U.S. patent number 3,580,132 [Application Number 04/762,593] was granted by the patent office on 1971-05-25 for buffer and delay mechanism for a firearm.
This patent grant is currently assigned to Olin Mathieson Chemical Corporation. Invention is credited to Edwin S. Vartanian.
United States Patent |
3,580,132 |
Vartanian |
May 25, 1971 |
BUFFER AND DELAY MECHANISM FOR A FIREARM
Abstract
A mechanism for reducing the recoil force caused by
reciprocation of a bolt assembly in a semiautomatic firearm, and
for delaying the return of the bolt assembly from its retired
position to its battery position. A slide block is mounted for
reciprocation adjacent to the barrel, and the bolt assembly is
mounted for reciprocation within the receiver. A pair of slide arms
are secured to the bolt assembly and extend toward the slide block,
normally abutting the latter. A spring engages the slide block to
decelerate the latter during rearward reciprocation thereof. The
slide block thus decelerates during its rearward stroke while the
bolt assembly and slide arms are thus free to move away from the
slide block to strike the rear of the receiver and rebound
forwardly therefrom. After rebound, the slide arms and bolt
assembly strike the rearwardly moving slide block to cause a pause
in the reciprocation cycle, after which pause the slide block,
slide arms, and bolt assembly all move forward to their original
positions under the influence of the spring.
Inventors: |
Vartanian; Edwin S. (North
Haven, CT) |
Assignee: |
Olin Mathieson Chemical
Corporation (N/A)
|
Family
ID: |
25065513 |
Appl.
No.: |
04/762,593 |
Filed: |
September 25, 1968 |
Current U.S.
Class: |
89/130;
89/191.01; 42/1.06; 89/198; 89/199 |
Current CPC
Class: |
F41A
5/18 (20130101); F41A 3/82 (20130101) |
Current International
Class: |
F41A
5/00 (20060101); F41A 5/18 (20060101); F41A
3/82 (20060101); F41A 3/00 (20060101); F41d
005/04 (); F41d 011/12 () |
Field of
Search: |
;89/130,191,198,199 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Bentley; Stephen C.
Claims
I claim:
1. In a firearm having a receiver and a barrel secured thereto, a
bolt actuating mechanism comprising:
a. a first body mounted for reciprocating movement adjacent said
barrel;
b. a second body mounted for reciprocating movement within said
receiver, said second body including bolt means;
c. elongate means extending between said bodies, said elongate
means being secured to one of said bodies and said elongate means
being in displaceable abutting contact with the other of said
bodies;
d. gas operated means connected to said barrel, said gas operated
means being operable to impel said bodies and said elongate means
through an actuation cycle having an initial rearward stroke and a
subsequent forward stroke;
e. spring means having one of its ends contacting said first body
and having the other of its ends contacting a nonreciprocating
portion of said firearm, said spring means being operative to
decelerate said first body during said rearward stroke to thus move
said elongate means out of abutting contact with said other body;
and
f. said second body being operative to sequentially strike said
receiver and rebound into its forward stroke during the decelerated
rearward stroke of said first body to cause said other body to
strike said elongate means so as to stop relative movement of said
bodies and create a pause in said actuation cycle, and to prevent
said first body from contributing substantially to the force of
impact imparted to said receiver by said bolt actuating
mechanism.
2. The bolt actuating mechanism of claim 1, further comprising
second spring means operative to bias said elongate means toward
said other body.
3. In a firearm having a receiver and a barrel secured to said
receiver, a bolt actuating mechanism comprising:
a. first means mounted for reciprocating movement within said
receiver, said first means including a bolt assembly;
b. second means mounted for reciprocating movement adjacent said
barrel, said second means abutting said first means;
c. gas operated means secured to said barrel and operative to impel
said first and second means through an actuation cycle having a
rearward stroke and a forward stroke;
d. spring means having one end contacting said second means and
having another end contacting a nonreciprocating portion of said
firearm to bias said second means toward said gas operated means,
said spring means being operative to decelerate said second means
during the rearward stroke of said actuation cycle to move said
second means out of abutting contact with said first means; and
e. said first means being operative to strike said receiver at the
end of its rearward stroke and rebound into said forward stroke,
and said first means subsequently being operative to strike said
second means to prevent the latter from contributing to the impact
imparted to said receiver and to create a pause in said actuation
cycle.
