U.S. patent application number 10/823854 was filed with the patent office on 2005-10-20 for firearm assembly.
Invention is credited to Tashjian, Paul.
Application Number | 20050229463 10/823854 |
Document ID | / |
Family ID | 35094773 |
Filed Date | 2005-10-20 |
United States Patent
Application |
20050229463 |
Kind Code |
A1 |
Tashjian, Paul |
October 20, 2005 |
Firearm assembly
Abstract
The present invention includes a receiver for a firearm having a
front recess to receive a barrel. The receiver has a load/eject
recess port open to the front recess and to a side or bottom of the
receiver to allow the insertion and removal of a cartridge from the
receiver. A slit along the front recess and the load/eject recess
port together form a single opening along the receiver whereby the
receiver can expand to allow the insertion of a barrel into the
front recess. Included is a firearm having the receiver of the
invention.
Inventors: |
Tashjian, Paul; (King of
Prussia, PA) |
Correspondence
Address: |
RATNERPRESTIA
P O BOX 980
VALLEY FORGE
PA
19482-0980
US
|
Family ID: |
35094773 |
Appl. No.: |
10/823854 |
Filed: |
April 14, 2004 |
Current U.S.
Class: |
42/75.02 |
Current CPC
Class: |
F41A 17/66 20130101;
F41A 3/66 20130101 |
Class at
Publication: |
042/075.02 |
International
Class: |
F41A 021/00 |
Claims
What is claimed:
1. A receiver for a firearm, said receiver comprising: a front, at
least two sides, and a bottom; a front recess to receive a barrel
or barrel extension, said front recess defined by a channel in said
receiver which is open longitudinally along a longitudinal slit in
said receiver; a load/eject recess open to said front recess and to
at least one side or said bottom of said receiver, said load/eject
recess sized to allow the insertion and removal of a cartridge from
said receiver; said slit and said load/eject recess together
forming a single opening to said receiver whereby said receiver can
expand to allow the insertion of a barrel or barrel extension into
said front recess.
2. The receiver of claim 1 wherein said slit and said load/eject
recess are open to said bottom of said receiver.
3. The receiver of claim 1 further comprising a clamping hole in
said receiver disposed through said longitudinal slit, said
clamping hole sized to receive clamping means whereby said slit is
compressible by said clamping means to apply a compressive force on
a barrel or barrel extension inserted into said front recess.
4. The receiver of claim 2 wherein said clamping means is a
bolt.
5. The receiver of claim 1 wherein said front recess is sized to
receive a barrel extension.
6. The receiver of claim 2 wherein said receiver has a plurality of
clamping holes.
7. The receiver of claim 1 wherein said receiver is comprised of a
material selected from the group consisting of aluminum, magnesium,
or alloys comprised of aluminum or magnesium.
8. The receiver of claim 1 wherein said receiver is comprised of a
polymeric material.
9. A receiver for a firearm, said receiver comprising: a front and
a bottom; a front recess to receive a barrel extension, said front
recess defined by a channel open longitudinally at its bottom along
a longitudinal slit; a load/eject recess open to said front recess
and to said bottom of said receiver to allow the insertion and
removal of a cartridge from said bottom of said receiver; and at
least one clamping hole in said receiver, said clamping hole
disposed through said longitudinal slit, said clamping hole sized
to receive clamping means; said slit and said load/eject recess
together forming a single opening along said bottom of said
receiver, and said front recess is expandable and contractible
along said slit whereby said slit is compressible by said clamping
means to apply a compressive force on a barrel extension inserted
into said front recess.
10. The receiver of claim 9 further comprising clamping means.
11. The receiver of claim 9 wherein said receiver has a plurality
of clamping holes.
12. The receiver of claim 9 wherein said receiver is comprised of a
material selected from the group consisting of aluminum, magnesium,
or alloys comprised of aluminum or magnesium.
13. The receiver of claim 9 wherein said receiver is comprised of a
polymeric material.
14. A barrel extension for a firearm barrel, said barrel extension
comprising: a metallic tube having an outer surface; and a
protrusion extending radially outward from said outer surface of
said metallic tube.
15. The barrel extension of claim 14 wherein said protrusion is a
pin.
