U.S. patent number 3,584,532 [Application Number 04/858,398] was granted by the patent office on 1971-06-15 for automatic gun with ejection actuated rammer.
This patent grant is currently assigned to Oberlikon-Buehrle Holding A.G. Zurich-Oerlikon. Invention is credited to Eugene M. Stoner, George W. Wight, Jr..
United States Patent |
3,584,532 |
Stoner , et al. |
June 15, 1971 |
AUTOMATIC GUN WITH EJECTION ACTUATED RAMMER
Abstract
An ammunition receiver is axially aligned with a reciprocating
barrel and is separated from the barrel by a pivotable deflector.
As the barrel is driven forwardly by springs loaded by recoil
forces from the previous firing, a round of ammunition is propelled
forwardly by a pneumatically driven rammer. The round pivots the
deflector out of its path and is then locked in the barrel and
fired. The recoil forces from the firing first overcome the forward
momentum of the barrel and then drive the barrel rearwardly, during
which time the expended cartridge is ejected rearwardly where it is
deflected transversely through an ejection port by the deflector.
Movement of the deflector caused by impact of the ejecting
cartridge actuates the rammer to drive another round of ammunition
forwardly into the barrel. A first round pulse and delay valve
initially controls actuation of the rammer and the delayed release
of the barrel from its sear in firing the first of a series of
rounds.
Inventors: |
Stoner; Eugene M. (Port
Clinton, OH), Wight, Jr.; George W. (Oak Harbor, OH) |
Assignee: |
Oberlikon-Buehrle Holding A.G.
Zurich-Oerlikon (Zurich, CH)
|
Family
ID: |
25328221 |
Appl.
No.: |
04/858,398 |
Filed: |
September 16, 1969 |
Current U.S.
Class: |
89/47 |
Current CPC
Class: |
F41A
9/37 (20130101); F41A 9/44 (20130101); F41A
9/42 (20130101) |
Current International
Class: |
F41A
9/37 (20060101); F41A 9/42 (20060101); F41A
9/44 (20060101); F41A 9/00 (20060101); F41f
017/16 () |
Field of
Search: |
;89/33R,33A,33B,33BB,33C,45,47 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Bentley; Stephen C.
Claims
What we claim is:
1. An automatic gun comprising:
a barrel having a firing chamber;
a rammer for driving a round of ammunition into the firing
chamber;
an expended cartridge ejection port adjacent the firing chamber;
and
means in the path of an ejected cartridge responsive to ejection of
the cartridge for initiating operation of said rammer so that a
round is started toward the chamber as the expended cartridge of
the previous round is being ejected.
2. The gun of claim 1 wherein said last recited means includes:
a deflector which is struck by an ejected cartridge causing the
cartridge to be deflected away from the gun, said deflector being
movable by the ejected cartridge; and
means responsive to movement of the deflector caused by the ejected
cartridge for initiating operation of the rammer.
3. The gun of claim 2 wherein:
the rammer is operated by pressurized fluid; and
the means responsive to movement of the deflector includes a
control rod which operates a valve controlling the application of
pressurized fluid to the rammer.
4. The gun of claim 3 including:
means operated by fluid pressure for actuating said control rod
independently of movement by the deflector.
5. The gun of claim 2 including:
an ammunition receiver positioned to the rear of the barrel having
a tubular portion aligned with the barrel for guiding a round of
ammunition toward the barrel firing chamber; and
the deflector being positioned between the forward end of the
receiver and the firing chamber.
6. The gun of claim 1 including:
an ammunition receiver positioned to the rear of the barrel having
a tubular portion aligned with the barrel for guiding a round of
ammunition toward the barrel chamber, the rammer being arranged to
advance a round from the receiver to the chamber;
a rammer valve actuated by said last recited means for controlling
the energization of said rammer;
a mechanism for feeding ammunition into said receiver;
a feed control valve having an input connected to an energizing
source and a first output leading to said feed mechanism and a
second output leading to said rammer valve;
a sensing element extending into the receiver for sensing the
presence or absence of a round of ammunition within the receiver,
the sensing element being connected to control the operation of the
feed control valve in a manner such that the output from the feed
control valve is applied to the rammer valve when the sensing
element senses the presence of a round of ammunition in the
receiver and the output is applied to the feed mechanism when the
sensing element senses the absence of a round of ammunition within
the receiver.
7. The gun of claim 1 including:
means for operation of said rammer independently of said means
responsive to cartridge ejection to start ramming of the first
round of a series of rounds.
8. The gun of claim 7 wherein:
said barrel is mounted for axial reciprocation; and including
spring means for driving said barrel forwardly;
a barrel sear for holding the barrel in a rearward position;
and
means for releasing said barrel from its sear shortly after said
rammer is operated by said independent rammer initiating means so
that said first round is propelled into the barrel as the barrel is
moving forwardly under the urging of said spring means.
9. An automatic gun comprising:
a barrel having a firing chamber;
a receiver having a tubular portion aligned with the barrel for
guiding a round of ammunition toward the barrel chamber;
an expended cartridge ejection port intermediate the receiver
tubular portion and the barrel;
a rammer mounted on the receiver for reciprocation to advance
rounds from the receiver tubular portion toward the barrel
chamber;
a deflector disposed between the ejection port and the receiver
tubular portion, and mounted for movement from the first position
obstructing the path between the barrel chamber and the receiver
tubular portion for deflecting ejected cartridges out the ejection
port, to a second position clear of said path to permit passage of
a round of ammunition travelling from the receiver tubular portion
to the barrel chamber, said deflector being movable when struck by
an expanded cartridge being ejected; and
means responsive to the deflector movement caused by an expanded
cartridge for actuating the rammer to advance a round of ammunition
from the receiver toward the barrel chamber.
10. The gun of claim 9 wherein:
the rammer is adapted to be driven forwardly by pressurized fluid;
and
the responsive means includes a valve for controlling the
application of pressurized fluid to the rammer, and a control rod
positioned to be moved by the deflector for operating said
valve.
11. The gun of claim 10 including:
a mechanism for feeding ammunition to said receiver, the mechanism
including a fluid operating feed piston;
a feed control having an input connected to a pressurized air
supply and a first output leading to said feed piston and a second
output leading to the rammer valve;
a sensing element extending into the receiver for sensing the
presence or absence of a round of ammunition within the receiver,
the sensing element being connected to control the operation of the
said feed control valve in a manner such that the output from the
feed control valve is applied to the rammer valve when the sensing
element senses the presence of a round of ammunition in the
receiver and the feed control valve output is applied to the feed
mechanism piston when the sensing element senses the absence of a
round of ammunition within the receiver.
12. The gun of claim 9 wherein:
said deflector is pivotally mounted to pivot between said first and
second positions and slideably mounted to be moved when struck by
an ejected cartridge;
said means responsive to the deflector movement includes a control
rod slideably mounted on the receiver with the forward end of the
rod positioned to be engaged by a portion of the deflector as the
deflector is moved towards the rod, and a valve for controlling the
application of pressurized fluid to the rammer for driving the
rammer, the control rod being connected to operate the valve when
moved by the deflector.
13. The gun of claim 12 including:
a control rod actuator comprising a piston formed on the control
rod, and means surrounding the piston to define a working chamber
adjacent the forward face of the piston so that by the application
of pressurized fluid to the chamber and the forward face of the
piston the rod may be moved to control the valve independently of
the deflector.
14. The gun of claim 9 wherein:
said responsive means includes a valve for controlling the
application of pressurized fluid to the rammer to drive the rammer,
and a control rod positioned to be moved by the deflector for
operating said valve; and including
a fluid operated control rod actuator for moving said control rod
independently of movement by the deflector;
means for mounting said barrel for axial reciprocation;
spring means for urging said barrel forwardly;
a barrel sear for holding said barrel in its rear position;
a fluid operated barrel sear release actuator for moving the sear
to release the barrel; and
a first round pulse and delay valve for controlling the application
of pressurized fluid to said control rod actuator moving the
control rod, and for operating the barrel sear release actuator, in
such a manner that when a first pulse of fluid pressure is applied
to the first round pulse and delay valve, pressure is immediately
applied to the means for moving the control rod and pressure is
initially delayed and then applied to the barrel sear release
actuator whereby the rammer is driven forwardly slightly before
said barrel is released for forward movement.
