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Патент USA US2410767

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Nov. 5, 1946.
F. o. wlsMAN ETAL
2,410,767
AUTOMATIC MACHINE GUN CHARGER
Filed June ll, 1943
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Patented Nov. 5, 1946
UNl'l'E
.
2,410,767
AUTQMATIC MACHINE GUN CHARGER
Franklin O. Wisman and William C. Rohm-South
Bend, Ind., assignors to Bendix-Aviation corpo
ration, South Bend, Ind., a corporation of Dela
Waffe
Application J une 11, 1943, Serial No. 490,458
5 Claims.
(Cl. 89--1)
1
2
This invention relates to automatic charging
systems for automatic guns, and is particularly
adaptable to both small and large caliber auto
over thev prior art in that it is readily adaptable
matic guns.
As is known to those skilled in the ordnance
are, guns of this type will not re-load automati
cally for automatic ñring whenever a “dud”
round has been inserted into the firing chamber,
for use with dilferent kinds of automatic guns,
i. e., both small caliber guns, and the larger cali
ber guns.
As is known to those skilled in the
. lire arms art, the small caliber automatic guns,
for'example, the caliber 30 and the caliber 50
machine guns elfect the re-loading operation for
automatic ñre by reciprocation of the breech
blocks in the following manner. The recoil op
since no force will be obtained to eject the un
ñred round and insert a fresh round into the 10 eration oi the gun causes the breech block to
ñring chamber. Guns of the automatic type may
be moved rearwardly to eject the ñred round
also fail at times to eifect an automatic re-load
and simultaneously to pick up alive round, which
ing operation because the parts thereof become
is forced into the iiring chamber by the forward
movement of the breech block, whereupon, if the
sear is still released, the firing pin moves for
ward to'ñre the fresh round.
In the larger types of automatic guns em
or for some other reason. Since guns of this type
ployed in modern warfare, as for example, the 37
are oftentimes located remotely from the opera
mm. cannon, which has‘been used in certain
tor, as for example, in the wings of an aircraft, 20 types of pursuit aircraft, and different types of
it is desirable that the re-loading operation be
ordnance vehicles, the re-loading operation is
effected automaticallyÀ without requiring the op
accomplished in a manner different from that
misaligned or otherwise inoperative. Accord
ingly, it is desirable to furnish means to effect
a re-loading operation in the event that the gun
fails to re-load because of defective ammunition
erator >to initiate and bring to completion a re
charging operation.
Many devices have been proposed for elîect
ing a re-loading operation of an automatic gun
upon failure to operate, but they have generally
employed electro-mechanical means, or electro
pneumatic means. Devices employing electro
mechanical means have been open to the objec
tion that they are oftentimes as heavy as the
automatic gun which they are to re-load. In
aircraft, Where space and weight are at a pre
mium, devices of this nature are obviously wholly
unsatisfactory. So too, are electro-pneumatic
devices, since they require for their successful
had with the caliber 50 machine guns referred
to above. In guns of this type the re-loading
operation is accomplished by the recoil forces
of the ñredv round causing the gun barrel to be
moved rearwardly, .carrying with it during such
movement the breech block, which then con
tinues to move rearwardly to complete its re
30 tractive movement after the gun barrel has iin
ished its recoil movement and has moved for
wardly to the firing position. The two move
ments justdescribed effects the ejection of the
fired round with the practically concurrent in
sertion of ,a new round into the feed way. Upon
forward movement of the breech block, the new
operation a source of gaseous pressure, which
round is moved into the firing chamber, and if
musiJ either be stored in cylinders furnished with
the sear is in the firing position, the gun con
the aircraft, or supplied by compressors driven
tinues to fire automatically.
from the aircraft engine. The instant invention 40
With the _foregoing problems in mind, it is an
avoids the objections to both electro-mechanical
object of this invention to provide an automatic
and electro-pneumatic charging or re-loading
charging system for both the smaller caliber and
devices, since it employs in its operation the usual
larger-caliber automatic weapons,'the latter be
fluid pressure system incorporated with most mil
itary aircraft. )Since the pressures employed in 45 ing adapted to» ñre- explosive rounds, asVA for ex
ample, the 37 mm. cannon which has been re
these systems are quite high, the usual pressure
ierred
to above.
values being maintained between 500 and 1,500
A further object is to provide an automatic
pounds per square inch, the motors used in the
charging system for one or a plurality of guns
recharging or re-loading operation need not be
unduly large, nor need they add much to the 50 of the type mentioned above which will employ
weight of the aircraft, since high power to weight
in its operation fluid supplied by any suitable
ratios are obtainable where the motivating fluid
fluid pressure system.
