U.S. patent number 3,800,657 [Application Number 05/104,610] was granted by the patent office on 1974-04-02 for modular liquid propellant gun.
This patent grant is currently assigned to Pulsepower Systems Incorporated. Invention is credited to Thomas M. Broxholm, Lester C. Elmore.
United States Patent |
3,800,657 |
Broxholm , et al. |
April 2, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
MODULAR LIQUID PROPELLANT GUN
Abstract
A gun of the kind in which liquid propellant is burned in the
firing chamber to fire a projectile from the gun is constructed so
that a number of gun modules can be combined in a modular gun. Each
gun module is cam controlled, and a common cam is used to control
each gun module in the modular gun. The cam can be a flexible cam
having a belt configuration to permit the gun modules to be
arranged in both circular groupings and in non-circular groupings,
such as side by side. The modular gun includes fixed, non-rotating
gun modules to eliminate the need for tangential velocity
correction factors in the fire control and the need to accelerate
the mass of the barrel assembly to operational speed. The
individual gun module includes propellant injection mechanism for
injecting propellant at high pressure when a non-hypergolic
bi-propellant is used as the propellant. One or more hydraulic
actuators are used to develop the high injection pressures and to
operate other components of the gun, such as the bolt. The
hydraulic actuators are also engaged with the cam to interlock the
actuators and the controls for the actuators through the cam. A
source of pressurized hydraulic fluid independent of the gun is
used to power the actuators so that the weight and profile of the
gun are kept to a minimum. The hydraulic system includes a compound
spool control valve which operates in a dual mode to permit normal
cyclic operation of the gun during firing and to maintain the gun
in an open bolt condition during armed but non-firing operations.
The hydraulic system includes a misfire detection mechanism and
module shutdown valve which locks a misfired gun module in the
closed bolt condition with the need to depressurize the hydraulic
circuits of the other gun modules and without the need to include
additional bypass circuits. The injection mechanism for injecting
the bi-propellant includes two pistons which are yoked together and
operated by a single actuator to inject the propellant into the
firing chamber both in metered amounts and in a constant mix ratio.
The pistons for injecting the bi-propellant include valves in the
pistons, and the pistons are drawn through the fuel on retraction
strokes of the pistons. The injection mechanism is retracted away
from the firing chamber after the firing of a burst to isolate the
propellant in the injection mechanism from the heat of the firing
chamber. A rotary lock is mounted closely adjacent the bolt
mechanism and engages a relieved area of the bolt in the locked
position of the lock so that a quite small force on the lock will
hold the bolt mechanism locked against high combustion chamber
pressures tending to open the bolt.
Inventors: |
Broxholm; Thomas M. (Palo Alto,
CA), Elmore; Lester C. (Portola Valley, CA) |
Assignee: |
Pulsepower Systems Incorporated
(San Carlos, CA)
|
Family
ID: |
22301400 |
Appl.
No.: |
05/104,610 |
Filed: |
January 7, 1971 |
Current U.S.
Class: |
89/7; 89/1.2;
89/1.41 |
Current CPC
Class: |
F41A
29/00 (20130101); F41F 1/08 (20130101); F41A
7/04 (20130101); F41A 7/08 (20130101); F41A
1/04 (20130101) |
Current International
Class: |
F41A
1/00 (20060101); F41A 7/04 (20060101); F41F
1/00 (20060101); F41A 1/04 (20060101); F41A
29/00 (20060101); F41A 7/00 (20060101); F41A
7/08 (20060101); F41F 1/08 (20060101); F41f
001/04 () |
Field of
Search: |
;89/7,8,9,1L,11,12,1,161 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Engle; Samuel W.
Attorney, Agent or Firm: Owen, Wickersham & Erickson
Claims
We claim:
1. A gun of the kind in which liquid propellant is burned in a
firing chamber to fire a projectile from the gun and including, a
barrel, a receiver, a bolt, means for reciprocating the bolt in the
receiver, a firing chamber, injection mechanism for injecting a
non-hypergolic bi-propellant liquid propellant into the firing
chamber on each cycle of reciprocation of the bolt, said injection
mechanism including a separate injector for each component of the
bi-propellant, each said injector comprising a chamber and a piston
of predetermined dimensions, means rigidly interconnecting said
pistons, actuator means for moving the interconnected injector
pistons as a unit whereby said predetermined dimensions and common
actuator establish accurate metering and a constant mix of the
bi-propellant injected directly into the firing chamber to fully
occupy said chamber, igniter means for igniting the non-hypergolic
bi-propellant in the firing chamber and control means effective to
actuate the igniter means to ignite the propellant after the
injection mechanism has filled the firing chamber with the
non-hypergolic bi-propellant mix.
2. A gun as defined in claim 1 wherein the actuator means include a
motor powered by a source of fluid separate from the gun.
3. A gun as defined in claim 2 including a control valve for each
motor, each said control valve having a control element driven by a
cam follower, and a rotatable cam engaged to provide cam control
and fluid actuator drive for the injection mechanism by each said
follower.
4. A gun as defined in claim 3 wherein said motor includes a
movable element including a cam follower and wherein the cam has a
trace engaged by a respective control element cam follower and has
a second trace engaged by the movable element of the motor to
insure a precise phase relationship between the control valve and
the motor.
5. A rapid firing gun of the kind in which liquid propellant is
burned in a firing chamber to fire a projectile from the gun said
gun comprising, a barrel, a receiver, a bolt, bolt actuator means
for reciprocating the bolt within the receiver, a combustion
chamber having wall structure of substantial mass subjected to heat
soak produced during the rapid firing of a burst of projectiles
from the combustion chamber, injection mechanism for injecting
liquid propellant into the combustion chamber, said injection
mechanism including a cylinder for containing the liquid propellant
to be injected and a piston reciprocable within the cylinder to
eject the propellant from the cylinder into the combustion chamber
on each cycle of reciprocation of the bolt, mounting means mounting
the injection mechanism for movement between a first, injection
position in which the injection mechanism is physically connected
to the combustion chamber for injecting liquid propellant into the
combustion chamber and a second, isolated position in which the
injection mechanism including the liquid propellant in the cylinder
are physically separated from the wall structure of the combustion
chamber to provide a thermal barrier to heat flow from the
combustion chamber wall structure to the propellant, actuator means
for moving the injection mechanism between the injection position
and the isolated position, and valve means within the piston
operable on retraction of the bolt to permit refilling of the
cylinder piston assembly with propellant as the piston is moved
rearward through the propellant within the cylinder after a firing
of a projectile from the gun.
6. A hydraulically controlled gun of the kind in which liquid
propellant is burned in a firing chamber to fire a projectile from
the gun including, a barrel, a receiver, a bolt, a first hydraulic
actuator for reciprocating the bolt within the receiver, a firing
chamber, injection mechanism for injecting a liquid propellant
directly into the firing chamber, a second hydraulic actuator
connected to actuate the injection mechanism, cam means, a control
valve for controlling movement of each said hydraulic actuator, a
hydraulic circuit interconnecting a source of high pressure
hydraulic fluid independent of the gun with said valve means and
said actuators to power said hydraulic actuators under the control
of the valve means, each said valve means having cam follower means
engaging said cam means whereby the injection of said liquid
propellant is coordinated with the reciprocation of said bolt.
7. A gun as defined in claim 6 wherein the liquid propellant is a
mono-propellant.
8. A gun as defined in claim 6 wherein the liquid propellant is a
non-hypergolic bi-propellant.
9. A gun as defined in claim 8 including actuators movable through
relatively large distances for reciprocating the propellant
injection mechanism and the bolt, cam followers movable through
relatively small distances for controlling the actuators and
wherein both the actuators and the cam followers are continuously
engaged with the cam to insure a precise phase relationship between
the actuators and the cam followers.
