Improvements in Machine Guns.
Year: 1895

page_text: Date of Application, 3rd Oct., 1895-Accepted, 16th Nov., 1895
COMPLETE SPECIFICATION.
Improvements in Machine Guns.
We ALBERT GRIGSBY DOUGHERTY Inventor, of Paoli, Indiana, THOMAS
BOSWELL BUSKIRK, Lawyer, also of Paoli Indiana, and OSCAR FOOTE Lawyer,
of 1406 G. Street Washington D.C. all in the U.S.A. do hereby declare the nature
of this invention and in what mauner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention is directed to that class of fire-arms known in the art as machine-
guns, which have for their object to produce a rapid firing of cartridges which are
fed, fired and discharged by the action of certain mechanisms operated by a crank,
or similar device. In machine-guns heretofore employed the mechanisms for
feeding, firing and discharging the cartridges are comparatively very complicated
in construction and thus the liability to wear and disorder is great, and the longevity
of the arms thereby reduced.
The object of this invention is to produce a machine-gun composed of few and
simply-constructed parts and in which the operations are reduced. in numbers as
compared with guns heretofore designed and employed.
Generally speaking the invention consists in a machine-gun, the mechanisms of
which are adapted to be operated by a crank, in mechanism for feeding forward
the cartridges in position to be received by a cartridge elevator; in a cartridge-
elevator to move the cartridge into a position in line with the bore, and adapted
thereby to discharge the exploded shell; in a breech-block, adapted by its move-
ment to simultaneously feed the cartridge into position for firing and to fire the
same in mechanism for preventing the recoil of the breech-block; and in
mechanism for extracting the shell.
Our invention also consists in the construction, relative arrangement, and
operation of the several parts of said mechanisms, all of which will hereinafter
fully and clearly appear from a reading of the following description taken in
connection with the accompanying drawings, which form a part of this Specification,
and in which
Figure 1 is a view in side elevation of a machine-gun embodying my improve-
ments, parts being broken away.
Figure 2 is a similar view of the opposite side thereof.
Figure 3 is a view of one side of the gun with parts removed, showing the
mechanism for feeding the cartridges.
Figure 4 is a vertical transverse sectional view on the line 4-4, Figure 3.
Figure 5 is a plan of the breech bolt and Figure 6 is a perspective view of the
cartridge elevator.
Figure 7 is a side view with portions broken away, showing the operating parts
in their normal positions.
Figure 8 is a similar view showing the breech-block drawn back and the
remaining parts in their corresponding relative position.
Figure 9 is a detail view illustrating the locking mechanism for the breech-
block.
Referring to the drawings by letters, A denotes the breech, which is formed
with a chamber, a, centrally arranged and adjacent to the inner end of the barrel.
One of the walls of said chamber is removably secured for convenience of con-
struction. Secured to the breech, and extending above the same, is a hopper B
which receives the cartridges and from which they fall successively through a

page_text: chute, b, into a ledge & where they are in a position to be fed forward by the feeding
mechanism, which I will now describe. D represents a feeder, which slides in a
groove, d, and which is adapted in operation to push the cartridge from the ledge b'
toward the elevating mechanism hereinafter described. The ledge b¹ is a continua-
tion of the bottom of the groove d, d' is a bell-crank lever pivoted at d 2 to the
breech, one arm of which, d 3, is pivotally connected to a rod d4 which is also
pivotally secured to the feeder D at d 5.
The other arm d6 of the lever, d 1, is free, and is provided with a projection d 7 for
a purpose to be presently explained. E is the crank-shaft, journaled in suitable
bearings in the breech, and which has secured thereto, at one side, a crank-handle e.
Keyed on this shaft, is a cam f, which at every complete revolution of the shaft
engages the projection d 7 of the lever d¹ and moves the lever against the resistance
of a leaf-spring d8 which movement is imparted, through the rod d 4 to the feeder D.
At the rear of the barrel, and in proximity thereto, is the cartridge-elevator F, the
top of which is concave, as shown, to conform to the surface of the cartridge.