4. The bolt actuating mechanism of claim 3 further comprising
spring means operative to bias said first means toward said second
means.
5. In a firearm having a receiver and a barrel secure to the
receiver, a bolt actuating mechanism comprising:
a. a slide block mounted for reciprocating movement beneath said
barrel;
b. a bolt assembly mounted for reciprocating movement within said
receiver;
c. at least one slide arm means connected to said bolt assembly and
extending toward said slide block for abutting contact
therewith;
d. gas operated means secured to said barrel forward of said slide
block, said gas operated means being operable to impel said slide
block, said bolt assembly, and said slide arm means on an actuation
cycle having a rearward stroke and a forward stroke;
e. spring means engaging said slide block and a nonreciprocating
portion of said firearm to decelerate said slide block during its
rearward stroke to move said slide block out of abutting contact
with said slide arm means; and
f. said bolt assembly being operative to strike said receiver to
terminate the rearward stroke of said bolt assembly and to rebound
the latter into its forward stroke, and said slide arm means then
being operative to strike said slide block to prevent the latter
from contributing to the impact delivered to said receiver and to
momentarily stop all relative movement of said mechanism to create
a pause in the actuation cycle.
6. The bolt actuating mechanism of claim 5, further comprising
spring means operative to bias said slide arm means toward said
slide block.
7. In a semiautomatic firearm having a receiver and a barrel
secured to the receiver, a bolt actuating mechanism comprising:
a. slide block means mounted for reciprocating movement beneath
said barrel, said slide block means including a yoke and at least
one laterally extending shoulder means;
b. a bolt assembly mounted for reciprocating movement within said
receiver;
c. at least one slide arm means secured to said bolt assembly and
extending toward said slide block means for abutting contact with
said shoulder means;
d. laterally extending pin means traversing said yoke and connected
to said slide arm means;
e. gas operated means secured to said barrel forward of said slide
block means, said gas operated means being operable to impel said
slide block means, said bolt assembly, and said slide arm means on
an actuation cycle having rearward stroke;
f. first spring means engaging said slide block to decelerate the
latter during its rearward stroke thereby moving said shoulder
means out of abutting contact with said slide arm means;
g. second spring means engaging said pin means to bias said slide
arm means toward said shoulder means; and
h. said bolt assembly being operative to strike said receiver to
terminate the rearward stroke of said bolt assembly and to rebound
the latter into its forward stroke; and slide arm means
subsequently being operative to strike said shoulder means to
momentarily stop all relative movement of said mechanism thereby
creating a pause in the actuation cycle.
Description
This invention relates to a mechanism for reducing the recoil force
and therefor increasing the life of the gun caused by the
reciprocation of the bolt assembly in a semiautomatic firearm as
the bolt assembly is moved from its battery position to its retired
position and returned. The mechanism also provides for delaying the
return movement of the bolt assembly from its retired position to
its battery position to permit a greater time period for the
operation of the cartridge extractor ejector and the feeding of a
new cartridge into a position to be picked up by the bolt assembly
and seated in the firing chamber.
The prior art semiautomatic firearms of the type utilizing a
reciprocating bolt assembly have exhibited several undesirable
traits relating to the reciprocation of the bolt assembly. When the
conventional bolt actuated semiautomatic firearm is fired, the bolt
assembly is driven from its battery position to a retired position
and return. The bolt assembly, upon reaching the retired position,
strikes the rear face of the receiver thus delivering a recoil
shock to the receiver and shooter. This recoil shock is
considerable due to the relatively large mass of the bolt assembly
needed to ensure complete reciprocation of the bolt assembly. It is
desirable to reduce the quantum of shock delivered to the receiver
and shooter without reducing the total mass of the bolt assembly in
order to concurrently provide for a more durable mechanism and more
comfortable shooting while insuring dependable reciprocation of the
bolt assembly.