16. A safety mechanism for a firearm to prevent unintentional
firing of the firearm, the safety mechanism comprising: a bolt
having: a bolt head disposed at a distal end, a proximal end, and a
longitudinal channel disposed in said bolt to house a firing pin; a
firing pin disposed in said longitudinal channel of said bolt, said
firing pin having a distal end at said bolt head and a proximal end
extending out of said longitudinal channel to allow activation of
said firing pin by a hammer; a safety bar disposed at said proximal
end of said firing pin wherein rotation of said bolt into a firing
position rotates said safety bar into an activation position
whereby said firing pin can be activated by a hammer striking said
safety bar, and rotation of said bolt into a non-firing position
rotates said safety bar out of said activation position whereby a
falling hammer cannot strike said safety bar or firing pin.
17. The safety mechanism of claim 16 wherein said safety bar is
rectangular.
18. The safety mechanism of claim 16 wherein said safety bar has at
least one curved edge.
19. The safety mechanism of claim 16 wherein the bolt rotation
between said activation position and said non-firing position is an
angle between 20.degree. and 50.degree. from the bolt's fully
closed position.
20. The safety mechanism of claim 18 wherein the bolt rotation
between said activation position and said non-firing position is an
angle between 10.degree. and 20.degree. from the bolt's fully
closed position.
21. A firearm comprising: a barrel; a barrel extension attached to
said barrel, said barrel extension having a protrusion extending
radially therefrom; and a receiver, said receiver comprising: a
front, at least two sides, and a bottom; a front recess to receive
a barrel or barrel extension, said front recess defined by a
channel in said receiver which is open longitudinally along a
longitudinal slit in said receiver; and a load/eject recess open to
said front recess and to at least one side or said bottom of said
receiver, said load/eject recess sized to allow the insertion and
removal of a cartridge from said receiver; said slit and said
load/eject recess together forming a single opening to said
receiver whereby said receiver can expand to allow the insertion of
a barrel or barrel extension into said front recess; whereby said
slit accepts said protrusion to guide said barrel extension into
said receiver.
22. The firearm of claim 21 further comprising a clamping hole in
said receiver disposed through said longitudinal slit, said
clamping hole sized to receive clamping means whereby said slit is
compressible by said clamping means to apply a compressive force on
said barrel extension.
23. The firearm of claim 22 wherein said clamping means is a
bolt.
24. The firearm of claim 21 further comprising a safety mechanism,
said safety mechanism comprising: a bolt having: a bolt head
disposed at a distal end, a proximal end, and a longitudinal
channel disposed in said bolt to house a firing pin; a firing pin
disposed in said longitudinal channel of said bolt, said firing pin
having a distal end at said bolt head and a proximal end extending
out of said longitudinal channel to allow activation of said firing
pin by a hammer; and a safety bar disposed at said proximal end of
said firing pin wherein rotation of said bolt into a firing
position rotates said safety bar into an activation position
whereby said firing pin can be activated by a hammer striking said
safety bar, and rotation of said bolt into a non-firing position
rotates said safety bar out of said activation position whereby a
falling hammer cannot strike said safety bar or firing pin.
Description
BACKGROUND OF THE INVENTION
[0001] Various methods and configurations for safe and reliable
firearms have been developed in the storied history of small arms
development. With the advent of smokeless powder in the late 19th
century, and the subsequent development of more powerful
chamberings in the early 20.sup.th century, bolt-action firearms
were developed as a way to handle the increased pressures of firing
these larger, more powerful rounds. These improvements have
continued to develop and advance ballistic performance and have
resulted in some very large cartridges, including the 0.50 BMG.
[0002] Generally, a bolt-action firearm comprises a bolt which
houses a firing pin. The bolt slides within the firearm receiver
between a rearward position which allows loading and unloading of a
cartridge, and a forward position. As the bolt slides forward, the
cartridge is pushed forward into a firing chamber. The bolt is then
typically closed by rotating it into a battery position, thus
locking the bolt behind the cartridge. The firing pin is then
activated by pulling the trigger which causes the firearm to
discharge. To expel the empty casing, the bolt is rotated out of
its locked position and slid rearward to extract the empty
casing.
[0003] As a part of the empty casing extraction, different
extractors have been developed. Most throw the casing outward and
away from the firearm in either an upward or sidewise direction.
