeve is attached. The special
yoke reinforces the modular sleeve while keeping the firearm barrel
free floating.
Inventors: |
Swan; Richard E. (East
Bridgewater, MA) |
Family
ID: |
46278777 |
Appl.
No.: |
10/811,794 |
Filed: |
March 29, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
10007590 |
Dec 10, 2001 |
6490822 |
|
|
|
60274147 |
Mar 9, 2001 |
|
|
|
Reissue of: |
10061515 |
Feb 1, 2002 |
06499245 |
Dec 31, 2002 |
|
|
Current U.S.
Class: |
42/71.01;
42/75.01; 42/124 |
Current CPC
Class: |
F41G
11/003 (20130101); F41C 23/16 (20130101); F41C
23/00 (20130101) |
Current International
Class: |
F41C
23/00 (20060101) |
Field of
Search: |
;42/71.01,75.01,124 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Eldred; J. Woodrow
Attorney, Agent or Firm: Barlow, Josephs & Holmes,
Ltd.
Parent Case Text
This application is a C-I-P of Ser. No. 10/007,590 filed Dec. 10,
2001, which claims benefit of Prov. No. 60,274,147 filed Mar. 9,
2001.
Claims
I claim:
1. In combination: a modular sleeve for interfacing modular
enhancements to a firearm, said firearm having minimally a receiver
with a stock and barrel attached thereto, said barrel defining the
forward portion of the firearm and said stock defining the rearward
portion of the firearm, said firearm longitudinal axis being
defined as horizontal and running from said stock through said
receiver to said barrel, said receiver having a forward portion, a
top and a rearward portion, said barrel being joined to the forward
portion of the receiver, said stock being joined to the rearward
portion of the receiver, said barrel being detachable secured to a
screw-threaded barrel port on said receiver forward portion by
means of a barrel nut having a generally cylindrical body with a
central longitudinal threaded opening permitting the nut to be slid
over the firearm barrel, said barrel nut threaded opening adapted
to engage the screw-threaded barrel port, said barrel nut having a
forward end with a plurality of prongs protruding radially outward
from the barrel nut body, said modular sleeve comprising: a
universal receiver sleeve having a top side, an underside and two
opposite sides connecting said top side with said underside, said
universal receiver sleeve being further defined as having a forward
portion and a rear portion, the underside of the rear portion of
the universal receiver sleeve being fixedly attached to the firearm
receiver top, said receiver sleeve forward portion extended forward
above the firearm barrel; an upper handguard piece having a front,
rear, top, open bottom, opposing sides, outer side surfaces and
inner side surfaces, said top, sides and bottom defining a hollow
interior, said front and rear defining an upper handguard piece
longitudinal axis, said upper handguard piece top being joined to
the underside of the forward portion of the receiver sleeve, each
said outer side surface having two longitudinal channels formed
therein, a large and shallow upper channel and a bottom interface
channel, said channels being separated by a longitudinal element,
said bottom interface channel being positioned near to the upper
hand guard piece bottom, said upper handguard piece having a small,
circular horizontal aperture formed through each upper hand guard
piece side near to the rear in the bottom interface channel; a
bottom handguard piece having a front, rear, open top, bottom,
opposing sides, outer side surfaces and inner side surfaces, said
bottom, sides and top defining a hollow interior, said front and
rear defining a bottom handguard piece longitudinal axis, said
bottom handguard piece being removably attached to the upper
handguard piece; wherein, said upper handguard piece and attached
bottom handguard piece surround the firearm barrel without touching
said barrel; a modular sleeve yoke, comprising: a U-shaped device
having two upright elements interconnected by a curvilinear
element, said device having a top, bottom, front, rear and two
opposite sides, said curvilinear element containing said device
bottom, said upright elements terminating at the device top, said
upright elements being generally rectangular block-like elements
protruding forwardly away from said device rear, each upright
element having two sides, each upright element having at least one
threaded, lateral aperture formed therethrough, said device rear
having a channel flange formed on the curvilinear element at the
device bottom opening upward; wherein, said device rear is
positioned at and against the forward end of the barrel nut, said
device adapted to engage the barrel nut body while the channel
flange a plurality of prongs; a threaded screw inserted through
each upper handguard piece small, circular horizontal aperture for
threaded engagement with each device upright element threaded,
lateral aperture.
2. The combination as recited in claim 1, further comprising: an
indentation formed about one side of each said device, upright
element, threaded, lateral aperture, each said indentation adapted
to receive a screw head.
3. The combination as recited in .[.claim 2.]. .Iadd.claim
1.Iaddend., further comprising: a rectangular notch formed in the
channel flange at the device bottom.
4. The combination as recited in .[.claim 3.]. .Iadd.claim
1.Iaddend., wherein: said firearm has a conventional handguard
delta ring, a delta ring spring, and a delta ring lock washer,
mounted on said screw-threaded barrel port; wherein said delta ring
substantially covers the barrel nut and a portion of the special
yoke.
5. The combination as recited in .[.claim 4.]. .Iadd.claim
1.Iaddend., wherein: said barrel nut and modular sleeve yoke are
each made from steel.