Astill further object of the invention is to pro
vide an rauton'iatic‘charging system, which, after
having been serviced for automatic operation,
is kept between the values mentioned above.
The automatic charging system disclosed in
the present invention is a further improvement
2,410,767
`
"
3
4
will not require the further attention of the pilot
the circuit for effecting a manual charging op-«
0r operator.
eration includes a source of electric power indi
Still another object is to provide a charging
system for manual charging of the guns to make
them ready for automatic operation, the manual
means of a lead 26 through a switch 28, which
cated generally at 2li which is connected by
charging being generally effected by the service
when closed on contact points 3i) passes current
to lead 32 to a contact point Bil of a manual
crew before the aircraft or other vehicle is en
charging switch indicated generally by the ordi
nal 3%. It may be noted that the manual charg
ing switch is not a conductor of current, and
the provision of a, novel circuit for one or more 10 when the switch is moved downwardly, as seen
in Figure 1, the ground of the switch 3E is broken
cf such guns, said control circuitbeing adapted
by the separation of contacts 3l’ and 3S, and cur
to manual charging of the guns during servicing
rent is then passed from the lead 32, through
operations, and to automatic charging of the
contact point Sli through a lead 3S, and thence
guns after the servicing operations have been
through a thermo~sensitive switch element di! of
completed.
a thermal switch
whence the current passes
A feature of the invention lies in the provision
through a lead Lili to the solenoid of the solenoid
of automatic cutout means in a charging system
operated valve 2‘2. Simultaneous with the ener
for a gun should it become jammed in such a
gization of the solenoid operated valve 22 is the
fashion that neither manual nor automatic
charging restore the gun to a firing condition.
20 energization of a winding 53 of a compound
wound relay iid. It will be seen that the circuit
The foregoing and other objects of the inven
just described causes the solenoid operated valve
tion will be apparent from the study of the de
gaged in combat.
Yet another object of the invention embodies
22 to operate, thereby admitting iiuid from the
accumulator 2€! to the fluid motor i-’i to effect
drawing which shows a preferred embodiment of
the invention. It is to be understood, however, 25 a retracting movement of the breech block pin
l2. Deenergization of the solenoid of the sole
that the invention is not limited by the embodi
noid operated valve 22 is effected by releasing
ment here shown, nor otherwise than by the
the manual charging switch 36, which then
terms of the claims appended hereto.
causes the fluid in the ñuid motor i4 to be eX
In the drawing which illustrates the inven
tion: '
30 hausted back to the reservoir i5. Completion of
the operation just described then places the guns
Figure 1 is a schematic diagram showing a pair
l 0 in condition for automatic operation and auto
of guns of the types referred to above, the circuit
matic charging,
for controlling the automatic operation and the
As shown in Figure l, the switch 28 is adapted
manual recharging operation being shown sche
matically;
35 to be closed upon a contact point 45, which per
forms two functio-ns. The first of these functions
Figure 2 is a View part in elevation and part in
is to pass current from the source 25 through
longitudinal section of a charging cylinder, par
the switch 23 to a lead 43 which is connected to
ticularly of the type adapted for use with larger
the lead 32, which has branching therefrom a
caliber automatic guns,
Referring now to Figure 1 of the drawing, there 40 lead 53 which is connected to one terminal of
an armature 52 of the compound relay 54, whence
is shown a plurality of automatic guns lll each
it passes through a lead 55 to energize the wind
having a breech block pin i2 which is secured to
ing of a time delay mechanism, indicated gen
the breech block (not shown) of each gun l0,
erally by the ordinal 58, thereby attracting the
and adapted to reciprocate therewith during nor
mal operation of the gun. Each gun is furnished 45 armature thereof to the left breaking contact at
a contact point 60. The second function taking
with a fluid motor I4 which is adapted to retract
place upon the closing,r of the switch 28 upon the
the breech block pin i2 upon failure of normal
contact point ¿SS is to pass current to a Contact
reciprocation of the breech block, under condi
point 62 of a firing relay 56. The system thus
tions later to be described.