This can cause a variety of problems, including striking the user
or a bystander, and losing the empty casing which the user often
may wish to retain. It is also a problem in military or law
enforcement situations when such movement of the flying casing
could reveal the location of the shooter. This is especially
undesirable in sniping situations.
[0004] Another problem which is often sought to be resolved in a
variety of ways includes the prevention of accidental or unintended
discharge. Because the firing pin is typically disposed within the
bolt, and the bolt (as described above) is typically pushed forward
against the rear of the cartridge as the cartridge is advanced into
the firing chamber, the potential for unintended discharge of the
weapon is present, particularly as the bolt is thrown forward to
chamber a round. A variety of solutions have been developed, with
varying degrees of success.
[0005] Still another problem encountered with the development of
higher chamber pressures is seen in the materials used to build
these firearms. With the larger pressures generated by the
development of larger and more powerful magnum loads and larger
cases, more and more material was needed in order to obtain
adequate strength. Competing with these increased material
dimensions, however, is a desire for lighter-weight (and/or less
costly) firearms. One way to remedy the weight problem is to use
lighter weight materials (e.g., aluminum instead of steel), but
strength problems can result. Thus, some prior art attempts at
building adequately strong, yet light weight receivers, have
included using aluminum and other light weight materials or alloys
where possible in the firearm. This introduced manufacturing
challenges, however, because heat treatments and other
manufacturing requirements treated the different materials
differently.
SUMMARY OF THE INVENTION
[0006] The present invention provides a receiver for a firearm
comprising a front, at least two sides, and a bottom. The receiver
has a front recess to receive a barrel or barrel extension, and is
defined by a channel in the receiver which is open longitudinally
along a longitudinal slit in the receiver. The receiver also has a
load/eject recess open to the front recess and to either a side or
bottom of the receiver. The load/eject recess is sized to allow the
insertion and removal of a cartridge from the receiver. The slit
and the load/eject recess together form a single opening to the
receiver whereby the receiver can expand to allow the insertion of
a barrel or barrel extension into the front recess. In a preferred
embodiment, the slit and load/eject recess are open to the bottom
of the receiver. The receiver is either biased against the
insertion of a barrel or barrel extension, such that it must be
pried open to allow insertion and its own at rest position (inward
bias) provides a compressive force to hold the barrel in place, or,
alternatively, it is biased open and a compressive force, such as a
bolt, closes the receiver against the barrel or barrel
extension.
[0007] In a preferred embodiment, the receiver has a front recess
to receive a barrel extension, the front recess defined by a
channel open longitudinally at its bottom along a longitudinal
slit. Included in this preferred embodiment is a load/eject recess
open to the front recess and to the bottom of the receiver to allow
the insertion and removal of a cartridge from the bottom of the
receiver. Also included in this preferred embodiment is at least
one clamping hole in the receiver disposed through the longitudinal
slit and sized to receive clamping means, such as a bolt. The slit
and the load/eject recess together form a single opening along the
bottom of the receiver. The front recess is expandable and
contractible along the slit whereby the slit is compressible by the
clamping means to apply a compressive force on a barrel extension
inserted into the front recess.
[0008] Also included as a part of the invention is a barrel
extension for a firearm barrel. The barrel extension is suited for
insertion into the receiver of the present invention. In a
preferred embodiment, the barrel extension comprises a metallic
tube having an outer surface, and a protrusion extending radially
outward from the outer surface of the metallic tube. In a preferred
embodiment, the protrusion is a pin.
[0009] Still also included in the present invention is a safety
mechanism for a firearm to prevent unintentional firing of the
firearm. The safety mechanism comprises a bolt having a bolt head
disposed at a distal end, a proximal end, and a longitudinal
channel disposed in the bolt to house a firing pin. A firing pin is
disposed in the longitudinal channel of the bolt, and has a distal
end at the bolt head and a proximal end extending out of the
longitudinal channel to allow activation of the firing pin by a
hammer. A safety bar is disposed at the proximal end of the firing
pin wherein rotation of the bolt into a firing position rotates the
safety bar into an activation position whereby the firing pin can
be activated by a hammer striking the safety bar, and rotation of
the bolt into a non-firing position rotates the safety bar out of
the activation position whereby a falling hammer cannot strike the
safety bar or firing pin.