10. A rapid firing gun of the kind in which liquid propellant is
burned in a combustion chamber to fire a projectile from the gun,
said gun comprising, a barrel, a receiver, a bolt, bolt actuator
means for reciprocating the bolt within the reciever, a combustion
chamber having wall structure of substantial mass subjected to heat
soak produced during the rapid firing of a burst of projectiles
from the combustion chamber, injection mechanism for injecting
liquid propellant into the combustion chamber, said injection
mechanism including a cylinder for containing the liquid propellant
to be injected and a piston reciprocable within the cylinder to
eject the propellant from the cylinder into the combustion chamber
on each cycle of reciprocation of the bolt, mounting means
including a bore in the receiver separate from the bolt mounting
the injection mechanism for movement between a first, injection
position in which the injection mechanism including said cylinder
is physically connected to the combustion chamber for injecting
liquid propellant into the combustion chamber and a second,
isolated position in which the injection mechanism including said
cylinder and the liquid propellant in the cylinder are physically
separated from the wall structure of the combustion chamber to
provide a thermal barrier to heat flow from the hot combustion
chamber wall structure to the propellant, and actuator means for
moving the injection mechanism between the injection position and
the isolated position.
11. A gun as defined in claim 10 including control means for the
actuator means effective to retain the injection mechanism in the
first, injection position during the firing of a burst and to
retract the injector mechanism in the bore to the second, isolated
position only after the firing of a burst has been completed.
12. A rapid firing gun of the kind in which liquid propellant is
burned in a combustion chamber to fire a projectile from the gun,
said gun comprising, a barrel, a receiver, a bolt, means for
reciprocating the bolt within the receiver, a combustion chamber
having wall structure of substantial mass subjected to heat soak
produced during the rapid firing of a burst of projectiles from the
combustion chamber, injection mechanism for injecting liquid
propellant into the combustion chamber, said injection mechanism
including a cylinder for containing the liquid propellant to be
injected and a piston reciprocable within the cylinder to eject the
propellant from the cylinder into the combustion chamber, mounting
means for the injection mechanism for movement between a first,
injection position in which the injection mechanism is physically
connected to the combustion chamber for injecting liquid propellant
into the combustion chamber and a second, isolated position in
which the injection mechanism and the liquid propellant in the
cylinder are physically separated from the wall structure of the
combustion chamber to provide a thermal barrier to heat flow from
the hot combustion chamber wall structure to the propellant, and
actuator means for moving the injection mechanism between the
injection position and the isolated position, and wherein the
mounting means mount the injection mechanism for reciprocation
within the bolt and the injection mechanism is retracted to the
second, isolated position with the retraction of the bolt after the
firing of each round.
13. A rapid firing gun of the kind in which liquid propellant is
burned in a combustion chamber to fire a projectile from the gun,
said gun comprising, a barrel, a receiver, a bolt, bolt actuator
means for reciprocating the bolt within the receiver, a combustion
chamber having wall structure of substantial mass subjected to heat
soak produced during the rapid firing of a burst of projectiles
from the combustion chamber, injection mechanism for injecting
liquid propellant into the combustion chamber, said injection
mechanism including a cylinder for containing the liquid propellant
to be injected, means for ejecting the propellant from the cylinder
into the combustion chamber on each cycle of reciprocation of the
bolt, mounting means including a bore in the receiver separate from
the bolt mounting the injection mechanism for movement between a
first, injection position in which the injection mechanism
including said cylinder is physically connected to the combustion
chamber for injection liquid propellant into the combustion chamber
and a second, isolated position in which the injection mechanism
including said cylinder and the liquid propellant in the cylinder
are physically separated from the wall structure of the combustion
chamber to provide a thermal barrier to heat flow from the hot
combustion chamber wall structure to the propellant, and actuator
means for moving the injection mechanism between the injection
position and the isolated position.
14. A rapid firing gun of the kind in which liquid propellant is
burned in a combustion chamber to fire a projectile from the gun,
said gun comprising, a barrel, a receiver, a bolt, means for
reciprocating the bolt within the receiver, a combustion chamber
having wall structure of substantial mass subjected to heat soak
produced during the rapid firing of a burst of projectiles from the
combustion chamber, injection mechanism for injecting liquid
propellant into the combustion chamber, said injection mechanism
including a cylinder for containing the liquid propellant to be
injected, means for ejecting the propellant from the cylinder into
the combustion chamber, mounting means mounting the injection
mechanism for movement between a first, injection position in which
the injection mechanism is physically connected to the combustion
chamber for injecting liquid propellant into the combustion chamber
and a second, isolated position in which the injection mechanism
and the liquid propellant in the cylinder are physically separated
from the wall structure of the combustion chamber to provide a
thermal barrier to heat flow from the hot combustion chamber wall
structure to the propellant, and actuator means for moving the
injection mechanism between the injection position and the isolated
position, and wherein the mounting means mount the injection
mechanism within the bolt and the injection mechansim is retracted
to the second, isolated position with the retraction of the bolt
after the firing of each round.
Description
This invention relates to a gun of the kind in which liquid
propellant is burned in the firing chamber to fire the projectile
from the gun.
This invention relates particularly to a liquid propellant gun
constructed as an individual gun module so that a number of gun
modules can be combined in a modular gun.
In conventional guns powder for firing each projectile is carried
in a case attached to the projectile.
A liquid propellant gun has a number of advantages over such
conventional guns.
If a liquid propellant gun uses the same size projectile as a
conventional gun, the projectile feed for the liquid propellant gun
can be simplified and can be made considerably lighter in weight
than for a conventional gun. Or, a considerably larger charge can
be used for higher performance without having to increase the size
of the projectile feed mechanism.
A liquid propellant gun can produce a flatter combustion chamber
pressure-time characteristic than a solid propellant gun. Hence
performance equivalent to a solid propellant gun can be obtained at
lower pressure.
High cyclic rates of fire are possible with a liquid propellant
gun.
Because the propellant is a liquid the propellant can be easily
pumped to the firing chamber from a storage area remote from the
gun itself. This permits flexibility of installation.
When the gun is installed in an aircraft and a nonhypergolic
bi-propellant is used, one of the components of the non-hypergolic
bi-propellant can be the fuel used for the engine of the
aircraft.
The liquid propellant gun permits a low profile, clean exterior
design so that an individual liquid propellant gun module, or a
modular grouping of liquid propellant gun modules, can be installed
in locations that would not accommodate a conventional gun.
It is a primary object of the present invention to incorporate
these inherent advantages of a liquid propellant gun in a modular
gun.
Further objects of the present invention include the specific
structures and features of operation noted in the abstract
above.
Other and further objects of the present invention will be apparent
from the following description and claims and are illustrated in
the accompanying drawings which, by way of illustration, show
preferred embodiments of the present invention and the principles
thereof and what are now considered to be the best modes
contemplated for applying these principles. Other embodiments of
the invention embodying the same or equivalent principles may be
used and structural changes may be made as desired by those skilled
in the art without departing from the present invention and the
purview of the appended claims.
IN THE DRAWINGS
FIG. 1 is an isometric exploded view (partially broken away to show
details of construction) of an individual gun module constructed in
accordance with one embodiment of the present invention. FIG. 1
shows the three main components of an individual gun module--the
barrel assembly, the receiver assembly, and the control
assembly;
FIG. 2A and FIG. 2B are a plan view (partly broken away along the
line and in the direction indicated by the arrows 2--2 in FIG. 11)
of the gun shown in FIG. 1;
FIG. 3A and FIG. 3B are a side elevation view in cross section of
the gun module shown in FIG. 1;
FIG. 4 is a fragmentary plan view taken generally along the line in
the direction indicated by the arrows 4--4 in FIG. 9;
FIG. 5 is a fragmentary top plan view taken generally along the
line and in the direction indicated by the arrows 5--5 in FIG.