15. The gun of claim 14 wherein said round pulse and delay valve
includes:
a cylinder;
a piston within the cylinder biased to one end of the cylinder by a
spring, means defining a fluid passage extending across the piston
spaced from said one end of the cylinder;
the cylinder having a first fluid inlet and a first fluid outlet
connected by said passage when the piston is biased by the spring
to said one end of the cylinder, the outlet being connected to the
means for moving the control rod;
the cylinder having a second fluid inlet in one end for applying
fluid to the end of the piston to move the piston in opposition to
the spring, and a second fluid outlet in the side of the cylinder
spaced between said one end of the cylinder and said first outlet
so that the second inlet and outlet are in communication only after
the piston has been moved away from said cylinder end sufficiently
to open the second outlet, the second outlet being connected to
said barrel sear release actuator, said passage being moved out of
communication with the first inlet and outlet when the piston is
moved sufficiently to permit communication between the second inlet
and outlet.
16. The gun of claim 9 including:
means for actuating said rammer independently of movement by the
deflector.
17. An automatic gun comprising:
a barrel having firing chamber;
a receiver having a tubular portion aligned with the barrel for
guiding a round of ammunition toward the barrel chamber;
an expended cartridge ejection port intermediate the receiver
tubular portion and the barrel;
a rammer mounted on the receiver for reciprocation to advance
rounds from the receiver tubular portion toward the barrel
chamber;
deflector mounting means mounted for slideable axial reciprocation
on the top forward portion of the receiver adjacent the ejection
port;
a deflector pivotally mounted on said deflector mounting means, the
deflector being urged by spring means to a first position extending
downwardly to obstruct the path between the barrel chamber and the
receiver tubular portion for deflecting ejected cartridges out of
the ejection port, and the deflector being pivotable to a second
position clear of said path to permit passage of a round of
ammunition traveling from the receiver tubular portion to the
barrel chamber, said deflector mounting means carrying the
deflector being slideable rearwardly when struck by an expended
cartridge being ejected; and
means responsive to the rearward deflector movement for actuating
the rammer to advance a round of ammunition from the receiver
toward the barrel chamber.
Description
RELATED APPLICATION
This invention is related to an application entitled Automatic Gun,
Ser. No. 662,614, filed Aug. 23, 1967 by Eugene M. Stoner, now U.S.
Pat. No. 3,500,718, issued Mar. 17, 1970.
BACKGROUND OF THE INVENTION
This invention relates to an automatic gun or cannon, particularly
adapted to provide a high rate of fire for relatively large caliber
ammunition.
In the earlier application referenced above, a reciprocating gun
barrel is driven by springs loaded by recoil forces from the
previous firing. An ammunition receiver located to the rear of the
barrel and aligned with the barrel guides a round of ammunition
toward the barrel chamber as the round is propelled by a
lightweight rammer mounted on the receiver. The rammer is driven by
a spring which is loaded by and released by movement of the barrel.
An expended cartridge is ejected rearwardly and then deflected
transversely out an ejection port by a deflector while the rammer
is driving the succeeding round forwardly towards the barrel firing
chamber. The deflector prevents the ejected cartridge from striking
the succeeding round. Overlapping the rammer feeding step with the
ejection operation provides high-speed operation. This is in
contrast with the slower more conventional reciprocating bolt
operation of other weapons.
While the foregoing arrangement is extremely fast and quite
reliable, there is some possibility that a jamming problem could
arise in view of the rammer cycle being triggered by the barrel. As
stated, a round of ammunition is driven forwardly by the rammer
when the barrel has reached a certain point in its previous cycle.
At this point the expended cartridge of the previous firing is in
the process of being ejected to make room for the succeeding round.
On rare occasions, an expended cartridge may stick in the barrel
firing chamber instead of properly ejecting. If this unusual
condition should occur, the succeeding shell would, nevertheless,
be driven forwardly by the rammer toward the firing chamber. As a
result, the mechanism would likely be jammed and possibly damaged.
It would then be necessary to stop operation and correct the
malfunction. In combat operations such delay could, of course, be
critical.
Accordingly, as an additional safety feature, it is highly
desirable that such gun be constructed to prevent such a situation.
It is also desirable that the rammer be driven in a positive manner
by means which are independent from the movement of the barrel.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a gun
having a barrel and a rammer for driving a round of ammunition into
the barrel firing chamber with the movement of an expended
cartridge in the process of being ejected being utilized to trigger
the release of the rammer. Thus, the succeeding round of ammunition
will not be driven toward the barrel until and unless positive
indication is received that the previous expended cartridge is
being ejected. This ensures that the firing chamber in the barrel
will be open to receive the succeeding round. In a preferred form
of this invention, a deflector positioned at the forward end of the
rammer, adjacent the cartridge ejection port is in the path of the
cartridge being ejected so that it deflects the cartridge
outwardly. In the process the deflector is moved, and this movement
of the deflector in turn is used to trigger the release of the
rammer.
Preferably, the rammer is pneumatically driven, and the application
of air pressure is controlled by a valve operated by movement of
the deflector. The rammer is returned by a spring with the result
that the rammer operation is independent from movement of the
barrel. This pneumatic system is used in conjunction with a
pneumatically driven mechanism which feeds ammunition into the
receiver.
There is also provided a first round pulse and delay valve which
first releases the rammer to drive a round of ammunition toward the
firing chamber of the barrel as soon as the gun is placed into
operation and then releases the barrel from a rear spring loaded
position slightly after the rammer is released. This insures the
proper initial timing relationship. So long as the gun is retained
in firing position, this valve then remains in a barrel release
position while no longer controlling the rammer operation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a gun constructed in accordance with
the invention;
FIG. 2 is a perspective view of the rear main portion of the
gun;
FIG. 3 is a side cross-sectional view of the portion of the gun
illustrated in FIG. 2;
FIG. 4a is an enlarged cross-sectional view of the rear portion of
the gun viewed in FIG. 3;
FIG. 4b is an enlarged cross-sectional view of the central portion
of the gun viewed in FIG. 3;
FIG. 5 is a cross-sectional view on line 5-5 of FIG. 4a
illustrating the rammer cylinder and a portion of the feed
mechanism;
FIG. 6 is a cross-sectional view on line 6-6 of FIG. 4a showing
further portions of the rammer assembly and the feed mechanism;
FIG. 7 is a cross-sectional view on line 7-7 of FIG. 4a looking
rearwardly to illustrate portions of the rammer assembly and the
reed mechanism;
FIG. 8 is a cross-sectional view on line 8-8 of FIG. 4a showing a
portion of the barrel sear mechanism;
FIG. 9 is a cross-sectional view on line 9-9 of FIG. 4b showing the
breech assembly of the gun;
FIG. 10 is a cross-sectional view on line 10-10 of FIG. 4b showing
additional structure of the breech assembly;
FIG. 11 is an enlarged perspective view of the breech assembly;
FIG. 12 is an enlarged cutaway perspective view showing a portion
of the breech block cam assembly and the barrel sear;
FIG. 13 is an enlarged perspective view of the cartridge ejection
mechanism;
FIG. 14 is a top plan view showing the mounting of the
deflector;
FIG. 15 is a cross-sectional view on line 15-15 of FIG. 14 further
illustrating the deflector mounting;
FIG. 16 and 17 are cross-sectional views on the lines 16-16 and
17-17 respectively of FIG. 15 further illustrating the deflector
mounting;
FIGS. 18--23 are side elevational views, partially in section of
the main portion of the gun illustrating its operation; and
FIG. 24 is a diagram of the pneumatic control system for the
gun.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIGS. 1--3, the gun may be considered to have
several major assemblies including a barrel assembly 12; a breech
ring assembly 14 attached to the rear of the barrel assembly; a
breech block cam assembly 16 in which the combined barrel assembly
and breech ring assembly are mounted for axial reciprocation; a
drive spring assembly 17 connected between the breech block cam
assembly and the combined barrel breech ring assembly; a rammer
assembly located to the rear of the breech block cam assembly 16
and axially aligned with the barrel assembly 13 for receiving a
round of ammunition and for propelling the round forwardly into the
barrel; an ammunition feed mechanism 20; a buffer-charger assembly
22; and a pneumatic control system 23 (FIG. 24).