6. In combination: a modular sleeve for interfacing modular
enhancements to a firearm, said firearm having minimally a receiver
with a stock and barrel attached thereto, said barrel defining the
forward portion of the firearm and said stock defining the rearward
portion of the firearm, said firearm longitudinal axis being
defined as horizontal and running from said stock through said
receiver to said barrel, said receiver having a forward portion, a
top and a rearward portion, said barrel being joined to the forward
portion of the receiver, said stock being joined to the rearward
portion of the receiver, said barrel being detachable secured to a
screw-threaded barrel port on said receiver forward portion by
means of a barrel nut having a generally cylindrical body with a
central longitudinal threaded opening permitting the nut to be slid
over the firearm barrel, said barrel nut threaded opening adapted
to engage the screw-threaded barrel port, said barrel nut having a
forward end with a plurality of prongs protruding radially outward
from the barrel nut body, said modular sleeve comprising: a
universal receiver sleeve having a top side, an underside and two
opposite sides connecting said top side with said underside, said
universal receiver sleeve being further defined as having a forward
portion and a rear portion, the underside of the rear portion of
the universal receiver sleeve being fixedly attached to the firearm
receiver top, said receiver sleeve forward portion extended forward
above the firearm barrel; an upper handguard piece having a front,
rear, top, open bottom, opposing sides, outer side surfaces and
inner side surfaces, said top, sides and bottom defining a hollow
interior, said front and rear defining an upper handguard piece
longitudinal axis, said upper handguard piece top being joined to
the underside of the forward portion of the receiver sleeve, each
said outer side surface having two longitudinal channels formed
therein, a large and shallow upper channel and a bottom interface
channel, said channels being separated by a longitudinal element,
said bottom interface channel being positioned near to the upper
hand guard piece bottom, said upper handguard piece having a small,
circular vertical aperture formed through the longitudinal element
along each upper hand guard piece side near to the upper handguard
piece rear, said upper hand guard piece side having a notch formed
along the bottom at the rear; a bottom handguard piece having a
front, rear, open top, bottom, opposing sides, outer side surfaces
and inner side surfaces, said bottom, sides and top defining a
hollow interior, said front and rear defining a bottom handguard
piece longitudinal axis, said bottom handguard piece being
removably attached to the upper handguard piece; wherein, said
upper handguard piece and attached bottom handguard piece surround
the firearm barrel without touching said barrel; a modular sleeve
yoke, comprising: a U-shaped device having two upright elements
interconnected by a curvilinear element, said device having a top,
bottom, front, rear and two opposite sides, said curvilinear
element containing said device bottom, said upright elements
terminating at the device top, said upright elements having
generally rectangular block-like elements protruding laterally
sideways, each laterally protruding block-like elements having a
top with at least one threaded, vertical aperture formed there
through, said device rear having a channel flange formed on the
curvilinear element at the device bottom opening upward; wherein,
said device rear is positioned at and against the forward end of
the barrel nut, said device adapted to engage the barrel nut body
while the channel flange a plurality of prongs; a threaded screw
inserted through each upper handguard piece small, circular
vertical aperture for threaded engagement with each device upright
element protruding block-like element threaded, vertical aperture;
wherein, each the top of each laterally protruding block-like
element engages each upper hand guard piece side notch.
7. The combination as recited in claim 6, further comprising: an
indentation formed on the top of each laterally protruding
block-like element said device, about each threaded, vertical
aperture.
8. The combination as recited in .[.claim 7.]. .Iadd.claim
6.Iaddend., further comprising: a rectangular notch formed in the
channel flange at the device bottom.
9. The combination as recited in .[.claim 8.]. .Iadd.claim
6.Iaddend., wherein: said firearm has a conventional handguard
delta ring, a delta ring spring, and a delta ring lock washer,
mounted on said screw-threaded barrel port; wherein said delta ring
substantially covers the barrel nut and a portion of the special
yoke.
10. The combination as recited in .[.claim 9.]. .Iadd.claim
6.Iaddend., wherein: said barrel nut and modular sleeve yoke are
each made from steel.
.Iadd.11. A system for attaching modular enhancements to a firearm,
said firearm having a receiver, said receiver having a top and a
barrel receiving receptacle at a forward end thereof, said firearm
further including a barrel received in said barrel receiving
receptacle and a barrel nut received around an outer surface of
said barrel receiving receptacle to retain said barrel within said
barrel receiving receptacle, said system comprising: a receiver
sleeve having a top, an underside, a forward portion and a rear
portion, wherein the underside of the rear portion of the receiver
sleeve is configured and arranged to be fixedly attached to the top
of said firearm receiver and said forward portion of said receiver
sleeve is configured to extend above at least a portion of the
firearm barrel; a handguard piece depending from the underside of
the forward portion of the receiver sleeve, said handguard piece
having a side wall that forms a hollow interior cavity, a forward
end, and a rearward end, wherein said sidewall of said handguard
piece surrounds the firearm barrel without touching said barrel,
said rearward end of said handguard piece being adjacent said
forward end of said receiver when said receiver sleeve is attached
to said firearm receiver; and a yoke configured and arranged for
engagement with said barrel nut, said yoke extending forwardly into
said reward end of said handguard piece, said yoke being further
configured and arranged for engagement with said rearward end of
said handguard piece, wherein said yoke supports said handguard
piece relative to said receiver..Iaddend.
.Iadd.12. The system of claim 11 wherein said yoke includes means
for releasably engaging said barrel nut, and further includes means
for releasably engaging said rearward end of said handguard
piece..Iaddend.
.Iadd.13. The system of claim 12 wherein said means for releasably
engaging said barrel nut comprises a flange channel..Iaddend.
.Iadd.14. The system of claim 12 wherein said means for releasably
engaging said rearward end of said handguard piece comprises a
fastener extending through an aperture in said rearward end of the
handguard piece, and into a threaded aperture in said
yoke..Iaddend.
.Iadd.15. The system of claim 11, wherein said top side of said
receiver sleeve includes a dovetail interface element extending
longitudinally along at least a portion of the top of the receiver
sleeve, said dovetail interface element being configured and
arranged for the mounting of ancillary equipment..Iaddend.
.Iadd.16. The system of claim 11, further comprising: at least one
external dovetail interface element arranged on the sidewall of
said handguard piece, said external dovetail element being
configured and arranged for the mounting of ancillary
equipment..Iaddend.
.Iadd.17. The system of claim 16 wherein said at least one external
dovetail interface element is removably secured to said sidewall of
said handguard piece..Iaddend.
.Iadd.18. The system of claim 16, wherein said at least one
external dovetail interface element comprises: three external
dovetail interface elements arranged on the sidewall of said
handguard piece at 3:00, 6:00 and 9:00 positions..Iaddend.
.Iadd.19. The system of claim 18 wherein said external dovetail
interface elements are removably secured to said sidewall of said
handguard piece..Iaddend.
.Iadd.20. A system for attaching modular enhancements to a firearm,
said firearm having a receiver, said receiver having a top and a
barrel receiving receptacle at a forward end thereof, said firearm
further including a barrel received in said barrel receiving
receptacle and a barrel nut received around an outer surface of
said barrel receiving receptacle to retain said barrel within said
barrel receiving receptacle, said system comprising: a receiver
sleeve having a top, an underside, a forward portion and a rear
portion, wherein the underside of the rear portion of the receiver
sleeve is configured and arranged to be fixedly attached to the top
of said firearm receiver and said forward portion of said receiver
sleeve is configured to extend above at least a portion of the
firearm barrel; an upper handguard piece depending from the
underside of the forward portion of the receiver sleeve, said upper
handguard piece having a side wall that forms a hollow interior
cavity, a forward end, and a rearward end, wherein said sidewall of
said handguard piece at least partially surrounds the firearm
barrel without touching said barrel, said rearward end of said
handguard piece being adjacent said forward end of said receiver
when said receiver sleeve is attached to said firearm receiver; and
a yoke configured and arranged for engagement with said barrel nut,
said yoke extending forwardly toward said reward end of said upper
handguard piece, said yoke being further configured and arranged
for engagement with said rearward end of said upper handguard
piece, wherein said yoke supports said upper handguard piece
relative to said receiver..Iaddend.