For supplying fluid under pressure to the fluid 50 far described has placed the guns ready for auto
matic operation, and has placed the system in
motor lf3, there is a reservoir I6 which supplies
readiness for automatic firing.
ñuid to a pump I8, which passes the supplied
A trigger switch 53 is provided, and is common
fluid Under pressure to an accumulator 28, where
to both of the guns iû shown, but it may be noted
it is stored for use as needed by the fluid motors
that the system is readily adaptable, where de
It.
55
sired, to use with a trigger switch for each gun,
In order to pass ñuid simultaneously to each
instead of a single switch for a p-lurality o-f guns
of the fluid motors i@ there are provided solenoid
as shown. Closing the trigger switch 66 causes
operated valves 22, which when energized, under
the ñring relay G4 to be energized, at the same
conditions later to be described, opens to pass
fluid from the accumulator 2D to the charging 60 time causing the armature thereof to be at
tracted to the left upon contact point 62. It will
motor ill to effect a retracting operation of the
be seen that this operation causes current to be
breech block stud l2, and when deenergized op
passed through leads 66 to energize a solenoid
erates to exhaust fluid from the motor I4 back
of a trigger motor 'lo associated with each of the
to the reservoir I6. |The solenoid operated Valve
22 is not claimed as a part of this invention, and 65 guns it. The function of the trigger motor 1D
is well known to those‘skilled in the art, i. e., to
has been described and claimed in Pontius et al.
actuate the seal', not shown, of the gun l0 to
application, Serial No. 464,610, ñled November 5,
effect automatic firing.
1942, said application being a division of Pontius
Simultaneous with the closing of the trigger
L' al. application Serial No. 371,742, filed Decem
ber 26, 1940.
70 switch 66 is the energization of a winding 55 of
the compound relay 541 which receives current by
Means are provided for effecting a manual
means of a lead 'I2 which branches from the lead
charging operation of each or both of the guns l0.
68. It will be remembered that energization of
This operation may be indicated whenever a
fresh supply of ammunition is desired to be pro
the compound relay 54 was had when the manual
vided for the guns i9. As shown in Figure 1, 75 charging switch 35 was closed, when current was
scription hereinafter, reference being had to the
2,410,767
5
Supplied to the other winding 53 of the relay 54
simultaneously with the energization of the sole
noid of the solenoid operated valve 22 which was
operated to effect a manual charging operation.
Energization of the compound wound relay 55 Cil
6
,
the trigger switch t5 is opened it will beseen
that the charging operation is brought> to com
pletion irrespective of the condition of the trigger
switch 55.
"
causes the armature 52 thereof to be attracted up
Means are provided in the system described
above to prevent the operation of the gun when
and
wardly,
5|] to
when
a lead
current
7:1 to one
is passed
end ofthrough
the armature
leads oi
ever it is impossible to carry to completion a re
tracting or reloading operation. The thermal
cutout switch 42 is provided with a resistance ele
ment 84 which receives current from the lead 38.
gun which is operating properly, a gunfswitch l5
The circuit of resistance element Slä'is completed
is provided near the rearmost point of travel or“
by lead 85 and a pair of contacts of manual switch
the breech block pin l2, and is adapted to close
36 to ground. These contacts are closed when the
each time the breech block pin I2 moves rear
switch is not depressed. Since resistance element
wardly during operation of the gun IE). Closing 15 8d is in parallel with the solenoid operated valve
of the switch 15 causes current to be received by a
22, it will be seen that any prolonged energization
lead 'I8 which branches from the lead 5i), whence
of the winding of the solenoid operated valve 22
it is passed through the switch 'i6 to a lead> Si] to
will heat the resistance 85 to an amount whereby
energize the time delay mechanism 53 causing the
the thermal responsive element 45 breaks the cir
armature thereof to be attracted to the left. How- _, cuit supplying current to the valve 22. The ther
ever, when the breech blocl; pin l2 fails to recipro
mal cutout switch l‘l2 is of the snap variety and
cate, because of improper gun operation, the
once opened must be reset manually. When the
switch 'i6 will fail to close, and the time delay
circuit has been opened by the thermal responsive
mechanism 58 will be de‘energized. It may be
element 45, it will be impossible thereafter to pass
noted that the period of discharge of the time de
current to the solenoid operated valve 22. It will
lay mechanism 58 is greater than the cyclic time
be seen, therefore, that successive retracting oper
of reciprocation of the breech block pin l2; thus,
ations will not be performed upon the gun i0.
