An Improved Automatic Machine Gun.
Year: 1898

page_text: An Improved Automatic Machine Gun.
We, ARTHUR TREVOR DAWSON, late Lieutenant of the Royal Navy, and LOUIS
SILVERMAN, Engineer, both of 32, Victoria Street, in the County of London, do
hereby declare the nature of this invention to be as follows:-
Our said invention relates to automatic machine guns and is designed to provide
for adapting to guns of larger calibre and heavier charge than heretofore the
mechanism which constitutes the peculiar feature of the now well known Maxim
guns.
These guns have usually been constructed for the firing of ammunition not much,
if any, heavier than that used for small arms but according to our present inven-
tion we have sought to adapt the automatic mechanism especially for guns say
of a calibre of about 1 inches or more.
The gun barrel is arranged to slide endwise on recoiling in a frame or cradle
against the resistance of a spring which is preferably a spiral spring placed around
the barrel within the water jacket. In order to avoid the use of a spring of undue
length we provide between it and the abutment on the barrel a fixed sleeve which
is perforated or otherwise formed to enable the cooling liquid in the water jacket
to come into direct contact with the barrel. The breech mechanism comprises
a lock which carries the cartridge feeding firing and extracting mechanism and
which is arranged in combination with a crank as in well known examples of
the Maxim gun, these various mechanisms and also the belt-feeding mechanism
being substantially the same as heretofore in such guns with such modifications
as may be necessary to adapt them for use with the heavier charges and greater
stresses thereby thrown upon the different parts of the apparatus. The crank
shaft has a spring arranged at one end thereof and is subject to the action of
the said spring so that after the crank has been turned back in the recoil and
has drawn back the lock and opened the breech the cycle of movements of the breech
mechanism is completed by the return movement of the crank. The crank is
coupled to the lock by a connecting rod or link usually made in two parts which
when in place are united by means of a screw threaded end on one part arranged
to enter a socket in the other part these parts having divided or interrupted
screw threads for facilitating their connection and disconnection.
Instead of this screw connection we now use a device similar to a bayonet-
joint so that by slightly turning one part relatively to the other part of the said
rod or link the two parts may be connected or disconnected. The use of this
bayonet joint ensures that there shall be no possibility of the lock being in-
accurately fitted to the connecting rod or link by the gunner.
Moreover we now combine with the breech mechanism a hydraulic buffer which
is placed within the frame at the rear of the crank and is especially arranged
that it may be readily accessible at any time and can be quickly removed and
replaced when necessary.
For this purpose we construct a cylinder of any suitable metal and arrange
the same with its rear end upon the rear end of the outer frame or cradle of
the gun. On the inner sliding frame there is a cross bar to which we attach the

page_text: piston rod of the hydraulic buffer so that as the said sliding frame moves back-
ward in the recoil the piston will move toward the rear end of the cylinder. The
bore of the cylinder is preferably taper toward the rear end. The piston is
made smaller than the bore at the forward end of the cylinder so that as it com-
mences to move back the liquid can pass freely from the rear to the front of the
piston but as the piston moves backward the passage gradually diminishes and
at the end of the stroke will be completely or nearly closed. Therefore the recoil
movement of the breech mechanism will be gradually checked. The said cylinder
is enclosed within a casing which communicates through a port or aperture at
the forward end with the bore of the said cylinder and which affords space for
containing the necessary quantity of liquid for the said brake or buffer."
In order that this hydraulic device may be readily accessible or removable we
screw the cylinder into its outer case or chamber and we form on the rear end
of the said cylinder a shank or extension which extends through the rear plate
of the frame, and has on its outer extremity a screw thread for receiving a nut
whereby it is secured in its place. The said shank or extension is hollow and
is closed by a screw plug which can be removed at any time to permit access to
the interior of the cylinder for any purpose.
The forward end of the cylinder is fitted with a cover through which the rod
passes, this rod being made to work fluid-tight through the said cover by suitable
packing. The piston may be a plain disc formed upon the end of the rod or
attached thereto in any suitable manner. The outer end of the rod is attached
to the cross bar by means of a head or collar formed on the rod and dropped
into a groove or recess in the cross-bar or by any other convenient means which
will permit its ready disconnection.
The gun is also provided with a safety device for enabling it to be adjusted
so as to fire single shots or continuously or to remain in an inoperative condition
We also provide a spring controlled arm or other device in the path of the lugs
of the cartridge carrier said arm being so arranged as to give way to the carrier
as it recoils but to prevent the return movement of the carrier unless it has fully
recoiled and otherwise performed its functions. Any liability of the carrier's
premature return to its original position and of its bringing the nose of the pro-
jectile of the cartridge it carries against the detonator of a cartridge in the feed
belt will be avoided."
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
We, ARTHUR TREVOR DAWSON, late Lieutenant of the Royal Navy, and LOUIS
SILVERMAN, Engineer, both of 32, Victoria Street, in the County of London, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to automatic machine guns and is designed to provide
for adapting to guns of larger calibie and heavier charges than heretofore the
mechanism which constitutes the peculiar feature of the now well known Maxim
Luns.

