U.S. patent number 3,846,928 [Application Number 05/389,710] was granted by the patent office on 1974-11-12 for bolt latch for auto loading firearm.
This patent grant is currently assigned to Strum, Ruger & Co., Inc.. Invention is credited to William B. Ruger, Harry H. Sefried, II.
United States Patent |
3,846,928 |
Ruger , et al. |
November 12, 1974 |
BOLT LATCH FOR AUTO LOADING FIREARM
Abstract
An auto-loading firearm having a bolt that moves rearwardly from
its forward closed position to its rearward open position and then
forwardly to its closed position when the firearm is fired is
provided with means for holding the bolt at its open position when
the magazine is empty and the last cartridge has been fired. The
bolt lock means comprises a bolt lock lever pivotally mounted on
the side of the receiver, said bolt lock lever having a magazine
follower engaging arm at the forward end thereof and a bolt stop
arm at the rearward end thereof, said forward and rearward ends of
the bolt lock lever being vertically movable between upper and
lower positions when the bolt latch lever is rotated about the
pivot thereof. A bolt stop lug is disposed at the rearward end of
the bolt in position to be clear of the bolt stop arm when the
rearward end of the bolt lock lever is at its upper position and in
position to be blocked by the bolt stop arm when the rearward end
of the bolt lock lever is at its lower position. A bolt lock
activating surface is disposed on the upper end of the
spring-pressed magazine follower of the magazine in position to
contact the magazine follower engaging arm of the bolt lock lever,
said bolt lock lever activating surface moving the forward end of
the pivoted bolt lock lever to its upper position and moving the
rearward end of the pivoted bolt lock lever to its lower position
when the magazine is empty.
Inventors: |
Ruger; William B. (Southport,
CT), Sefried, II; Harry H. (New Haven, CT) |
Assignee: |
Strum, Ruger & Co., Inc.
(Southport, CT)
|
Family
ID: |
23539393 |
Appl.
No.: |
05/389,710 |
Filed: |
August 20, 1973 |
Current U.S.
Class: |
42/16;
89/138 |
Current CPC
Class: |
F41A
17/36 (20130101) |
Current International
Class: |
F41A
17/00 (20060101); F41A 17/36 (20060101); F41c
011/00 (); F41d 001/00 () |
Field of
Search: |
;42/16 ;89/138 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Jordan; C. T.
Attorney, Agent or Firm: Pennie & Edmonds
Claims
I claim:
1. In an auto-loading firearm having a receiver, a barrel having a
chamber secured to the receiver, a bolt mounted for longitudinal
travel in the receiver behind the barrel, an auto-loading mechanism
connected to the bolt for moving the bolt from a forward closed
position to a rearward open position and return when the firearm is
fired, a magazine disposed beneath the bolt, said magazine being
adapted to contain a plurality of cartridges and having a
spring-pressed vertically movable magazine follower that moves the
cartridges contained in the magazine upwardly into position to be
loaded into the chamber of the barrel, and bolt lock means for
locking the bolt in its open position when the magazine is empty
and the last cartridge from the magazine has been fired, the
improvement in bolt lock means which comprises:
a longitudinally extending bolt lock lever pivotally mounted on the
receiver, said bolt lock lever having a magazine follower engaging
arm at the forward end thereof and having a bolt stop arm at the
rearward end thereof, said forward and rearward ends of said bolt
lock lever each being vertically movable between predetermined
upper and lower positions when the bolt lock lever is rotated about
the pivot thereof,
a bolt lock lever spring that urges the forward end of the pivoted
bolt lock lever to its lower position and the rearward end of said
bolt lock lever to its upper position,
a bolt stop lug disposed at the rearward end of the bolt in
position to be clear of the bolt stop arm of the bolt lock lever
when the rearward end of the bolt lock lever is at its upper
position and in position to be blocked by the bolt stop arm of the
bolt lock lever when the rearward end of the bolt lock lever is at
its lower position, and
a bolt lock activating surface disposed on the upper end of the
spring-pressed magazine follower in position to contact the
magazine follower engaging arm of the bolt lock lever when the
magazine is empty, said bolt lock activating surface moving the
forward end of the pivoted bolt lock lever to its upper position
and moving the rearward end of the pivoted bolt lock lever to its
lower position when said magazine is empty.
