Improvements in Automatic Guns.
Year: 1895

page_text: Date of Application, 30th May, 1895
Complete Specification Left, 2nd Mar., 1896-Accepted, 30th May, 1896
Improvements in Automatic Guns.
I, HIRAM STEVENS MAXIM, of Baldwyn's Park, Bexley, in the County of
Kent, Mechanical Engineer, do hereby declare the nature of this invention to be
as follows:-
:-
This invention relates to improvements in automatic or Maxim guns and is
chiefly designed to facilitate the working of such guns with cartridges or charges of
modern high explosives.
At the time automatic guns were first introduced very large and powerful
cartridges were used therein. These, in all cases, gave sufficient energy to work
the guns with great rapidity, but with the new smokeless powders and very small
bore guns such as those now used the energy of the recoil is much less than in the
early guns and it is desirable to provide against any deficiency arising from this
cause.
For this purpose I have devised certain modifications in the construction of my
automatic guns and in the means for operating the mechanism thereof which I will
now describe.
In its general construction my improved gun closely resembles that which is now
used in the Services and known as the Maxim gun, but instead of arranging the
barrel to recoil in the water jacket I use a fixed or non-recoiling barrel which is
secured at each end of the water jacket through an absolutely fluid-tight joint and
I place in the waterjacket, a cylinder communicating with the barrel at one end and
with a space in the box or case enclosing the breech-mechanism at the other end.
There is no communication between the waterjacket and the cylinder.
The barrel is perforated at a short distance from the muzzle end to allow a
portion of the gases to pass either directly into the cylinder or into an annular space
about the barrel; the barrel is secured by screw-threads or otherwise in such a
manner that it may be removed and replaced by a new one without disturbing the
cylinder connections. The cylinder is surrounded by the water in the jacket and
is thereby protected against overheating by the gases.
As the cylinder extends through the waterjacket and opens into the box or case,
the piston may be very easily removed, cleaned or oiled. The piston moves freely
to and fro and the space may be regulated by adjusting the piston on its rod or
otherwise so as to modify the force and suddenness of the blow by the amount of
clearance existing between the aperture in the barrel and the piston. The greater
the space in the cylinder between the piston and the said aperture the slower and
less violent will be the shock or blow. The piston is attached by a rod to a system
of levers inside the box in such a manner that some of the functions of the
mechanism are performed while the piston is moving backwards under the pressure
of the gases. At the same time a suitable spring is compressed or coiled, and the
stored energy of this spring is utilised for forcing the piston back into the cylinder
and also for performing the remaining functions of the mechanism.
Connections are made between the moving parts of the piston and rod and the
levers which actuate the feed-mechanism, so that as the gun is fired the cartridges
are automatically fed into position exactly the same as heretofore, by the recoil
action of the barrel and its attachments. No point of resistance however is required
on the external part of the frame, as the crank handle is turned over by the action
of the aforesaid piston.

page_text: It has been found in some instances that when cartridges are fired with very
great rapidity, the ebullition of the water in the jacket is so violent that the steam
carries over a large amount of water with it. In other words the waterjacket
primes. It is not practicable in the guns as heretofore constructed to increase the
pressure and thereby prevent this rapid boiling because the water and steam would
then be blown through the stuffing box into the mechanism, but with a gun in which
no stuffing boxes are employed it is possible to increase the pressure for the above
purpose. Moreover as no steam or water can escape until the pressure is very high
in the water jacket, in many cases no loss of water will occur and the dripping from
the waterjacket will be avoided.
The waterjacket is provided with a small valve over the barrel to allow the steam
to escape only after a very high pressure has been obtained.
As the quantity of gas admitted to the piston is practically unlimited any degree
of energy may be obtained and therefore the parts of the mechanism may be
sufficiently strong to prevent yielding at the instant of firing and consequently
there will be less liability than heretofore to breakage of the cartridge cases.
With regard to the breech mechanism I prefer to use the arrangement wherein,
after the carrier-slide has risen and seized a cartridge in the belt, the breech block
completes its forward movement and the slide is firmly pressed against the head of
the cartridge in the chamber by the action of the toggle levers.
Dated this 30th day of May 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
I, HIRAM STEVENS MAXIM formerly of Baldwyn's Park, Bexley, in the
County of Kent, but now of 18 Queen's Gate Place in the County of Middlesex,
Mechanical Engineer, 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 improvements in automatic or Maxim guns and is
chiefly designed to facilitate the working of such guns with cartridges or charges of
modern high explosives.
At the time when automatic guns were first introduced very large and powerful
cartridges were used therein. These were in all cases capable of developing
sufficient energy to work the guns with the required rapidity, but with smokeless
powders and very small bore guns such as those now used the energy of the recoil
is much less than in the early guns and it is desirable to provide against any
deficiency arising from this cause.
For this purpose I have devised certain modifications in the construction of my
automatic guns and in the means for operating the mechanism thereof.
My improved gun is in its general construction similar to that which is now used
in the Services and known as the "Maxim" gun, but instead of arranging the
barrel to recoil in the water-jacket I use a non-recoiling barrel which is secured at
each end of the water-jacket by an absolutely fluid-tight joint. Moreover I employ
a gas-cylinder surrounded by the water of the water-jacket and provide for
admitting to this cylinder a portion of the gases of discharge from the barrel
80 as to actuate a piston within the said cylinder and thereby operate the
breech mechanism of the gun through the agency of suitably arranged levers and
springs.
I also provide means for securing the barrel to the gun in such a manner that it