[0010] Included also is firearm comprising a barrel, a barrel
extension attached to the barrel, the barrel extension having a
protrusion extending radially therefrom, and a receiver. The
receiver comprises a front, at least two sides, and a bottom, a
front recess to receive a barrel or barrel extension, the front
recess defined by a channel in the receiver which is open
longitudinally along a longitudinal slit in the receiver, and a
load/eject recess open to the front recess and to at least one side
or bottom of the receiver. The load/eject recess is sized to allow
the insertion and removal of a cartridge from the receiver. The
slit and load/eject recess together form a single opening to the
receiver whereby the receiver can expand to allow the insertion of
a barrel or barrel extension into the front recess. The slit
accepts the protrusion to guide the barrel extension into the
receiver. A preferred embodiment of the firearm includes the safety
mechanism described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a view of a partial firearm in accordance with the
present invention with the barrel removed from the receiver;
[0012] FIG. 2 is a view of a partial firearm in accordance with the
present invention as shown in FIG. 1 but with the barrel inserted
into the receiver;
[0013] FIG. 3 is a view of a receiver in accordance with the
present invention;
[0014] FIG. 4 is a view of the underside of the receiver shown in
FIG. 3;
[0015] FIG. 5 is a view of the front end of the receiver shown in
FIG. 3;
[0016] FIG. 6 is a view of the receiver of FIG. 3 but with clamping
means shown;
[0017] FIG. 7 is a view of a barrel, barrel extension, and bolt in
accordance with the present invention;
[0018] FIG. 8 is a view of a bolt incorporating the safety
mechanism of the present invention where the bolt is in an open
position;
[0019] FIG. 9 is a view of a bolt incorporating the safety
mechanism of the present invention where the bolt is in its closed
position; and
[0020] FIG. 10 is a view of a safety bar in accordance with one
embodiment of the safety feature of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention provides several advantages over known
firearm configurations. These advantages are seen with respect to
both safety and ease of manufacture. One aspect of the present
invention is the receiver. A second aspect relates to a safety
mechanism in a novel bolt/firing pin configuration.
[0022] FIG. 1 shows a firearm utilizing the receiver aspect of the
present invention, with the barrel separated from the receiver for
illustration purposes. Specifically, FIG. 1 shows a firearm 100
having barrel 110, receiver 120, and stock 130. Not shown is the
trigger assembly, which is not necessary to an understanding of the
present invention. Muzzle brake 140 and utility rail 150 (such as a
picatinny rail) for a scope or carry handle, are also shown. As can
be seen in FIG. 1, barrel 110 is integrally attached to barrel
extension 115 in this embodiment. Typically this connection would
be a threaded connection, but it could also take the form of other
connections including welding or adhesives, among others. Barrel
extension 115 in turn extends into receiver 120 and is connected to
receiver 120 in accordance with the present invention, as shown in
FIG. 2. FIG. 2 is the firearm shown in FIG. 1 but with barrel 110
(along with barrel extension 115) inserted into receiver 120.
[0023] FIG. 3 shows receiver 120 in more detail. FIG. 3 shows
receiver 120 without utility rail 150 attached thereto, without
barrel extension 120 inserted therein, and without stock 130
attached. As can be seen, receiver 120 has front recess 122 formed
therein with slit 125 formed along the bottom of the front recess.
Front recess 122 is configured to receive either a barrel or a
barrel extension. Front recess 122 is defined by a channel open
longitudinally at slit 125. Slit 125 is preferably disposed along
the bottom of receiver 120 as shown in FIG. 3, but could be located
on either side of the receiver (not shown) or top side (not shown)
so long as it connects to a load/eject port as described more fully
below. FIG. 3 also shows utility rail mounting holes 200 and
utility holes 210 such as may be used for mounting a bipod.
[0024] Included as a part of receiver 120 is load/eject recess 160,
which can be better seen in FIG. 4 which is a bottom-angled view of
receiver 120. In this preferred embodiment, the slit and load/eject
recess are open to the bottom of the receiver. More specifically,
load/eject recess 160 is open to front recess 122 and to the bottom
of receiver 120 to allow the insertion and removal of a cartridge
(or cartridge casing) from the bottom of receiver 120.
