U.S. patent number 3,695,246 [Application Number 05/151,681] was granted by the patent office on 1972-10-03 for pneumatic machine gun with photo cell interrupted circuit.
This patent grant is currently assigned to The United States of America as represented by the Secretary of the Navy. Invention is credited to Ernest A. Filippi, Larry E. Hughes, Jack B. Watson.
United States Patent |
3,695,246 |
Filippi , et al. |
October 3, 1972 |
PNEUMATIC MACHINE GUN WITH PHOTO CELL INTERRUPTED CIRCUIT
Abstract
A pellet firing pneumatic machine gun wherein a toothed wheel
carries pels from a hopper and conveyer assembly to a position
adjacent one end of a barrel through which the pellets are
propelled by an air blast from a solenoid valve, the periodic
energization of which is effected by a photo-cell exposed to a
light source, wherein the light source is placed on the opposite
side of the periphery of the pellet delivering wheel from the
photo-cell such that upon rotation of the wheel, the teeth thereof
act to interrupt light from the light source falling on the
photo-cell. In addition, a pellet slitting device mounted on the
other end of the barrel, wherein the device includes adjustable
blades which score the skin of dye containing pellets shot from a
gun to render the pellets more frangible upon impact.
Inventors: |
Filippi; Ernest A. (Newhall,
CA), Watson; Jack B. (Newhall, CA), Hughes; Larry E.
(Newhall, CA) |
Assignee: |
The United States of America as
represented by the Secretary of the Navy (N/A)
|
Family
ID: |
22539810 |
Appl.
No.: |
05/151,681 |
Filed: |
June 10, 1971 |
Current U.S.
Class: |
124/72; 42/106;
124/48; 124/77; 273/317; 124/32; 124/51.1; 124/82; 434/19 |
Current CPC
Class: |
F41B
11/71 (20130101); F41B 11/00 (20130101); F41B
11/57 (20130101) |
Current International
Class: |
F41B
11/00 (20060101); F41f 001/02 () |
Field of
Search: |
;124/11,32,48,50,51R,51A
;35/25 ;89/33E |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pinkham; Richard C.
Assistant Examiner: Stouffer; R. T.
Claims
What is claimed is:
1. In a pellet propeller operable from a source of A.C. electrical
power and a source of compressed air and including a motor, a
toothed wheel adapted to be driven in rotation by said motor for
conveying pellets from storage means to a firing position adjacent
a barrel, and firing solenoid valve means for releasing a blast of
compressed air to fire each pellet, the improvement comprising:
a light source disposed on one side of the periphery of said
wheel;
photo-cell means mounted on the opposite side of the periphery of
said wheel such that light from said source falling on said
photo-cell means is periodically interrupted by teeth of said wheel
and said photo-cell provides an electrical output which fluctuates
at the frequency of the passing of said teeth; and
circuit means responsive to said fluctuations to effect
energization of said solenoid valve means in timed relation to
rotation of said wheel.
2. A pellet propeller as defined in claim 1, and further
comprising:
pneumatic clutch means between said motor and said wheel;
clutch operating solenoid valve means connected between said source
of compressed air and said clutch means;
firing switch means operable to energize said clutch solenoid valve
means to cause said clutch means to complete connection of said
motor to said wheel to initiate firing.
3. A pellet propeller as defined in claim 2, and further
comprising:
pelter slitter means mounted on said barrel and comprising blade
means extending into the path of said pellets and operative to slit
the pellets as they are fired.
4. A pellet propeller as defined in claim 3 and wherein said
slitter means comprises:
a body having a central bore in axial alignment with said barrel,
said body having a plurality of radial bores extending inwardly
toward said central bore but terminating short thereof, a plurality
of radially extending slots each connecting one of said radial
bores with said central bore;
a plurality of blades each disposed in one of said slots;
a plurality of blade holders each having one of said blades fixed
thereto and each disposed for radial movement in said radial
bores;
spring means resiliently urging said blade holders and blades
radially outwardly from said central bore; and
screw means disposed in said radial bores and operative to advance
or retract said blade holders and blades with respect to said
central bore.
Description
BACKGROUND OF THE INVENTION
This invention relates to pneumatic machine guns or pellet
propellers useful for training purposes, and more particularly to
an improved propeller capable of "firing" dye filled gelatin
pellets which burst upon impact against trainee to provide a
lasting and realistic indication of hits.
A variety of pneumatic machine guns have been proposed heretofore
and generally share an arrangement by which pellets are conveyed
from a magazine and placed, one at a time, in position to be
propelled through a barrel by pressurized air released by a valve
in timed relation to the arrival of the pellet in position to be
fired. The timed relation has in most instances been determined by
rotary cam means geared to the pellet conveyer means and
mechanically actuating the valve or switch means in the case of a
solenoid valve. An alternative has been a reciprocating air motor
which controls the pellet delivery and valve operation.