page_text: may be removed and replaced by a new one without disturbing the aforesaid gas-
cylinder and its connections.
Instead of allowing the steam generated in the water-jacket to escape at a low
pressure I provide on the water-jacket a valve or similar contrivance which will
allow the steam to escape only after a high pressure has been attained. In this
way I avoid the blowing off of the water with the steam, which occurs when the
steam is allowed to escape at a low pressure.
In order that my invention may be clearly understood and readily carried into
effect I will proceed to describe the accompanying drawings, in which
Figure 1 is a longitudinal section of the gun, the breech mechanism being
removed for sake of clearness.
Figure 2 is a sectional plan and
Figure 3 is a side elevation of the mechanism on the left-hand side of the gun.
Figures 4, 5, 6, 7 and 8 are transverse sections taken respectively on the
lines 1. 1. 2. 2. 3. 3. 4. 4. and 5. 5. of Figure 1.
Figure 9 is a view similar to Figure 3 but shews a modification of the mechanism
there illustrated.
Figure 10 is a longitudinal section of the rear portion of the gun, shewing a
modified manner of securing the barrel in place.
Figures 11 and 12 are transverse sections taken respectively on the lines 6. 6.
and 7.7. of Figure 10.
Figure 13 is a detail sectional view of the muzzle end of the gun shewing a
modified arrangement of the gas-cylinder.
Like letters of reference indicate similar parts in all the above figures.
A is the barrel; B the water-jacket; the feed-box; D the oscillating lever
for operating the cartridge feed; E the crank-shaft, E¹ the crank; E' the crank-
arm outside the gun; F F the two side plates of the casing enclosing the breech
mechanism; F¹ the hinged rear plate; G lugs to which the elevating device is
connected; and G'a transverse aperture to receive the trunnion pin.
The barrel A is formed near its breech end with a shoulder a which is adapted to
fit into a correspondingly shaped socket in a neck or rearward extension B' with
which the water-jacket is provided. Suitable packing material is inserted in the
space a between the shoulder a and the socket to produce a fluid-tight joint.
The barrel is also provided near its breech end with lateral projections or studs a¹ a¹
which fit into corresponding cavities formed in a pair of side bars a² a², see
Figure 6. These side bars are furnished with guides a³ by which the breech-block
or lock is guided in its reciprocating movements. These guides are of the
construction ordinarily used with a lock of the kind described in the Specification
of my prior Patent No. 5864 A.D. 1895, that is to say a lock in which the cartridge
carrier moves vertically with the lock and assumes its position of rest before the
lock attains its closed or firing position. The rear ends of these bars a³ are
increased in thickness to form rectangular blocks at which enter end slots or
recesses (Figures 1 and 4) in the side plates F. A lug a is formed on each
bar a². A transverse pin a, passing through this lug, prevents any longitudinal
movement of the said bars.
The crank-shaft E is taper and passes through openings in the side bars a² when
these latter are in place. This tapered shaft is formed with flat portions e, and the
hole in the sleeve e¹ of the crank E' is similarly shaped so that when the said shaft
is passed through the sleeve, the crank becomes keyed to the shaft.
By taking out the aforesaid shaft E and pin a and turning down the hinged rear
plate F', the lock and parts connected therewith can be taken out and the barrel
can be then readily removed by merely withdrawing the bars a² longitudinally
from the gun.
A new barrel can thus be conveniently inserted into the place of
the old one without disturbing the gas-cylinder or its connections.
In Figures 10 11 and 12 I bave illustrated a somewhat modified construction of
this part of my invention, in which the side bars a³ are permanently secured to the
plates F. In this case the said side bars are formed with longitudinal slots a' in