2. The firearm according to claim 1 in which the bolt lock lever is
pivotally mounted on the side of the receiver for rotation about a
generally horizontal axis.
3. The firearm according to claim 1 in which the magazine follower
engaging arm extends laterally from the forward end of the bolt
lock lever and the bolt stop arm extends laterally from the
rearward end of the bolt lock lever.
4. The firearm according to claim 1 in which the bolt lock lever is
pivotally mounted on the outside of a side wall of the receiver, in
which the magazine follower engaging arm extends laterally inwardly
through an opening formed in said side wall above the bolt
activating surface of the magazine follower, and in which the bolt
stop arm extends laterally inwardly through an opening formed in
said side wall adjacent the bolt stop lug of the bolt when the bolt
is at its rearward position.
5. The firearm according to claim 1 in which the bolt stop arm of
the bolt lock lever is formed with a rearwardly facing surface that
is contacted by a matching forwardly facing surface of the bolt
stop lug of the bolt when the bolt is at its rearward position and
the rearward end of the bolt lock lever is at its lower
position.
6. The firearm according to claim 5 in which the rearward facing
surface of the bolt stop arm is slanted slightly rearwardly and in
which the forward facing surface of the bolt stop lug is slanted
slightly forwardly so that said forward facing surface slightly
overlies said rearward facing surface to detain the rearward end of
the bolt lock lever at its lower position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to auto-loading firearms, and in particular
to gas-operated auto-loading rifles.
2. Prior Art
Auto-loading firearms of the type to which the present invention
relates have a receiver, a barrel mounted on the forward end of the
receiver, a bolt slidably mounted for longitudinal travel in the
receiver behind the barrel, an auto-loading mechanism (usually,
gas-operated) connected to the bolt for moving the bolt from its
forward closed position to its rearward open position and return
when the firearm is fired, a trigger and related parts of the
firing mechanism, and a cartridge magazine disposed in the receiver
beneath the bolt. When the firearm is fired, the bolt is caused by
the auto-loading mechanism to travel from its closed position to
its open position and to return to its closed position, the bolt
extracting and ejecting the spent cartridge case as it travels
rearwardly to its open position and then picking up a fresh
cartridge from the magazine and inserting the cartridge in the
chamber of the barrel as it returns to its closed position.
Typically, the magazine comprises a box-like structure that is
adapted to contain a plurality of cartridges and to feed the
cartridges to the loading mechanism of the firearm. The magazine is
provided with a vertically movable spring-pressed magazine follower
that moves the cartridges upwardly toward the open upper end of the
magazine where the cartridges are loaded, one at a time, into the
barrel of the firearm. As noted, the bolt moves from its normally
closed position to its open position and then back to its closed
position each time the firearm is fired. After the last cartridge
from the magazine has been fired and extracted and the magazine is
empty, the bolt would normally return to its closed position unless
means are provided to automatically lock the bolt in its open
position when the magazine is empty. When the bolt is automatically
locked in its open position, the shooter is made aware of the fact
that the magazine is empty and reloading of the empty magazine is
greatly facilitated.
Various mechanisms have heretofore been proposed for locking the
bolt in its open position when the magazine is empty and the last
cartridge therefrom has been fired, extracted and ejected. Many of
these mechanisms are unduly complicated or are unreliable or
subject to structural failure. After an intensive investigation of
the limitations and problems associated with the design of a
satisfactory bolt lock arrangement for semiautomatic firearms, we
have now devised a new bolt lock for such firearms which is sturdy,
reliable and simple in operation.
SUMMARY OF THE INVENTION
As previously mentioned, firearms to which the present invention
relates have a receiver, a barrel, a bolt mounted in the receiver
behind the barrel, an auto-loading mechanism connected to the bolt
for moving the bolt from its forward closed position to its
rearward open position and return when the firearm is fired, a
cartridge magazine disposed beneath the bolt and bolt lock means
for locking the bolt in its open position when the magazine is
empty and the last cartridge from the magazine has been fired. The
magazine is adapted to contain a plurality of cartridges and has a
spring-pressed vertically movable magazine follower that moves the
cartridges contained in the magazine upwardly into position to be
loaded into the chamber of the barrel.
