U.S. patent number 3,687,000 [Application Number 05/033,456] was granted by the patent office on 1972-08-29 for gas operated firearm muzzle attachment.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Army. Invention is credited to John R. Csizmar, Herbert A. Hebeler.
United States Patent |
3,687,000 |
Csizmar , et al. |
August 29, 1972 |
GAS OPERATED FIREARM MUZZLE ATTACHMENT
Abstract
A gas operated firearm muzzle attachment for generating
sufficient gas prure in the barrel to operate the firearm gas
system when blank cartridges are used and comprising a solid
restrictor insertable into the barrel bore to partially block the
escape of discharge gases therefrom and a clamp for quickly and
easily mounting the restrictor to the barrel.
Inventors: |
Csizmar; John R. (Davenport,
IA), Hebeler; Herbert A. (Davenport, IA) |
Assignee: |
The United States of America as
represented by the Secretary of the Army (N/A)
|
Family
ID: |
21870513 |
Appl.
No.: |
05/033,456 |
Filed: |
April 30, 1970 |
Current U.S.
Class: |
89/14.5 |
Current CPC
Class: |
F41A
21/26 (20130101) |
Current International
Class: |
F41A
21/00 (20060101); F41A 21/26 (20060101); F41f
017/12 (); F41c 021/18 () |
Field of
Search: |
;89/14E,14R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Jordan; C. T.
Claims
We claim:
1. An attachment to the muzzle of a firearm barrel having a flash
suppressor attached thereto, said attachment comprising a
restrictor insertable into said barrel muzzle for partial
restriction thereof and a clamp of unitary construction for
releasably securing said restrictor to said barrel muzzle, said
clamp being fabricated from a resilient material and comprising an
embossed portion forming a pocket for receiving the front end of
said flash suppressor in response to attachment to said barrel
muzzle, an aperture centrally located in said embossed portion, a
flared portion associated with said aperture disposed for receiving
one end of said restrictor, means on said restrictor cooperating
with said flared portion for fixedly securing said restrictor to
said clamp, and said means being disposed for cooperation with said
flash suppressor and said pocket for aligning said restrictor with
said barrel muzzle.
2. The invention as defined in claim 1 and including integral jaw
means on said clamp engageable with an annular groove in said flash
suppressor for releasably securing said attachment to said
suppressor.
3. The invention as defined in claim 1 wherein said clamp comprises
a pair of leaf springs extending oppositely from said embossed
portion, each of said leaf springs being of U-configuration in
longitudinal cross section and comprising a hand gripping portion
extending along the length of said flash suppressor and an arm
extending inwardly at right angles from said hand gripping portion
toward said flash suppressor, and a pair of jaws extending from
said arms for engagement with said groove in response to said hand
gripping portions being manually squeezed together.
4. The invention as defined in claim 3 wherein said jaws are
normally disposed in spaced apart relation a distance greater than
the diameter of said groove.
5. The invention as defined in claim 3 wherein said leaf springs
include means for releasably securing said jaws in a closed
position in response to engagement with said groove.
6. The invention as defined in claim 5 wherein said means for
securing said jaws closed comprises a pair of locking bars
extending oppositely from one of said pair of jaws, a pair of
latching portions of leaf configuration extending oppositely from
the other one of said pair of jaws and arranged to be resiliently
displaceable about a lateral axis respective to said attachment,
and a tab formed on each of said latching portions for cooperation
with a respective one of said locking bars to releasably hold said
jaws closed.
7. The invention as defined in claim 6 wherein each of said tabs
comprises a portion of said latching portions disposed on opposite
sides of the respective jaw portion and providing a recess open at
both sides and the bottom formed between said tab and said latching
portion to receive the respective one of said locking bars in
response to said hand gripping portions being squeezed together
sufficiently to engage said jaws with said groove.
8. The invention as defined in claim 6 wherein said means on said
restrictor cooperating with said flared portion includes a flange
dimensioned to function as a shear area thereby to permit
separation of said clamp from said restrictor in response to a
projectile in said barrel engaging said restrictor.
Description
The invention described herein may be manufactured, used, and
licensed by or for the Government for governmental purposes without
the payment to us of any royalty thereon.