.Iadd.21. The system of claim 20 wherein said yoke includes means
for releasably engaging said barrel nut, and further includes means
for releasably engaging said rearward end of said upper handguard
piece..Iaddend.
.Iadd.22. The system of claim 21 wherein said means for releasably
engaging said barrel nut comprises a flange channel..Iaddend.
.Iadd.23. The system of claim 21 wherein said means for releasably
engaging said rearward end of said upper handguard piece comprises
a fastener extending through an aperture in said rearward end of
the upper handguard piece, and into a threaded aperture in said
yoke..Iaddend.
.Iadd.24. The system of claim 20, wherein said top side of said
receiver sleeve includes a dovetail interface element extending
longitudinally along at least a portion of the top of the receiver
sleeve, said dovetail interface element being configured and
arranged for the mounting of ancillary equipment..Iaddend.
.Iadd.25. The system of claim 20, further comprising: at least one
external dovetail interface element arranged on the sidewall of
said handguard piece, said external dovetail element being
configured and arranged for the mounting of ancillary
equipment..Iaddend.
.Iadd.26. The system of claim 25 wherein said at least one external
dovetail interface element is removably secured to said sidewall of
said handguard piece..Iaddend.
.Iadd.27. The system of claim 25, wherein said at least one
external dovetail interface element comprises: three external
dovetail interface elements arranged on the sidewall of said
handguard piece at 3:00, 6:00 and 9:00 positions..Iaddend.
.Iadd.28. The system of claim 27 wherein said external dovetail
interface elements are removably secured to said sidewall of said
handguard piece..Iaddend.
.Iadd.29. A system for attaching modular enhancements to a firearm,
said firearm including a receiver having a forward portion and a
top, and further including a barrel joined to the forward portion
of the receiver, said system comprising: a receiver sleeve having a
top, an underside, a forward portion and a rear portion, wherein
the underside of the rear portion of the receiver sleeve is
configured and arranged to be fixedly attached to the top of said
firearm receiver and said forward portion of said receiver sleeve
is configured to extend above at least a portion of the firearm
barrel; a handguard piece depending from the underside of the
forward portion of the receiver sleeve, said handguard piece having
a side wall that forms a hollow interior cavity, a forward end, and
a rearward end, wherein said sidewall of said handguard piece
surrounds the firearm barrel without touching said barrel, said
rearward end of said handguard piece being adjacent said forward
end of said receiver when said receiver sleeve is attached to said
firearm receiver; and a yoke element coupled to said forward
portion of said receiver, said yoke element extending forwardly
from said receiver into said rearward end of said handguard piece,
said yoke element being configured and arranged for engagement with
said rearward end of said handguard piece, wherein said yoke
element supports said handguard piece relative to said
receiver..Iaddend.
.Iadd.30. A system for attaching modular enhancements to a firearm,
said firearm including a receiver having a forward portion and a
top, and further including a barrel joined to the forward portion
of the receiver, said system comprising: a receiver sleeve having a
top, an underside, a forward portion and a rear portion, wherein
the underside of the rear portion of the receiver sleeve is
configured and arranged to be fixedly attached to the top of said
firearm receiver and said forward portion of said receiver sleeve
is configured to extend above at least a portion of the firearm
barrel; a handguard piece depending from the underside of the
forward portion of the receiver sleeve, said handguard piece having
a side wall that forms a hollow interior cavity, a forward end, and
a rearward end, wherein said sidewall of said handguard piece
surrounds the firearm barrel without touching said barrel, said
rearward end of said handguard piece being adjacent said forward
end of said receiver when said receiver sleeve is attached to said
firearm receiver; and a supporting element engaged with said
forward portion of said receiver, said supporting element extending
forwardly from said forward portion of said receiver into said
reward end of said handguard piece, said supporting element being
configured and arranged for engagement with said rearward end of
said handguard piece, wherein said supporting element supporting
said handguard piece relative to said receiver..Iaddend.
.Iadd.31. A system for attaching modular enhancements to a firearm,
said firearm having a receiver, said receiver having a top and a
barrel receiving receptacle at a forward end thereof, said firearm
further including a barrel received in said barrel receiving
receptacle and a barrel nut received around an outer surface of
said barrel receiving receptacle to retain said barrel within said
barrel receiving receptacle, said system comprising: an upper
handguard piece having a forward end and a rearward end, and
further having a dovetail rail extending longitudinally between the
forward end and the rearward end; a U-shaped supporting yoke
removably secured to said rearward end of said upper hand guard,
said U-shaped supporting yoke including engagement surfaces
configured to cooperatively engage an outer surface of said barrel
nut and thereby support said upper handguard piece relative to said
barrel nut, wherein said upper handguard piece extends from said
forward end of said upper receiver forwardly above said barrel
without engaging said barrel..Iaddend.
.Iadd.32. The system of claim 31, wherein said upper handguard
piece includes opposing side walls that extend outwardly and
downwardly from said dovetail rail, said opposing side walls
terminating in opposing interface channels..Iaddend.
.Iadd.33. The system of claim 32 wherein each of said
longitudinally extending interface channels has an upper wall and a
lower wall, and said lower wall comprises a plurality of spaced
wall segments..Iaddend.
.Iadd.34. The system of claim 31 further comprising a bottom
firearm accessory, said upper handguard piece and said bottom
firearm accessory including interfitting mating formations for
removably securing said bottom firearm accessory to said upper
handguard piece..Iaddend.
.Iadd.35. The system of claim 32 further comprising a bottom
firearm accessory having opposing side walls that extend outwardly
and upwardly, said opposing sidewalls including protrusions that
interfittingly engage within said interface channels..Iaddend.