A second undesirable feature of the prior art bolt actuated
semiautomatic firearms relates to the time period during which the
bolt assembly is approximately in its retired position. The time
period during which the bolt assembly is in its retired position is
critical because it is during this period that the fired cartridge
casing is ejected from the firing chamber and a fresh cartridge is
positioned for feeding into the firing chamber. The bolt assembly
must be in its retired position for a predetermined minimum time
period in order to insure that these several operations are
completely performed. Should the bolt assembly be returned to its
battery position before these operations are completely performed,
jamming of the action of the gun will occur. Therefore, in order to
insure that the specified operations are completely performed
before the bolt assembly is returned to its battery position, it is
desirable to delay the bolt assembly in or adjacent to its retired
position.
The preferred embodiment of the mechanism of this invention
includes a bolt assembly comprising a bolt slide and a bolt
reciprocally mounted in the receiver of a firearm. A slide block
member is reciprocally mounted for sliding movement beneath and
parallel to the barrel of the firearm, the slide block being acted
upon by a gas piston after a cartridge is fired from the gun. A
pair of slide arms are connected to the bolt assembly and are
spring biased into abutting engagement with the slide block. A
return spring is operative to act upon the slide block to bias the
latter toward the gas piston. When the bolt assembly is in its
battery position, the slide block is disposed adjacent to the gas
piston and the slide arms are abutted against the slide block, so
that the bolt assembly, the slide block, and the slide arms form an
interconnected mechanism. When a cartridge is fired, the gas piston
acts upon the slide block to impel the latter rearwardly on the
gun. The rearward movement of the slide block forces the latter
against the slide arms to move the slide arms and the bolt assembly
rearwardly toward the retired position at a first velocity. Thus
the initial portion of the reciprocation of the mechanism is
accomplished with the slide block, slide arms, and bolt assembly
all moving as a unit. Rearward movement of the slide block
compresses the slide block spring, which in turn operates to
decelerate the slide block. The bolt assembly and slide arms are
not, however, decelerated, and continue to move rearwardly at
substantially their initial velocity. The resulting difference in
respective velocities causes the bolt assembly and slide arms to
move away from the slide block, and the slide arms are thus moved
out of abutment with the slide block. The bolt assembly and slide
arms continue to move rearwardly independently of the slide block
until the bolt assembly strikes the rear of the receiver and
rebounds forwardly. The forwardly moving bolt assembly and slide
arms then strike the rearwardly moving slide block and the bolt
assembly, slide arms, and slide block momentarily cease movement in
either direction. The slide block spring then acts against the
slide block to carry the slide block, the slide arms, and the bolt
assembly back to their respective original positions. The mass of
the bolt assembly and slide arms on one hand, and the slide block
on the other hand are chosen so as to cause a halt in the motion of
the components upon impact between them. The resultant halt in
movement provides for an extended time period during which the
cartridge extraction and ejection, and fresh cartridge feeding are
insured of being fully performed. Also the bolt assembly and slide
arms are the only components of the system which rebound against
the receiver, thus the shock delivered to the receiver and stock,
and to the shooter after the gun is fired is substantially
reduced.
It is, therefore, an object of this invention to provide a bolt
actuating mechanism in a semiautomatic firearm wherein the recoil
force on the receiver and that experienced by the shooter from
reciprocation of the mechanism is substantially reduced.
It is a further object of this invention to provide a bolt
actuating mechanism of the character described wherein an extended
actuating time period is afforded to insure that the fired
cartridge is extracted and ejected, and a fresh cartridge is
properly fed into position for chambering.