This elevator is adapted to be moved in vertical lines in order to raise the cartridge
into a position in line with the bore of the barrel. Extending downward from the
inner end of the elevator is an arm f', which has a slot f2 adapted to receive one
end of a rocking-lever G said end being pivotally secured, as shown, at g. The
arm bears against the front wall of the chamber a and serves with a guide-
piece f3, to maintain a true movement of the elevator. The elevator is adapted to
be raised by the rocking lever G through the action of the cam H, which is keyed
to the shaft E within the chamber a the pivotal projection on said cam engaging
at each complete revolution the free end of the rocking lever G, which is beveled
to reduce friction. When said rocking-lever G is relieved from the operation of
the cam the parts return to their normal position by the action of gravity. X is a
passage communicating with the groove d said passage being cut away for about
the length of a cartridge towards its forward, inner end, the bottom X' thereof
being slanted down to the elevator so as to insure the cartridges falling readily
thereon, when fed forward by the feeder D.
The mechanism for inserting and firing the cartridges consists of a reciprocating
bar I, hereinafter called the breech-block, which is adapted to be moved backward
against the resistance of a leaf-spring i by a rocking-lever J, the upper end of
which is pivotally connected to said breech-block by a pinj working in a slot in
said bar. The lever J is pivoted at j' to the breech and its lower free end, i 2 is
normally in the path of a projection on the cam II. Said cam, by its engage
ment with the lower end of the rocking-lever J moves the breech-block I to the
rear against the resistance of the spring ia distance equal to the length of a
cartridge and when said rocking-lever is freed from the action of the cam the
spring operates to impel the breech block forward to insert and fire the cartridges.
To provide against recoil of the breech-hluck, we provide a spring catch K one
end of which is sccured at / to the breech, and the other end of which is bent at
an angle and passing through the breech, engages a recess A, made in the breech-
block. The spring-catch K is located within a longitudinal groove 2 formed in
the breech. The spring-catch is adapted to be disengaged from the breech-block,
in advance of the action of the cam-projection . The mechanism for disengaging
the catch and breech-block consists of a slide-rod L vertically movable in a
groove, in the breech, the upper end of which is beveled and is adapted when
said rod is moved upward, to prize the catch outward a sufficient distance to
disengage it from the recess, k¹. This slide-rod L is moved upward against the
resistance of a leaf-spring, 12 by a cam m which is keyed to the shaft E, and
operates at each revolution to effect the unlocking of the breech-block as just
<described. Secured to the forward end of the bar I, at each side thereof,
are two extractor fingers n n which in operation, when the lockig-pin is being
moved rearwardly, engage the flange of the cartridge and remove the empty
shell. These ngers move in grooves in the silt of the chater which
serve, with the pins 22 placed, respectively, above and below the breech-block I,

page_text: near the outer end thereof, as guides to insure the movement of said breech-block
in a horizontal plane. A firing-pin is formed on the forward end of the breech-
block for the purpose of striking the cap of a cartridge and exploding the same
when the breech-block is impelled forward under the action of the spring i. The
cam H before referred to, has the fixed cam-projection ', and the projection h
thereon is made yielding, being pivotally secured at h2 and moved against the
resistance of a spring 3 which is secured as shown within said cam, when such
projection comes in contact with either of the rocking-levers J or G. This
yielding cam is designed, as before stated, to actuate the rocking-lever G and the
elevator F, but the rocking-lever J being within the path of said projection, the
latter is made to yield sufficiently to pass the same without actuating the breech-
block, which latter is actuated by the fixed projection of the cam.
The operation is as follows:-
The hopper being supplied with cartridges, the latter fall successively through
the chute and rest on the ledge b¹. The shaft being revolved by turning the
handle, the feeder is actuated to move the lowest cartridge forward until the
latter falls down the incline X' into the elevator F. A continued revolution of
the shaft causes the elevator, through the medium of the yielding projection of
the cam and the rocking-lever G to raise said cartridge into a position in axial
line with the bore. During this operation the breech-block is unlocked and is
moved rearwardly by the action of the fixed cam-projection ¹ on the rocking-
lever J. When the lever J is released by the cam the spring i impels the breech-
block forward, and the cartridge, being then in line with said breech-block as well
as with the bore, it is pushed home and fired by the pin, striking the cap thereof.