.Iadd.36. The system of claim 33 further comprising a bottom
firearm accessory having opposing sidewalls that extend outwardly
and upwardly, said opposing sidewalls including protrusions that
interfittingly engage within said interface channels, said
protrusions comprising a plurality of spaced protrusions that
matingly interfit between said spaced wall segments..Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates to integration means, and more particularly
to a device added to a firearm for incorporating ancillary
equipment.
As the field of combat and commercial weaponry expands, numerous
add-on enhancements have become available for attachment to
standard firearms thereby significantly upgrading the capability of
the firearm. Various methods and means have been developed for
interfacing the various add-on enhancements to firearms.
Applicant's U.S. Pat. No. 5,142,806, incorporated herein by
reference, discloses a universal receiver sleeve having an upper
interface portion with standard, universal dimensions regardless of
the firearm and having a lower interface portion specific to a
particular firearm.
Although the principles of the above identified patented device are
generally applicable to all firearms, the specific firearm example
identified in the patent was the U.S. military M16 rifle and
carbine. The M16 has been in service for a number of years and will
continue to be a popular rifle both in the U.S. military and
foreign military for the foreseeable future. However, with the
increasing development and refinement of laser technology, it has
become highly desirable to integrate laser technology capabilities
onto and into firearms, especially the commonly used M16.
The problem with integrating laser technology to firearms is the
inherent conflict between a gun barrel's physical functioning and
the rigid environment required for laser operations. For maximum
results, a gun barrel should be physically isolated, i.e.,
"floating". It is preferred that nothing be attached to the gun
barrel, thereby isolating the barrel physically and eliminating
bending and "droop" along the barrel's longitudinal axis. The ideal
arrangement for lasers and ancillary optics and electronics is one
of complete isolation from the gun barrel. The temperature of a gun
barrel in use can rise to 900.degree. F. This type of heat, as well
as the physical shock on the gun barrel from firing, will quickly
destroy lasers and ancillary optics and electronics.
The heat generated by the gun barrel transfers directly to any
devices touching it thereby directly transferring enough heat to
burn hands and destroy attached electrical devices. Further
compounding this problem is the requirement that gun barrels be
extra heavy to support the added weight attached by means of the
collars. This in turn means more cantilevered stress on the barrel
where it is joined with the M-16's aluminum receiver. The
combination of heat and barrel weight tend to pull the barrel
chamber out of alignment with the bolt lead, thereby causing bolt
lug and extractor failure.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types
of devices now present in the prior art, the present invention
provides a modular receiver sleeving system. As such, the general
purpose of the present invention, which will be described
subsequently in greater detail, is to provide a new and improved
interface means for firearms which will isolate the gun barrel
while providing various capabilities for mounting and integrating
optics, lasers and sensors.
To attain this, the present invention extends the Swan universal
receiver sleeve forward above the firearm barrel to a position just
short of the firearm front sight. A weaver type interface return
portion may be provided on the underside of the sleeve, or left
solid over the barrel in front of the receiver to accommodate solid
handguards or modular, dovetailed handguards. The underside of the
rear portion of the sleeve is fixedly attached to the receiver top.
The underside of the forward portion of the sleeve has an upper
handguard piece attached thereto. A bottom handguard piece is
fitted about the bottom of the gun barrel and is attached to the
upper handguard piece via a unique channel and track system. The
handguard pieces are not physically connected in anyway to the gun
barrel. The sleeve is self supported by the connection of the rear
portion underside to the receiver top. Laser, electronics and
optics modules may optionally be attached to the sleeve top side or
to the upper handguard piece via special male and female dovetail
track devices. The barrel of the rifle is essentially free
floating. This permits greater shooting accuracy and protects
sensitive electrical components integrated into and onto the
firearm via the invention. Lighter weight barrels can be utilized
as they are no longer deflected by outside pressure and direct
transfer of heat to the hand is also eliminated.
Although the modular sleeve is self supported by the connection of
the rear portion underside to the receiver top, additional support
may be provided by the addition of a special yoke about the barrel
nut of the firearm to which the modular sleeve is attached. The
special yoke of the present invention, reinforces the modular
sleeve while keeping the firearm barrel free floating.
Specifically, the present invention is a modular sleeve for
interfacing modular enhancements to a firearm, said firearm having
minimally a receiver with a stock and barrel attached thereto, said
barrel defining the forward portion of the firearm and said stock
defining the rearward portion of the firearm, said firearm
longitudinal axis being defined as horizontal and running from said
stock through said receiver to said barrel, said receiver having a
forward portion, a top and a rearward portion, said barrel being
joined to the forward portion of the receiver, said stock being
joined to the rearward portion of the receiver. The modular sleeve
is made up of a universal receiver sleeve having a top side, an
underside and two opposite sides connecting said top side with said
underside, said universal receiver sleeve being further defined as
having a forward portion and a rear portion, the underside of the
rear portion of the universal receiver sleeve being fixedly
attached to the firearm receiver top, said receiver sleeve forward
portion extended forward above the firearm barrel. The modular
sleeve has an upper handguard piece with a front, rear, top, open
bottom, opposing sides, outer side surfaces and inner side
surfaces, said top, sides and bottom defining a hollow interior,
said front and rear defining an upper handguard piece longitudinal
axis, said upper handguard piece top being joined to the underside
of the forward portion of the receiver sleeve. The modular sleeve
also has a bottom handguard piece having a front, rear, open top,
bottom, opposing sides, outer side surfaces and inner side
surfaces, said bottom, sides and top defining a hollow interior,
said front and rear defining a bottom handguard piece longitudinal
axis, said bottom handguard piece being removably attached to the
upper handguard piece. The upper handguard piece and attached
bottom handguard piece surround the firearm barrel without touching
said barrel. A special yoke is positioned about the firearm barrel
nut of the firearm to which the modular sleeve is attached, said
upper handguard piece rear being attached to said special yoke. The
special yoke is held in place on the barrel nut by attachment to
the modular sleeve and the barrel nut. The special yoke may be
further held in place by a delta ring with those firearms with a
handguard delta ring.
The present invention provides a foundation for integrated laser
fire control devices, sensors, communications, and a vast array of
quickly attached ancillary devices, such as standard night vision,
thermal, shot guns, grenade launchers, and other special
systems.
