IMPROVEMENTS IN MACHINE GUNS
Year: 1879

page_text: LETTERS PATENT to Henry Harris Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
IMPROVEMENTS IN MACHINE GUNS." A communication from abroad by
Edward Granville Parkhurst, of Hartford, Connecticut, United States of
America, Gentleman.
Sealed the 13th February 1880, and dated the 16th December 1879.
COMPLETE SPECIFICATION filed by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 16th December 1879.
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINE GUNS." A
communication from abroad by Edward Granville Parkhurst, of Hartford, Con-
necticut, United States of America, Gentleman.
This Invention relates to improvements in machine guns, such as are usually
furnished with one or more barrels, and are automatically loaded and fired by
mechanism at the breech, which mechanism is operated by turning a crank to
discharge the gun with great rapidity.
The form of gun to which the said improvements are more particularly adapted
is that described and shown in the Specification of former Letters Patent granted to
me the 2nd day of April, A.D. 1879, No. 1317.
The object of the present Invention is to render the gun more effective and
serviceable by providing better and more positively acting mechanism for with-
drawing and throwing out the expended shell than has heretofore been in use, and
by also providing improved lock mechanism, the firing devices of which can bo
thrown in or out of action as desired.
The said Invention consists in the construction and arrangement of the several
parts, as will be hereinafter described.
In the accompanying Drawing-
Figure 1 is a longitudinal vertical section through the breech mechanism and
part of one of the barrels of a gun embodying my improvements, showing the working
parts of the breech mechanism.
Figure 2 is a horizontal section through the breech and part of the barrels
showing the breech mechanism in plan.
Figure 3 is a side view, partly in section, of one of the locks detached, also
showing one of the circular cams which operate the locks, and
Figure 4 is a plan or top view of the same.
Like letters indicate the same parts throughout the Drawing.

page_text: A is the outside case of the breech of the gun forming a box within which the
mechanism for loading and firing operates. B and B are the barrels, of which only
a part is shown in the Drawing. They may be of any ordinary length or con-
struction, and are screwed into or otherwise attached to the front end of the
case A. C is the cascabel, which is constructed so as to unscrew and release the
top of the case A, so that it can be raised to afford access to the interior containing
the working parts.
The case A is hinged to the carriage at A¹ to serve as trunnions for the gun.
The carriage is constructed in the usual manner. D is a crank the turning of
which operates the mechanism of the gun. E and E' are the lock bars, which are
alternately moved forward and back by the cams G and G'. These lock bars push
the cartridges into the barrels to be fired, and withdraw the empty shells, so that
they drop down through the opening H in the case A. The forward ends of these
lock bars are furnished with firing pins and mechanism for withdrawing the
expended shells.
J is the bolt of the lock, the parts of which and the method of operating it will
be hereinafter described. The gun is furnished with means for supplying it with
cartridges and for supplying them to the barrels in the ordinary manner, or as
described in the said former Specification, and in all its working parts, except as
herein described, it operates substantially like the gun described in the said former
Specification.
The lock mechanism, the details of which are more particularly delineated in
Figures 3 and 4, is constructed and arranged as follows, that is to say:-The firing
bolt J has upon its rear end the head J³, and near its forward end it is provided
with a fixed collar J³; J is a sleeve sliding freely upon the bolt J; J' is a spiral
spring acting between the sleeve J' and the fixed collar J³; Je is a rocking lever
pivoted to the lock bar E. The upper end of this rocking lever is provided with a
toothed segment working in a rack on the underside of the sleeve J, J7 is a hooked
lever which catches upon the head Ja when the latter is drawn to the rear by the
lever Jo. This hook is released by the cam G acting upon the upper end of the
said lever. A³ is a fixed block and A' is a sliding block for operating the lower
arm of the lever Jo.
The operation of these parts is as follows, that is to say -In Figure 1 the lock
is shown in full lines in the position it occupies when the gun has just been fired.
When the cam G draws back the lock bar E the lower end of the lever Jo mounts
upon the block A³, releases the pressure upon the spring, and throws the bolt back
so that its head engages with the hook on the lever J'. The spring then remains
relaxed until the lock bar has again passed forward to a point where the end of the
lever Jo passes off from the block AS and engages with the block A*. The sleeve is
then thrown forward and the spring compressed. This movement takes place just
before the lock bar arrives at its extreme forward position When the cartridge is
pressed entirely home the cam releases the lever J', and the firing bolt is driven
forward by the spring. It will thus be seen that the cocking of the lock is effected
by the sliding block A just before the firing.
A5 is an exterior handle crank connecting by means of a shaft with the interior
crank Aº, which is attached to the sliding block A' by the connecting link A? By
means of the handle A³ the block A' can be readily drawn back out of reach of
the lever Jo, so that it will not operate it and cock the gun. The spring then
remains relaxed, and cartridges can be run through the gun without firing them, if
desired. The discharging of the gun can be at any time instantly stopped by
means of the handle A³, even while the locks are in operation and cartridges are
in the gun.
The extracting mechanism is operated by the movement of the lock bar E.
B is the retractor. It consists of a bent lever having a fixed pivot in the
case A at the rear of the barrel. Its forward end forms a hook which rests directly
under the enlarged rim of the cartridge shell, and its rear end forms an arm which
enters into a recess in the forward end of the lock bar shown at B³ in Figures 1, 2,