page_text: These guns have usually been constructed for the firing of charges of ammuni-
tion not much, if any, heavier than those used for small arms, but according to
our present invention we have adapted the automatic mechanism to guns having
a calibre of about 1 inches or more.
According to our said invention we combine with the breech mechanism an
hydraulic buffer which is placed within the gun casing at the rear of the crank
so as to mitigate the violence of the recoil which by reason of the heavy charges
would otherwise be injurious to the breech mechanism working on the Maxim
principle. The said hydraulic buffer is so arranged that it can be readily
replenished with liquid without removing it from the gun. It is capable however
of being quickly removed for inspection or repair and of being as quickly replaced.
We also provide a device, consisting of a spring-controlled arm or finger or
a pair of such arms, in the path of the horns of the cartridge carrier, said device
being so arranged that it will give way to the carrier as it recoils but will prevent
the premature return movement of the carrier, thereby obviating any liability
of the carrier to bring the point of the shell of the cartridge it carries against
the detonator of the succeeding cartridge in the feed box.
The gun barrel is arranged to slide endwise, on recoiling, in a frame or cradle,
against the resistance of a spiral spring placed around the barrel within the water
jacket.
In order that our said invention may be clearly understood and readily carried
into effect we will proceed to describe the same more fully with reference to the
accompanying drawings in which:
-
Figure 1 is a vertical longitudinal section of the rear portion of the gun;
Figure 2 is a plan of the same with the top cover removed, and
Figure 3 is a vertical longitudinal section of the forward portion of the gun.
Like letters of reference indicate similar parts in all the figures.
A is the casing enclosing the breech mechanism; B is the barrel; C is the
breech block or lock, C¹ the cartridge carrier, C the lifting levers therefor, C³ the
firing pin, C the tumbler, C5 the safety sear, and C the hand sear; D is the
crank shaft, D¹ the crank, D2 the crank handle, and D³ the casing enclosing the
spring which acts to return the crank to its firing position; E is the trigger;
F is the water-jacket. All of these parts are of usual construction except that
they are made heavier and stronger than those in ordinary "Maxim"
guns to
bear the increased stresses to which they are subjected when used for the purpose
of this invention.
H is the hydraulic buffer comprising a cylinder of suitable metal arranged at
the rear end of the casing of the gun. Within the said cylinder is a piston H¹
from which extends, through the cover of the cylinder, a rod H2 having at its
outer end a head or shoulder H3 to engage with a recess formed in a cross bar H
which connects the opposite sides of the inner sliding frame H. As the said sliding
frame moves backward in the recoil, the piston moves toward the rear end of the
cylinder which is preferably made taper as shewn. The piston is made smaller than the
bore at the forward end of the cylinder, so that as the said piston commences to
move backward the liquid can pass freely from the rear to the front thereof but
as the piston continues its backward movement, the annular passage between the
cylinder and the periphery of the piston gradually diminishes and at the end of
the stroke will be completely or nearly closed, the recoil movement of the breech
mechanism being thereby gradually checked. It will be obvious that instead of
employing a cylinder having a tapering or conical bore, we may use
a cylinder having any other contrivance for retarding the flow of liquid
from one side of the piston to the other as said piston is driven rearwardly by
the recoil of the gun barrel. The aforesaid cylinder is surrounded by a casing H
which communicates with the cylinder through a port H' at the forward end of
the said cylinder, such casing affording space for containing the necessary quantity
of liquid for the hydraulic buffer. There is a hole H in the wall of the cylinder
near the rear end thereof which relieves the pressure and allows the liquid to