The extra heavy barrels required on conventional rifles and
carbines are no longer required with the present invention. A
standard heavy or light weight barrel can be utilized because the
present invention isolates and prevents hand, sling, and bipod
pressure from deflecting the barrel. With the present invention,
barrel handguards are not attached to the hot barrels, and provide
a much cooler grip for the shooter. Weight reductions of at least
one-half pound can be accomplished by use of a light weight barrel
and the elimination of conventional solid aluminum and/or plastic
handguards and their barrel hardware.
The modular sleeve is attached to the firearm upper receiver in a
manner that provides a solid system, attachable or removable by a
qualified armorer or a trained soldier. Greater accuracy is
accomplished because the firearm has a free floating barrel with
the instant invention and thereby no outside forces deflecting
point of aim.
These together with other objects of the invention, along with
various features of novelty which characterize the invention, are
pointed out with particularity in the claims annexed hereto and
forming a part of this disclosure. For a better understanding of
the invention, its operating advantages and the specific objects
attained by its uses, reference should be had to the accompanying
drawings and descriptive matter in which there is illustrated a
preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a standard combat firearm.
FIG. 2 is a front perspective view of a universal receiver
sleeve;
FIG. 3 is a front perspective view of the rear portion of the
sleeve of FIG. 2.
FIG. 4 is a front perspective view of a modular sleeve mounted on a
firearm.
FIG. 5 is a front, exploded perspective view of a modular
sleeve.
FIG. 6A is a diagrammic front view of a modular sleeve, with bottom
handguard attached, positioned about a rifle barrel.
FIG. 6B is a diagrammic front view of another embodiment of a
modular sleeve, with bottom handguard attached, positioned about a
rifle barrel.
FIG. 6C is a diagrammic front view of the modular sleeve of FIG. 6A
with dovetail interface element attached.
FIG. 7 is a bottom perspective view of the bottom handguard.
FIG. 8 is a top perspective view of the upper handguard.
FIG. 9 is a top sectional view of the bottom handguard with
exploded attachment element.
FIG. 10 is a top sectional view of the bottom handguard with
attachment element.
FIG. 11 is sectional view of the interior of the bottom
handguard.
FIG. 12 is a close-up view of a section of the bottom
handguard.
FIG. 13 is a front, top perspective view of the bottom
handguard.
FIG. 14 is a rear perspective view of the modular sleeve.
FIG. 15 is a rear perspective view of another embodiment of the
modular sleeve.
FIG. 16 is an exploded view of the modular sleeve embodiment of
FIG. 15.
FIG. 17 shows a side elevational view of the connection between the
firearm barrel and the firearm receiver.
FIG. 18 provides a disassembled, or exploded, view of the parts of
the assembly shown in FIG. 17.
FIG. 19 is a side elevational view of the various parts of the
assembly shown in FIG. 18.
FIG. 20 is a front elevational view of each of the parts shown in
FIG. 19.
FIG. 21A is a front elevational view of the special yoke of the
present invention.
FIG. 21B is a rear elevational view of the special yoke of the
present invention.
FIG. 21C is a bottom view of the special yoke of the present
invention.
FIG. 21D is a top view of the special yoke of the present
invention.
FIG. 21E is a side elevational view of the special yoke of the
present invention.
FIG. 22 is a sectional side view along the line 22--22 of FIG.
21B.
FIG. 23A is a front, perspective view of the upper hand guard
piece.
FIG. 23B is a rear perspective view of the upper hand guard
piece.
FIG. 24 is a side view, partly in section, of the special yoke
engaging the firearm barrel nut.
FIG. 25 is a bottom view of the yoke engaged to the barrel nut.
FIG. 26A is a front elevational view of another embodiment of the
special yoke of the present invention.
FIG. 26B is a rear elevational view of the special yoke of FIG.
26A.
FIG. 26C is a bottom view of the special yoke of FIG. 26A.
FIG. 26D is a top view of the special yoke of FIG. 26A.
FIG. 26E is a side elevational view of the special yoke of FIG.
26A.
FIG. 27 is a sectional side view along the line 27--27 of FIG.
26B.
FIG. 28A is a front, perspective view of another embodiment of the
upper hand guard piece.
FIG. 28B is a rear perspective view of the upper hand guard piece
of FIG. 28A.
FIG. 29 is a side view, partly in section, of the second embodiment
special yoke engaging the firearm barrel nut.
FIG. 30 is a bottom view of the second embodiment special yoke
engaged to the barrel nut.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in detail wherein like elements are
indicated by like numerals, there is shown in FIG. 1 an outline of
a conventional combat firearm 10 having a conventional stock 11,
upper receiver 12 with flat top 13, lower receiver 17, barrel 16,
pistol grip 7, and magazine 9. The barrel 16 is joined to the upper
receiver 12. The barrel 16 defines the forward portion of the
firearm 10 and the stock 11 defines the rearward portion of the
firearm 10. The longitudinal axis of the firearm 10 runs from stock
11 through receiver 12, 17 to barrel 16. The barrel 16 is joined to
the forward portion 14 of the upper receiver 12, i.e., the upper
receiver 12 "receives" the barrel 16. The stock 11 is joined to the
rear portion 15 of the upper receiver 12. The barrel 16 has
protective handguards 18 about its circumference.
As shown more particularly in FIGS. 17-20, the firearm barrel 16 is
detachably secured to a screw-threaded barrel port 160 at the front
of the upper receiver forward portion 14 by means of a barrel nut
assembly 161. The barrel nut assembly 161 is comprised of a barrel
nut 170, a delta ring 162, a delta ring spring 163, and a delta
ring lock washer 164. The delta ring 162 is used to hold
conventional handguards (not shown) in place. As may be best seen
in FIG. 20, the tops of the barrel nut 170, delta ring 162, delta
ring spring 163 and delta ring lock washer 164 are either notched
or open to accommodate the firearm's gas tube (not shown). When the
barrel nut assembly 161 is assembled as shown in FIG. 17, the
spring 163 urges the delta ring 162 over the barrel nut 170.
The present invention provides a modular sleeve 1 about the firearm
barrel 16 replacing the firearm's conventional handguards with a
handguard assembly integrated into the modular sleeve 1. The
present invention is anchored by the universal receiver sleeve 2
disclosed in applicant's U.S. Pat. No. 5,142,806, issued on Sep. 1,
1992, "Universal Receiver Sleeve", to Richard E. Swan, and
incorporated herein by reference.