At this time, the spring-catch K enters the recess in the breech-block and locks
it against recoil. The next revolution of the shaft is attained with the same
results, with the addition that when the breech-block is moved rearwardly the
fingers n n grasp the flange of the cartridge causing its extraction, and the
ascending fresh cartridge expels the same.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
1. In a machine-gun, the feed-chute, the ledge beneath said chute, the feed-arm
adapted to slide on said ledge and engage the lowermost cartridge in said chute
and feed the came forward, the elevator adapted to receive the cartridge from
said ledge and elevate the same on a line with the bore, the breech-block adaptad
to insert, fire and extract the cartridges, the crank-shaft for operating said parts
the spring-arm engaging said breech-block and adapted to prevent the recoil of
the latter, and means for releasing said spring-arm from engagement with said
breech-block, substantially as set forth.
2. In a machine gun, the feed-chute, the ledge beneath said chute, the feed-arm
designed to slide on said ledge and engage the lowermost cartridge in said chute
and feed the same forward, the elevator adapted to receive the cartridge from
said ledge and elevate the same on a line with the bore, the breech-block adapted
to insert and fire the cartridge, the extractor fingers on the forward end of said
breech-block, the crank-shaft for operating said parts, the spring-arm engaging
said breech-block and adapted to prevent the recoil of the latter, and the beveled
rod for releasing said spring from engagement with said breech-block, sub-
stantially as set forth.
3. In a machine gun, the feed-chute, the ledge beneath said chute, the feed-
arm designed to slide on said ledge and engage the lowermost cartridge, the levers
connected to said feed-arm the crank-shaft for operating said levers whereby said
feed-arm is moved forward, the spring for returning said feed-arm to its normal
position, the elevator also operated by said crank-shaft adapted to receive the
cartridge from said ledge and elevate the same on a line with the bore, the breech-
block, also operated by said crank-shaft, adapted to insert, fire and extract the

page_text: cartridge, and means for preventing the recoil of said breech-block, substantially
as set forth.
4. In a machine gun, the feed-chute, the ledge beneath said chute, the feed-arm
designed to slide on said ledge and engage the lowermost cartridge, the levers
connected with said feed-arm, the crank-shaft, the cam thereon adapted to engage
and move one of said levers whereby said feed-arm is moved forward, the elevator
adapted to receive the cartridge from said ledge and raise the same in a line
with the bore, the breech-block adapted to insert, fire, and extract the cartridge,
and means for preventing the recoil of said breech-block substantially as set
forth.
5. In a machine gun, the herein described feeding-mechanism, comprising the
chute adapted to receive the cartridge, one on top of the other, the ledge beneath
said chute the feed-arm adapted to slide on said ledge and engage the lowermost
cartridge in said chute, the rod or arm pivotally connected to said feed-arm, the
depending bell-crank lever pivotally connected at its upper end to said rod or arm,
the crank-shaft, the cam thereon adapted to engage and move said bell-crank
lever and move the same forward, and the spring for returning said feed-arm to
its normal position.
6. In a machine gun of the kind described, the combination with the feeding
mechanism, of means for raising the cartridges into position to be inserted and
fired comprising an elevator provided with a vertically depending arm, the
rocking-lever pivoted to the breech and having one of its ends pivotally secured
to eaid depending arm, the operating shaft, and the cam on said shaft having a
pivoted projection adapted to engage the free end of said rocking lever and move
the same, whereby said lever is raised, substantially as set forth.
7. The herein-described improvement in machine guns, comprising the spring-
pressed breech-block the depending rocking-lever pivotally connected thereto, the
cartridge elevator having a lower depending arm, the rocking lever pivotally
connected to said arm, the drive-shaft and the cam thereon having a rigid
projection and a yielding projection for engaging, respectively, the rocking-levers
of said breech-block and said cartridge-elevator, substantially as set forth.
8. The combination of the feeding mechanism, comprising a feeding-arm, and a
bell-crank lever pivotally connected thereto, the spring-pressed breech-block, the
depending rocking-lever pivotally connected thereto, the cartridge-elevator
having a lower depending arm, the rocking-lever pivotally connected to said arm,
the drive-shaft, the cam thereon having a rigid projection and a yielding
projection for engaging, respectively, the rocking-levers of said breech-block and
said cartridge-elevator and the second cam on said drive-shaft designed to engage
said bell-crank lever and operate the feeding-mechanism, substantially as set forth.
Dated this 3rd day of October 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.