The improved bolt lock means of the invention comprises a
longitudinally disposed bolt lock lever pivotally mounted on the
side of the receiver, the bolt lock lever having a magazine
follower engaging arm at the forward end thereof and a bolt stop
arm at the rearward end thereof. The forward and rearward ends of
the bolt lock lever are each movable vertically between
predetermined upper and lower positions when the bolt lock lever is
rotated about the pivot thereof. A bolt lock lever spring urges the
forward end of the pivoted bolt lock lever to its lower position
and the rearward end of said bolt lock lever to its upper position.
A bolt stop lug is disposed at the rearward end of the bolt in
position to be clear of the bolt stop arm of the bolt lock lever
when the rearward end of the lever is at its upper position and in
position to be blocked by the bolt stop arm of the bolt lock lever
when the rearward end of the lever is at its lower position. A bolt
lock activating surface is disposed on the upper end of the
spring-pressed magazine follower in position to contact the
magazine follower engaging arm of the bolt lock lever when the
magazine is empty, said bolt lock activating surface moving the
forward end of the pivoted bolt lock lever to its upper position
and moving the rearward end of the lever to its lower position when
the magazine is empty .
BRIEF DESCRIPTION OF THE DRAWINGS
The bolt lock arrangement for semi-automatic firearms of the
invention will be better understood from the following description
thereof in conjunction with the accompanying drawings of which:
FIG. 1 is a fragmentary side elevation of an auto-loading rifle
embodying the invention,
FIG. 2 is a sectional view along the vertical plane intersecting
the longitudinal center line of the receiver portion and the
adjacent stock and forearm portions of the rifle of FIG. 1,
FIG. 3 is a fragmentary side elevation of the left side of the
rifle of FIG. 1 showing the bolt lock lever in its unlocked
position,
FIG. 4 is a sectional view along line 4,7 -- 4,7 of FIG. 3 showing
the bolt in its rearward position and the bolt lock lever in its
unlocked position,
FIG. 5 is a sectional view along line 5, 8 -- 5, 8 of FIG. 3
showing the bolt in its rearward position and the bolt lock lever
in its unlocked position,
FIG. 6 is a fragmentary perspective view showing the bolt in its
rearward position and the bolt lock lever in its bolt locked
position,
FIG. 7 is a sectional view along line 4, 7 -- 4, 7 of FIG. 3
showing the bolt lock lever in its bolt lock position,
FIG. 8 is a sectional view along line 5, 8 -- 5, 8 of FIG. 3
showing the bolt lock lever in its bolt lock position,
FIG. 9 is a sectional view along line 9 -- 9 of FIG. 3 showing the
bolt in rearward position and the bolt lock lever in the bolt
locked position,
FIG. 10 is a perspective view showing the bolt lock assembly
mounted on the side of the receiver, and
FIG. 11 is an exploded perspective view corresponding to FIG.
10.
DETAILED DESCRIPTION
As shown best in FIG. 1, the principal externally visible
components of a typical gas-operated auto-loading rifle of the type
to which the present invention relates include a barrel 10, a
receiver 11 to which the barrel is secured, a longitudinally
movable bolt 12 mounted in the receiver 11 behind the barrel 10, a
longitudinally movable slide 13 having a slide cocking handle 14
that is connected to the bolt 12, a trigger 15 and trigger guard
16, a magazine latch 17, a stock 18 having a stock forearm 19, a
forearm upperhand guard 20, a gas block 21 having a block clamp
portion 22, a rear sight 23, and a safety activating lever 24. As
shown in FIG. 2, the stock 18 is formed with a vertical slot or
cut-out portion 25 in which the firing mechanism associated with
the trigger 16 and the magazine associated with the magazine latch
17 are received, and the stock forearm 19 is formed with a
channel-shaped recess 26 in which the forward end of the slide 13
and the parts associated therewith are received.
Referring again to FIG. 2, the barrel 10 is formed with a bore 28
having a cartridge chamber 29 at the rearward end thereof. The
longitudinally movable bolt 12 is provided with a firing pin 30 in
position to strike a cartridge received in the chamber 29, an
extractor 31 (shown best in FIGS. 4, 7 and 9), and a spring loaded
ejector 32. The trigger 15 is pivotally mounted on a pivot pin 34,
the trigger being provided with a sear arm and sear 35 and with a
trigger spring 36. Secondary sear 37 is also mounted on the pivot
pin 34, the secondary sear being provided with a secondary sear
spring 38. A hammer 40 is pivotally mounted on a pivot pin 41 in
position to strike the rearward end of the firing pin 30 when the
bolt 12 is in its closed position. The hammer 40 is provided with a
rearwardly extending sear notch arm having a primary sear notch 43
and a secondary sear notch 44. A hammer strut and spring 46 presses
the hammer 40 toward its firing position as shown in FIG. 2.