The rear of the gun may be secured with a variety of mounts,
depending on the use for the weapon. No particular mount is
described herein but for purposes of illustration, the breech block
cam assembly 16, the rammer assembly 18, and the buffer-charger
assembly 22 are removably attached to a supporting housing 24 which
may be mounted for movement in suitable trunnions (not shown).
I RAMMER ASSEMBLY
a. Receiver
The rammer assembly will be described with particular reference to
FIG. 4a as well as with reference to the various sections
illustrated in FIGS. 5--8. Included in the rammer assembly 18 is a
tubular ammunition receiver 16 having an inner diameter adequate to
receive a round of ammunition 28 shown positioned within the tube.
While the gun can be made in a variety of sizes, the illustrated
embodiment is designed for 35 mm. ammunition. As seen from FIG. 6,
the receiver 26 has openings 30 on either side for receiving
ammunition from the ammunition feed mechanism 20. The central top
portion of the receiver 26 is closed by an upper plate 32 of the
feed mechanism 20. The rear of the receiver 26 is open, even though
the ammunition enters from the sides.
A holding pawl 34 is pivotally mounted on a pin 35 secured to the
rear upper portion of the ammunition receiver 26. The lower portion
of the pawl 34 is urged by a pawl spring 36 clockwise as viewed in
FIG. 4a to extend downwardly through an opening 37 in the upper
wall of the rammer tube 26. The lower end of the pawl 34 engages
the rear of the round of ammunition 28 to prevent the round from
sliding rearwardly in the tube.
b. Deflector
The forward end of the receiver 26 is tapered rather sharply so
that the upper portion is considerably shorter than the lower
portion. This creates an outlet or ejection port 27 between the
tube and the breech-block cam assembly 16 through which spent
cartridges are ejected. A cartridge or case deflector 38 having a
forward curved surface extends completely across the front end of
the receiver 26 and also extends somewhat above the receiver. This
deflector is pivotally and slideably mounted on the forward end of
the receiver to form a variety of functions.
Referring now to FIGS. 14--17, it can be seen that the deflector 38
is formed with a large rearwardly extending tongue 38a with the
rear portion of the tongue being of slightly reduced thickness,
such that a pair of rearwardly facing shoulders 38b are formed. The
rearwardmost portion of the tongue 38a is notched forming a
downwardly facing sloping cam surface 38c. The lower portion 38d of
the tongue 38 a extends downwardly through an opening 42 in the
receiver slightly spaced from the round of ammunition 28 but in the
path of the round as it is moved forwardly by the rammer.
A pin 39 extends transversely through the tongue 38a and the ends
of the pin extend into mating holes in a pair of mating slideable
blocks 40. Each block is formed with a recess 40a on its inner side
within which is positioned a coil spring 42 mounted on the pin 39.
One end of each spring extends vertically and engages the
rearwardly facing shoulders 38b of the tongue 38a. The other end of
each spring engages the bottom surface of the recess 40a in a
slideable block. The springs 41 are oriented so that the deflector
is urged to pivot clockwise into the position illustrated in FIGS.
4a and 15, i.e., into the position obstructing the patch between
the rammer tube and the firing chamber. The deflector is, of
course, movable in the opposite direction against the resistance of
the springs so as to be clear of the path between the rammer tube
and the firing chamber.
The slideable blocks 40 are formed with depending portions 40b
which extend into the opening 42 in the receiver 26. As can be seen
from FIGS. 14 and 15, the length of the blocks and the depending
portions is slightly less than the length of the opening 42 in the
receiver; and consequently, the blocks may be slid that limited
amount on the upper surface of the receiver with the ends of the
opening marking the limits of the movement. The slideable blocks
are retained in slideable engagement with the receiver by means of
a clamp 43 having somewhat of a square C-shape when viewed from
above as in FIG. 14. The distance between the arms of the clamp is
sufficient to receive the upper portions of the blocks 40 together
with the pin 39 carrying the springs and the deflector tongue. The
lower portion of the space between the clamp arms is undercut on
each side to form rearwardly extending grooves 43a into which
extend outwardly extending ribs 40c formed on blocks. As can be
seen from FIG. 17, the ribs 40c fit snugly within the grooves 43a
so that by securing the clamp to the receiver, the blocks are
prevented from moving upwardly and transversely; and as already
explained, the rearward and forward movement of the blocks is
limited by the opening 42 in the receiver.
As seen from FIG. 15, the rear portion of the C-shaped clamp, which
extends completely across the receiver is formed with an opening
43b for receiving a control rod 64, thus forming a bearing for the
rod which will be subsequently described in greater detail.
c. Rammer Housing and Backplate Assembly
As can be seen from the cross-sectional views in FIGS. 5 and 6, an
elongated U-shaped housing 44 having a bottom wall 44a and
sidewalls 44b is positioned beneath the ammunition receiver 26. The
upper ends of the housing sidewalls 44b are attached by suitable
means to lugs 26b depending from the receiver 26. As seen in FIG.
4a, a backplate assembly 48 fits within the end of the housing 44
and includes a rectangular backplate 49 attached to the rammer
assembly by two quick-disconnect pins 51 which extend through
backplate 49 and the sidewalls 44b of the rammer housing 44.
A rammer tube 50 extends through an opening in the backplate 49 and
into the housing 44, being attached to the plate in cantilever
fashion by a pair of nuts 52 threaded onto the tube 50 and abutting
the backplate 49. Slideably mounted on the rammer tube 50 is a
cylindrical rammer piston 54 having a closed forward end. The
tolerance between the rammer tube and the rammer cylinder is
sufficiently close, such that the cylinder may be fired forwardly
by applying pressurized fluid through the rammer tube against the
inner closed end of the rammer piston. The outer surface of the
rammer piston 54 is formed with an enlarged portion 54a spaced
slightly from the rear end of the piston. A return spring 56
surrounds the forward portion of the rammer piston 54 with its rear
end abutting against a forwardly facing shoulder formed by the
enlarged portion 54a of the piston. The other end of the spring 56
extends forwardly and engages a vertical support plate 57 mounted
in the housing 44.
A rammer pawl 58 is pivotally mounted on a pin 59 transversely
supported on the enlarged portion 54a of the rammer piston. This
pawl 58 is urged upwardly in a counterclockwise direction as viewed
in FIG. 4a by a compression spring 60 which extends between the
free end of the pawl and the cylinder enlargement 54a. As can be
seen from FIG. 5, the rammer pawl 58 extends upwardly into the
receiver 26 through an elongated slot 62 formed in the lower wall
of the receiver 26 between the depending lugs 26b. The pawl 58
engages the rear of the round of ammunition 28 when the rammer
cylinder 54 is driven forwardly.
Still referring to FIG. 5, the rammer piston 54 is formed with a
pair of outwardly extending ribs 54b on its opposite sides which
slide within mating grooves in the housing sidewalls 44b. The
grooves extend in a direction parallel to the barrel axis so that
the rammer piston 54 will reciprocate on such a line.
It desired, a rammer sear may also be mounted on the backplate 49
as a safety device to prevent inadvertent firing of the rammer
piston 54; however, for sake of simplicity, the sear is not shown
in the drawings or described in detail herein.
d. Rammer Control Means
In accordance with the invention, the movement of the deflector 38
is utilized to trigger the operation of the pneumatically powered
rammer piston 54. For a description of the means responsive to
movement of the deflector for initiating operation of the rammer,
still refer to FIGS. 1 and 4a. The control rod 64 is mounted for
longitudinal reciprocation on the top of the receiver aligned with
the deflector tongue 38a. The forward end of the rod is positioned
in the hole forming a bearing on the clamp 43 while portions of the
remainder slide within an elongated guide tube 66 attached to the
receiver. The forward end of the control rod is angled or beveled
to form a cam surface 64a which cooperates with the notched surface
on the rear portion of the deflector 38. The rear end of the rammer
control rod engages a rammer valve 68 mounted on the top of the
receiver 26 to control operation of the valve. Pressurized air is
ducted into the rammer valve by means of an airline 70 connected to
a source of pressurized air schematically shown in FIG. 24. The
output line 72 of the rammer valve 68 is connected to the rear of
the rammer tube 50.
