U.S. patent application number 13/191640 was filed with the patent office on 2012-02-02 for unitary breechblock assembly.
This patent application is currently assigned to Smith & Wesson Corp.. Invention is credited to MARK C. LANEY.
Application Number | 20120023800 13/191640 |
Document ID | / |
Family ID | 45525255 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120023800 |
Kind Code |
A1 |
LANEY; MARK C. |
February 2, 2012 |
UNITARY BREECHBLOCK ASSEMBLY
Abstract
A single-shot break action firearm includes a receiver, a
barrel, and a stock. The receiver has a breach portion that defines
a cavity that is sized and shaped to house a breechblock therein.
The breechblock is constructed from a powdered metal formed by
metal-injection-molding. The breechblock is form from a higher
strength material than the receiver to contain explosive forces
produced during discharge of the firearm. The barrel is connected
with the receiver and extends forward therefrom. The stock is
connected with the receiver and extends rearward therefrom.
Inventors: |
LANEY; MARK C.; (Lee,
NH) |
Assignee: |
Smith & Wesson Corp.
Springfield
MA
|
Family ID: |
45525255 |
Appl. No.: |
13/191640 |
Filed: |
July 27, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61367950 |
Jul 27, 2010 |
|
|
|
Current U.S.
Class: |
42/8 |
Current CPC
Class: |
F41A 3/58 20130101 |
Class at
Publication: |
42/8 |
International
Class: |
F41A 3/58 20060101
F41A003/58 |
Claims
1. A single-shot break action firearm comprising: a receiver having
a breech portion, the breech portion defining a cavity being sized
and shaped to house a breechblock therein, the breechblock being
constructed from a powdered metal formed by
metal-injection-molding, the breechblock being constructed of a
higher strength material than the receiver to contain explosive
forces produced during discharge of the firearm; a barrel connected
with the receiver and extending forward therefrom; and a stock
connected with the receiver and extending rearward therefrom.
2. The single-shot break action firearm according to claim 1,
further comprising at least one moveable component housed within
the receiver and constructed from a powdered metal formed by
metal-injection-molding, the at least one movable component being
selected from the group consisting of a hammer, a trigger, a firing
pin, a barrel catch, and an extractor.
3. The single-shot break action firearm according to claim 1,
further comprising a sight mount constructed from a powdered metal
formed by metal-injection-molding, the sight mount being attached
to the top of the barrel by screws that extend into the barrel.
4. The single-shot break action firearm according to claim 1,
wherein the breech block is pivotally connected with a barrel catch
to form a slide-in unitary breech block and barrel catch assembly,
the receiver being formed by die cast, the receiver being sized and
shaped to receive the slide-in unitary breech block and barrel
catch assembly.
5. The single-shot break action firearm according to claim 1,
wherein the receiver houses a firing mechanism, the firing
mechanism including a firing pin and firing pin spring clamped
between the receiver and the breech block.
6. The single-shot break action firearm according to claim 1,
wherein the barrel is connected to the receiver by a barrel tang
that is bolted to the barrel and is pivotable with respect to the
receiver and stationary with respect to the barrel.
7. The single-shot break action firearm according to claim 6,
wherein a pivot pin connects the barrel tang with the receiver by
extending through transverse holes in both the receiver and the
barrel tang, the barrel being void of a direct connection to the
receiver.
8. The single-shot break action firearm according to claim 6,
wherein the upper interior surfaces of the die cast receiver being
machined to provide interference flats that complement flats formed
on a barrel tang to enhance engagement of the barrel catch with the
barrel tang.
9. The single-shot break action firearm according to claim 1, the
receiver being constructed from a material selected from the group
consisting of being formed from a base metal that is die cast,
being formed of a thermoset plastic, and being formed of a
fiber-resin composite.
10. The single-shot break action firearm according to claim 1,
wherein the powdered metal used to construct the breechblock being
a steel powder.
11. The single-shot break action firearm according to claim 1, the
breech block being connected with the receiver with a breech bolt
extending from the breech portion of the receiver into the breech
bock.
12. The single-shot break action firearm according to claim 1,
wherein the breech block pivotally supporting a barrel catch for
retaining the barrel in a closed position, the barrel catch being
void of any pivotal connections to the receiver.