[0025] FIG. 5 shows an angled front view of receiver 120 and
illustrates the communication between front recess 122 and
load/eject recess 160. Load/eject recess 160 allows direct access
to the firing chamber when the bolt (shown and discussed below) is
open to allow access, through load/eject recess 160, to the firing
chamber at the proximal end of the barrel or barrel extension. As
can be seen in FIGS. 4 and 5, slit 125 and load/eject recess 160
together form a single opening along the bottom of receiver 120. In
alternative embodiments, the slit and port may together be
positioned on any side of the receiver, including the top side.
[0026] The relationship between the receiver's front recess and the
barrel or barrel extension (the later of which is shown in FIG. 1),
can take a number of forms. The receiver's front recess can: (1) be
in a slip-fit relationship with the barrel or barrel extension in
which case it can be compressed by means of compression means
(discussed in more detail below) after the barrel or barrel
extension is inserted; (2) be larger than the outside dimension of
the barrel or barrel extension (even more so than the case in (1),
above), in which case it is also compressed by means of compression
means (discussed in more detail below) after the barrel or barrel
extension is inserted; or (3) be smaller than the outer dimension
of the barrel or barrel extension, in which case it can be
mechanically (or otherwise, such as thermally) expanded to allow
the insertion of a barrel or barrel extension into the front recess
and allowed to return to its at-rest position and thereby anchor
the barrel or barrel extension in place with respect to the
receiver.
[0027] The combination of slit 125 and load/eject port 160 to form
a single opening achieves several advantages. One advantage relates
to the connection of the barrel or barrel extension to the
receiver. In one embodiment, a mechanical leverage can be applied
to the sides of the receiver that are separated by slit 125 and
which form front recess 122 so as to pry them apart and allow the
insertion of a barrel or barrel extension. When the prying force is
removed, the sides can return and clamp the barrel or barrel
extension into place.
[0028] As in the embodiments shown in FIGS. 1-5, there can be
clamping holes formed in receiver 120, which are preferably
perpendicular to the longitudinal axis of front recess 122 along
the length of front recess 122. These clamping holes allow for the
insertion of bolts, screws, or other appropriate fasteners through
the front portion of receiver 120 to radially compress front recess
122 after a barrel or barrel extension is telescopically positioned
within front recess 122. As noted above, although adequate
compressive force against the barrel or barrel extension may be
achieved by manufacturing a radially inward bias in the receiver so
that the at-rest position of front recess 122 is smaller than the
barrel or barrel extension radius, the use of appropriate fasteners
as described above can aide in this compressive and clamping force.
Alternatively, the at-rest position of the receiver can be
substantially the same as the outer dimension of the barrel or
barrel receiver (as in the slip-fit arrangement described above),
or greater than the barrel or barrel extension radius. In such
cases, the fastening means just described can be the sole source of
compressive force. In either of the above three embodiments,
however, adequate force is achieved through compression to hold the
barrel in place. Because the cartridge to be fired is placed into
the barrel or barrel extension, and it is the barrel or barrel
extension which contains the explosive pressure of the ignited
charge in the casing during firing, the receiver's only job is to
hold the barrel (and/or barrel extension) in place with respect to
the remaining parts of the rifle. The advantages to this
configuration will be discussed in more detail below.
[0029] Another advantage to the receiver configuration discussed
above relates to both ergonomic and safety advantages, particularly
when the rifle is to be used for tactical purposes (although the
advantages can be enjoyed for both hunting and target shooting
scenarios as well). This aspect concerns the fact that the loading
of a cartridge, as well as the unloading of a cartridge casing or
an unfired cartridge, is preferably done with minimal movement. The
receiver configuration described above allows for minimal cartridge
movement with minimal hand movement. Importantly, it allows for the
ejection, by hand, of empty casings so that, unlike the case with
most prior art ejectors, the casing does not fly away from the
weapon and operator, and risk sun glare reflection and the position
compromise associated therewith. Moreover, with the design noted
above, particularly in the embodiment with the slit and port
disposed at the bottom of the receiver, the operator can easily
position his hand directly beneath the bottom opening to allow the
cartridge or empty casing to drop directly into his hand or a
positioned container as the bolt is pulled rearward. Still another
advantage is seen when an unfired cartridge is removed. Prior art
rifles which forcibly eject live rounds risk unintended ignition of
those live rounds when they strike the ground. The present receiver
configuration reduces such a risk considerably.