BACKGROUND OF THE INVENTION
This invention relates to attachments for muzzles of firearm
barrels and pertains more particularly to a muzzle attachment for
gas operated firearms to provide automatic operation thereof when
firing blank cartridges.
For both safe and economical reasons, it is advisable in the
training of troops to fire blank cartridges in firearms to simulate
actual firing conditions. When the firearms are operated by gas
pressure produced by the discharge of cartridges, an attachment
must be mounted to the muzzle of the firearm barrel, when blank
cartridges are used, so as to at least partially block the escape
of gases therefrom and thereby generate sufficient back pressure to
operate the firearm gas system. .p It has been found that these
attachments are quickly eroded beyond safe limits, and are also
easily mislaid which is costly as present attachments are complex
as to structure and therefore are relatively expensive to
manufacture.
SUMMARY OF THE INVENTION
It is, therefore, a principal object of this invention to provide
for gas operated firearms a blank firing attachment which is
economically manufactured and is easily installed on the firearm
barrel.
It is a further object of this invention to provide such an
attachment which comprises only two pieces, a restrictor and a
clamp economically fabricated as a single unit for releasably
attaching the restrictor to the barrel.
It is a further object of this invention to provide for such an
attachment a restrictor which is of a solid, cylindrical
configuration to reduce the erosion which occurs if the restrictor
is of a tubular configuration, as in existing attachments.
Further objects and advantages of the invention will be apparent
from the following specification and the accompanying drawing which
is for the purpose of illustration only.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a longitudinally cross-sectioned view of the blank firing
attachment of this invention mounted to a firearm barrel;
FIG. 2 is a perspective view of the attachment mounted to a firearm
barrel;
FIG. 3 is a perspective view of the attachment with the jaws shown
in their open positions; and
FIG. 4 is a fragmentary, cross-sectional view taken along line 4--4
of FIG. 1.
DESCRIPTION OF A PREFERRED EMBODIMENT
Shown in the figures is a barrel 12 of a firearm which is arranged
for automatic operation by gas pressure produced by the discharge
of cartridges therein. The barrel is provided with a muzzle mounted
flash suppressor 14 in which an annular groove 16 is formed in the
outer surface adjacent to the rear portion thereof.
Shown installed on the muzzle end of barrel 12 is a blank firing
attachment 20 whereby sufficient gas pressure is generated in the
barrel when blank cartridges are fired therein for practise
purposes to operate the firearm gas system. Attachment 20 comprises
two parts, a restrictor 22 and a clamp 24. Restrictor 22, when
inserted into bore 26 of barrel 12, at least partially blocks the
escape of discharge gases therefrom, and clamp 24 functions to
quickly and easily mount the restrictor to the barrel and
releasably hold it therein.
Restrictor 22 is of solid cylindrical configuration and is of a
length to extend through attachment 20 into bore 26. The diameter
of restrictor 22 is so related to the diameter of bore 26 that when
a blank cartridge is fired therein approximately the same gas
pressure is momentarily generated E the bore as would be generated
when a cartridge with a projectile is fired therein. For example
the bore diameter is 0.222 inches, a diameter of 0.203 inches for
restrictor 22 has been found to be effective. Formed on the front
portion of restrictor 22 so as to be spaced from the front end
thereof is an annular flange 32 which assists in securing the
restrictor to clamp 24, as hereinafter described.
Clamp 24 is preferably formed as by stamping process from a single
piece of sheet metal having resilient qualities and comprises a
circular embossed portion 36 that forms a rearwardly facing pocket
38 for receiving the front end of flash suppressor 14 when
attachment 20 is mounted thereon. An aperture 40 is punched
centrally through embossed portion 36 from the front side thereof
to form a rearwardly projecting annular flare 42. To assemble clamp
24 and restrictor 22 the front end of the restrictor is inserted
into flare 42 until flange 32 contacts the rear edge thereof. The
front end of restrictor 22 is then peened over, as indicated at 30,
to retain restrictor 22 and clamp 24 together. Embossed portion 36
is so dimensioned that pocket 38 locates on the outside diameter of
flash suppressor 14 to align restrictor 22 with bore 26, as shown
in FIG. 1. Further assistance in aligning restrictor 22 with bore
26 is provided by the engagement of flange 32 with the inside
diameter of flash suppressor 14. Flange 32 is also dimensioned to
function as a shear area, permitting separation of restrictor 22
and clamp 24 in case a cartridge with a projectile is accidentally
fired in barrel 12 when attachment 20 is installed thereon.