It is yet another object of this invention to provide a bolt
actuating mechanism of the character described wherein the bolt
assembly and slide block move as a unit during one stage of the
actuation, and the bolt assembly moves independently of the slide
block during another stage of the actuation.
It is still a further object of this invention to provide a bolt
actuating mechanism of the character described wherein the momentum
of the bolt assembly and the opposite momentum of the slide block
are operative to stop movement of the mechanism for a predetermined
time period during operating of the mechanism.
These and other objects and advantages of this invention will
become more readily apparent from the following detailed
description and accompanying drawings in which:
FIG. 1 is a side elevation partially in section of a portion of a
firearm incorporating a preferred embodiment of the bolt actuating
mechanism of this invention, the bolt assembly being shown in its
battery position;
FIG. 2 is a top view of the slide block taken along line 2-2 of
FIG. 1, showing the means with which the slide arms are maintained
in abutment against the slide block;
FIG. 3 is a side sectional view taken along line 3-3 of FIG. 2;
FIG. 4 is a slide elevation partially in section similar to FIG. 1,
but showing the bolt assembly and slide arms having moved
relatively away from the slide block during the actuation of the
mechanism and while all three elements are moving rearwardly on the
gun; and
FIG. 5 is a side elevation partially in section similar to FIG.
4.
Referring now to FIG. 1, a bolt actuated semiautomatic firearm,
denoted generally by the numeral 2, is shown. Various parts of the
firearm, such as the trigger assembly, hammer assembly, and
cartridge magazine have been omitted for purposes of clarity. It is
understood that a conventional trigger assembly, hammer assembly,
and cartridge magazine may be used with this invention without
departing from the spirit thereof. The firearm 2 includes a
receiver 4, a barrel 6 connected thereto, and a stock 8, all of
which are of a conventional nature and form no part of this
invention. A forearm 10 is mounted on the barrel 6 to house the
mechanism of this invention. A bracket 12 being hollowed out to
contain a gas chamber 14. A gas bleed port 16 is drilled through
the bracket 12 and the barrel 6 to provide fluid communication
between the gas chamber 14 and barrel bore 18 through which port 16
high-pressure gases are bled from the bore 18 into the chamber 14
after a bullet is fired from the gun. A piston 20 is slidably
mounted in the chamber 14, the piston 20 being operable to act upon
a slide block 22 movably mounted below the barrel 6. The slide
block 22 includes a yoke portion 24 and a pair of laterally
extending shoulders 26, the latter of which provide abutting
surfaces against which the forward ends 28 of a pair of slide arms
30 are disposed. Each of the slide arms 30 includes a keyhole slot
32 in which a laterally extending pin 34 is slidably mounted. The
underside of the slide block 22 is hollowed out at 36 to provide a
surface 38 against which the forward end of a return spring 40 is
disposed. The rearward end of the return spring 40 is seated
against the front wall 42 of the receiver 4. The slide arms 30
extend rearwardly through a pair of slots 44 in the receiver wall
42, and the rearward ends of the slide arms 30 are connected to a
conventional bolt assembly 46 having a bolt member 47 reciprocally
mounted on a pair of rails 48 (only one of which is shown) in the
receiver 4.
Referring now to FIGS. 2 and 3, details of the means for
maintaining the abutting contact between the slide arms 30 and the
slide block 22 are shown with greater clarity. A spring member
indicated generally by the numeral 50 is disposed in the slide
block yoke 24, the spring 50 including a pair of laterally offset
coil portions 52 interconnected by a laterally extending bar 54.
The coil portions 52 each are integral with an upwardly extending
finger portion 56. The bar 54 bears against the rear face 24' of
the yoke 24 and the upwardly extending fingers 56 bear against the
pin 34 to force the latter against the forward ends of the
respective slide arm slots 32. The forward ends 28 of the
respective slide arms 30 are thus forced by the spring 50 against
the respective laterally extending shoulders 26 on the slide block
22. It will be readily appreciated that the slide arms 30 are thus
not connected to the slide block 22, but rather merely abut the
slide block 22. The slide arms 30 can be moved away from the slide
block shoulders 26 by simply overcoming the force of the spring
50.