In most of the foregoing arrangements the timing has been
determined by mechanical arrangements, particularly cams and
followers which are subject to wear and change of adjustment which
adversely affect the nicety of timing which is needed for proper
operation. Other timing arrangements such as have depended upon a
build-up of pressure through a restriction, are limited to
applications where the repetition rate is very low, e.g. in
propelling baseballs for batting practice.
Prior art pneumatic machine guns have had as their principal
purpose the training of personnel in operation and aiming at
targets. There has been lacking a suitable machine gun or pellet
propeller which could be used to provide simulated machine gun fire
from a "nest" or building to be attacked by trainees. In this
regard, it is considered desirable to fire dye containing pellets
with sufficient velocity as to burst and mark trainees, when hit,
and yet be relatively safe so as not to cause injury to the
trainees.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is one important object of the
invention to provide an improved pneumatic propeller for pellets of
the type utilizing a motor driven notched feeder wheel for carrying
pellets from a supply to a position adjacent the barrel, and
solenoid controlled valve for releasing a blast of air at the
proper time to drive the pellet through the barrel, the improved
propeller being characterized by novel valve actuating timing
means.
Another important object of the invention is the provision, in an
improved propeller of the foregoing character, of means for
slitting or scoring the walls of a dye containing pellet as it
passes from the propeller so that bursting of the pellet is assured
upon impact even though the impact velocity is sufficiently low to
render it unlikely that physical injury of a person hit would
occur.
Other objects and advantages of the invention will become apparent
from the following description of a presently preferred embodiment
when read in conjunction with the accompanying sheets of
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a pellet propeller embodying
the invention with portions broken away to reveal other
portions;
FIG. 2 is a diagrammatic plan view of the pellet propeller;
FIG. 3 is a diagrammatic perspective illustration of the
propeller;
FIG. 4 is a simplified electrical diagram illustrating the control
system of the propeller;
FIG. 5 is a sectional view on an enlarged scale taken along line
4--4 of FIG. 1 and illustrating the pellet slitter forming part of
the propeller; and
FIG. 6 is a sectional view taken substantially along line 6--6 of
FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the form of the invention illustrated in the drawings and
described hereinafter, there is provided a pellet propeller 10
which is operable from a source of pressurized air and a source of
electric power such as 115 volts A.C. The pellet propeller 10
comprises a housing 12 formed of sheet aluminum or other suitable
material and including 12a, 12b, side walls 12c, 12d, a tap wall
12e, and a bottom wall 12f. Within the housing is a frame 14
comprising a base plate 14a spaced above the bottom wall 12f by
channel members 16, and various upright and transverse members 14b,
14c, 14d, 14e, and 14f on which components described hereinafter
are mounted.
These components include a barrel 20 mounted parallel to the base
plate 14a and extending from adjacent the rim of a feeder wheel 22
toward the end wall 12b where it terminates in a pellet slitting
device 24. The feeder wheel 22 which has a plurality of evenly
spaced teeth defining pellet receiving recesses in the periphery
thereof is fixed to a shaft 26 and is adapted to be rotated during
firing of the propeller by an electrical motor 28. To this end the
motor 28 is coupled through a gear reducer 30 to a pneumatic clutch
32 which is normally disengaged. The clutch 32 is actuated by
pressurized air via line 34 when a solenoid valve 36 is energized,
the latter being connected via line 38 to receive air brought to
the propeller from a suitable source to a connection 40 at end wall
12a.
Mounted above the feeder wheel 22 is a pellet hopper and conveyer
assembly, generally indicated at 44. This assembly is driven in
consonance with the feeder wheel 22 by a chain 46 leading around a
sprocket 48 on shaft 26, an idler sprocket 50 mounted on frame
member 14d, and a sprocket 52 fixed to a shaft 54 extending from
the hopper and conveyer assembly 44. As is best illustrated in FIG.
3, the assembly 44 comprises as part thereof, a moving belt
conveyer 55. A feed tube 56 having a vertical passage therethrough
is mounted beneath the assembly 44 and terminates over the upper
reach of the feeder wheel 22. The feed tube 56 receives pellets
from the belt 55 of the assembly 44 and deposits them one by one in
the recesses in the periphery of the feeder wheel as it
rotates.
The hopper assembly 44 advantageously further comprises means such
as belts 57 carried by upper and lower rollers 58a and 58b, the
lower rollers being driven by suitable miter gears (not shown) from
a chain 59 and associated sprockets. The purpose of the belts 57 is
to agitate the pellets P within the hopper assembly 44 to prevent
the formation of arches of pellets carried by the belt 55. The
hopper may additionally include heating means such as electrical
resistance heating strips under the control of a thermostat to
prevent the pellets from becoming hard or brittle under cold
conditions and possibly injuring a trainee.