3B;
FIG. 6 is an elevation view taken along the line and in the
direction indicated by the arrows 6--6 in FIG. 3A;
FIG. 7 is an elevation view taken along the line and in the
direction indicated by the arrows 7--7 in FIG. 3B;
FIG. 8 is an elevation view taken along the line and in the
direction indicated by the arrows 8--8 in FIG. 3B;
FIG. 9 is an elevation view taken along the line and in the
direction indicated by the arrows 9--9 in FIG. 3B;
FIG. 10 is an elevation view taken along the line and in the
direction indicated by the arrows 10--10 in FIG. 3B;
FIG. 11 is an elevation view taken along the line and in the
direction indicated by the arrows 11--11 in FIG. 3B;
FIG. 12 is an elevation view taken along the line and in the
direction indicated by the arrows 12--12 in FIG. 3A. FIG. 12
illustrates how four individual gun modules can be arranged in a
circular grouping in a modular gun constructed in accordance with
an embodiment of the present invention;
FIG. 13 is a schematic front end elevation view illustrating the
way in which the projectiles are spaced at one half the pitch
between adjacent gun modules. FIG. 13 illustrates how four
individual gun modules may be arranged side by side in a modular
gun constructed in accordance with an embodiment of the present
invention;
FIG. 14A and FIG. 14B are a schematic diagram of a hydraulic drive
control system for a single gun module as shown in FIG. 1;
FIG. 15 is a top plan view of a cam having a hollow cylindrical
configuration for use with four gun modules arranged in a circular
grouping as best illustrated in FIG. 12. Parts of FIG. 15 have been
broken away to show the cam faces on the interior surface of the
hollow cylindrical cam;
FIG. 16 is an end view of the cam shown in FIG. 15 and is taken
along the line and in the direction indicated by the arrows 16--16
in FIG. 15;
FIG. 17 is a fragmentary cross sectional view like FIG. 3A showing
a modification of the fuel injection mechanism for the gun module
shown in FIG. 1. FIG. 17A illustrates how the propellant injection
mechanism is retracted away from the firing chamber after the
firing of a burst;
FIG. 18 is an inside developed view of the inside surface of the
hollow cylindrical cam shown in FIG. 15;
FIG. 19 is a fragmentary cross section view taken along the line
and in the direction indicated by the arrows 19--19 in FIG. 18;
FIG. 20 is a pictorial view of one embodiment of a bolt locking
mechanism for the gun module shown in FIG. 1. FIG. 20 shows the
bolt locking mechanism in the unlocked mode;
FIG. 21 is a view like FIG. 20 showing the lock mechanism in the
locked mode;
FIG. 22 is a view like FIG. 21 but with parts partially broken away
to show details of construction;
FIGS. 23 and 24 are side elevation views of the lock mechanism of
FIGS. 20-21 showing the bolt and lock in the unlocked position in
FIG. 23 and in the locked position in FIG. 24;
FIGS. 25 and 26 are views like FIGS. 23 and 24 of another
embodiment of a lock mechanism constructed in accordance with the
present invention;
FIGS. 27 and 28 are views like FIGS. 23 and 24 of still another
embodiment of the lock mechanism constructed in accordance with the
present invention; and
FIG. 29 is a pictorial view of the bolt and actuator
sub-assembly.
An individual gun module constructed in accordance with one
embodiment of the present invention is indicated generally by the
reference numeral 31 in FIG. 1.
The gun module 31 includes three main components--a barrel assembly
33, a receiver assembly 35, and a control assembly 37.
The gun module 31 may be used by itself or (as will be described in
greater detail below) may be arranged in both circular groupings
(as shown in FIG. 12) or in non-circular groupings (as shown in
FIG. 13) to form modular guns. The modular guns are indicated
generally by reference numerals 39 and 41 in FIGS. 12 and 13.
The gun module 31 is a liquid propellant gun. The gun burns a
liquid propellant in the firing chamber to propel the
projectile.
The particular embodiment of the gun 31 shown in the drawings and
described below is constructed to use a bi-propellant, a propellant
having two components which are mixed in the firing chamber. The
gun module 31 shown in FIG. 1 uses a non-hypergolic bi-propellant.
The two components of the bi-propellant do not ignite on
contact.
Non-hypergolic bi-propellants have this advantage over hypergolic
bi-propellants. The non-hypergolic bi-propellant can be handled in
the same way as a mono-propellant. For example, the firing chamber
can be fired, without spontaneous ignition, as in a
mono-propellant. Because of this fact, the chamber can be fired
without having to pump against combustion pressure; and the
propellant can be loaded in an exact amount before ignition is
started. It should be noted, however, that many of the principles
of the present invention could be applied to liquid propellant guns
using hypergolic bi-propellants. Most of the principles of the
present invention can be applied to liquid propellant guns using
mono-propellants.
The bi-propellant is ignited in the combustion chamber by a spark
plug in the embodiment of the gun module shown in FIG. 1. Ignition
can also be accomplished by compression ignition or by injecting a
chemical into the propellant. The present invention is not
restricted to spark ignition.
The gun module 31 is a cam-controlled, hydraulically powered gun.
The main cam maintains a proper sequence and timing relationship
between the various components of the gun while hydraulic power is
the primary energy source.
The cam for controlling the gun module 31 is shown in FIGS. 15, 16,
18 and 19.
A hydraulic drive control system of the control assembly 37 is
shown in schematic diagram in FIGS. 14A and 14B.
The bolt and injector sub-assembly of the receiver assembly 35 is
shown in FIG. 29.
Details of construction of the gun module 31 will now be described
with reference primarily to FIGS. 3A and 3B and FIGS. 2A and
2B.
The barrel assembly 33 includes a barrel 43.
The receiver assembly 35 includes a receiver 45.
The receiver assembly 35 also includes an end plate 47 attached to
the back end of the receiver 45 by a number of cap screws 46.
The hydraulic control assembly 37 is mounted on the receiver 45 in
front of the end plate 47.
A main cam 49 is mounted for rotation between the receiver 45 and
the hydraulic control assembly 37. The main cam 49 is a hollow,
cylindrical member (as best shown in FIGS. 15 and 16), and the rear
end of the cam 49 is mounted for rotation on a bearing 51 in the
end plate 47. The front end of the cam 49 may also be mounted for
rotation on a bearing (not shown in the drawings) or may rotate on
the receiver 45. The cam 49 has cam traces on both the inside and
the outside peripheries. As will be described in greater detail
below, the cam traces on the inside peripheries engage cam
followers of actuators in the receiver 45 while the cam traces on
the outside periphery engage cam followers of control valves in the
hydraulic control assembly 37.
The cam 49 in the embodiment shown in FIG. 12 can be a rigid
member. In other applications, e.g., the FIG. 13 embodiment, the
cam 49 must be a flexible member as illustrated to accommodate
non-circular groupings of modules. As will become more apparent
from the description to follow, a flexible cam is possible because
of the low cam face loads of the present invention. The low cam
face loads are possible because the cam does not drive the bolt
assembly. The force for driving the bolt assembly is supplied by
hydraulic actuators, and the cam serves only to maintain the proper
phase relationship between the actuators and the control
valves.
The cam 49 includes gear teeth 53 on the outside periphery of the
cam. An electric or hydraulic motor (not shown in the drawings)
drives the cam (in counterclockwise rotation as viewed in FIGS.
8-11) by means of the gear teeth 53.
The receiver 45 mounts a bolt 55 and propellant injection mechanism
for reciprocation toward and away from combustion chamber 57 at the
inlet end of the barrel 43.
The bolt and injector sub-assembly is best illustrated in FIG. 29.
In FIG. 29 the propellant injection mechanism 59 includes a yoke
61, an acid piston 63, a fuel piston 65 and a hydraulic actuator
68. In the embodiment of the invention shown in FIGS. 2A, 2B, 3A,
3B and FIG. 29, the acid piston reciprocates within a cylinder 70
formed in the bolt 55, and the fuel piston 65 reciprocates within a
cylinder 69 formed in the bolt 55.
The acid, or oxidizer, component of the bi-propellant is injected
from the cylinder 70 through a port 71 into a central bore or
pre-combustion chamber 73 of the bolt 55 and then into the
combustion chamber 57.