Referring to FIG. 5, the mechanism of this invention is shown
during the rearward stroke of the bolt actuation after a cartridge
is fired from the gun. After the bullet passes the bleed port 18
high-pressure gases are introduced into the gas chamber 14 causing
the piston 20 to move toward the rear of the gun and strike the
slide block 22. The slide block 22 is thus driven to the rear
against the slide arms 30 causing the bolt assembly 46 to move
toward its retired position in the receiver 4. Thus the slide block
22, slide arms 30, and bolt assembly 46 move rearwardly as a unit
during the initial portion of the rearward stroke of the mechanism.
Rearward movement of the slide block 22 compresses the return
spring 40, which in turn tends to slow the rate at which the slide
block 22 moves rearwardly. Since the slide arms 30 are not rigidly
secured to the slide block shoulders 26, the resistance of the
spring 40 is not transferred to the bolt assembly 46 and slide arms
30 except negligibly through the spring 50. Thus, while the slide
block 22 is decelerated by the spring 40, the bolt assembly 46 and
slide arms 30 continue to move rearwardly at substantially their
original velocity. It is thus readily apparent that a point will be
reached during the rearward stroke of the mechanism when the bolt
assembly 46 and slide arms 30 will move away from the slide block
shoulders 26. Such a point is shown in FIG. 4, the slide block
shoulders 26 being spaced apart from the forward ends 28 of the
slide arms 30.
Referring now to FIG. 5, the mechanism is shown after the bolt
assembly 46 has struck the rear wall 58 of the receiver 4 and begun
to move forwardly in the direction of the arrow 60 toward its
battery position. At the same time the slide block 22 is still
moving rearwardly in the direction of the arrow 62. The slide arms
30 are thus moved toward the slide block shoulders 26 to impact the
latter. The rearward momentum of the slide block 22 and the forward
momentum of the bolt assembly 46 and slide arms 30 are of such
magnitude as to cancel each other out at impact. Thus the bolt
assembly 46, slide arms 30, and slide block 22 stop movement in
either direction momentarily after impact, and since the respective
momentums are equal and opposite in direction, no recoil is felt by
the shooter when impact occurs. After the pause in relative
movement occurs, the return spring 40 acts upon the slide block 22
to return the slide block 22, bolt assembly 46 and slide arms 30 to
their respective positions shown in FIG. 1.
It will be readily appreciated that the bolt actuating mechanism of
this invention insures complete actuation of the bolt by providing
a releasable interconnection between the slide block, the slide
arms, and the bolt assembly. This permits the individual elements
to move as a unit initially in the rearward actuating stroke
thereby gaining high momentum. Subsequently in the rearward stroke,
the individual elements move separately with one of them rebounding
from a rearward surface before the other of them reaches the
rearwardmost point of its movement. Thus the actuation recoil
delivered to the receiver and shooter results from a momentum which
is one-half the initial momentum of the mechanism, thus doubling
the life of the receiver and is, of course, more comfortable for
the shooter. After the actuation recoil occurs, the separated
elements are moving in opposite directions with substantially equal
momentum. The separated elements then collide with each other with
the result that relative motion in the mechanism stops for a
predetermined time period, thus extending the overall duration of
the actuation time. It is noted that the collision results in
substantially no recoil to the shooter, since the momentums are
substantially equal and in opposite directions. The extended period
of the actuation time insures complete extraction and ejection of
the spent cartridge and feeding of a fresh cartridge into a
position for chambering. The mechanism of this invention thus
buffers the recoil impact delivered to the firearm receiver and to
the shooter and reduces the occurrence of jamming during actuation
of the bolt.
Since many changes and variations of the disclosed embodiment of
the invention may be made without departing from the inventive
concept, it is not intended to limit the invention otherwise than
as required by the appended claims.
* * * * *