For actuating the rammer control rod independently of the
deflector, there is provided a cylinder 74 surrounding a central
portion of the control rod 64 and mounted on the top receiver. The
control rod has an enlarged portion forming a piston 64b which
slides within the cylinder 74 and forms a working chamber 76
between its forward face and the surrounding walls of the cylinder.
This chamber is connected to a pressurized air input line 78
mounted in the forward wall of the cylinder. Thus, the control rod
64 may be moved rearwardly by the application of air pressure to
the working chamber 76. A coil spring 79 surrounds the control rod
and extends between the rear face of the piston 64b and the rear of
the cylinder 74 so that the rod is continually urged forwardly into
engagement with the deflector. The connection of the control rod 64
to the rammer valve 68 is such that the rammer valve is normally
closed when the control rod is in its forwardmost position.
e. Rammer Buffer
Positioned within the forward portion of the housing 44 in line
with the rammer piston 54 and the spring 56 is a buffer housing 80
having a closed forward end positioned in a forward plate 85
supported by the housing. An outwardly extending flange formed on
the open rear end of the housing is clamped between the support
plate 57 and adjacent slots in the housing 44 so that the housing
is permanently fixed. A short buffer piston 82 is formed with an
enlarged forward portion which slides within the housing 80 and a
rear portion of reduced diameter which extends through the support
plate 57 into the forward end of the rammer spring 56. Extending
between the forward face of the buffer piston 82 and the closed
forward end of the buffer housing 80 are a plurality of rings 84
arranged in the form of two concentric overlapping columns with the
rings of each column being laterally aligned with the gap between
adjacent rings in the other column. The diameters of the rings are
such that each ring is normally slightly spaced from the adjacent
rings in its column. Hence, the two columns of rings can be axially
compressed somewhat, the inner column of rings receiving a
compressing force radially inwardly and the outer column receiving
a radially stretching force. Such an arrangement is capable of
absorbing considerable force.
f. Barrel Sear Release Mechanism
Still referring to FIG. 4a, there is shown beneath the buffer, a
pneumatic cylinder 86 supported by the rear vertical plate 57 and
the forward vertical plate 85. The rear of the cylinder 86 is
tubular with a reduced diameter which extends through the plate 57.
A pair of nuts 88 threaded onto the threaded end of the cylinder
holds the cylinder fixed. An air line 89 extends through the ends
of the cylinder and opens into the cylinder. Within the cylinder is
a piston 90 attached to a rod 91 extending through the forward end
of the cylinder. Attached to the forward end of the rod 91 is a
release cam 92 having a forward cam surface 92a arranged to slope
upwardly from its lower edge at approximately an angle of
45.degree. towards its upper edge.
II. BARREL, BREECH RING AND BREECH BLOCK CAM ASSEMBLIES
a. Barrel and Breech Ring
Referring now to FIG. 4b for a description of the breech section of
the gun, it can be seen that a barrel 13 in the barrel assembly 12
has a chamber 132 formed in its rear end for receiving a round of
ammunition. Flutes 133 on the chamber walls reduce friction between
the walls and a cartridge to facilitate ejection of the cartridge.
The outer rear portion of the barrel is provided with a series of
interrupted arcuate ribs 134 which mate with grooves between
similar interrupted ribs 136 formed on the interior of a strong
relatively massive breech member or ring 138. As can be seen in
FIG. 10, the ribs are in three axially aligned sets that extend
arcuately approximately 60.degree. and are arcuately spaced
60.degree.. Thus, in assembly, the spaces of the breech ring are
arcuately aligned with the ribs on the barrel so that the ring may
be moved axially into the barrel. When the proper axial depth is
reached, the ring 138 is rotated 60.degree. so that the ribs 134
and 136 are arcuately aligned and interengaged as shown.
Referring to FIGS. 4b and 9, to lock the breech ring 138 to the
barrel in this position, there is provided a barrel latch 140
pivotally mounted on a latch pin 142 supported by lugs 143 on the
breech ring 138. A latch spring 144 extends between the rear 140a
of the barrel latch and the breech ring, urging the barrel latch in
a clockwise direction, as viewed in FIG. 4b, so that the massive
forwarding depending lug 140b on the barrel latch fits within a
notch 145 in the upper wall of the barrel immediately in front of
the leading barrel rib 134a. In order to release the ring 138 from
the barrel 13, it is necessary to depress the rear end 140a of the
barrel latch 140 to pivot the forward end 140b upwardly.
b. Breech Block Cam
The breech block cam assembly 16 includes a breech block cam 147
which is a generally U-shaped support member having, as seen from
FIGS. 9, 10 and 12, a pair of axially extending grooves 148 formed
in its sidewalls 149. Secured to the cam 147 within these grooves
by suitable fasteners 153 (FIG. 2) are a pair of axially extending
hardened tracks 151 each having a square cross section which mates
with the grooves 148 and with grooves 152 formed in the lower rear
portion 138a of the exterior of the breech ring 138. This track and
groove arrangement slideably supports the weight of the barrel and
breech ring assembly within the breech block cam assembly 16 for
high-speed axial reciprocation.
c. Barrel Sear Mechanism
Referring now to FIGS. 4b, 9 and 12, a barrel sear mechanism 129
releasably latches the barrel against axial reciprocation relative
to the breech block cam. The barrel sear mechanism includes a sear
lever 130 having bifurcated forward arms 130b. A transverse pin 180
extends through the arms 130b and through a cam block 182 which is
secured to the bottom wall 150 of the breech block cam 147 by
suitable threaded fasteners 184. Springs 186 extend between the
arms 130b of the barrel sear and the bottom wall 150 to urge the
tongue 130a of the barrel sear upwardly, or in a clockwise
direction, as viewed in FIG. 12. Each arm 130b of the barrel sear
includes a sear surface 130d which faces rearwardly to engage
notches 188 formed in the lower wall of the breech ring 138, as can
be seen in FIG. 11. The sear surfaces 130d engage the notches 188
of the breech ring attached to the barrel to hold the barrel in its
rearwardmost position when the gun is at rest.
It may be seen that the sloping cam surface 92a of the barrel sear
release cam 92 engages the rearward tongue 130a of the barrel sear
130. Forward movement of the cam 92 depresses the tongue 130a
causing the barrel sear 130 to pivot about the pin 180 to release
the breech ring 138 attached to the barrel 13.
d. Breech Block
For opening and closing the end of the barrel chamber 132, there is
provided a rugged breech block 190 having a shape which fits within
the inverted U-shaped opening 191 in the breech ring 138, as can be
seen from FIG. 11. The breech block 190 is mounted on a pin 192
which extends through vertically elongated openings 194 in the
sidewalls of the breech ring 138 and further extend into elongated
cam slots 196 formed in the sidewalls 149 of the U-shaped breech
block cam 147. A pair of square shaped shoes 198 are mounted on the
breech block pin 192 to support the pin slideably within the
openings 194. On the outer ends of the breech block pin 192 are
positioned a pair of rollers 200 which ride within the cam slots
196. The cam slots 196 are formed with a lower, rear, horizontally
extending portion 1962, connected by a sloping intermediate portion
196c to a forward higher horizontally extending portion 196b. In
the example of the invention illustrated, the portion 196c is
oriented at an angle of about 39.degree. with respect to the
horizontal. In view of this relationship, the rollers 200 carrying
the pin 192 and the breech block 190 are moved up and down by the
cam slots 196 as the barrel is axially reciprocated.
In a plunger housing 146 formed integral with the breech ring 138
and located beneath the barrel, there is slideably positioned a
plunger piston 209 attached to a piston rod 210, and a plunger
compression spring 212 surrounding the rod 210 and urging the
piston 209 rearward. A plunger link 214 having one end pivotally
connected to piston 209 and its other end pivotally connected by a
pin 215 to the base or bottom of the breech block 190, provides a
constant force on the breech block in a clockwise direction as
viewed in FIG. 4b. Or, in other words, the breech block 190 is
constantly urged to pivot to a vertical position where it blocks or
obstructs the entrance to the barrel chamber 132, and is in
position to be moved by cam slots 196 to the upper position wherein
the barrel chamber is locked or closed by the breech block.