The fuel in an aircraft installation may be the same fuel (such as
JP 4) used for the aircraft engine. The fuel is injected from the
cylinder 69 into the pre-combustion chamber 73 and the combustion
chamber 57 through a port 72 shown in FIGS. 2A.
Piston 63 includes a one-way check valve 75 at the forward end of
the piston.
The piston 65 includes a one-way check valve 77 at the forward end
of the piston.
These check valves permit the fuel to flow through the interior of
the pistons and through the head of the piston into the cylinder 70
and the cylinder 69 during the retraction strokes of the pistons
within the cylinders 70 and 69.
The strokes of the pistons 63 and 65 are the same since the pistons
are yoked together by the yoke 61. The proper mix ratio for the two
components of the bi-propellant is obtained by the relative
diameters of the pistons 67 and 65. The two components of the
bi-propellant are therefore injected into the firing chamber in
both metered amounts and in a constant mix ratio.
A spark plug 79 is mounted for reciprocation within the bolt 55 in
a bore 81 which forms a continuation of a pre-combustion chamber
73.
The spark plug 79 closes off the propellant injection port 71 of
the cylinder 70 and the port 72 for the cylinder 69 as the spark
plug is moved forward during a cycle of operation to control the
end of the propellant injection strokes.
As best shown in FIG. 29, the bolt is actuated by a hydraulic
actuator 83 and an actuator rod 85.
The bolt 44 includes a bolt cam follower 87.
The fuel injection yoke 61 includes a cam follower 89.
The spark plug includes a spark plug cam follower 91.
With continued reference to FIG. 29, the hydraulic fluid for the
propellant injection mechanism actuator 68 is brought in through a
hydraulic line 93 and a hydraulic port 95.
The fuel for the fuel piston 65 is supplied through a fuel line
97.
The oxidizer for the acid piston 63 is supplied through a line
99.
The injector actuator 68 includes a piston 64 slidable in a bore
66. The piston 64 in turn has an inner bore 66A.
The injector actuator hydraulic line 96 (see FIG. 4 and FIG. 29 and
also FIG. 10) slides within the bore 66A in a trombone type
arrangement as the injector yoke 61 is reciprocated back and forth
by the action of the piston 64 within the bore 66.
As best shown in FIGS. 2B and 3B, the fuel piston and fuel line and
the acid piston and acid line also have similar trombone type
arrangements.
Thus, the fuel piston 65 has a hollow interior forming a bore 65A,
and this hollow bore slides back and forth on the outside of the
fuel line 97 during reciprocation of the piston 65 by the yoke
61.
The acid piston 63 has a bore 62, and this bore 62 slides back and
forth on the exterior of the acid line 99 as the acid piston 63 is
reciprocated by the yoke 61.
Suitable seal means, as shown in the drawings, are provided to
accomplish the necessary sealing.
As best shown in FIG. 3B, the fuel line 97 is connected through the
end plate 47 to a fuel port 101, and the acid line 99 is connected
through the end plate 47 to an acid port 103.
FIG. 3A shows the bolt 55 at its full forward position.
A projectile 105, as shown in FIG. 3A, has been forced forward to
the position illustrated by the forward movement of the bolt 55 and
also by the liquid propellant injected behind the projectile 105
into the firing chamber 57 by the forward movement of the fuel
piston 65 and the acid piston 63. The projectile 105 is forced
forward by the liquid propellant injected in the chamber 57. The
forward motion is stopped by the resistance produced by the forcing
cone. The way in which the projectile is loaded into the receiver
and forced forward by the bolt and the liquid propellant insures
that the firing chamber 57 and pre-combustion chamber 73 are
completely filled with liquid propellant to eliminate an ullage
problem.
The projectile 105 may preferably be fed to the receiver by a
linkless belt 105 as shown in FIG. 12.
As shown in FIG. 12 (and as also shown in the lower lefthand corner
of FIG. 14A), a projectile loader lever 109 bats a projectile 105
out of the belt 107 and into a curved slot 111 shaped to drop the
projectile 105 into the proper position in the receiver assembly 31
in front of the bolt 55.
The projectile loader lever 109 is in the form of a bell crank (as
best shown in FIG. 14A) and is pivotally connected to the receiver
45 by a pin 110.
The lever 109 is pivoted about the pin 110 by a hydraulic actuator
indicated generally by the reference numeral 112 in FIG. 14A.
The actuator 112 includes a housing 114 and a piston 116
reciprocable within a bore in the housing. A rod of the piston 116
is connected to the lever 109 in a pin-joint connection 118.
As shown in FIG. 3A the projectile 105 in the receiver above the
bolt 55 is positioned to be moved downward and in front of the
front face of the bolt 55 by the lever 109 when the bolt 55 is
retracted.
Each gun module 31 includes a misfire detection and module shutdown
system. This system will be described in detail with reference to
FIGS. 14A and 14B, but at the present time it should be noted that
the system includes a detector mechanism indicated generally by the
reference numeral 113 in FIG. 2A. The mechanism 113 includes a
housing 115 clamped to the front end of the barrel 43 by bolts and
nuts as illustrated. The housing 115 has a restricted orifice 117
which fits within an opening 119 in the barrel. The orifice 117
opens into a cylinder 121 in the interior of the housing 115. A
second restricted orifice 123 also communicates with the interior
of the cylinder 121 and extends through the wall of the housing 115
to connect the cylinder with the ambient atmosphere.
A piston 125 is reciprocable within the cylinder 121.
A piston rod 127 extends from the rearward end of the piston 125
through an end wall of the housing 115 and through a tube 129 back
to a module shutdown control valve 223 as shown in FIG. 14B and as
will be described in greater detail below.
An opening 131 extends through the front end wall of the housing
115 to vent the cylinder in front of the piston 125 to ambient
atmosphere to prevent lock-up.
The orifices 117 and 123 are controlled orifices. The high pressure
gas behind the projectile 105 enters the chamber within the
cylinder 121 behind the piston 125 through the orifice 117 as the
projectile is fired out of the barrel 43. The orifices 117 and 123
permit the escape of the pressurized gas from the interior of the
housing 115 at a controlled rate to provide a certain leak down
time. If another projectile is not fired within this leak down time
the piston rod 127 is pulled back (to the right as viewed in FIG.
2A) by hydraulic pressure exerted on a face of the control valve,
as will be described in greater detail below with reference to FIG.
14B.
The detection mechanism 113 thus detects a misfire. The detection
mechanism 113 remains in the position illustrated in FIG. 2A so
long as the gun module continues in normal cyclic operation and
does not misfire. On a misfire the piston 125 is shifted rearward
(to the right as viewed in FIG. 2A).
As shown in FIGS. 2A and 3A an inlet port 133 and an outlet port
135 are connected to the top of the barrel 43 through openings in
the receiver 45 for supplying fluid to the combustion chamber 57 to
purge the chamber 57 in the event of a misfire.
As best shown in FIG. 6 the fluid from the inlet port 133 flows
into the combustion chamber 57 through a port 139 when a valve
member 141 is positioned to permit flow between the ports 133 and
139.
As best shown in FIG. 14A a companion valve 143 controls the flow
of the purge fluid out of the combustion chamber 57 through a port
145 (like the port 139) and through the outlets of 135 to sump.
As shown in FIG. 14A the valve members 141 and 143 are yoked
together by a yoke 147 and spring biased, by springs 149 and 151,
to the positions illustrated in which the valve members close off
the ports 139 and 145.
A hydraulic actuator 153, which includes a piston 155 spring biased
by the spring 157 to the position illustrated in FIG. 14A, opens
the ports 139 and 145 by moving the valve members 141 and 143 to
the left as viewed in FIG. 14A when hydraulic pressure is admitted
to the interior of the actuator 153 through the conduit 159. The
flow of hydraulic fluid through the conduit 159 is under the
control of a three-way time control valve 161. The three-way time
delay valve 161 is controlled by the misfire detection and module
shutdown system, as will be described in greater detail with
reference to the description of FIGS. 14A and 14B.