it will be noted, that during automatic tiring and
The electrical system may be conveniently di
during normal operation of the gun lß, the time
vided into a iìrst and a second circuit. The iirst
delay mechanism 58 will be in energized condi
circuit comprising the battery 24, switch 2S, con
tion, and the armature thereof will be attracted to
-tact 52, trigger motor lil, and the coil 55 of the
the left. Now if the breech block pin I2 fails to
compound relay 55. The second circuit comprises
reciprocate and remains in static position long
the battery source 25, switch 28, trigger switch
enough, the time delay mechanism will be deen
56,. ñring relay 55, normally closed means 52, time
ergized, and the armature thereof will close upon
delay relay 58, wire lll, thermal cut-out device
contact point 50. A circuit is thus made to eiiect
e2, electrically operated valve 22, coil 53A of the
an automatic recharging operation.
compound relay, normally open means for switch
The circuit is made from the source 24, through
l5, and a manually operated switch 36.
.
the electrical time delay mechanism 58.
In order to prevent' charging operations upon a
the switch 28, through leads 48, 32, 55, 14, and
- Referring now to Figure 2 of the drawing there
thence through a lead 82 to a juncture with the 40
is shown an embodiment of the fluid motor ylll
lead 38. The current then passes through the
thermal responsive element 453 of the thermal cut
out switch 42 through the lead 45 through the
solenoid of the solenoid operated valve 22 and
thence to ground. Simultaneously with this oper
ation, the winding 53 of the compound relay 54 is
energized. The solenoid operated valve 22 then
operates to retract the breech block pin I2, there
by reloading the gun lll for automatic operation
once more.
which has been found particularly adaptable to
eñect the retracting operation upon the larger
typesof automatic guns, as for example, the 37
mm. cannon.
The iiuid motor ld comprises a
cylindrical tube 88 which is secured to the gun
by means of a mounting bracket 99 as shown.
Reciprocable within the cylinder S3 is a piston
92 which has a skirt portion 9d, encompassed by
a spring 96 which is bottomed at one end against
the piston 52, and which is bottomed at the other
As soon as the breech block pin I2 has moved 50
end
by a threaded member 98 which is held to
rearwardly to close the switch 1-6, the time delay
the
cylinder
88 by means of a threaded element
mechanism 58 will be again energized,- thereby
§55. The rearward end of the skirt 5t has thread
breaking contact at contact point 6D and thus
ed thereto a flanged member E52 which is adapt
deenergizing the solenoid operated valve Z2 to
ed to engage the breech block pin l2 as shown.
pass the motivating fluid to the reservoir I6.
Fluid is supplied to the cylinder 88 at an entrance
Means are thus provided to insure the ccm
port IM whence it impinges against the piston
S2 to drive it rearwardly to eñect a retractíng
of the condition of the trigger switch 55, i. e.,
whether it be closed or opened during a charging
movement of the breech block and the breech
operation. It was noted that the winding 55 of 60 block pin I2. When the solenoid operated valve
the compound relay 54 was energized as soon as
22 is moved to the exhaust position, the cylindri
the trigger switch 56 was closed, at which time
cal spring 95 moves the piston forwardly, and the
the current was passed through the armature of
exhaust fluid back to the reservoir l5.
the ñring relay S4, through the leads 58 and ‘l2
Thus has been described a system adaptable
and thence to the compound relay 54. However, it 65 for recharging automatic guns of both the smaller
may be noted that as soon as the charging oper
types, as for example, the caliber 30 and caliber
ation thus described was initiated, the winding
50 machine guns, and the larger type, as for ex
53 of the compound wound relay 54 was energized
ample, the 37 mrn. cannon, which will automati
also. With the winding 53 energized, the arma
ture 52 of the compound wound relay 55 remained 70 cally charge or re-load said Aguns upon> failure of
automatic operation. While the invention has
in the upward position, thereby passing current
been described with particular reference to a
through the lead '14, lead 82, and thence through
proved embodiment thereof it is to be' distinctly
leads 38 and 44 to operate the solenoid operated
valve 22. ` Since the winding 53 of the compound
understood that the invention is Anot limited in
wound relay 54 will remainV energizedeven after 75 terms of the system hereinabove described, nor
pletion of a charging cycle or stroke regardless -
2,410,767
8
otherwise than by the terms of the claims ap
pended hereto.