13. A receiver defining a cavity being sized and shaped to house a
breechblock therein, the breechblock being constructed from a
powdered metal formed by metal-injection-molding, the breechblock
being constructed of a higher strength material than the receiver
to contain explosive forces produced during discharge of the
firearm.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] room This application claims the benefit of U.S. Provisional
Application No. 61/367,950, filed Jul. 27, 2010, entitled "UNITARY
BREECH BLOCK ASSEMBLY", the aforementioned application being hereby
incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to firearms and, more
particularly, to single-shot break action firearms.
BACKGROUND OF THE INVENTION
[0003] Single-shot break action firearms, typically, have a barrel
enclosing a bore that extends from a breech end to a muzzle end of
the barrel. The barrel is pivotally mounted to a receiver disposed
near the breech end of the barrel. The receiver includes a
breechblock, which blocks the breech end of the barrel when the
barrel is in a closed position. Pivoting motion of the barrel on
the receiver shifts the barrel to an open position wherein the
breechblock does not block the breech end of the barrel. The
breechblock typically houses a firing pin, which is aligned with an
inner diameter of the barrel bore when the barrel is closed. The
receiver typically houses a pivotally movable hammer and a trigger,
by which the firing pin may be actuated toward the muzzle end of
the barrel when the barrel is closed. Typical firearms also include
ergonomic parts, such as a stock and a fore end, which are attached
to the receiver. Typical break action firearms further include some
sort of mechanism for securing the barrel in the closed
position.
[0004] For loading the typical break action firearm, the barrel
opened and a single cartridge of ammunition is inserted into the
breech end of the barrel with the bullet toward the muzzle end of
the barrel and with the primer rim fitted snugly to the breech end.
The barrel then is closed. For firing, the trigger is pulled to
release the hammer, which drives the firing pin forward against the
primer rim of the cartridge, discharging the round down the
bore.
[0005] Break action firearms typically are marketed either as
economical sporting goods, or as finely crafted works of
gunsmithing. In a gunsmithed break action firearm, all of the metal
parts including the receiver and the firing mechanism are forged
and machined from high quality materials such as steel. The use of
high quality materials and time-intensive manufacturing processes
results in high costs. On the other hand, for casual sporting
firearms, it is common to economize on materials and modes of
manufacture. In particular, the receiver of a break action firearm
typically is die cast, with moving parts such as the hammer and
trigger being pivoted on pins pressed through the receiver.
[0006] One potential problem with economical firearms is that the
breechblock portion of the receiver can become worn by pivoting
motion of the barrel. This wear, in turn, may adversely affect the
performance of cartridges--for example, by permitting the rim of a
cartridge to shift in the gap between the breechblock and the
breech end of the barrel.
[0007] Accordingly, there is a need for an economically
manufactured single shot firearm, in which the wear parts are
formed from high quality materials at low cost, while non-moving
parts are cast from lower cost materials.
SUMMARY OF THE INVENTION
[0008] According to the present invention, a firearm receiver is
die cast at low cost and is adapted to receive a slide-in unitary
breechblock and barrel catch assembly, which provides sturdy wear
surfaces at minimal cost of manufacture.
[0009] Additionally, upper interior surfaces of the die cast
receiver are machined to provide interference flats, which engage
complementary flats formed on a barrel tang, thereby enhancing
engagement of the barrel catch with the barrel tang.
[0010] Additionally, the barrel tang, barrel catch, trigger, and
hammer are mutually positioned to provide an interlock that
prevents closing the barrel with the hammer cocked, and that also
prevents releasing the hammer unless the barrel is fully closed or
fully opened.
[0011] These and other objects, features and advantages of the
present invention will become apparent in light of the detailed
description of the best mode embodiment thereof, as illustrated in
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a side view of a break action firearm according
to an embodiment of the present invention.
[0013] FIG. 2 shows a left side sectional assembled partial view of
a receiver, barrel assembly, catch mechanism, and firing mechanism
of the firearm shown in FIG. 1, with the barrel assembly in a
closed position.
[0014] FIG. 3A shows a left side view of the firing mechanism
without the receiver of the break action firearm shown in FIGS. 1
and 2.
[0015] FIGS. 3B shows a left side view of the receiver without the
firing mechanism of the break action firearm shown in FIGS. 1 and
2.
[0016] FIG. 4 shows a front exploded view of the break action
firearm shown in FIGS. 1 through 3.
[0017] FIG. 5 shows a perspective exploded view of the firearm
shown in FIGS. 1 through 4.
[0018] FIG. 6 shows a right side sectional exploded view of the
receiver, catch mechanism, and firing mechanism shown in FIG.