As best shown in FIGS. 20-22 the gun module 31 includes a breech
lock mechanism. This breech lock mechanism is indicated generally
by the reference numeral 163 in FIGS. 20-22.
The breech lock mechanism, as best shown in FIG. 14A, includes a
lock 165 and an actuator 167.
The actuator 167 includes a piston 169 and a rod 171. The forward
end of the rod 171 has gear teeth 173 which engage corresponding
gear teeth 175 on the lock. The rod 171, gear teeth 173 and gear
teeth 175 form a rack-and-pinion arrangement for rotating the lock
165.
The lock 165 is a cylindrical member mounted for rotation about its
longitudinal axis. The rotational axis of the lock 165 extends
transverse to the axis of reciprocation of the bolt 55.
The lock 165 has a cutout or relieved area 177 which permits the
lock to be mounted with the rotational axis of the lock closely
adjacent to the outer periphery of the bolt 55. The relieved area
177 is shaped to, in effect, let the bolt reciprocate within the
lock 165 with the outer periphery of the bolt in closely adjacent
relationship to the surface of the cutout 177 of the lock when the
lock is in the unlocked position.
The bolt 55 has a similar cutout or relieved area 181 which
provides an abuttment face when the lock 165 is rotated into the
cutout or relieved area 181.
This action is best shown in FIGS. 23 and 24.
In the configuration of the parts shown in FIGS. 23 and 24 the lock
265 has an abuttment face 179. The face 179 abutts the
corresponding abuttment face 181 of the bolt 55, which is a part of
the relieved area 177 of the lock 165.
FIGS. 25 and 26 and FIGS. 27 and 28 show modified lock and bolt
arrangements in which the abuttment face 179 of the lock is not
part of the relieved area 177 of the lock.
In this instance, however, the abuttment face 179 of the lock
engages a substantial part of the relieved area of the bolt in the
locked position so that only a small force exerted by the actuator
167 is required to hold the bolt in the locked position.
Since the combustion pressure developed in the combustion chamber
57 is quite large, the force on the forward face of the bolt 55
during firing is also quite large. This force on the face of the
bolt acts in a direction tending to open the bolt, and it is
therefore important that the lock mechanism 163 be effective to
hold the bolt in the locked position.
As best illustrated in FIG. 22 the spark plug 79 also has a cutout
or relieved area which engages the lock 165 when the lock 165 is
rotated to the locked position.
As also illustrated in FIGS. 21 and 22, the piston 63 of the
propellant injection mechanism may also be formed with a locking
element 185 projecting outwardly from the piston 63 for engagement
with a locking face 187 of the lock 165 when the lock is rotated to
the locked position.
The locking element 185 is slidable within a slot 189 of the bolt
65. The locking of the fuel injection mechanism is not as critical
as the locking of the bolt 55 and the spark plug 79 because the
fuel injection mechanism is not directly exposed to the combustion
pressure within the combustion chamber 57.
Before going to a discussion of the control mechanism shown in
FIGS. 14A and 14B, it should be noted that FIG. 17 and 17A
illustrate a modification of a propellant injection mechanism. In
these figures the cylinder 70 and piston 63 are mounted for
reciprocation within a bore 70A formed in the barrel 43 and in the
receiver 45 rather than in the bolt 55.
The cylinder 70 has a front end portion constructed to withstand
the high pressures developed during combustion in the combustion
chamber 57.
Seals, such as O-rings 401, prevent the loss of combustion chamber
pressure.
A spring biased check valve 403 is mounted in the front end portion
of the cylinder 70 to permit the flow of propellant from the
cylinder through the port 71 to the combustion chamber.
The piston 63 includes a one-way check valve 75 at the forward end
of the piston.
In the operation of the embodiment shown in FIGS. 17 and 17A, the
cylinder 70 remains in the forward position illustrated in FIG. 17
during the firing of a burst while the piston 63 reciprocates back
and forth within the cylinder 70 during the firing of each round.
After the firing of a burst, the entire cylinder 70 and piston 63
assembly is retracted to the position shown in FIG. 17A to isolate
the propellant from the hot barrel 43.
The present invention retracts the propellant injection mechanism
away from combustion chamber 57 so that the injection mechanism and
the liquid propellant within the injection mechanism are physically
isolated from the hot combustion chamber to provide a thermal
barrier, that is, a physical barrier to prevent heat flow from the
hot combustion chamber to the propellant. This eliminates problems
of heat soak which can lead to cookoff or unwanted vaporization of
fuel and combustion in the gun module 31. It is important to
provide such thermal isolation after the firing of a burst. During
firing the flow rates of the liquid propellant are normally high
enough to provide sufficient cooling. Thus, while the FIG. 3A
embodiment of the present invention discloses retraction after each
individual firing, it should be recognized that it might be
desirable in some instances to retract the entire injection
mechanism only after the firing of a burst as in the FIGS. 17 and
17A embodiment.
In some instances, it may be desirable to include a low
conductivity thermal barrier between the barrel and the receiver to
further reduce the possibility of transfer of heat to the
propellant after the firing of a burst.
A schematic diagram of the hydraulic drive control system for the
gun module 31 as shown in FIGS. 14A and 14B. Pressurized hydraulic
fluid for driving the various actuators is brought into the system
through a line 191. The motor for producing this pressurized
hydraulic fluid is preferably separate from the gun itself so that
the gun can be kept light in weight and small in profile.
If the gun is installed in an aircraft the source of the
pressurized hydraulic fluid can be the hydraulic system of the
aircraft.
One of the features of a hydraulic control system is fast response.
In the present invention the first shot is made at full cyclic
rate.
The hydraulic fluid is returned from the control system to the
source by a line 193.
The control system includes a bias control valve indicated
generally by the reference numeral 195. The bias control valve is
an on-off valve and is controlled by a trigger solenoid 197. The
trigger solenoid 197 is shown in the "on" position in FIG. 14.
The bias control valve 195 includes a housing 199 and a valve spool
201 reciprocable within a bore in the housing 199.
Pressurized fluid flows into the housing 201 through an inlet
conduit 203.
Outlet conduits 205 and 207 lead from the valve housing 199 to a
housing 209 forming a part of the misfire detector mechanism 113.
Outlet conduits 211 and 213 extend from housing 199 downward to
other conduits which are connected to ports at opposite ends of the
various control valve housings. Outlet conduits 215 and 217 connect
with the return conduit 193.
Lands 219 and 221 on the spool of the bias control valve control
the flow through the various conduits.
The valve spool 201 includes a cam follower 220 which engages a
trace 222 in the cam 49 in the armed condition of the system with
the trigger solenoid in the off position. When the trigger solenoid
is energized to the on position, the cam follower remains in the
cam trace 222 until a cross-over path 224 permits the cam follower
to shift to the trace 226. This insures that the trigger solenoid
will move the valve spool 219 to the on position in the proper time
sequence with the other components of the hydraulic control
system.
The valve housing 209 of the misfire detector mechanism 113 has a
valve spool 223 mounted for reciprocation within the housing and
connected to the rod 127. Outlet conduits 225 and 227 extend
downward from the housing 209. Flow from the inlet conduit 191 and
to the outlet conduits 225 and 227 is controlled by lands 229 and
231 on the valve spool 223. The conduit 225 contains an orifice
233.
A spring 235 acting on the backface of the land 231 biases the
spool 223, and the rod 127, in a forward direction.
Pressurized fluid, conducted through the housing 209 by the conduit
207, acts on a forward face of a land 237 to bias the spool 223 in
a rearward direction.
A cam follower 239 is connected to the rearward extension of the
valve spool 223 and is normally engaged in a trace 241 of the cam
49. The cam trace 241 extends around the outside circumference of
the cam 49 and parallel to a second cam trace 243. A path 245
connects the traces 241 and 243.