Extending diametrically opposite from embossed portion 36 is a pair
of leaf springs 44 each of which is of U-configuration in
longitudinal cross section, as shown in FIG. 1, and includes an arm
46 that extends inwardly at right angles from the rear end of a
longitudinally disposed hand gripping portion 48. Leaf springs 44
extend along the length of flash suppressor 14 so that jaws 50,
formed as extensions of arms 46, are engageable with groove 16 in
the flash suppressor when hand gripping portions are squeezed
inwardly. When leaf springs 44 are unloaded, as shown in FIG. 3,
jaws 50 are opened sufficiently to perit the passage thereof over
flash suppressor 14 when attachment 20 is mounted thereto. Jaws 50,
when squeezed together against the bias of leaf springs 44 into
engagement with channel 16, as shown in FIGS. 1 and 2, are disposed
normal to the longitudinal axis of flash suppressor 14.
Referring to the illustrations of attachment 20 in the drawing for
the hereinafter described relationship of the reference elements,
jaws 50 are seen to include an upper jaw 52 and a lower jaw 54.
Upper jaw 52 is provided with an arcuate recess 56, which has
approximately the same radius as groove 16, and is formed in the
bottom edge thereof so as to fit into and around such groove for
full engagement therewith when the hand gripping portion 48
respective thereto is squeezed inwardly. Extending laterally from
opposite sides of upper jaw 52 is a pair of locking bars 58 each of
which projects outwardly from and below a vertically disposed edge
60 of the upper jaw.
Lower jaw 54 includes an arcuate lip 62 which has substantially the
same radius as groove 16 and which is offset forwardly from the
remainder of the lower jaw so as to be receivable by the groove
while the remaining portion of the jaw is located rearwardly of
upper jaw 52, to permit passage thereby during relative
displacement of jaws 50. Extending laterally and upwardly from
opposite sides of lower jaw 54 is a pair of latch portions 66 of
leaf configuration, which are resiliently displaceable about a
lateral axis relative to attachment 20. Each of the latch portions
66 is provided with a tab 68 of rectangular configuration which is
pierced therefrom and bent so as to extend downwardly and forwardly
from the front face of the respective latch portion to form a
recess 70 which is open at the sides and bottom between the tab and
the front surface. Thus, locking bars 58 are permitted upward entry
behind tabs 68 for releasably holding jaws 50 closed, as shown in
FIG. 4. With jaws 50 closed, inner side 72 of each of the tabs 68
is in close contact with one of the edges go of upper jaw through
open 52, as shown in FIG. 4, to prevent relative side movement
between lower jaw 54 and upper jaw 52.
Attachment 20 is installed on barrel 12 by passing flash suppressor
14 through open jaws 50 so that the free end of restrictor 22 is
inserted through flash suppressor 14 into bore 26. At the same
time, the front end of the flash suppressor is received by pocket
38 to hold the restrictor aligned with the bore. Hand gripping
portions 48 are then manually squeezed together against the bias of
leaf springs 44 to move locking bars 58 downwardly in front of
latching portions 66 and into camming contact with the front
surfaces of tabs 68. Continued squeezing pressure on hand gripping
portions 48 moves jaws 50 into engagement with groove 16 while
locking bars 58 move along the front surfaces of tabs 68, causing
latching portions 66 to be resiliently displaced, until the locking
bars snap off the ends of the tabs. Thus, when the squeezing
pressure applied to hand gripping portions 48 is released and lower
jaw 54 and upper jaw 52 are pressed apart through the bias of the
energized leaf springs 44, locking bars 58 enter recesses 70 and
are located behind the respective tabs 68 to hold the jaws closed
and in secure engagement with groove 16.
Attachment 20 is removed from barrel 12 by squeezing inwardly on
hand gripping portions 48 until locking bars 58 are moved out of
recesses 70 and then pulling rearwardly on latching portions 66 to
where tabs 68 are free of the locking bars. Jaws 50 are thereby
free to open through the bias of leaf springs 44.
We wish to be understood that we do not desire to be limited to the
exact details of construction shown and described, for obvious
modifications will occur to a person skilled in the art.
* * * * *