The forward end of the plunger housing 146 is enclosed by an
elongated cap 218 which covers the forward end of the piston rod
210 and a nut 211 mounted on the end of the rod. In FIGS. 4b and 9,
the breech block 190 cannot be pivoted into its vertical blocking
position in response to the urging of the plunger spring 212
because the upper edges 182a of the cam block 182 mounted on the
wall 150 engage the breech block 190 so that the block is held in
its horizontal position.
The cam block 182 is axially located slightly to the rear of the
cam slot sloping surface 196c so that the breech block 190 is
disengaged from the cam block 182 and is in a vertical position
when the rollers 200 engage the sloping surface. Consequently, the
breech block upper end may be received between the end of the
barrel and a lug 219 depending from the rear upper edge of the ring
138. The breech block is thus locked in that position and the
chamber 132 is blocked.
For detonating a round of ammunition, there is provided a hammer
224 which is pivotally mounted on the breech block pin 192 and
centrally positioned within the breech block 190 in a space
conforming to the shape of the hammer 224 as can be seen from FIG.
4b. The lower portion of the hammer is formed with an elongated
slot 225 through which the link pin 215 extends. This causes the
hammer to pivot with the breech block but permits limited pivoting
of the hammer relative to the breech block. Note in FIG. 9 that
when the breech block is in its open position the hammer fits
within the semicylindrical recess 182c in the cam block 182.
The upper end of the hammer 224 is formed with an elongated tip
224a which extends through an aperture 190a in the breech block
190. As can be seen, the aperture 190a extends completely through
the breech block and the length of the hammer tip 224a is such that
it extends beyond the forward surface of the breech block when the
hammer is pivoted into its most extreme position.
A spring 226 mounted within a socket in the breech block 190
engages the hammer 224 to urge the hammer in a counterclockwise
direction so that its tip 224a does not extend beyond the forward
surface of the breech block 190. The hammer tip 224a is, of course,
axially aligned with the center of a round of ammunition when the
breech block is in its chamber locking position so that the hammer
is able to detonate the round of ammunition.
For tripping the hammer to strike a round of ammunition against the
urging of the spring 226, the hammer is formed with a tongue 224b
which when the breech block 190 is in its vertical position, is
depending so that when the barrel reciprocates forward, the tongue
engages a tubular inertia block 230. The block 230 is slideably
mounted within a housing 232 secured to the bottom wall 150 of the
fixed support member by suitable fasteners 233, as illustrated in
FIG. 10. The inertia block 230 is urged forwardly by a compression
spring 234 confined between a socket in the forward end of the
inertia block 230 and a plug 236 threadably closing the forward end
of the inertia block housing 232.
e. Extractor
Also included in the breech ring assembly 14 is a cartridge
extractor mechanism generally indicated at 360 in FIGS. 9 and 13.
As can be seen from FIG. 9, the mechanism includes a pair of
extractors 362 positioned on opposite sides of the breech ring 138,
each of the extractors being provided with an inwardly extending
tip 362a which fits within the groove 363a in the rear portion of a
cartridge for a round of ammunition 363 schematically illustrated
in FIG. 13. The extractor 362 includes a shaft 362b which extends
through the sidewall of the breech ring 138, and an end 362 c (FIG.
11) which extends outwardly beyond the exterior of the breech
ring.
An extractor lever 366 is fixed by a pin 364 to the end 362c of the
extractor shaft. As best seen from FIGS. 11 and 13, the extractor
lever 366 has a somewhat flattened triangular shape with its bottom
wall having a depending portion 366a at its forward edge. The
extractor lever is located so that it engages the upper surface 368
of the sidewall 149 of the breech block cam 147, FIGS. 2 and 12.
This upper surface 368 has a forward portion 368a which is slightly
lower than a rearward portion 368b. The extractor lever 366 is
vertically located such that the lever is unaffected by the forward
portion 368a of the upper surface 368; however, the rearward
portion 368b being slightly higher causes the extractor lever to
pivot so that the forward depending edge 366a and the rear edge
366b ride on the surface 368b.
To accommodate the injection of a round of ammunition into the
barrel chamber 132, the extractor 362 and its shaft 364 is radially
slideable outwardly as can be visualized from FIG. 9. A detent
spring 370 and a cooperating detent 372 react against the inner
surface of the breech ring 138 to urge the extractor inwardly.
Reaction of the extractor tip 362a with the groove in a round being
injected also pivots the extractor lever 366 so that the rear edge
366b does not ride on the forward portion 368a of the upper surface
368.
III DRIVE SPRING ASSEMBLY
Still referring to FIG. 11, on the forward end of the breech ring
138 are formed a pair of large outwardly extending ears 156 each of
which has an axially extending opening 157 therethrough and a
smaller vertical aperture 158. As best seen from FIGS. 1 and 2, the
leading or forward portion of the breech block cam 147 is formed
with a pair of massive, upwardly extending ears 160 each having an
axially extending opening. The breech ring assembly 14 and the
breech block cam assembly 16 are interconnected by a pair of drive
spring assemblies 17 in cooperation with the ears 156 and 160.
Referring to FIGS. 1 and 2, each drive spring assembly 17 includes
a strong guide tube 162 having mounted thereon rugged, compression
drive springs 164 which, in the example illustrated, are formed in
three sections separated by spacers 165. A bushing 166 is mounted
on the tube 162 with a cylindrical portion extending into the
aperture in the ear 160 on the breech block cam 147. A flange on
the forward end of the bushing 166 engages the forward face of the
ear 160 and the rear end of the springs 164.
The rear end of the tube 162 extends into the aperture 157 (FIG.
11) in the ear 156 of the breech ring 138 and is secured thereto by
a quick-disconnect pin 168 extending through the aperture 158 in
the ear 156 and through the end of the tube 162.
The springs 164 are confined on the forward end of the tube 162 by
a spacer 165 backed by a suitable nut 169 and a jam nut 170
threaded onto the tube. With this arrangement it can be seen that
the guide tube 162 moves with the breech ring 138 and that the
springs 164 are compressed between the ear 160 and the nut 169 when
the breech ring 138 is moved rearwardly relative to the breech
block cam 147.
A bushing nut 171 threaded onto the rear end of the tube 162 serves
to confine the bushing 166 and the springs 164 on the tube before
assembly to the gun. The nut has an outer diameter which fits
within the ear 160 so that the rear of the tube 162 carrying the
nut 171 may be inserted into the ear 160 during assembly and then
secured to the ear 156.
The forward, unsupported end of the guide tube 162 terminates
adjacent to a barrel sleeve 176 which is a convenient mounting
surface for various mounting enclosures that may be employed for
the gun, depending on the particular application. Also, with such
enclosures, provision may be included for receiving the forward
reciprocating end of the guide tube 162.
IV BUFFER-CHARGER ASSEMBLY
Turning now to FIGS. 2, 3, and 4b, the buffer-charger assembly 22
is attached to the rest of the gun by means of a quick-disconnect
pin 240 extending through a bracket 242 of the assembly and the
forward end of the plunger cap 218. The bracket 242 is threaded to
the end of a recoil piston rod 244 and further secured by a
retaining ring 243. The rod 244 extends into a buffer housing 246
fixed to the support 24 by means of a flange 246a (FIG. 1). The rod
244 is provided with a piston head 245 which slides within the
housing slightly spaced from the housing walls, as can be seen from
FIG. 3. The rear end of the buffer housing 246 is closed by a cap
248 and the forward end is closed by another cap 254.
Positioned within the buffer housing 246 on opposite sides of the
piston head 245 are a pair of orifice sleeves 258a and 258b. These
sleeves are formed with a tapered inner surface which decreases in
diameter toward their respective ends of the housing. The housing
246 is normally filled with hydraulic fluid which must be displaced
past the piston head as the head reciprocates within the buffer
housing 246. The resistance to fluid flow increases as the piston
head moves into the tapered section 258 so that the buffer provides
increased buffering as the barrel approaches the ends of its
stroke.
A plurality of Belleville springs 160 confined between the end cap
248 and the sleeve 158a provide additional buffering effect.