As will be described in greater detail below in the description of
the operation of the gun, the cam follower 239 remains in the trace
241 so long as a misfire does not occur. The pressure developed
within the bore 121 of the housing 115 at the end of the barrel
during cyclic firing is sufficient to keep the piston 125 forward,
as illustrated, when the path 245 is aligned with the cam follower
239. However, if a misfire occurs, there is insufficient pressure
in the chamber 121 behind the piston 125, and the force developed
by the pressurized hydraulic fluid acting on the forward face of
the land 237 shifts the valve follower 239 from the trace 241
through the path 245 and into the trace 243; and the cam follower
239 thereafter remains in the trace 243. This cuts off the flow of
fluid through the conduit 227 and transmits pressurized hydraulic
fluid through the conduit 225 by shifting the land 229 to the other
side of conduit 191.
The phantom outline shows the cam follower 239 shifted to the trace
243.
In the misfire condition, the bolt 55 and injector 63 will remain
locked in the forward position as illustrated. This mode of
operation will be further described with reference to the cam
traces shown in FIGS. 16 and 18 below.
The angle of the cam path 245 is such that the cam follower 239
will remain in the path 243 because of the direction of rotation of
the cam 49. The valve spool 223 will thus remain in the rearward
position illustrated by the phantom outline against the bias of the
spring 235.
The conduits 211 and 213 extend from the bias control valve 195
down to a bolt and injector system control valve indicated
generally by the reference numeral 247.
The control valve 247 includes a valve housing 249. The valve
housing 249 has a longitudinally extending central bore 251.
A compound spool is axially shiftable within the bore 251.
The compound spool includes an inner spool 253 and a sleeve 255.
The sleeve 255 is axially shiftable on the reduced diameter central
portion of the spool 253 between abuttment stops 257 and 259 at
opposite ends of the spool 253.
The conduit 211 connects to the forward end of the housing 249 and
the conduit 213 connects to the rearward end of the housing 249.
When pressurized fluid is supplied through the conduit 211 as
illustrated in FIG. 14B the sleeve 255 is shifted rearward and into
engagement with the stop 259.
A cam follower 261 on the valve spool 253 rides in a trace 263 on
the main cam 49. Rotation of the cam 49 periodically shifts the cam
follower 261 forward to the position indicated by the dotted line
to cause corresponding shifting of the valve spool 253 and the
sleeve 255 engaged with stop 259.
Pressurized fluid is led into the control valve 247 by the conduit
227.
Conduits 262 and 265 extend from the valve housing 249 to the rear
ends and to the front ends respectively of the actuators 83 and 68
for the bolt 55 and the yoke 61 of the propellant injection
mechanism.
With the cam 49 in the position illustrated and the valve sleeve
255 pressed against the stop 259 of the spool 253, the pressurized
fluid flows from the conduit 227 past a land 267 and to the conduit
262 and the back sides of the actuators 83 and 68. The respective
pistons and the actuators are thus forced forward to the positions
illustrated in FIG. 14B.
When the cam 49 rotates to a position in which the trace 263 shifts
the cam follower 261 to the dotted line position shown in FIG. 14B
the land 267 closes off flow through the conduit 262 and directs
the flow to the conduit 265 to reciprocate the pistons in the bolt
actuator 83 and the propellant injection actuator 68 to the
rear.
In this mode of operation the control valve 247 acts as an on-off
valve or flow switching valve to cause reciprocation of the bolt
and propellant injection mechanism with the movement of the cam
follower 261. Conduits 269 and 271 extend downward from the valve
housng 249 and connect with the return conduit 193. Flow through
these conduits 269 and 271 is controlled by lands 273 and 275 on
the valve sleeve 255. These lands open one side of each of the
actuators 83 and 68 to hydraulic fluid return when the other side
of each actuator is being pressurized.
Pressurized hydraulic fluid is supplied through the conduit 213 to
shift the sleeve 255 forward against the stop 257 when the gun is
placed in the armed condition (a condition in which the main cam
drive motor is energized, the main cam is rotating and hydraulic
power is applied to the gun module) and the trigger solenoid 197 is
in the off position. In this condition of operation the
reciprocation of the spool 253 by the cam trace 263 is not
effective to produce any reciprocation of the bolt and propellant
injectors. Instead, pressurized hydraulic fluid is continuously
transmitted from the conduit 227 to the conduit 265 past the land
267 and to the forward end of the actuators 83 and 68. The bolt and
propellant injectors are thus held in the open position ready to
start firing as soon as the trigger solenoid 197 is energized to
the on position.
As illustrated in FIG. 14A the hydraulic drive control system
includes a breech lock control valve indicated generally by the
reference numeral 277 and a projectile loader control valve
indicated generally by the reference numeral 279.
These control valves control the breech lock actuator 163 and the
projectile loader actuator 112.
The control valves 277 and 279 are compound spool control valves
like the bolt and injector control valve 247 and operate in a dual
mode like the control valve 247.
Thus, a conduit 211 is connected to the forward end of a valve
housing 281 of the control valve 277 and the conduit 211 is also
connected to the forward end of a valve housing 283 of the control
valve 279.
A conduit 213 is connected to the rearward end of the housing 281
and a rearward end of the housing 283. Pressurized hydraulic fluid
is supplied to a central part of each valve housing 281 and 283 by
the conduit 227 during normal operation.
The pressurized fluid from the line 227 is directed alternately to
the front and to the back side of the breech lock actuator 167
through conduits 285 and 287.
The breech lock control valve 277 includes a compound spool. The
compound spool has an inner spool 289 and a valve sleeve 291. The
valve sleeve 291 is shiftable on the spool 289 between the stops
293 and 295.
A land 297 controls the fluid from conduit 227 to the conduits 285
and 287.
On a misfire, pressurized fluid from the main hydraulic line 191 is
directed to the conduit 225 (see FIG. 14B), through an orifice 233,
and, in the case of the breech lock actuator 163, through a conduit
299 and a one-way check valve 301 to the front end of the housing
167 to hold the breech lock in the locked position illustrated.
During normal cyclic firing operation pressurized hydraulic fluid
is supplied to the front end of the housing 281 of the breech lock
control valve to position the sleeve 291 against the stop 295 as
illustrated in FIG. 14A.
A cam follower 303 on the valve spool 289 rides in a trace 305 on
the cam 49. As the cam 49 rotates, the trace 305 periodically
shifts the cam follower 303 to the forward position illustrated by
the dotted outline. This in turn shifts the valve spool 289 and the
vlave sleeve 291 to produce reciprocation of the piston 168 in the
breech lock actuator. Conduits 307 and 309 connect the valve
housing 281 with the return line 193.
If the trigger off but armed condition pressurized hydraulic fluid
is directed through the conduit 213 to the rear face of the sleeve
291 to move the sleeve forward against the stop 293. In this
condition of operation, the breech lock actuator is maintained in
the unlocked position ready for the start of firing. The
reciprocation of the valve spool 295 by the cam follower 303 is not
effective to change the flow of pressurized hydraluic fluid from
the conduit 287 to the back side of the piston 169.
The conduit 227 includes a one-way check valve 311 and the conduit
309 includes a one-way check valve 313 for preventing bleed-off of
pressure from the front part of the hydraulic actuator 167 during a
misfire condition in which the breech lock is maintained in the
locked position.
The projectile loader control valve 279 includes an inner valve
spool 315 and a valve sleeve 317. The valve spool 315 has stops 319
and 321 at opposite ends of the valve spool. A cam follower 323
rides in a trace 325 on the cam 49 and is shiftable between the
solid line position and the dotted line position shown to
reciprocate the valve spool 315.
Pressurized hydraliuc fluid supplied to the forward end of the
valve housing by the conduit 211 during normal cyclic firing
operation shifts the valve sleeve 317 rearward against stop 321 as
illustrated.
Pressurized hydraulic fluid supplied through the conduit 213 to the
rearward end of the valve housing 283 shifts the valve sleeve 317
forward against the stop 319 during the armed but non-firing
condition of the gun.