[0030] Still another advantage with the slit/open port
configuration of the present invention relates to the manufacture
and durability of the rifle. The receiver of the present invention
is not subject to forces from the operating pressures of cartridge
firing (except, of course, for recoil related stresses). Because it
is the barrel or barrel extension which contains firing chamber
pressures upon cartridge detonation, the receiver component of the
rifle according to the present invention provides a rigid housing
from an alloy or polymer that is relatively immune to temperature,
moisture, and stress failures, despite the low overall ultimate
tensile strength of these materials compared to traditional steel.
Due to the overall lower requirements for alloy or polymer
strength, there is no need to harden and temper the alloy or
polymer in order to increase its overall strength. In distinction,
of course, is the fact that hardening and tempering is a virtual
necessity for traditional steel receivers in order to increase the
overall strength of those receivers. Thus, the characteristics of
appropriate alloys and polymers benefit overall weight, accuracy,
reliability, wear reduction, and ease of manufacture. The light
weight alloy or polymer used for the receiver of the present
invention will allow for a receiver size which is dimensionally
larger than the typical steel receivers and stock combinations but
which will maintain a near equivalent weight.
[0031] As noted above, and as shown in FIG. 6, bolt 600 is shown
removed from bolt clamping hole 610. Other compressive means could
be used and can imagined by those skilled in the fastening art. A
screw or bolt, with any head configuration, could be used. The
number of fastening means and holes is also not critical, although
the most preferred number is four. More than one hole is preferred
so that should one fastener loosen, at least one other will
maintain the compression against the barrel or barrel
extension.
[0032] In addition to slit 125 allowing the necessary movement of
front recess 122 to allow insertion of the barrel or barrel
extension, the fact that slit 125 extends to load/eject recess 160
to form a single opening along receiver 120 is important to allow
this movement. Because of the openings in receiver 120 as
discussed, much more "give" is provided for along front recess 122
to allow the insertion of a barrel or barrel extension, as compared
to the case where a slit would end at the back (or proximal) end of
front recess 122. Moreover, the slit and load/eject port combine to
allow easier insertion of a barrel or barrel extension by providing
more flexibility within the frame of receiver 120 (as compared to a
slit alone).
[0033] Another benefit to the mechanical advantage gained by the
slit/port combination is seen with respect to the alignment of a
barrel or barrel extension during insertion. It should be noted
here that although the invention concerns the insertion of a barrel
or barrel extension, preferably a barrel extension will be what is
inserted into receiver 120. This is especially true in the case of
larger caliber chamberings, such as the 0.50 BMG. In such cases,
the barrel itself will be connected to a thicker-walled barrel
extension which houses the firing chamber. The thicker wall is
necessary to withstand the pressures generated during firing of
such chamberings. Thus, for purposes of this discussion, the
embodiment using a barrel extension (as is shown in FIG. 1) will be
addressed. The invention is not necessarily limited, however, to
situations where a barrel extension is inserted directly into the
receiver of the present invention, but would include those
situations where just a barrel is inserted, or where the barrel and
barrel extension may be integrally formed to form a single unitary
barrel with a flared end.
[0034] As shown in FIG. 7, barrel extension 700 is shown disposed
opposite bolt 710 which is the position of bolt 710 before bolt 710
is pushed forward and rotated down into its battery position within
barrel extension 700. The mating relationship between barrel
extension 700 and bolt 710, particularly bolt head 720, is known to
those skilled in the art. In this embodiment, barrel extension 700
is a metallic tube to which barrel 730 is fixedly attached. Not
shown in FIG. 7 is a cartridge which would be inserted, as bolt 710
closes into battery, within barrel extension 700 and perhaps part
of barrel 730. Important in this embodiment is protrusion 750 which
is shown extending from the outer surface of barrel extension 700.
In a preferred embodiment, protrusion 750 is a pin.