Referring more particularly to FIGS. 2 and 3, a universal receiver
sleeve 2 is fully illustrated. FIG. 2 illustrates a full universal
receiver sleeve 2 comprised of a front portion 3, a rear portion 4
and two sides 5. FIG. 3 illustrates the receiver rear portion 4
only. The receiver sleeve rear portion 4 only is actually joined to
the upper receiver 12. The rear portion 4 is attached to the upper
receiver 12 by means of one or more fasteners 33 joined through the
sleeve sides 5 across the receiver top 13. The sleeve front portion
3 extends forwardly over the firearm barrel 16. The Swan sleeve 2
has a top section 20 (see FIGS. 2 and 3) and a bottom section 40
(see FIG. 3) and a longitudinal axis extending in spaced, parallel
relation to the longitudinal axis of the firearm 10. The receiver
sleeve top section 20 has a longitudinal, horizontally positioned
base portion 21 along its length. The base portion 21 has two long
side edges 29. A first longitudinal rail 22 extends upward from the
base portion 21 adjacent one of the long side edges 29 and a second
longitudinal rail 23 extends upward from the base portion 21
adjacent the other of the long side edges 29. The second rail 23 is
in spaced parallel relationship to the first rail 22. A
longitudinal opening, i.e., channel 28, is formed between the first
and second rails 22, 23. The upper surface 24 of the first rail 22
lies on the same horizontal plane as the upper surface 25 of the
second rail 23. Optional notches 26 may also be provided in the
rails 22, 23. The notches 26 provide additional means of engaging
other components. The quantity and placement of pairs of notches 26
are as required or needed. Each of the two long side edges 29 of
the base portion 21 and rails 22, 23 are integral with external
angled engagement surfaces 30 which extend the full length of the
top section 20.
The receiver sleeve top section 20 is joined to the receiver sleeve
bottom section 40. The receiver sleeve bottom section also has a
longitudinal, horizontally positioned base portion 41 along its
length. The base portion 41 has two long side edges 49. A first
rail 42 extends downward from the base portion 41 adjacent one of
the long side edges 49 and a second rail 43 extends down-ward from
the base portion 41 adjacent the other of the long side edges 49.
The second rail 43 is in spaced parallel relationship to the first
rail 42. The top section base 21 is joined in a mirrored, face to
face relationship to the bottom section base 41. The lower surface
44 of the first rail 42 lies on the same horizontal plane as the
lower surface 45 of the second rail 43. Each of the two long side
edges 49 of the base portion 41 and the rails 42, 43 are integral
with an angled engagement surface 50 which extends the full length
of the bottom section 40. A longitudinal resultant channel 48 is
formed between the integrated rail-angled engagement surfaces 42,
50 and 43, 50. The cross section shape of the channel 48 will vary
from firearm to firearm depending on the upper receiver top 13
contour of the particular firearm. The channel 48 is the interface
and engagement means between the receiver sleeve 2 and the firearm
10 or the sleeve 2 and other firearm ancillary elements. The
nominal cross section of the channel 48 and the cross section of
the receiver sleeve top section 20 are identical. This permits
complex integration of various modules to a firearm 10. In this
embodiment of the invention the channel cross section provides a
weaver type interface return.
The present invention provides for extension of the receiver sleeve
2 forward above the firearm barrel 16 to a position just short of
the firearm front sight 19. This is the sleeve front portion 3
described above. The receiver sleeve bottom section 40 may be a
weaver type interface or left solid over the barrel 16 in the
receiver front portion 3 to accommodate solid handguards or
modular, dovetailed handguards. The bottom section 40 of the rear
portion 4 of the sleeve 2 has a weaver type interface and is
fixedly attached to the receiver top 13. In the present invention
the bottom section 40 of the front portion 3 of the sleeve 2 has an
upper handguard piece 50 attached thereto. A bottom handguard piece
70 is fitted about the bottom of the gun barrel 16 and is attached
to the upper handguard piece 50. The handguard pieces 50, 70 are
not physically connected in any way to the gun barrel 16. The
sleeve 2 is self supported by the joining of the sleeve rear
portion 4 bottom section 40 to the receiver top 13. In another
embodiment of the invention shown in FIG. 6A the top of the 53
upper handguard 50 and receiver sleeve bottom section 40 may be
integrated into one piece, thereby forming a resulting upper
handguard piece top 53, said resulting upper handguard piece top
having an upper surface 49 and an undersurface 59. Laser,
electronics and optics modules may optionally be attached to the
sleeve top section 20 or to the upper handguard piece 50 via
special male and female dovetail track devices. The barrel 16 of
the firearm 10 is essentially free floating. This permits greater
shooting accuracy and protects sensitive electrical components
integrated into and onto the firearm. Lighter weight barrels can be
utilized as they are no longer deflected by outside pressure and
direct transfer of heat to the hand is eliminated.
As may also be seen in FIGS. 2 and 3, in practice, the receiver
sleeve rear portion 4 would incorporate a standard non-optical,
flip up sight 6 at the rear 35 of the receiver top section 20.
Windage and elevational adjustments 36 and 37 may also be included.
Although for illustrative purposes the flip up sight 6 is not shown
in the modular sleeve figures, as a desired feature, a flip up
sight would normally be included with the modular sleeve 1.
Referring more particularly to FIGS. 4-16, the upper handguard
piece 50 has a front 51, rear 52, top 53, open bottom 54, opposing
sides 55, outer side surfaces 56 and inner side surfaces 57, said
top 53 and sides 55 defining an interior 58. The front 51 and rear
52 define the upper handguard piece's longitudinal axis. The top 53
may be formed into a male weaver type interface. Each of the upper
handguard side outer surfaces 56 have two longitudinal channels
formed therein, i.e., a large and shallow upper channel 60 and a
bottom interface channel 61. The concave shape formed in the upper
handguard piece by the channel 60 permits heat to escape faster
from the firearm barrel area. The channel also permits ancillary
equipment to be placed closer to the center line of the barrel
bore. The bottom interface channel 61 is positioned near to the
bottom 54 and has a general female, T-shaped cross section.
The bottom handguard piece 70 has a front 71, rear 72, open top 73,
bottom 74, opposing sides 75, outer side surfaces 76 and inner side
surfaces 77, said bottom top 74 and sides 75 defining an interior
78. The front 71 and rear 72 define the bottom handguard piece's
longitudinal axis. The bottom 74 may be formed into a male weaver
type interface. Each of the bottom handguard side outer surfaces 76
have two longitudinal channels formed therein, i.e., a small and
shallow upper channel 80 and a larger, shallow bottom channel 81.