page_text: and 4, when the shell is pushed home into the barrel. When the lock bar is drawn
to the rear, the arm of the retractor B' moves out of this recess and passes over the
end of the lock bar, thereby drawing the shell back a short distance and loosening
it from its seat in the chamber of the barrel. C is a spring extractor, attached at
its rear end to the lock bar, and provided with a hook at its forward end which
hooks over the rim of the cartridge when it is pushed home in the barrel. This
extractor draws back the expended shell until it is out of the barrel and is dis-
charged by the ejecting lever T which strikes it just above the middle and expels
it by forcing it downward through the opening H. In connection with this
extractor C the retractor B* serves another purpose than that before described of
withdrawing the shell from the barrel. It holds the head of the cartridge out of
the barrel until the hook on the extractor C³ passes over the rim, so that this
operation is always outside of the chamber and does not require a larger recess for the
hook end of the extractor than will just permit it to enter. If the cartridge should
be pushed home by the blow of the lock bar striking it, it will be withdrawn again
when the end of the lock bar renches the arm of the retractor B³, and allow it to
hook under the extractor before the arm of the said retractor enters the recess B³.
By means of this construction, the recess in the barrel being only just large
enough to receive the end of the extractor, the explosion of the cartridge cannot
bulge out the shell so as to force back the hook and prevent it from holding upon
the rim of the shell.
Figure 3 shows more particularly the construction of the cams which operate the
lock bars to drive the cartridges into the barrels.
It has been found that the cams as ordinarily constructed soon wear out by
reason of the difficulty of hardening them or the lock bars, on account of their
peculiar form. I therefore attach a separate plate G² to the faces of the cams
which obviates the difficulty. These tempered plates are attached by screws, as
shown in the Drawing. The said plates extend across the face of the cams and
operate against the forward vertical part of the lock bars to drive home the
cartridge.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent and the manner of performing the same, I wish it understood
that I claim,-
First. The combination of the bolt J with its head and collar, the releasing hook,
the sleeve, the spring, and the lever operating to cock the lock after the bolt is
hooked, substantially as above described.
Second. The combination of the fixed block and the movable block with the
lever J, whereby the parts of the lock are operated, substantially in the manner
herein described.
Third. The combination of the retractor turning on a fixed pivot at the rear end
of the barrel, with a movable lock bar provided with a notch or recess by which said
retractor is operated, substantially as above specified.
Fourth. The combination of the retractor, the extractor, and the lock bar, sub-
stantially as and for the purpose herein described.
Fifth. The hardened plate G³ in combination with the cam and the lock bar,
substantially as above described.
In witness whereof, I, the said Henry Harris Lake, have hereunto set my
hand and seal, this Sixteenth day of December, in the year of our Lord
One thousand eight hundred and seventy-nine.