A magazine 48 adapted to contain a plurality of cartridges 49 is
located in the slot 25 of the stock 18 directly below the bolt 12
when the bolt is in its closed position. The magazine 48
advantageously comprises a box-like structure that is removable
from the slot 25, the magazine being held in position in the slot
by the front magazine latch 50 and the manually operated rear
magazine latch 17. A magazine follower 51 is disposed within the
magazine 48 below the cartridge 49, the magazine follower having a
follower spring 52 (shown best in FIGS. 4 and 7) that presses the
magazine follower upwardly, thereby moving the cartridge 49 into
position to be loaded into the chamber 29 by the bolt 12.
As noted, the auto-loading mechanism is preferably gas operated,
although other types of mechanisms are well known in the art, the
action shown in the drawings being a modification of the bolt and
auto-loading mechanism of the M-14 rifle. In this modification a
slide block (not shown) is located within the channel-shaped recess
26 of the forearm 19, the slide block being connected to the slide
13 and being held in its forward position by the slide spring 54
that is mounted on the slide spring guide rod 55. When the rifle is
fired, powder combustion gases drive the slide block rearwardly
against the pressure of the slide spring 54 thereby causing the
bolt 12 to move rearwardly to its open position, the slide spring
54 then moving the bolt 12 forwardly to its closed position in a
manner well known in the art.
The firing and auto-loading operations proceed as follows: The
rifle is in its cocked and ready to fire condition when the hammer
40 is rotated rearwardly against the pressure of the hammer strut
and spring 46 so that the sear notch 43 is engaged and held by the
sear 35, the bolt 12 is in its closed position, and a live
cartridge is in the chamber 29. When the trigger 15 is pulled, the
sear notch 43 is disengaged from the sear 35 thereby allowing the
hammer 40 to spring forward against the rearward end of the firing
pin 30 which, in turn, strikes and fires the cartridge in the
chamber 29. Powder combustion gases force the slide 13 rearwardly
against the pressure of the slide spring 54. Rearward movement of
the slide 13 causes the bolt 12 to move from its forward closed
position to its rearward open position. Rearward movement of the
bolt 12 extracts and ejects the spent cartridge case and also
rotates the hammer 40 rearwardly so that the secondary sear notch
44 is engaged and held by the secondary sear 37. The pressure of
the slide spring 54 then causes the slide 13 to move forward
carrying with it the bolt 12. As the bolt 12 moves from its open
position to its closed position it picks up a fresh cartridge 49
from the magazine 48 and inserts the cartridge in the chamber 29 in
the manner known in the art. When the trigger 15 is released and
allowed to return to its usual position, the sear notch 43 is
engaged and held by the sear 35 while, at the same time, the
secondary sear notch 44 is released by the secondary sear 37. The
rifle is now again in its cocked and ready-to-fire condition. This
sequence of operations is repeated until the magazine 48 is empty
and the last cartridge 49 has been fired.
As previously noted, it is important to provide means for retaining
the bolt 12 in its open position when the magazine 48 is empty and
the last cartridge is fired. As shown best in FIGS. 3 through 11,
the bolt lock means of the invention comprises a longitudinally
disposed bolt lock lever 57 pivotally mounted on the generally
horizontally disposed pivot stud 58 that projects from the side
wall of the receiver 11. The bolt lock lever 57 is provided with a
magazine follower engaging arm 60 that extends laterally inwardly
from the forward end of the bolt lock lever, and it is also
provided with a bolt stop arm 62 that extends laterally inwardly
from the rearward end of the bolt lock lever 57. In the embodiment
shown in the drawing the bolt lock lever 57 is mounted on the
outside of the side wall of the receiver 11, the side wall of the
receiver being formed with a forward arm opening 64 through which
the magazine follower engaging arm 60 extends and with a rear arm
opening 65 through which the bolt stop arm 62 extends. In another
embodiment of the invention the bolt lock lever 57 may be mounted
within a housing (not shown) that either forms an integral part of
the side wall of the receiver 11 or is secured to the side wall of
the receiver.