The channels 80, 81 provide hand gripping means for a user.
The upper handguard rear 52 and bottom handguard piece rear 72 may
be shaped to accommodate various firearm barrel-receiver connection
means. FIG. 14 illustrates an example of a military application for
a firearm which has the normal handguard delta ring 162 removed.
FIG. 15 illustrates a typical commercial application wherein the
firearm normal handguard delta ring 162 has not been removed. This
requires that the upper handguard piece rear 52 be cut back more
than the military version shown in FIG. 14 in order to accommodate
the delta ring 162.
The bottom hand guard inner side surfaces 77 each have a
longitudinal T-shaped protrusion 82 position near to the top 73,
each protrusion being a mirror of the other. The bottom handguard
piece 70 is adapted to being joined to the upper handguard piece 50
by sliding the bottom handguard longitudinal T-shaped protrusion 82
into the upper handguard bottom interface channel 61.
Referring more particularly to FIGS. 9-13 spring-loaded connectors
88 are inserted through the bottom handguard piece sides 75 to hold
the handguard pieces 50, 70 in proper alignment.
Apertures 62 may be formed in the upper handguard shallow upper
channel 60 for heat ventilating purposes. The upper handguard rear
52 may also be tapered back toward the top 53 to add strength to
the invention. Apertures 84 may also be formed in the lower
handguard lower channel 81 for heat ventilating purposes.
Referring particularly to FIGS. 6A and 6B, the lower handguard
piece left and right T-shaped protrusions 82 engage the upper
handguard piece bottom interface channels 61. In one embodiment of
the invention, the bottom handguard piece 70 is positioned fully to
the upper handguard piece front 51 and then brought back rearwardly
in order to have the lower handguard piece left and right T-shaped
protrusions 82 engage the upper handguard piece bottom interface
channels 61. To eliminate this requirement, the invention
embodiment shown provides for an interrupted interface railing
system comprised of cutout portions 65, 85 in the upper handguard
interface channel 61 and bottom handguard upper channel 80. Each
remaining stud 66, 86 of the interface channel 61 and channel 80 is
a nominal 3/4 inch in longitudinal length. The cutout portions 65,
85 are also a nominal 3/4 inch in longitudinal length. This allows
the lower handguard piece 70 to be placed a nominal 3/4 inch
forward of and in alignment with the upper handguard piece 50. The
lower handguard piece 70 is then pulled back rearwardly 3/4 inch.
The studs 66, 86 then fully engage and lock into one another.
Referring more particularly to FIGS. 5, 6A, 6B, 8, and 14-16, the
upper handguard piece top 53 and/or receiver sleeve front portion
3, may have a longitudinal gap 130 formed therein. This permits the
direct attachment of various aiming, optical and directed energy
devices to the upper handguard top 53, or the attachment of various
interface longitudinal elements 131 adapted and configured to join
various aiming, optical and directed energy devices to the modular
sleeve upper handguard piece top 53. See FIG. 8. The gap 130
provides room to compensate for various height requirements for the
various devices. The gap 130 is most clearly shown in FIG. 14. An
interface element 131 attached to the gap 130 is most clearly shown
in FIG. 15. In another embodiment of the invention shown in FIG.
16, a hinging element 132 is fixed to the upper handguard piece top
53 at the front 51 and is adapted to pivotally join an interface
element 131 which may have different attachment configurations on
each surface.
Referring more particularly to FIGS. 6C, and 9-13, the modular
sleeve is further enhanced wherein several of the studs 86 of the
bottom handguard piece 70 are reduced in longitudinal length to a
nominal 1/2 inch. This permits engagement of an external dovetail
interface element 90. Each external dovetail interface element 90
has an exterior horizontal surface 91 with a cross-sectional
dovetail shape adapted to attach ancillary equipment, and an
opposite, generally flat, interior surface 93 having one or more
T-shaped protrusion 92 adapted to engage the cutout portions 85 of
the lower handguard upper channels 80 and come into alignment with
the studs 86 for engagement with the upper handguard interface
channel 61. Any number of studs 86 may be modified in any nominal
longitudinal length to accommodate dovetail interface elements 90
of varying lengths. The dovetail interface elements 90 also have
one or more apertures 94 formed therethrough, said apertures 94
adapted to receive a screw 96. The screw 96 enables a dovetail
interface element 90 to be engaged directly to the modular sleeve 1
at one of the apertures 98 formed directly at various points in the
modular sleeve 1. The modular sleeve apertures 98 may have
helicoils 99 inserted therein to provide threaded engagement with a
screw 96.
The receiver top 13 has a plurality of notches 8 formed thereon,
each said notch 8 having a rectangular cross section and are formed
transverse to the longitudinal axis of the firearm 10. The
universal receiver sleeve 2 has an elongated rectangular opening
150 formed in a first universal receiver sleeve opposite side 5,
said rectangular opening 150 extending from the universal received
sleeve opposite side lower surface 45 a predetermined distance
toward the universal receiver top side 25 terminating in a
rectangular opening upper edge 151, said rectangular opening upper
edge having a plurality of rectangular notches 141 formed therein.
The second universal receiver sleeve opposite side 5' has a
plurality of apertures 152 formed therein, each said aperture 152
being formed directly opposite a first universal received sleeve
opposite side rectangular notch 141.
A sleeve dovetail interface element 140 is provided for engagement
with the universal receiver sleeve rear portion 4. The sleeve
dovetail interface element 140 has an exterior horizontal surface
142 with a unique cross-sectional dovetail shape adapted to attach
ancillary equipment, and an opposite interior surface 143 with a
standard dovetail configuration for securing the universal receiver
sleeve rear portion 4 to the receiver top 13. There are a plurality
of projecting elements 144 formed on the sleeve dovetail interface
element interior surface 143, each said projecting element 144
having a rectangular cross-section, said projecting elements 144
adapted to engage the notches 8 across the receiver top 13. The
sleeve dovetail interface element interior surface 143 is adapted
to engage said universal receiver sleeve opposite side elongated
opening 150 and a side 153 of said receiver top 13. The sleeve
dovetail interface element interior surface projecting elements 144
are adapted to engage the elongated rectangular opening rectangular
notches 141, the receiver top notches 8 and the apertures 152 in
said second received sleeve opposite side 5'. Special nuts 145,
each adapted to engage a portion of a sleeve dovetail interface
element interior surface projecting element projecting through each
aperture 152 are also provided. The sleeve dovetail interface
element 140 permits devices to be secured to the side of a firearm,
adjacent to the upper receiver without interfering with the
functions or handling of the firearm.