[0035] Protrusion 750 slides into and along slit 125 of front
recess 122 of receiver 120 as barrel extension 700 is inserted into
receiver 120 during assembly/manufacture. This alignment is
important because, as noted above (and as shown in FIG. 7), bolt
head 720 mates with barrel extension 700 during closing of the
action as indicated by the arrow in FIG. 7. Because barrel 730 and
barrel extension 700 are round, but the bolt head/barrel extension
relationship is not, proper orientation of the barrel and barrel
extension is necessary during assembly to achieve proper
bolt/barrel extension alignment. This alignment is easily realized
through the use of protrusion 750 and its relationship to slit 125
during insertion of barrel extension 700 into receiver front recess
122. Moreover, by providing protrusion 750 extending
perpendicularly from a tangent on barrel extension 700 (or directly
from barrel 730 in an embodiment where no barrel extension is
used), the barrel extension can be easily inserted into the
receiver without the need for angular alignment gauges. The bolt
head will always enter and exit the extension opening without
impacting the opening of the extension during use. Protrusion 750
is preferably a pin, as shown, but could take the form of a rail or
any other suitable guide.
[0036] Another aspect of the firearm assembly in accordance with
the present invention relates further to the bolt itself and its
relationship with a hammer. FIG. 8 shows a bolt in accordance with
this aspect of the invention. Specifically, FIG. 8 shows bolt 800
with bolt head 820 disposed at its distal end. Also shown is handle
840. Within bolt 800 is a longitudinal channel disposed in the bolt
to house a firing pin. The proximal tip of the firing pin extends
slightly proximal to the end of the firing pin channel and has a
distal end at the bolt head and a proximate end extending out of
the longitudinal channel to allow activation of the firing pin by a
hammer. In this embodiment, a recess 850 is cut from a section of
bolt 800 to allow access by a hammer (not shown) to the proximal
end of the firing pin (not shown). In an alternative embodiment,
the proximal end of the firing pin could simply extend out the back
of bolt 800.
[0037] As can be seen in FIG. 8, safety bar 860 is disposed at the
proximal end of the firing pin. When bolt 800 is in its open
position, such as is shown in FIG. 8, safety bar 860 is rotated
such that a hammer strike to the bolt would impact a point
indicated by reference numeral 870. In such a case, no movement of
the firing pin would result because the hammer would not transfer a
force to the proximal end of the firing pin. The hammer, in such
case, would strike the bolt face at point 870 but not the firing
pin.
[0038] FIG. 9 shows the same bolt as that of FIG. 8, but which has
been rotated 90.degree. into what would be a fully closed, or
battery, position. As can be seen from FIG. 9, rotation of bolt 800
into a firing position rotates safety bar 860 into an activation
position whereby the firing pin can be activated by a hammer
striking and contacting safety bar 860 at point 870. As noted
above, bolt head 820 is also rotated into its battery position.
Then, after firing, rotation of bolt 800 via handle 840 into a
non-firing position rotates safety bar 860 out of the activation
position whereby a falling hammer cannot strike safety bar 860 and
cause unintended firing.
[0039] The safety mechanism just described can be utilized in a
firearm having any degree of bolt rotation between a fully closed
position (firing position) and a fully open position. Typically
this angle is between 60.degree. and 100.degree.. Preferably, the
angle of rotation of the bolt between the fully closed position and
fully open position, however, is between 85.degree. and 95.degree.,
and most preferably it is 90.degree.. Because of the safety
mechanism just described, however, the bolt does not have to rotate
to its fully open position for the firearm to be in a non-firing
condition. Preferably, the safety bar will move from its activation
position (FIG. 9) to a non-firing position by a bolt rotation of
between only 20.degree. and 50.degree., preferably about
30.degree., from its fully closed position.
[0040] Although safety bar 860 is shown in the above embodiment as
rectangular, a rounded edge embodiment, such as is shown in FIG.
10, could be used to decrease even further the chance of a hammer
striking the firing pin until the bolt is completely (or nearly
completely) closed. The use of this embodiment would mean that the
safety bar will move from its activation position to a non-firing
condition by only a small upward bolt rotation, for example only
10.degree., from the bolt's fully closed position.
[0041] Although the invention is illustrated and described herein
with reference to specific embodiments, the invention is not
intended to be limited to the details shown. Rather, various
modifications may be made in the details within the scope and range
of equivalents of the claims and without departing from the
invention.
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