As shown best in FIGS. 9, 10 and 11, the bolt lock lever 57 is held
in place on the pivot stud 58 by the retainer plate 67, the
retainer plate 67 being received in the slots 68 and 69 and being
held in place therein by the retainer plate plunger 70 and plunger
spring 71. As noted, the bolt lock lever 57 is pivotally mounted on
the pivot stud 58 so that the magazine follower engaging arm 60 at
the forward end of the lever 57 and the bolt stop arm 62 at the
rearward end of the lever 57 are movable between predetermined
upper and lower positions as hereinafter more fully explained. A
bolt lock plunger 72 and bolt lock plunger spring 73 are mounted in
a bore 74 formed in the receiver 11, the bolt lock plunger and
spring urging the forward end of the bolt lock lever 57 to its
lower position and the rearward end of the bolt lock lever to its
upper position as shown best in FIG. 3.
The magazine follower 51 of the magazine 48 is provided with an
upstanding bolt lock activating surface 76 that is positioned
directly below the inner end of the magazine follower engaging arm
60 of the bolt lock lever 57. The spring-pressed magazine follower
51 is disposed in the magazine 48 below any cartridge or cartridges
49 that may be contained in the magazine. As long as there is at
least one cartridge 49 remaining in the magazine 48 the bolt lock
activating surface 76 is maintained out of contact with the
magazine follower engaging arm 60 of the bolt lock lever 57 as
shown in FIG. 4. When the last cartridge 49 has been removed from
the magazine 48 and the magazine is empty, the bolt lock activating
surface 76 of the magazine follower 51 contacts the magazine
follower engaging arm 60 of the bolt lock lever 57 and moves the
forward end of the bolt lock lever to its upper position as shown
in FIGS. 6 and 7. That is to say, when the magazine 48 is empty and
the bolt lock activating surface 76 contacts the magazine follower
engaging arm 60 the upward force of the magazine follower spring 52
overcomes the downward pressure of the bolt lock plunger spring 73
and causes the forward end of the bolt lock lever 57 to move
upwardly as described.
When the magazine follower engaging arm 60 at the forward end of
the bolt lock lever 57 is at its lowest position as shown in FIG.
4, the bolt stop arm 62 at the rearward end of the lever 57 is at
its upper position as shown in FIG. 5. When the magazine follower
engaging arm 60 is at its upper position as shown in FIG. 7, the
bolt stop arm 62 is at its lower position as shown in FIG. 8.
As noted, the bolt 12 normally travels from its forward closed
position to its rearward open position and then back to its closed
position when the rifle is fired. In the embodiment shown in the
drawings, the rearward end of the bolt 12 is provided with a bolt
stop lug 78 in position to clear (that is, to move freely beneath)
the bolt stop arm 62 of the bolt lock lever 57 when the rearward
end of the bolt lock lever is at its upper position as shown in
FIG. 5. However, the bolt stop lug 78 of the bolt 12 does not clear
(that is, it is blocked by) the bolt stop arm 62 of the bolt lock
lever 57 when the rearward end of the lever is at its lower
position as shown in FIG. 8.
The bolt stop arm 62 of the bolt lock lever 57 is formed with a
rearwardly facing surface 80 that is contacted by a matching
forwardly facing surface 79 of the bolt stop lug 78 of the bolt 12
when the bolt is at its rearward position and the rearward end of
the bolt lock lever 57 is at its lower position as shown best in
FIG. 8. The rearward facing surface 80 of the bolt stop arm 62 is
slanted slightly rearwardly and the forward facing surface 79 of
the bolt stop lug 78 is slanted slightly forwardly so that the
forward facing surface 79 of the bolt stop lug 78 slightly overlies
the rearward facing surface 80 of the bolt stop arm 62 so as to
detain the rearward end of the bolt lock lever 57 at its lower
position. This permits the empty magazine 48 to be removed and
replaced by a loaded magazine without releasing the bolt lock and
thereby allowing the bolt 12 to move forwardly to its closed
position. After the loaded magazine is latched in place, the bolt
lock is released by pulling on the slide handle 14 which disengages
the bolt stop arm 62 and the bolt stop lug 78, thus allowing the
lever 57 to return to its normal "unlock" position.
* * * * *