Approximately one quarter of the rim portion of the feeder wheel 22
is covered by a fender or shroud 60 which serves to prevent the
pellets P from falling from the recess in the feeder wheel rim
during their travel from the hopper and conveyer assembly 44 to the
point of firing.
Mounted in alignment with the inner end of the barrel 20, and on
the other side of the path of travel of the feeder wheel 22, is a
solenoid valve 62, which valve is connected via line 64 to an
accumulator 66. Referring to FIG. 2, the accumulator 66 is
connected via line 68, an oiler 70, line 72, a regulator 74, and
line 76 to the high pressure air connection 40. The regulator 74
serves to reduce the high pressure input to a lower, more constant
value. The oiler 70, serves to introduce a small quantity of oil
into the air supplied to the valve 62 to lubricate the pellet and
ease its travel through the barrel 20. The regulator 74 and oiler
70 are conventional commercially items and need not be described in
detail.
Mounted approximately 180.degree. from the solenoid valve 62,
around the feeder wheel 22, are a light source 80 and a photocell
82 between which is the path of travel of the peripheral teeth 22a
of the feeder wheel. The photo-cell 82 forms part of the electrical
control circuitry of the propeller which will be discussed more
fully as the specification proceeds. The photo-cell 82, the
solenoid valves 36 and 62, are connected by electrical cables 90,
92, and 94, to a box 100 containing control circuit means later
discussed with reference to FIG. 4.
The propeller 10 is provided with an electrical cable 102 for
connection to a source of A.C. power, conveniently 115 volts. A
power switch 104 is mounted on the end panel 12a as is a firing
switch 106. These switches, the power cable 102, the motor 28, and
the logic means are suitably interconnected as by electrical cables
108, 110.
Referring now to the diagram of FIG. 4, the A.C. power supply is
represented as lines L1 and L2. The switch 104 controls the supply
of A.C. power via line 112 to the motor 28 such that upon closing
the switch 104, the motor will begin to run, which is the normal
condition even though the propeller is not firing. The light source
80 is conveniently energized from a transformer 114 energized via
switch 104.
The firing switch 106 provides A.C. line current via lines 116 to a
control circuit 120 for the firing solenoid valve 62, and via line
122 to the clutch operating solenoid valve 36. The photo-cell 82 is
connected to the control circuit 120 which, in its simplest form,
can comprise means such as trigger circuitry responsive to output
of the photocell above a selected threshold to effect energization
of the firing solenoid valve 62. Preferably, however, the control
circuit 120 also includes circuitry such as that disclosed in U.S.
Pat. No. 3,418,494 which will assure that the solenoid valve 62
will be come energized at the beginning of the half A.C. cycle,
either positive or negative, following the reaching of the
threshold, and will persist only for that half cycle. This provides
for crisp, positive, and uniform action of the firing solenoid
valve 62.
Referring to FIGS. 5 and 6, the pellet slitter 24 comprises a
generally flat circular body 130 having an externally threaded
central boss 132 which extends through an opening in the end panel
12b of the propeller housing and is adapted to receive a cap to
exclude dirt and moisture when the propeller is not in use The
slitter 24 is conveniently secured to the end panel 12b by screws
134 extending through the body 130. The boss 132 has a central bore
136 the diameter of which matches that of the barrel 20. A large
counter bore 138 receives one end 142 of a barrel adapter 144 which
has a radial flange 146 secured to the body 130 as by screws
148.
The adapter 144 is externally threaded and is received in the
correspondingly internally threaded end of the barrel 20.
The body 130 has four radial bores 150 extending from the periphery
thereof inwardly as far as the counter bore 138. The outer portions
of the bores 150 are counterbored as at 152 and threaded as at 154.
The bores 150 communicate with the bore 136 through slots 156 which
are adapted to receive knife blades 160. The blades 160 are fixed
to radially movable blade holders each having a stem portion 162
slideable in the bore 150 and larger diameter head portion 164 in
the counterbore 152. A compression spring 170 is disposed in each
counterbore 152 and resiliently urges the blade holder and blade
160 outwardly. An adjusting screw 172 is threaded into each of the
counterbores 152 and bears against the head portion 164 of the
corresponding blade holder. The screws 172 may be turned to adjust
the amount of the knife blades 160 which will protrude into the
bore 136 and may be secured in adjusted position by lock nuts 176.
With the knife blades fully retracted, the pellets are not
affected. However, the blades may be extended into the bore 136 as
shown to make four shallow slits in the pellet skin as it leaves
the barrel. Such slitting causes the pellets to rupture more easily
upon impact, thereby reducing the pain inflicted on persons
hit.
Obiously many modifications and variations of the present invention
are possible in the light of the above teachings. It is therefore
to be understood that within the scope of the appended claims the
invention may be practiced otherwise than as specifically
described.
* * * * *