2.
[0019] FIG. 7 shows a forward partially exploded view of the firing
mechanism and the barrel catch mechanism shown in FIGS. 1 through
6.
[0020] FIG. 8 shows a right side sectional exploded view of the
firing mechanism and the barrel catch mechanism shown in FIGS. 1
through 7 in a partially open position.
[0021] FIG. 9 shows a top perspective view of the receiver shown in
FIGS. 1 through 7.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] Referring to FIG. 1, a break action rifle 10 includes a
barrel 12, which is pivotally mounted to a receiver 14 that
supports a fore end 16 and a stock 18. The receiver also houses a
firing mechanism 20, of which a hammer 22 and a trigger 24 are
shown in FIG. 1, and a catch mechanism 66 (shown in FIG. 2). The
barrel 12 has a breech end 26 and a muzzle end 28.
[0023] Referring to FIG. 2, the barrel 12 is connected to the
receiver 14 by way of a barrel tang 30 and a pivot pin 32, located
near the barrel breech end 26. The barrel tang 30 is attached to
the barrel 12 by bolts 34 threaded into holes 35 tapped into the
outer surface of the barrel 12. The barrel tang 30 includes a
transverse through hole 36, while the receiver 14 includes
transverse holes 38. The pivot pin 32 is inserted through the
transverse holes 36, 38 to pivotally mount the barrel 12 to the
receiver 14. The barrel 12 is pivotal between a closed position,
where the breech end 26 rests against a breech portion 40 of the
receiver 14, and an open position, where the breech end 26 is
raised away from the receiver 14 permitting access to the barrel
bore 41, as shown in FIG. 8.
[0024] With additional reference to FIGS. 5 through 7, the breech
portion 40 of the receiver 14 houses a breechblock 42. When the
barrel 12 is in the closed position, the breechblock 42 secures a
cartridge 43 into the breech end 26 of the bore 41. The receiver 14
may be die cast from base metal or even from a thermoset plastic or
fiber-resin composite. However, the breechblock 42 is
injection-molded from high quality metal (such as steel powder) to
form a high-strength, temperature- and wear-resistant structure
suitable for containing the explosive forces produced by discharge
of a rim fire rifle cartridge 43. In addition to enhanced strength
over what can be achieved by die casting, metal-injection-molding
(MIM) offers dimensional tolerances approaching what can be
achieved by machining stock metal, so that MIM parts do not require
the same level of finish machining as do conventionally die-cast
parts. Thus, the separate structures of the receiver 14 and of the
breechblock 42 offer optimal strength and fit at the critical
location surrounding the breech end 26 of the barrel 12, with lower
cost of manufacture than can be achieved by machining the receiver
14 and breechblock 42 as a single piece.
[0025] The breechblock 42 houses a firing pin 44 and a firing pin
spring 46, which are parts of the firing mechanism 20. The firing
pin 44 is positioned to be driven forward by the hammer 22, which
is forwardly biased around a hammer pin 48 by a hammer spring 50.
When the hammer 22 is pulled back to a cocked position, the trigger
24 is biased rearward around a trigger pin 52 by a trigger spring
54 so that a sear finger portion 56 of the hammer 22 engages a
cocking notch 58 formed on the top end 25 of the trigger 24,
thereby restraining the hammer 22 in the cocked position. By
pulling the finger part 60 of the trigger 24 rearward, a shooter
can release the hammer 22 to drive the firing pin 44 forward
against the rim of a cartridge 43 loaded into the barrel bore
41.
[0026] Additionally, the breechblock 42 includes laterally
extending pivots 62, which support a barrel catch 64 that is part
of the catch mechanism 66 mentioned above. The barrel catch 64 is
forwardly biased around the pivots 62 by a catch spring 68, which
presses downwardly against a heel 70 of the barrel catch 64 to push
the barrel catch 64 into a notch 72 formed in the rearward part of
the barrel tang 30. Engagement of the barrel catch 64 into the
notch 72 of the barrel tang 30 secures the barrel 12 in the closed
position. The catch mechanism 66 also includes a trigger guard 74,
which is pivotally mounted on a transverse pin 76, and a guard
spring 78 with one end fastened to the receiver 14. The other end
of the guard spring 78 rests against an inner surface 80 of the
trigger guard 74 to downwardly bias the trigger guard 74 around the
transverse pin 76. When a shooter pulls the trigger guard 74
rearward and upward against the guard spring 78, an upper finger 82
of the trigger guard 74 pushes upward on the heel 70 of the barrel
catch 64 to release the barrel catch 64 from the barrel tang 30,
thereby permitting the barrel 12 to pivot to the open position.