We claim:
l. A gun charging apparatus for retracting th
breech bolt of a gun to charge the same compris
ing a fluid pressure motor adapted to be mounted
on the gun and constructed and arranged to en
gage the breech bolt, an electrical system includ
ing a source of current and a first and a second
structed and arranged to disconnect the valve
from circuit after a predetermined number of
successive attempts at charging the gun have
failed.
l
3. A gun charging apparatus for retracting the
breech bolt of a gun »to charge the same compris
ing a fluid pressure motor adapted to be mount
ed on the gun and constructed and arranged to
engage the breech bolt, an electrical system in
circuit, a switch constructed and arranged for 10 cluding a source of current and a first and a sec
ond circuit, a switch constructed and arranged
connecting said source of current to the first and
for connecting said source of current to the ñrs-t
second circuits, an electrically operated valve in
and second circuits, an electrically operated
the second circuit for controlling the fluid under
valve in the second circuit for controlling the
pressure to the motor, a time delay relay, a nor
fluid under pressure to the motor, a time delay
mally closed means connecting said time delay
relay, a normally closed means connecting said
relay to the second circuit, a normally open
time delay relay to the second circuit, a normal
means in the second circuit adapted to be
ly open means in the second circuit adapted to
mounted on the gun and constructed and ar
be mounted on the gun and constructed and ar
ranged to be closed by the breech bolt when re
tracted for connecting said time delay relay to 20 ranged to be closed by the breech bolt when re
tracted for connecting said time delay relay to
the second circuit, a compound relay in the first
the second circuit, a compound relay in the first
and second circuits, a trigger switch in the second
and second circuits, a trigger switch in the sec
circuit, and means in the second circuit respon
ond circuit, and means in the second circuit re- '
sive to closing of the trigger switch for closmg
the first circuit to energize the compound relay, 25 sponsive to closing of the trigger switch for clos
ing the ñrst circuit to energizeV the compound re
said compound relay being constructed and ar
lay, said compound relay being constructed and
ranged so that when it is energized it will open
arranged so that when it is energized it will open
the normally closed means connecting the sec
the normally closed means connecting the sec
ond circuit to said time delay relay and tend to
connect the valve and compound relay to said 30 ond circuit -to said time delay relay and tend
to connect the valve and compound relay to said
second circuit, ‘whereby a charging cycle once ini
second circuit, whereby a charging cycle once
tiated will be completed irrespective of the posi
initiated will be completed irrespective of the po
tion of the trigger switch, said time delay relay
sition of the trigger switch, said time delay relay
being constructed and arranged to disconnect
being constructed and arranged -to disconnect
said compound relay and said Valve from the sec
ond circuit during normal gun operation.
said compound relay and said valve from the
second circuit during normal gun operation and
to connect said valve and said compound relay
breech bolt of a gun to charge the same compris
to the second circuit in the event of gun failure
ing a fluid pressure motor adapted to be mounted
on the gun and constructed and arranged to en 40 ,to cause the bolt to be retracted for charging the
gun.