Similarly, Belleville springs 264 are confined between end cap 254
and the forward end of the orifice sleeve 258b.
In the event of minor leakage of hydraulic fluid from the buffer
housing, a small supply of replenishing fluid may be provided in
the tubular rear end (not shown) of the piston 244. The fluid may
automatically be supplied through the use of a replenisher rod 272
which extends out of the rear end of the piston rod 244 and is
slideably received in a bushing 274 which is attached to the rear
end of the buffer piston 244 by means of a suitable retaining ring
276 as seen in FIG. 4b. The details regarding the replenishing are
not disclosed herein since they are not necessary to an
understanding of the claimed invention.
Referring to FIG. 3, threaded to the forward end of the housing cap
254 is a charger housing 280. A charger piston head 282 is threaded
to the forward end of the piston rod 244 to slide within the
charger housing 280. A compressed air inlet connection 284 is
positioned in the forward end of the charger housing 280. A
plurality of outlets (not shown) in the sidewalls of the charger
housing between the charger piston 282 and the housing cap 254.
Consequently, in the event of a misfire, pressure applied through
the connection 284 against the forward end of the piston 282 forces
the piston 244 rearwardly together with the barrel and breech
ring.
V AMMUNITION FEED MECHANISM
Refer now to the ammunition feed mechanism 20 which as previously
mentioned is adapted to feed ammunition from either side of the
rammer assembly 18 so that the gun may be fed two different types
of ammunition as desired. As can be seen from FIGS. 2 and 5--7 the
mechanism includes a large frame 290 which fits over the top and
the two sides of the rammer assembly. The upper wall 32 of the
frame mates with the upper portion of the rammer tube 26 to form,
in effect, the upper wall for the portion of the rammer tube where
a round of ammunition is inserted, as can be seen from FIGS. 2 and
4a.
Since the mechanism is symmetrical, only one side need be described
in detail. As can be seen from FIGS. 6 and 7, there is a space 310
between sidewall 291 of the frame 290 and the rammer tube 26 sized
to receive a belt of ammunition 312 for vertical feed movement. The
rounds of ammunition 31 and 33 are carried by interconnected links
314, each having its outwardly extending edge portion 314a
slideably received in a vertically extending slot 316 formed in the
frame 290.
The belt of ammunition 312 is supported vertically by a pair of
holding pawls 318. The rear holding pawl 318a engages the rear
portion of a round of ammunition, as illustrated in FIG. 5 and in
FIG. 2, while the forward holding pawl 318b engages a portion of
reduced diameter on a round of ammunition as can be seen in FIG. 7.
The holding pawls are pivoted to lugs 319 located on the outer
sides of the wall 291, and they extend inwardly into the ammunition
space 310 through openings formed in the wall. The portion of the
frame defining the lower wall of the openings limits the downward
or counterclockwise movement of the pawls 318 so that they are held
at the oblique angle illustrated in FIG. 7 to support the best of
ammunition 312. The free ends of the pawls 318 are pivotable
upwardly to enable the belt of ammunition to be moved upwardly.
Suitable springs (not shown) are associated with each pawl 318 to
urge the free end of the pawl downwardly and inwardly to the
position illustrated in FIG. 7.
Referring to FIG. 6 a feed slide 294 is slideably mounted to
reciprocate vertically within the frame 290. The feed slide 294 is
attached to a feed piston rod 297 carrying a piston confined within
a cylinder 300 fixed on the wall 291. The feed slide 294 is powered
upwardly within the slots 292 by applying air pressure to the
underside of the piston within the cylinder 300 through suitable
connections as shown in FIG. 24. Suitable springs 304, FIG. 2, urge
the slide 294 downwardly when the air pressure is interrupted and
suitable air exhaust means (not shown) may be provided.
A pair of feed pawls 305 pivotally attached to the feed slide 294
on each side of the feed slide extend into the ammunition space 310
in the path of the ammunition belt 312 to the position illustrated.
When a downward force is applied to the inner end of a feed pawl
305, its lower outer end engages the inner sidewall of the feed
slide 294 so that further downward pivoting movement is prevented.
However, upward movement on the pawl pivots it out of the
ammunition space 310 against the urging of the spring 308.
Referring now to FIGS. 5, 7 and 2, on either side of the feed slide
294 and the adjacent frame structure, there is mounted a pair of
obliquely oriented cam levers 324, each having its lower end
pivotally attached to the frame 290. Each cam lever 324 has a cam
slot 326 which extends partially through the thickness of the lever
from the feed slide side of the levers. Each cam slot has a lower
portion 326a and a longer upper portion 326b, which is more
vertically oriented than the lower portion when the lever 324 is at
rest as illustrated in FIGS. 5 and 7.
Cam follower pins 328 carried by the feed slide guides 295 extend
outwardly into the cam slots 326 in the cam levers 324.
Consequently, when the feed slide 294 reciprocates vertically, the
pins 328 are moved vertically and the engagement of the pins with
the cam slots 326 causes the upper end of each lever 324 to pivot
inwardly.
Pivotally attached to the upper end of each cam lever 324 is a
side-stripping or delinking arm 330 having an inner end 330a which
is curved to conform to the curvature of a round of ammunition 31
located at the height of the rammer tube 26 but positioned
outwardly from the tube, as may be seen in FIG. 7. The arm is
limited in its pivotal movement in the counterclockwise direction
to the horizontal position illustrated in FIGS. 2, 5 and 7, and a
spring 331 attached to the side-stripping arm 330 and the cam lever
324 urges the side-stripping arm counterclockwise in the horizontal
position. However, the side-stripping arm 330 is pivotable
clockwise so that its inner end is movable upwardly through a slot
333 by a cartridge of a round of ammunition.
Since the rammer tube 26 is open on both sides, it is desirable
that a round of ammunition be prevented from moving laterally out
of the rammer receiver in either direction. For this purpose, there
is provided a pair of positioning pawls 332 pivotally mounted to
the rear upper portion of the feed mechanism frame 290 as can be
seen in FIGS. 2 and 5. These pawls are pivotable about axes
extending parallel to the rammer receiver 26. As a round of
ammunition is moved inwardly, the pawl 332 in the path of the round
pivots inwardly until the round is centrally positioned. It then
snaps downwardly and outwardly under a spring bias to the position
illustrated in dotted lines in FIG. 5.
There is also provided a pair of positioning pawls 334 located more
forward from the pawls 332 near the reduced diameter portion of a
round of ammunition as illustrated in FIG. 7. Each pawl 334 is
mounted to pivot about an axis 335 which is obliquely oriented, and
the length of the pawl is such that the pawl 334 will pivot in a
manner to cause its inner end to move both in a vertical and
horizontal fashion. This is necessary since these pawls must pivot
out of the transverse or lateral path of an incoming round of
ammunition and out of the axial path of a round of ammunition being
rammed forwardly towards the barrel. Also, each pawl 334 is
provided with a suitable spring 336 urging the pawl to pivot into
the holding position illustrated in FIG. 7.
VI PNEUMATIC CONTROL SYSTEM
Refer now to the schematic illustration of FIG. 24 for a
description of a pneumatic control system for operating the gun. As
can be seen, there is included a source of pressurized air 342
having an output line 343 connected to a trigger valve 344 having
its output line 345 connected to a feed control valve 348 which
carries a sensing arm 349 that extends into the rammer tube 26. A
first output line 350 from the feed control valve is connected to a
feed selector valve 351 having two output lines 352 and 353 leading
to the respective sides of the ammunition feed mechanism 20. Air
line 352 is shown leading to the feed cylinder 300 containing the
feed piston rod 297 carrying a second round of ammunition 31. When
pressurized air is applied to the feed cylinder 300, the second
round of ammunition 31 is moved upwardly toward the rammer tube 26.
It will be understood from FIGS. 5, 6 and 7 a vertically moving
round of ammunition replaces another round which is transversely
thrust into the rammer tube 26.
The feed control valve 348 is provided with a second output line 70
connected to the rammer valve. Within the feed control valve 348,
there is provided a suitable device for directing the pressurized
air input to either one or the other of the two outlets, as
controlled by a sensing arm 349 that extends into the rammer tube
26. By way of example, there is schematically illustrated a piston
354 mounted on the end of the rammer control arm 349, the piston
being positioned and sized so that it closes the outlet to the feed
selector valve 351 when there is a round of ammunition within the
rammer causing the sensing arm 349 to be positioned as illustrated.