[0027] Referring briefly to FIG. 8, it can be seen that when the
barrel 12 is opened, a knuckle 73 formed on the barrel tang 30
presses the barrel catch 64 rearward against the trigger 24. In
case the hammer 22 is cocked when the barrel 12 is opened, pressure
of the barrel catch 64 against the trigger 24 captures the sear
finger portion 56 into the cocking notch 58, so that the trigger 24
cannot be pulled rearward to release the hammer 22. Thus the cocked
weapon cannot be discharged unless the barrel 12 is fully closed;
alternatively, the hammer 22 cannot be decocked unless the barrel
12 is fully opened. This interlock averts discharging a loaded
cartridge with the barrel 12 less than fully latched closed.
[0028] Referring briefly to FIG. 9, the barrel tang 30 includes
protruding side posts 83 with flattened lower faces 85. When the
barrel 12 is fully closed, the lower faces 85 of the side posts 83
rest against complementary flats 87 machined into the receiver 14.
The barrel catch 64 wedges into the notch 72 of the barrel tang 30
to firmly seat the complementary flats 87 together, and the opposed
flats reciprocally push the notch 72 upwards to maintain the barrel
catch 64 firmly engaged.
[0029] Referring back to FIG. 2, between the barrel 12 and the
barrel tang 30, an extractor 84 is captured on the bolts 34. The
extractor 84 includes longitudinal slots 86 (better shown in FIG.
3A) for receiving the bolts 34 so that the extractor 84 can slide
lengthwise along the barrel 12 between forward (retracted) and
rearward (extended) positions when the barrel 12 is pivoted to the
opened position, as further explained below.
[0030] Referring to FIGS. 3A through 4, the receiver 14 encloses an
action cavity 88 housing the firing mechanism 20 and the catch
mechanism 66, a barrel tang slot 89 for receiving the barrel tang
30, and a breech cavity 90 for receiving the breechblock 42. For
assembly of the hammer 22 and the trigger 24, the receiver 14
includes pinholes 92 and 94, respectively, as well as a hammer slot
93 and a trigger slot 95. For assembly of the catch mechanism 66
into the receiver 14, the receiver 14 also includes a catch spring
groove 96, lateral pivot grooves 98, a guard spring groove 100, a
guard recess 102, a guard pinhole 103, and a breech bolt hole 104.
The breechblock 42 is fastened to the receiver 14 by a breech bolt
106 threaded into the breechblock 42 via the breech bolt hole 104.
For operation of the extractor 82, the receiver 14 also includes a
camming surface 108 offset from the pivot pin 32 at the forward end
of the receiver 14. When the barrel 12 is pivoted to the open
position, the forward end of the extractor 84 contacts the camming
surface 108 so that the extractor 84 is pushed rearward to pull the
cartridge 43 out of the breech end 26 of the bore 41. For assembly
of the stock 18, the receiver 14 also includes a stock bolt hole
110.
[0031] In addition to the breechblock 42, the hammer 22, the
trigger 24, the firing pin 44, the barrel catch 64, and the
extractor 82 preferably are metal-injection-molded for enhanced
dimensional accuracy and durability.
[0032] Opposite the barrel tang 30, a sight mount 111 is fixed to
the upper side of the barrel 12 by screws 112 threaded into tapped
holes 113. The sight mount 111 also can be metal-injection-molded,
or can be die cast.
[0033] The fore end 16 is fastened to the barrel 12 by bolts 113,
while the stock 18 is fastened to the receiver 14 by a single large
bolt 114. The stock 18 includes an aesthetic cap 116 snapped over
the large bolt 114, and also includes a shock-absorbing butt piece
118, which is secured to the stock by screws 120.
[0034] One advantage of the present invention is that the
pre-assembled breechblock and catch ensure proper alignment of the
catch with the notch formed in the barrel tang. Also, the
pre-assembled breechblock and catch reduce the number of holes that
must be formed at mutually accurate positions in the receiver. The
catch spring and guard spring grooves further simplify assembly of
the catch mechanism relative to previously known designs.
[0035] Although this invention has been shown and described with
respect to detailed embodiments thereof, it will be understood by
those skilled in the art that various changes in form and detail
thereof may be made without departing from the spirit and the scope
of the invention.
* * * * *