Referring more particularly to FIGS. 17-25, the firearm barrel 16,
is detachably secured to a screw threaded barrel port 160 at the
front of the upper receiver forward portion 14 by means of a barrel
nut assembly 161. The assembly barrel nut 170 has a generally
cylindrical body 174 with a central longitudinal threaded opening
171 permitting the nut to be slid over the firearm barrel 16 and
cooperatively engaging a flange (not shown) on the barrel 16. Said
barrel nut threaded opening 171 adapted to engage the screw
threaded barrel portion 160 at the front of the upper receiver
forward portion 14. The barrel nut 170 has a forward end 172 with a
number of prongs 173 protruding radially outward from the barrel
nut body 174. The barrel nut prongs 173 are adapted to be engaged
by a wrench to tighten or loosen the barrel nut 170.
The special yoke 180 is a U-shaped device having two upright
elements 181 interconnected by a curvilinear element 182. The
special yoke 180 has a top 183, bottom 184, front 185, rear 186 and
two opposite sides 187. The curvilinear element 182 contains the
yoke bottom 184. The upright elements 181 terminate at the yoke top
183. In this embodiment of the invention, the upright elements 181
are generally rectangular block-like elements protruding forwardly
away from the special yoke rear 186. The side 187 of each upright
element 181 each has at least one threaded, lateral aperture 188
formed therethrough. Other embodiments could have more than one
lateral aperture. The side 187 of each upright element 181 also has
an indentation 189 formed therein about each said aperture 188. The
indentation 189 is adapted to receive a screw head. The rear 186 of
the curvilinear element 182 has a channel flange 190 formed at the
yoke bottom 184 opening upward. The channel flange 190 and yoke
bottom 184 have a rectangular notch 191 formed therein.
As may be best seen from FIG. 24, the special yoke 180 is
positioned in front of the barrel nut 170 so that the special yoke
rear 186 is against the barrel nut forward end 172. The rear 186 of
the special yoke channel flange 190 is positioned to engage the
barrel nut body 174 while the channel 190 covers the lower half
prongs 173 without actually touching the prongs 173. The special
yoke of FIG. 22 corresponds to the view shown in FIG. 24.
FIG. 25 is a bottom view of the special yoke 180 engaged to the
firearm barrel nut 170 with only two prongs 173 visible through the
special nut notch 191. The bottom handpiece 70 has been removed and
only a portion of the upper handguard piece 50 is visible. As may
be seen from both FIGS. 24 and 25, once the special yoke 180
engages the barrel nut 170, the delta ring 162, which is spring
loaded and is held back with a screw driver or the like while the
special yoke 180 is installed, is released and moves forward
substantially covering the barrel nut 170 and a portion of the
special yoke 180. The special yoke notch 191 provides access for a
screw driver or other tool in manipulating the delta ring 162 and
special yoke 180. On those firearms with the delta ring 162
removed, the special yoke 180 is positioned exactly the same way
over the barrel nut 170.
As may be seen from FIGS. 23A and 23B, the upper handguard piece 50
has a small, circular horizontal aperture 63 formed through each
upper hand guard piece side 55 near to the rear 52 in the bottom
interface channel 61. Referring again to FIG. 25, threaded screws
195 are inserted through the upper handguard piece small, circular
horizontal apertures 63 for threaded engagement with the special
yoke lateral apertures 188. The upper handguard piece 50 is then
supported not only by the rear portion underside 40 to the receiver
top 13, but also by the engagement of the upper handguard piece 50
with the special yoke 180. The special yoke 180 is joined to the
barrel nut 170 and optionally held in position by the delta ring
162. The special yoke 180 does not touch the firearm barrel 16.
Additional downward pressure on the upper handguard piece top 53
translates by means of the special yoke 180 to the firearm barrel
nut 170. The firearm barrel nut 170 and special yoke 180 are made
from steel thereby slowing down heat transfer from the firearm
barrel 16 to the aluminum upper receiver 12.
In another embodiment of the invention, the special yoke upright
elements 181 have generally rectangular block-like elements 192
protruding laterally sideways. See FIGS. 26A-27. The top 193 of
each laterally protruding element 192 each has a threaded, vertical
aperture 188 formed therethrough. The top 193 of each laterally
protruding element 192 also has an indentation 189 formed therein
about each said aperture 188. Each indentation 189 is adapted to
receive a screw head. As may be seen from FIGS. 28A and 28B, in
this embodiment of the invention the upper handguard piece 50 has a
small, circular, vertical aperture 63 formed through the
longitudinal element 64 along each upper hand guard piece side 55
separating the shallow upper channel 60 from the bottom interface
channel 61. The aperture 63 is formed near to the rear 52 of the
upper hand guard piece 50. A notch 67 is also formed in the upper
handguard piece cut out portion 65 at the upper handguard rear 52.
The special yoke laterally protruding elements 192 each engage an
upper handguard piece notch 67. Referring also to FIGS. 29 and 30,
threaded screws 195 are inserted through the upper handguard piece
small, circular, vertical apertures 63 for threaded engagement with
the special yoke vertical apertures 188. The upper handguard piece
50 is then supported not only by the rear portion underside 40 to
the receiver top 13, but also by the engagement of the upper
handguard piece 50 with the special yoke 180. The special yoke 180
is joined to the barrel nut 170 and optionally held in position by
the delta ring 162. The special yoke 180 does not touch the firearm
barrel 16. Additional downward pressure on the upper handguard
piece top 53 translates by means of the special yoke 180 to the
firearm barrel nut 170. The firearm barrel nut 170 and special yoke
180 are made from steel thereby slowing down heat transfer from the
firearm barrel 16 to the aluminum upper receiver 12.
It is understood that the above-described embodiment is merely
illustrative of the application. Other embodiments may be readily
devised by those skilled in the art which will embody the
principles of the invention and fall within the spirit and scope
thereof.
* * * * *