Pressurized hydraulic fluid from the conduit 227 flows past a
one-way check valve 327 and into the central part of the bore
within the housing 283. From there the pressurized fluid flows
either through a conduit 329 to the rearward end of the projectile
loader actuator or through a conduit 331 to the forward end of the
projectile loader actuator 112. The flow of pressurized fluid
through the conduit 329 and 331 is controlled by a land 333 on the
sleeve 317. Fliuid is returned to the return line 193 from the
housng 283 by conduits 335 and 337. The conduit 335 contains a
one-way check valve 339.
A conduit 341, having a one-way check valve 343 connects the
forward end of the actuator 112 with the conduit 225. When the
misfire detection mechanism directs pressurized fluid through the
conduit 225 to the projectile loader actuator 112, the actuator is
moved rearward to hold the projectile loader in an open
position.
It is an important feature of the present invention that several of
the controlled elements are interlocked through the cam to the
control valve controlling these components.
Thus, both the bolt and the propellant injectors are interlocked
through the cam to the bolt and injector control valve. This
insures precise phase relationship between the control valve and
the actuators and also precise phase relationship between actuated
components. Because hydraulic boost is used for actuation, cam face
loadings are quite low. And because of the interlock a simple
on/off flow switching valve can be used without the need for
expensive and complex feedback mechanisms of conventional hydraulic
serve motor systems.
As illustrated in FIG. 14B, the cam follower 87 of the bolt 55
rides in a trace 345 during normal cyclic firing of the gun. As
best shown in FIG. 18 this trace 345 is located on the inner
periphery of the cam and accommodates the reciprocatory motion of
the bolt.
The cam follower 89 of the propellant injection mechanism rides in
a trace 347 during normal cyclic firing of the gun.
The spark plug cam follower 91 rides in a trace 349 during normal
cyclic firing of the gun.
The traces 345, 347 and 349 connect with straight through traces
351, 353 and 355 respectively as illustrated in FIG. 18. These
straight through traces are the traces in which the cam followers
ride during the open bolt static condition after the gun has been
armed but beore the trigger solenoid 197 has been moved to the on
position to initiate firing.
The traces 345, 347 and 349 also connect with additional straight
through traces 357, 359 and 361 respectively as illustrated in FIG.
18. These last three straight through traces provide the paths for
the respective cam followers in the closed bolt or misfire
condition of operation.
The cam 49 is rotated in the direction indicated in the drawings by
a hydraulic motor or other suitable drive means engaged with the
gear teeth 53.
The operation of the gun module 31 will now be described. The
mechanical operation of the gun will be described first, and the
operation of the hydraulic control circuit will then be
summarized.
The following is a description of the operation of the gun
mechanism.
When the gun is placed in the armed position, the main cam drive
motor (not shown in the drawings) is energized and hydraulic power
is supplied to the gun module through the main hydraulic supply
line 191.
If the trigger is in the off position, the hydraulic control system
(shown in FIGS. 14A and 14B) will unlock the breech lock 165 and
will position the projectile loader lever in the up position. The
bolt 55 and the injector yoke 61 will be positioned in the rear
position. As long as the gun is in the armed condition with the
trigger off these components will remain in these positions. This
is generally referred to as the open bolt position.
When the trigger solenoid 197 is put into the on position, the
hydraulic control system and main cam 49 will cover the following
sequence of events:
1. The projectile loader lever 109 moves down, forcing a new
projectile 105 into the loading tray 111.
2. The bolt 55 moves forward, ramming the projectile 105 into the
combustion chamber 57. When the bolt 55 is fully forward, the
breech lock 165 is locked.
3. The injector pistons 63 and 65 initially move forward with the
bolt 55. However, until the bolt 55 stops, there will be no
relative movement between the injector pistons 63 and 65 and the
bolt 55. When the bolt 55 stops, the injector pistons 63 and 65
continue to move forward, injecting a charge of fuel and acid
through the pre-combustion chamber 73 and then into the combustion
chamber 57. The injected propellant will force the projectile 105
forward as it is injected. Since the diameter and stroke of the
fuel and acid pistons 65 and 63 are constant, each forward motion
of the injectors will meter a fixed propellant charge with a
constant, pre-determined mixture ratio.
4. When the injector pistons 63 and 65 are fully forwad and the
injection is completed, the spark plug 79 is moved forward sealing
off the injection ports 71 and 72. It should be noted at this point
that in the case of the mono-propellant, metering of the propellant
can be accomplished without the need for a cut-off valve. In the
case of a mono-propellant, it is often possible to use tank
pressure without a hydraulic boost for injecting the propellant
into the firing chamber. The injection of the mono-propellant can
start by putting the fuel into the chamber behind the projectile
simply by opening a valve. The mono-propellant continues to flow
into the combustion chamber behind the projectile until the
resistance to continued forward movement of the projectile produced
by the forcing cone is greater than the force developed by the
pressurized fuel on the back face of the projectile. At that point
the projectile stops and a metered amount of propellant is in the
firing chamber.
5. When the spark plug 79 is full forward, electrical power is
supplied to the spark plug; and the gun is fired.
6. The breech lock 165 is then unlocked.
7. The projectile loader lever 109 moves to the up position.
8. The bolt 55 and injector pistons are driven to the rear. when
the rewarward movement of the bolt 55 stops, the rearward movement
of the injector pistons 63 and 65 continues for the length of the
stroke of the pistons. As the pistons move to the rear, propellant,
(i.e., acid and fuel) flows through the ball check valves 75 and 77
and fills the volumes created by the rearward movement of the
pistons relative to the bolt. The pistons are, in effect, drawn
backwards through the propellant to fill the injector cylinders
during retraction of the pistons. This is the charge that will be
injected into the firing chamber 57 for the next round.
9. The next firing cycle is then repeated.
10. In the event of a misfire, the misfire detection mechanisms 113
and module shutdown valve 223 will shut off the hydraulic supply
(see the hydraulic control circuit of FIGS. 14A and 14B). The
breech lock 165 will be locked, the projectile loader lever 109
will go to the up position, and the bolt 55 and injector pistons 63
and 65 will be forced to the forward position. The misfired module
will remain in the shutdown position until maintenance can be
performed. However, the other modules of the gun cluster remain in
operation.
The operation of a hydraulic control circuit is believed to be
evident from the detailed description of FIGS. 14A and 14B above
but will now be summarized.
The hydraulic control circuit illustrated in FIGS. 14A and 14B has
three basic elements. The basic elements of the circuit are:
1. The primary control components. These components include the
misfire detection mechanism 113 and the module shutdown valve 223.
The primary control components also include the bias control valve
195.
2. The secondary control components. The secondary control
components include the bolt and injector system control valve 247,
the projectile loader control valve 279 and the breech lock control
valve 277.
3. The auxiliary control components. The auxiliary control
components include the gun purge valves 141 and 143 and the
three-way time delay valve 161 and the valve actuator 153.
The primary control components consist of the misfire detection
mechanism 113 and the module shutdown valve 223 and the bias
control valve 195. The bias control valve 195 is operated by the
electrical solenoid 197, which in turn is controlled by the gun
trigger. The bias control valve 195 controls the hydraulic fluid
supply to the secondary control valves.
The design and operation of the secondary control valves is a
unique feature of the present invention and is fundamental to the
operation of the hydraulic control circuit. The bolt and injector
system control valve 247 is typical of the secondary control
valves. The valve 247 consists of the outer valve body 249, the
hydraulically operated sleeve 255 and the cam-operated inner spool
253. The cam follower 261 attached to the rear end of the spool 253
engages the groove 263 of the cam 49. As the cam 49 rotates, the
spool is caused to translate forward and rearward in the outer
valve body. The spool is shown in FIG. 14B in its rear position
(the dotted line illustrates the maximum forward position of the
cam follower). The sleeve 255 is concentric to the spool and its
position relative to the spool is controlled hydraulically by means
of the bias control valve 195. Hydraulic pressure applied to the
front end of the sleeve 255 will force the sleeve rearward against
the rear stop 259 of the spool 253, and hydraulic pressure applied
to the rear of the sleeve 255 will force the sleeve forward against
the forward stop 257 of the spool. In either the forward or the
rear position relative to the spool, the sleeve will translate
forward and rearward in the outer valve body 249 as the piston
moves. The position of the sleeves with respect to the spool in
each of the secondary control valves 247, 277 and 279 is controlled
by means of the bias control valve 195, which, in turn, is actuated
by the trigger solenoid 197. When the trigger solenoid 197 is
energized, the bias control valve 195 is pulled to the rear, thus
allowing hydraulic fluid to flow to the forward end of all of the
secondry conrol valves. This forces the sleeves rearward against
the rear stops of the related spools. When the trigger solenoid 197
is deenergized, the trigger solenoid during spring 196 pushes the
bias control valve forward. This allows hydraulic fluid to flow to
the rear end of all the secondary control valves and forces the
sleeves forward against the forward stops of the related
spools.