page_text: escape from the space behind the piston when the latter is completing its rearward
stroke. By increasing or diminishing the size of this hole it is possible to very
accurately adjust the length of the recoil.
In order that the said cylinder may be readily removable, we form on its rear
end a shank or neck H³ which extends through the rear plate of the gun framing
and has on its outer extremity a screw thread for receiving a nut H whereby it
is secured in place. The said shank or neck is hollow and is closed by a suitable
stopper or screw plug H which can be removed at any time without detaching
the cylinder, to permit access to the interior of the cylinder from the exterior of
the gun, for example, for replenishing it with liquid, the gun being for this
purpose turned about its trunnions into an approximately vertical position with
the mouth of the aforesaid neck uppermost. There is also provided another
screw plug H in the casing He for enabling the air, displaced by the liquid when
the cylinder is being replenished, to escape from the casing, the said plug also
serving if required for charging the cylinder with liquid from the interior of
the gun casing when the hinged top cover thereof is opened. In this case it is
unnecessary to shift the gun from its horizontal position to effect the charging
of the said cylinder.
I I are arms or fingers which are pivoted to the side frame of the gun-casing
in a position to enable their free ends to normally project above the upper sur-
face of the inside cams A¹ and into the path in which the horns C* on the cartridge
carrier travel as the lock recedes to open the breech. The aforesaid arms are
furnished with springs I which retain them in their aforesaid normal position
and permit them to give way to the carrier as the latter recedes but cause them
to resume their original position immediately the carrier has passed, so that if
the carrier should tend to return to its original position whilst the horns C* are
still travelling on the upper surface of the cams A¹ the arms would act as stops
to prevent the point of the shell of the cartridge in the carrier from being brought
against the detonator of the cartridge in the feed-box.
K is the feed-lever which is of similar construction to the feed-lever ordinarily
employed in Maxim guns, but in order to decrease the total length of the gun
and thereby economize space, the pivot K¹ of the said lever is arranged on the side
of the feed-box opposite to that which it usually occupies. K³ is a stud on one
of the arms of the said lever, which stud engages with the barrel and receives
its motion therefrom. K³ is a projection or stud on the feed plate with which the
other arm of said lever engages to actuate said plate and cause the belt to be fed
through the gun.
G is the recoil spring which is placed around the barrel in the water-jacket,
one end thereof resting against a partition F1 in the said water-jacket and the
other end resting against a sleeve G¹ fixed to the barrel. By employing this
sleeve we are able to avoid the use of a spring of inconvenient length. G² G²
are perforations in the said sleeve for permitting the cooling liquid in the water-
jacket to come into direct contact with the barrel.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. An automatic gun substantially as described, having the Maxim breech-
mechanism arranged in combination with the hydraulic cylinder or buffer in such
a manner as to operate as set forth for the purposes specified.
2. The hydraulic cylinder or buffer arranged at the breech end of the gun sub-
stantially as described so that it can be replenished with liquid without removing
it from the gun.
3. The combination with the aforesaid cylinder of a surrounding casing com-
municating therewith and provided with a detachable plug for the purpose
specified.

page_text: 4. The means whereby the said cylinder and its piston can be readily discon-
nected from the gun substantially as described.
5. The spring-controlled device arranged to act in conjunction with the cartridge
carrier substantially as described and for the purpose specified.
6. The combination with the recoil spring arranged around the barrel in the
water-jacket of a sleeve fixed to the barrel for the purpose specified.
7. An automatic gun of large calibre having its parts constructed arranged
and operating substantially as described with reference to the accompanying
drawings.
Tated this 16th dow of June 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.