page_text: which the studs a¹ on the barrel are capable of sliding. To secure the barrel in
its position at the front end of these slots, I employ a transverse pin as which
passes completely through the side plates F and the breech end of the barrel (see
Figure 12).
Near the muzzle end of the barrel I form one or more transverse openings A¹
through which some of the gases escape at each discharge, and either enter
directly into the gas-cylinder H or into the surrounding chamber A³ which
communicates with the aforesaid gas-cylinder, by a passage H'. Within the gas
cylinder is a piston which may be connected to the piston rod in such a manner
as to permit of its being adjusted longitudinally on the said rod. The gas-cylinder
is situated laterally with respect to the barrel and terminates at its front end in a
removable screw plug H2 and at its rear end in a socket B2 with which the interior
of the water-jacket is provided. This socket has a bushed opening at its rear
through which the piston rod extends into and through a long pocket B³ forming
part of the water-jacket. The rear end of the piston rod is formed with an
enlargement which works between brackets or guides f¹ on the left-hand side
plate F. This end of the rod is also provided with a flat extension having
lugs projecting from the inner surface thereof. The outer end of the feed-
lever D enters between these lugs and is thus actuated when the piston rod moves,
thereby operating the feed plate D' (Figures 1 and 2) to carry the cartridge belt
through the feed-box in the usual and well known manner.
The mechanism for transmitting the motion of the piston rod to the crank-shaft
may be of any appropriate kind. In Figure 3 I have shewn an oscillatory lever I
which is pivoted at i to the left-hand side plate F. The upper extremity of this
lever bears against the enlargement on the piston-rod and its lower end is
connected by a rod 11 to a tappet I². In the discharge the gases entering the
cylinder H act on the piston, and the rod ' is forced backward, causing the curved
portion 13 of the tappet to bear against an arm I on the crank-shaft, thereby
turning the said shaft and stretching a spiral spring 15, one end of which is
connected to the lower limb of the lever I and the other end to a fusee I' carried
by the crank-shaft. 17 is a stop which lies in the path of the arm I* and limits the
extent of the crank-shaft's rotation. The re-action of the spring 15 closes the
breech and returns the piston h to its firing position.
In some cases I dispense with the oscillatory lever I and connect the piston-rod /¹
directly to the tappet 12 by a bar Is as shewn in Figure 9. I then provide the
rear end of the piston-rod with a guide plate having therein a slot 46 with which
a fixed stud / on the side plate Fengages. In this instance I prefer to employ in
addition to the spiral spring 15 another spiral spring within the gas-cylinder, to
assist in bringing the piston back to its firing position.
Instead of arranging the gas-cylinder H as shown in Figures 1 and 2 I sometimes
prefer to arrange it as illustrated in Figure 13 so that the gases are led to the
gas-cylinder by an external conduit H* which is substantially of the same diameter
as the cylinder.
I have already stated that the piston his adjustably arranged on its rod. This
adjustment allows the force and suddenness of the shock, arising when the gases act
on the piston, to be modified by varying the amount of clearance existing between
the piston and the apertures in the gun-barrel. The greater the space in the gas-
cylinder between the piston and the said apertures, the slower and less violent will
be the shock or blow.'
On reference to Figure 2 it will be seen that the gas-cylinder is so constructed
and arranged that its piston can be very easily removed for cleaning, oiling or
other purposes without unduly interfering with other parts of the gun.
The muzzle end of the barrel where it passes through the water-jacket is
provided with a stuffing box L which forms a fluid-tight joint and also allows the
barrel to freely expand and contract under variations of temperature.
J (Figure 8) is a valve with which the water-jacket is provided. This valve
may be of any desired construction, that shewn in the drawings consisting of a

page_text: cone-valve which is held on its seating by a spiral spring surrounding the stem
of the valve. The steam generated in the water-jacket can reach this valve
from either end of the jacket by passing through the tube K which communicates
at one of its ends with a passage k leading to the aforesaid valve.
As a non-recoiling barrel is employed, absolutely fluid-tight joints can be
made where the barrel passes through the water-jacket and consequently although
the pressure within the water-jacket may be great, there is little or no danger of
leakage of water.
As the quantity of gas that can be admitted to the gas-cylinder is practically
unlimited, any required degree of energy may be obtained, and if the parts of
the mechanism are made sufficiently strong to prevent yielding at the instant
of firing the liability of the cartridge cases to become broken will be much less
than heretofore.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatic gun provided with a non-recoiling barrel which is secured in
place by a pair of sliding side bars loosely connected to the barrel, and of a pin or
other means for detachably securing the said bars in the gun when the barrel is in
place, substantially as described.
2. The modified construction, wherein the said side bars are permanently
connected to the gun, and the barrel alone is detachable substantially as described.
3. In an automatic gun the manner of connecting a non-recoiling barrel to the
water-jacket substantially as described, so that the said barrel is free to expand and
contract longitudinally in the water-jacket.
4. An automatic gun in which the gas-cylinder and piston for working the
breech mechanism are situated within the water-jacket or are otherwise arranged
relatively thereto so as to be cooled by the water of the jacket.
5. An automatic gun in which the barrel has fluid-tight joints where it passes
through the water-jacket and in which means are provided for preventing the
escape of steam or water from the water-jacket until the steam has attained a high
pressure, for the purpose specified.
6. An automatic gun in which my above described improvements are incorporated
substantially as herein before described with reference to the accompanying
drawings and for the purposes specified.
Dated this 2nd day of March 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.