A passage 355 through the piston 354 connects the air input line
345 to the second output line 70 leading to the rammer. When the
piston 354 is in a second lower position, the outlet 350 is open to
the inlet 345, and the output line 70 is blocked. A spring 356
positively urges the piston and control arm 349 downwardly although
the piston is also urged ie this direction by he incoming air
pressure since the exposed area on the upper surface of the piston
is greater than that on the lower.
Branching from the output line 70 is a line 357 leading to a first
round pulse and delay valve 346 which includes a floating piston
358 urged towards the upper end of a chamber within the valve 346
by a spring 359. Within the line 357 is a restricted orifice 360.
The piston 358 is formed with an annular groove 358a around its
periphery spaced from the ends of the piston. The air line 357
leading to the first round pulse and delay valve 346 is separated
into a first section 357a leading to the upper end of the valve,
and a second section 357b leading to the side of the valve aligned
with the annular groove 358a when the piston 358 is in its upper
position. The air outlet 78 leading to the cylinder 74 mounted on
the top of the gun receiver is aligned with the inlet section 357b.
Hence, when the piston 358 is in its upper position as illustrated,
the inlet 357b and the outlet 78 are in communication by way of the
annular groove 358a.
A second outlet 362 from the first round pulse and delay valve 346
is spaced between the end of the valve and the outlet 78 so that it
is closed by the piston 358 with the piston positioned as
illustrated. The outlet 362 is connected to the barrel sear release
cylinder 86.
The air supply 342 has another outlet 364 leading to a charger
switch 366 which in turn is connected by a line 368 to the barrel
charger 22.
VI OPERATION OF THE GUN
While operation of the gun may be apparent from the foregoing
structural description, a more thorough explanation follows. A
discussion of the weapon cycle may be conveniently commenced with
the gun as shown in FIG. 18. The breech ring assembly 14 is seared
in its rear position by the sear 130, the rammer piston 54 is in
its rear position due to the urging of the spring 56, and a round
of ammunition 28 is positioned in the rammer tube 26. Upon
operating the trigger valve 344 of the pneumatic control system
shown ie FIG. 24, pressurized air is applied to the feed control
valve 348. With the valve 348 positioned as shown in FIG. 24
pressure applied to the feed control valve 348 is transmitted
through the passage 355 to the air line 70 leading to the closed
rammer valve.
Pressure in line 70 is also applied to branch line 357 leading to
the valve 346. Section line 357b is initially in communication with
the valve outlet line 78 through the annular groove 358a. Thus
pressure is applied to the chamber 76 in the cylinder surrounding
the control rod 64 and reacts against the forward face of the
piston causing the control rod to move rearwardly against the
resistance of the spring 79. The movement of the control rod 64
mechanically opens the rammer valve 68. As the rammer valve is
opened by the control rod 64, the pressure applied through the line
70 passes through the rammer valve into the line 72 leading to the
rammer tube 50. As explained above, application of pressure to the
rammer tube 50 causes the rammer piston 54 to be fired forwardly
causing the pawl 58 attached to the rammer cylinder to engage the
rear of the round of ammunition 28 and ram the round forwardly
towards the barrel 13, as illustrated in FIG. 19. As the round
moves forwardly it engages the deflector depending projection 38d
causing the deflector to pivot upwardly as shown in FIGS. 19 and
23. The projection 38d is provided to prevent the forward tip of
the round from striking the deflector, which could cause damage to
high explosive fuses.
As pressure is applied to the first round pulse and delay valve
causing the control rod to actuate the rammer valve 68, pressure is
also simultaneously applied through the line 357a to the end of the
piston 358 in the first round pulse and delay valve 346. There is a
very slight delay as the piston 368 is moved downwardly against its
spring 359, moving the annular passage 358a out of alignment with
the inlet 345b and outlet 78, so that no further pressure is
applied to move the rammer rod 64.
Downward movement of the piston 358 also opens the outlet line 362
to the high-pressure air with the result that pressure is applied
to the barrel sear release cylinder 86. This pressure causes the
cam 92 carried on the end of the piston rod 91 to be driven
forwardly so that its end cam surface 92a transmits a force to the
rear end 130a of the barrel sear 130. This action causes the sear
130 to pivot against the urging of the springs 186 (FIG. 12)
causing the lug 130d to be removed from the notches 188 in the
breech ring 138, thereby releasing the breech ring assembly 14 and
the barrel assembly 12, as illustrated in FIG. 19. Releasing the
barrel sear 130 causes the barrel assembly 12 to be driven
forwardly under the impulse of the driving springs 164, thus
starting the firing cycle shortly after the initiation of the
ramming cycle. As the rammer piston 54 completes its forward stroke
causing the round of ammunition to be propelled forwardly, the
final forward movement of the rammer is stopped by the rings 83 in
the rammer buffer 80.
When pressure is no longer applied through the air line 78 to the
chamber 76 to hold the control rod 64 in its rearward position, the
spring 79 urges it forwardly. However, when the round of ammunition
28 holds the deflector 38 in the position where it is pivoted
upwardly as shown in FIGS. 19 and 23, the rear cam surface 38c of
the deflector interferes with the forward surface 64a of the rod 64
causing the rod to be held in its rear position actuating the
rammer valve 68, thus holding the valve open. Pressure is applied
to the rammer piston 54 until the first round of ammunition 28 is
moved out of the receiver to the point where the sensing rod 349
extending from the feed control valve senses the absence of a round
and is moved downwardly by the spring 356, thus blocking the air
line 70 leading to the rammer valve. As soon as this occurs, the
rammer cylinder is returned to its rear position by its return
spring 56, to the position illustrated in FIG 20.
After the round of ammunition 28 has moved beyond the deflector 38
into the firing chamber, the deflector is pivoted in a clockwise
direction by its springs 41 to the position shown in FIG. 20
wherein the deflector blocks the forward end of the receiver 26.
With the deflector in this position the rod 64 is free to move
forwardly in response to the urging of its spring 79, thus enabling
the rammer valve to be closed.
Downward movement of the piston 354 in the feed control valve 348
permits air pressure to be applied to the ammunition feed mechanism
so that a second round 31 is fed into the receiver while the first
round is being fired. Once in the receiver 26, the second round
shifts the piston 354 upward so pressure is again applied to the
rammer valve 68. Due to the restricted orifice 360 in the air line
357, the momentary shifting of the piston 354 does not cause the
pressure on the first round pulse and delay valve to fall enough to
allow its piston 358 to move upwardly and allow pressure to be
applied to the control rod 64.
While this rammer and feed operation is occuring, the firing cycle
is continuing with the forward travel of the breech ring assembly
14 and barrel assembly 12. The breech block 190 slides forwardly
beyond the cam block 182 and is then free to pivot about the breech
block pin 215 due to the force of the plunger spring 212 upon the
breech block acting through the piston 208 and the link 214. As
shown in FIG. 20 the breech block is almost pivoted to a position
wherein it obstructs or closes the barrel chamber 132. The round 28
has, of course, already entered the chamber.
Further forward motion causes the breech block 190 to move upward,
finally chambering the round and locking the breech block, as shown
in FIG. 21. This upward motion is accomplished by the breech block
pin 192 and its rollers 200 following the path of the cam slots
196. More specifically, the rollers move from the rear portion 196a
up the sloping portion 196c to the upper forward portion 196b of
the cam slots. The upper portion of the breech block 190 thus moves
in front of the depending lug 219 on the breech ring so that the
block is locked in position closing the barrel chamber 132. It
should be noted from FIG. 20 that the breech block has not moved
upwardly by the cam slots 196 and that the breech block has been
released by the cam block 182 so that it is pivoting out of its
horizontal position into its vertical or blocking position.
The hammer 224 moves with the breech block 190. Just after final
locking of the breech block, the tongue 224b of the hammer 224
strikes the spring-biased or yieldable inertia block 230, pivoting
the hammer about the breech pin 215 as permitted by the elongated
slot 225 and driving the forward tip 224a of the hammer forwardly
to sharply strike the primer of the chambered round, as shown in
FIG. 21, thereby causing ignition. The shell 29 leaves the
cartridge 28a and speeds forward as shown.