The relative positions of the various components in respect to the
cam follower and sleeve position are tabulated in the following
table I.
TABLE I
BOLT, INJECTOR, BREECH LOCK, AND PROJECTILE LOADER POSITIONS AS A
FUNCTION OF SLEEVE* AND CAM* POSITION
Forward Rear Sleeves (trigger (trigger on) off) forward Cam
follower Position tf of rear rear Bolt and bolt actuator rear
forward rer Injector and injector a ctuator rear forward rear
Breech lock actuator forward rear forward and breech lock unlocked
locked unlocked Projectile loader actuator rear forward rear and
projectile loader lever up down up * Sleeves and cam followers on
bolt and injector valve, breech lock control valve ane projectile
loader control valve
When the trigger is in the off condition, the bias valve 197 is
forced forward by a bias control spring 196. Hydraluic fluid flows
to the rear of each of the secondary control valves 247, 277 and
279, thus forcing the sleeves into the forward position. With the
sleeves in the forward position, the bolt and injector control
valve 247 will allow hydraulic fluid to flow to the forward port of
the bolt actuator 83 and to the forward port of the injector
actuator 69, thus forcing the bolt 55 and the injector pistons 63
and 65 to the rear. The breech lock control valve 277 allows
hydraulic fluid into the rear chamber of the breech lock actuator
167 which forces the breech lock forward into the unlocked
position.
The projectile loader control valve 279 allows hydraulic fluid to
flow into the forward chamber of the projectile loader actuator
112, forcing it rearward and causing the projectile loader lever
109 to move into the up position. As the cam 49 rotates, the cam
followers and systems of all the secondary control valves 247, 277
and 279 will translate forward and backward. The sleeves will
translate with However, piston. However in this trigger off
condition, the valve ports are arranged so that the bolt 55,
injector pistons 63 and 65, projectile loader lever 109, and breech
lock 165 wil remain in position as the sleeves translate.
When the trigger is energized or on, the bias control valve 195
moves rearward, and hydraluic fluid flows to the forward chambers
of the secondary control valve 247, 277 and 279 forcing the sleeves
to the rear. The sleeves will translate with the valve spools as
the main cam 49 rotates. However, with the sleeves in the rear
position, the valve ports are arranged so that the following is
accomplished:
In the bolt and injection control valve 247, with the sleeves
positioned to the rear, translation of the spool 253 and the sleeve
255 forward as the main cam 49 rotates allows hydraulic fluid to
flow to the forward chamber of the bolt actuator 83 and the
injector actuator 68, thus forcing the bolt 55 and the injector
pistons 63 and 65 to the rear. Translation of the spool 253 and
sleeve 255 rearward allows hydraulic fluid to flow to the rear
chamber of the bolt and injector actuators, thus forcing the bolt
and injector piston forward.
In the breech lock control valve 277 with the sleeves 291 in the
rear position, translation of the sleeve 291 and spool 289 forward
as the main cam 49 rotates allows hydraulic fluid to flow into the
rear chamber of the breech lock actuator 163, forcing it forward
and unlocking the breech. Translation of the sleeve and spool to
the rear allows hydraulic fluid to flow into the forward chamber of
the breech lock actuator 163, forcing it rearward and locking the
breech.
In the projectile loader conrol valve 279 with its sleeve 317 in
the rear position, translation of the sleeve 317 and spool 315
forward as the main cam 49 rotates allows hydraulic fluid to flow
to the forward chamber of the projectile loader actuator 112
forcing the actuator rearward and positioning the projectile loader
lever 109 in the up position. Translation of the sleeve and spool
to the rear allows hydraulic fluid to flow to the rear chamber of
the projectile loader actuator 112 forcing it forward and
positioning the projectile loader lever into the down position.
Sequencing of the movement of the bolt 55, injector piston 63 and
65, breech lock 165 and the projectile loader lever 109 are
controlled by the design of a main cam 49. One revolution of the
main cam 49 will result in one cycle of operaton of the bolt,
injectors, breech lock and projectile loader with trigger in the on
position.
The other primary control components are a misfire detection
mechanism 113 and a module shutdown valve 223. The main function of
the module shutdown valve 223 is to shut off hydraulic supply in
the event of a misfire. A cam follower 239 is attached to the rear
end of the valve 223 and engages one of two grooves or traces 241
and 243 in the main cam 49. The normal position of the misfire
detection mechanism and module shutdown valve is when the cam
follower engages its forward trace 241, or the valve 223 in the
forward position or open position. The valve is acted upon by
several forces, depending on the control mode.
In the trigger off (bias control valve 195 in the forward position)
condition, hydraulic fluid is allowed to flow into the spring
chamber 235 of the misfire detection module shutdown system valve.
The combination of the spring and the hydraulic pressure forces the
valve to remain in the forward position with the cam follower 239
engaged in the forward cam trace 241.
In the trigger on (bias control valve 195 in the rear position)
condition, hydraulic fluid flows into the rear chamber, acting on
the rear piston 237 and exerting a force rearward on the valve 223.
However, during normal firing, high pressure propellant gases are
bled into the gas chamber 121 which exert a force to maintain the
valve 223 in the forward position. The combination of the bleed gas
pressure and spring exert a greater force than the hydraulic force
so that valve stays in the forward direction.
In the event of a misfire, there will be no propellant gas
pressures generated. The hydraulic fluid pressure in the rear
chamber of the housing 209 acting on the rear piston 237 will
overcome the force of the spring 235 and will exert a net rearward
force. As the main cam 49 rotaes around, the cam follower 239 will
engage the transfer groove or path 245 and will move rearward to
engage the rear groove or trace 243. The misfire detection and
module shutdown valve 223 will be forced to the rear and will
remain in this position. In moving to the rear position, the valve
will shut off the primary hydraulic flow from the conduit 191 to
the bias control valve 195, the bolt and injector control valve
247, the breech lock control valve 277 and the projectile loader
control valve 279. The shutdown hydraulic circuit is opened, and
hydraulic fluid will flow through the restricting orifice 233 and
through the check valve 301 to the forward end of the breech lock
actuator 163 and through the check valve 343 to the forward end of
the projectile loader actuator 112. The breech lock actuator 163 is
forced to the rear into the locked position. The projectile loader
actuator 112 is also forced to the rear. Hydraulic fluid also flows
through the three-way time delay valve 161 and forces the purge
valve piston yoke 147 forward, opening the chamber purge valve 141
and 143. Fuel (which may be JP-4 in the case of an aircraft
installation) or other fluid (such as water) from the purge supply
will flow through the chamber and out to the purge sump, flushing
the propellant charge out of the firing chamber 57. After a
suitable time delay, the three-way valve 161 will bypass the
hydraluic fluid to the return line 193, and the purge valve spring
157 will force the purge valve piston to the rear, closing the
chamber purge valves.
In the misfire, condition, the bolt 55 and the injector piston 65
will remain locked in the forward position, and the gun module 31
will shutdown until serviced.
While we have illustrated and described the preferred embodiments
of our invention, it is to be understood that these are capable of
variation and modification, and we therefore do not wish to be
limited to the precise details set forth, but desire to avail
ourselves of such changes and alterations as fall within the
purview of the following claims.
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