gage the breech bolt, an electrical system includ
2. A gun charging apparatus for retracting the
ing a source of current and a first and a second
circuit, a switch constructed and arranged for
connecting said source of current to the ñrst and
second circuits, an electrically operated valve in
the second circuit for controlling the fluid under
pressure to the motor, a time delay relay, a nor
-mally closed means connecting said time delay
relay to the second circuit, a normally open means
in the second circuit adapted to be mounted on
the gun and constructed and arranged to be
closed by the breech bolt when retracted for con
necting said time delay relay to the second cir
cuit, a compound relay in the ñrst and second
circuits, a trigger switch in the second circuit,
means in the second circuit responsive to closing
of the trigger switch for closing the ñrst circuit
to energize the compound relay, said compound
4. A gun charging apparatus for retracting the
breech bolt of a gun to charge the same compris
ing a fluid pressure motor adapted to be mounted
on the gun and constructed and arranged to en
gage the breech bolt, an electrical system includ
ing a source of current and a ñrst and a Second
circuit, a switch Vconstructed and arranged for
connecting said source of current to the ñrst and
second circuits, an electrically operated valve in
the second circuit for controlling the fluid under
pressure to the motor, a time delay relay, a nor
mally closed means connecting said time delay
relay to the second circuit, a normally open means
in the second circuit adapted to be mounted on
the gun and constructed and arranged to be
closed by the breech bolt when retracted for con
> necting said time delay relay Ito the second cir
cuit, a compound relay in the first and second
relay being constructed and arranged so that
when it is energized it will open the normally 60 circuits, a trigger switch in the second circuit,
means in the second circuit responsive to closing
closed means connecting the second circuit to
of the trigger switch for closing the first circuit
said time delay relay and tend to connect the
to energize the compound relay, said compound
Valve and compound relay to said second circuit,
relay being constructed and arranged so that
whereby a charging cycle once initiated will be
completed irrespective of the position of the trig 65 when it is energized it will open the normally
closed means connecting the second circuit to
ger switch, said time delay relay being constructed
said time delay relay and tend to connect the
and arranged to connect said electrically oper
valve and compound relay to said second circuit,
ated Valve to the second circuit in the event of
whereby a charging cycle once initiated will be
gun failure to cause the bolt to be retracted for
charging the gun, and a thermal cut-out device 70 completed irrespective of the position of the
trigger switch, said time delay relay being con
in the second circuit including a thermal respon
structed and arranged to connect said valve to
sive element in series with the second circuit and
the second circuit in the event of gun failure
a resistor disposed adjacent said element and
to admit fluid to said fluid motor 4to cause the
connected in parallel with said electrically op
erated Valve, said cut-out device being con 75 bolt to be retracted for charging the gun, a
2,410,767
10
thermal cut-out device in the second .circuit in
said time delay relay to the second circuit, a
cluding a thermal responsive element in series
normally Aopen means in the second .circuit
with the second circuit and a resistor connected
adapted to be mounted on the gun and con
in parallel with said electrically operated valve,
structed and arranged to be closed by the breech
said cut-out device being constructed and ar
bolt when retracted for connecting said time de
ranged to disconnect the valve from circuit after
lay relay to the second circuit, a compound relay
a predetermined number of successive attempts
in the first and second circuits, a trigger switch
at charging the gun have failed, and a manually
in lthe second circuit, means in the second cir
operated normally open switch in the second cir
cuit responsive to closing of the trigger switch for
cuit constructed and arranged to -connect the lí) closing the ñrst circuit to energize the compound
electrically operated valve to said second circuit
relay, said .compound relay being constructed and
ythrough a shunt around said normally closed
arranged so that when it is energized it will open
means to thereby charge the gun at will.
the normally closed means connecting the second
5. A gun charging apparatus for retracting the
circuit Ito said time delay relay and tend to con
breech bolt of a gun to charge the same compris
nect the valve and compound relay to said second
ing a fluid pressure motor adapted to be mounted
circuit, whereby a charging cycle once initiated
on the gun and constructed and arranged to en
will be completed irrespective of the position of
gage the breech bolt, an electrical system includ
the trigger switch, said time delay relay being
ing a source of current and a first and a second
constructed and arranged to disconnect said com
circuit, a two-position switch disposed between
pound relay and said valve from the second cir
the source and the first and second circuits and
cuit during normal gun operation, and a manu
constructed and' arranged to connect the source
ally operated normally open switch in the second
to the ñrst and second circuits when in one posi
circuit constructed and arranged to connect the
tion and to connect the source to the second cir~
electrically operated valve to said second circuit
cuit only when in one position and t0 connect the
.through a shunt around said normally -closed
source to the second circuit only when in .the
means to charge the gun irrespective of whether
other position, said positions being battery and
the two position switch is in battery or safety
safety positions respectively, an electrically op
erated valve in the second circuit for controlling
the ñuid under pressure to the motor, a time
delay relay, a normally closed means connecting
position.
FRANKLIN O. WISMAN.
WILLIAM C. ROHN.
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