The barrel assembly 12 and the breech assembly 14 continue to
travel forward a short distance due to their momentum and the
continued urging of the drive springs 164 until the recoil force
caused by ignition of the round overcomes the forward momentum and
reverses the direction of movement. As the recoiling parts now move
rearward, the breech block rollers 200 along with the breech block
pin 192 and the breech block 190 follow the breech block cam slots
196 downward, drawing the breech block out of its locking recess in
front of the lug 219 on the breech ring 138, and unlocking is
accomplished, as shown in FIG. 22. The complete unlocking time has
been arranged to minimize chamber gas leakage and to provide
sufficient residual force to properly eject the expended case
28a.
With the recoiling parts moving to the rear just after the instant
of the unlocking of the breech block 190, the extractor levers
forward portions 266a engage the sloping surface 368c of the breech
block cam assembly support member, causing the levers to pivot
quickly, together with the extractors 362 FIGS. 9 and 13). This
movement of the extractors gives an initial sharp extraction force
to the cartridge case through the annular groove 28b formed on the
case 28a of FIG. 21, should it be needed. However, it should be
noted that mechanical extraction is normally not required since the
use of the fluted chamber 132 allows the cartridge case to be
ejected easily from the barrel.
The breech block 190 now begins to pivot open, first by the gas
pressure acting on the cartridge head, and then by its lower end
striking the cam block 182, which action cams the breech block 190
to its horizontal or full open position and compresses the plunger
spring 212. Once the breech block 190 has pivoted out of the way,
the cartridge case 28a is blown clear of the chamber 132, past the
breech block 190, and it strikes the case deflector 38 which
deflects the case upwardly through the outlet 27 clear of the
weapon, as illustrated in FIG. 22.
As the recoiling parts near the end of their rearward movement,
they are first slowed and then stopped by the action of the buffer
assembly 22 (FIG. 3). The buffer piston 245 is also moved
rearwardly within the fixed buffer housing 246, as seen in FIG. 4b.
Normal buffer operation is accomplished by the buffer piston
approaching the rear tapered sleeve 258a in the buffer housing.
This tapered sleeve 258a forms a variable area orifice with the
area decreasing in the direction of travel of the piston so that
hydraulic fluid is throttled around this area. Extra buffer
capacity is provided by the stack of Belleville springs 260 in the
event this is necessary. Note that the rod 272 can extend into the
inertia block housing plug 236.
It should be mentioned at this point that buffering on the forward
stroke is provided by the tapered sleeve 258b within the buffer
housing 246 in the same manner described above. This is necessary
in the event of a misfire where a round does not fire when struck
by the hammer, or in the event the breech block is closed on an
empty chamber.
It should also be noted that during the central portion of the
stroke of the buffer piston 244 in its housing 246 the area between
the piston and the housing forms a velocity sensitive constant area
orifice which limits the maximum velocity of the recoiling
parts.
Once the ejected cartridge 28a has cleared the gun, the second
round of ammunition 31 can be received in the barrel. In accordance
with the invention, the action of the ejection cartridge striking
the deflector 38 is used to initiate the ramming of the second
round of ammunition towards the barrel. The deflector in effect
senses that the cartridge is being ejected. More specifically, the
force caused by the ejected cartridge 28a as it engages the
deflector as shown in FIG. 22 slides the deflector rearwardly in
view of its being mounted on the slideable blocks 40 shown in FIGS.
14--17. This rearward motion of the deflector is transmitted to the
rammer rod 64 by the rear portion 38c of the deflector tongue.
Thus, in the manner described above, the control rod 64 actuates
the rammer valve to cause the rammer to ram a second round of
ammunition forwardly, as illustrated in FIG. 23. Since the second
round is not started forwardly until the deflector is moved by the
ejected cartridge of the first round, there is no danger of jamming
the gun due to a misfire condition or a failure of the ejector.
The rearward movement of the deflector 38 and its mounting blocks
40 is limited by the interference between the slot 42 in the
receiver and the block depending portions 40b. As the deflector is
pivoted upwardly by the second round of ammunition, the deflector
and the blocks 40 are forced forwardly by the interference between
the control rod 64 and the rear of the deflector. Also, the
interference between the deflector and the round tends to move the
deflector forwardly, This forward movement is limited by the
forward edge of the slot 42 and by the block portions 40b.
From the foregoing description, it will be appreciated that the
first round pulse and delay valve establishes the initial timing
relationship between the movement of the barrel and the operation
of the rammer. Subsequent timing occurs automatically as triggered
by the movement of the deflector 38, since the delay valve 346
remains energized. Thus, high-speed operation is obtained but yet
after the initial firing cycle a cycle does not start until the
cartridge of the previous round is in the process of being safely
ejected.
As described, the second round of ammunition 31 was started
automatically into the rammer tube 26 as soon as the sensing arm
349 of the feed control valve 348 (FIG. 24) sensed that the tube
had space for the second round. The pressurized air through the
control valve 348 flows through the line 352 to the feed slide
cylinder 300, as determined by the manually controlled feed
selector valve 351. Air pressure applied to the underside of the
feed slide piston rod 297 powers the feed slide 294 quickly
upwardly carrying the cam pins 328 and the feed pawls 305. As may
be visualized from FIGS. 5--7, the vertical movement of the pins
328 in the lower cam slot portions 36a causes the cam levers 324 to
pivot inwardly which in turn cases the sidetripping arm 330 to move
inwardly. This side thrust strips a round 31 of ammunition from a
link 314 and urges the round toward the rammer receiver 26. The
succeeding round 33 being moved upwardly by the pawl 305 tends to
move the round 31 into the rammer receiver after it has been
delinked or stripped from its link.
The angle of the lower slot portion 36a is such that the delinking
operation is completed in the short time that it takes the follower
pin to move from its lowest position to the upper end of the lower
slot portion 326a. When the follower pin has reached the juncture
between the upper and lower slot portions, the upper portion 326b
extends approximately vertical or parallel to the movement of the
feed slide 294 so that the continued upward movement of the feed
slide and its pins causes no further inward movement of the
side-stripping arms. The continued upward movement does, however,
lift the round 33 into position adjacent to the rammer tube, the
side-stripping arms 330 pivoting upwardly due to the upward
movement of the ammunition belt. The subsequent downward movement
of the feed slide causes the levers 324 and the side-stripping arms
330 to return to the position illustrated in FIGS. 5 and 7. This
feed cycle is completed before the spent cartridge of the previous
round strikes the deflector. Air pressure through the feed control
valve is interrupted as soon as the round 31 forces the sensing arm
upwardly. However, the volume of the air line 50 is sufficient to
complete the upward movement of the feed slide 296.
As a round of ammunition is moved into the rammer tube, the link
314 which was carrying that round continues to move upwardly out of
the feed mechanism. The connections between the links are arranged
such that the links are separated as they are ejected from the feed
mechanism.
The gun cycle of operation will continue to be repeated as long as
the trigger valve 344 is depressed and ammunition is delivered by
the feed mechanism 20 into the rammer assembly 18. When the trigger
valve is released, the compressed air supply to the rammer is
interrupted so that no more rounds can be rammed forwardly. Also,
as the round in the chamber 132 fires and causes the barrel and
breech ring assemblies to recoil to the rear, the sear lever 130,
now free, engages and holds them, stopping the cycle.
If it is desired that ammunition of a different type from the other
side of the dual feed mechanism be fed into the rammer assembly, it
is only necessary to actuate the feed selector switch 351 in FIG.
24 to connect fluid pressure from the air supply 342 to drive the
other side of the feed mechanism.
The foregoing description was given on the assumption that a round
of ammunition was in the receiver when the trigger was first
depressed to start the cycle of the weapon. However, since the
ammunition feed mechanism is pneumatically operated by the same
switch, it is possible that a round of ammunition is not in the
receiver when the trigger is depressed. In this event, the feed
control valve 348 would prevent air pressure from being applied to
the rammer valve and, instead, a round of ammunition would be fed
to the receiver. The first round pulse and delay valve would, of
course, not function until pressure was applied to the rammer
valve.
* * * * *