Improvements relating to Machine Guns.
Year: 1885

page_text: Improvements relating to Machine Guns.
I THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
Civil Engineer do hereby declare the nature of this invention to be as follows:-
My invention applies to machine guns in which the breech is closed by a
transversely sliding breech block, and in which a cartridge made up in a metallic
case or capsule is employed. Such guns are usually so arranged and mounted that
the breech block moves in a vertical plane and when opening the breech the
weight of the breech block operates very effectively upon the extractor to with-
draw the cartridge case from the barrel. In machine guns of large size however
the weight of the breech block is so great that the operator cannot conveniently
raise it to close the breech ready to again fire. overcome this difficulty whilst
still deriving advantage from the weight of the breech block to work the extractor
by so arranging and mounting the gun that the movoment of the breech block
takes place in a plane which is inclined, the inclination being such that the weight
of the breech block is not unduly felt in the operation of closing the breech whilst
nevertheless it affords efficient aid in operating the extractor when opening the
breech after firing.

page_text: a transverse passage or recess at the breech end of the gun being guided therein by
projections on either side of the recess which engage with grooves A. A. in the
breech block. These projections and grooves are somewhat inclined, so that as the
breech block moves in the opening of the breech it recedes from the face, in which
the bore of the gun terminates. The breech block being armed with extracting
hooks B. B, embracing the flange of the cartridge and by them the cartridge is
partially withdrawn from the gun during the movement of the breech block along
the guiding projection. After this has taken place the ejector shown by Figures 10
comes into operation and propels the cartridge case rapidly rearwards and thrusts
it out of the bore of the gun. Movement is imparted to the breech block by means
of a hand lever applied to the axis C; on this axis there is a short lever arm C¹
carrying a friction roller C³, When the breech of the gun is closed the breech
block is supported by a projecting rim Cs, at the inner end of the axis C and which
enters a cavity D in the side of the breech block. When the axis is turned by
means of the handle, in order to open the breech, the projection C³, passes into the
groove E in the side of the breech block and then the block is no longer supported
by the projection O³ but comes to be supported by the roller C³, which by this time
has entered into the groove F in the side of the breech block. During this time
the cocking of the firing mechanism contained within the breech block has taken
place; it has been effected by means of the projection C, upon the axis C. As
this firing mechanism forms no part of my present invention and is described in
the Specification to which I have already referred it is needles now to further
explain it. The breech block has jointed to it at G the ejector which is shown by
Figures 10. This ejector at its upper end has a flange or lip H and this as the
breech block descends follows down after the extracting hooks B. on the block
itself and enters behind the rim of the cartridge case. The breech block descends
in consequence of the movement of the axis C by the band lever until towards the
end of the motion the projection I of the ejector comes against the stationary
projection J within the passage in which the breech block works. The collision
between these parts gives a rearward rapid motion to the head of the ejector and
the cartridge case is thrown out of the gun as previously stated.
All these arrangements are very similar to those explained in the former
Specification to which I have referred, but the novel feature of this gun is that
the passage or recess in which the breech block works is inclined, so that the
breech block does not descend and ascend in a vertical plane, but in a plane which
is inclined at a considerable angle to the vertical, so that the weight of the breech
block is to a very great extent supported upon the under side of the recess in
which the breech works, and consequently the gunner in working the gun lifts the
breech block through a much smaller height than he does in a similar gun in
which the breech block moves in a vertical plane. Nevertheless the breech block
is not wholly borne by the side of the recess of the gun but in opening the breech
gravity acting on the breech block aids in producing the necessary movements and
especially in the withdrawal and ejection of the cartridge case.
My invention is not limited in its application to guns in which the mechanism
for operating the breech block and for extracting and ejecting the cartridge case
are precisely such as are shown by these drawings but wherever in breech loading
guns a heavy breech block is moved by a lever handle and where simultaneously
an extractor or ejector is made to operate it is advantageous to mount the breech
block so that its movement takes place in an oblique direction as herein described
and neither in a vertical plane nor in a horizontal plane, for in the first case undue
labour is imposed on the gunner in raising the breech block to close the breech,
and in the second the gunner receives no aid from the weight of the breech block
in working the mechanism for extracting and ejecting the cartridge case from the .
bore of the gun.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
:
A machine gun in which the breech is closed by a breech block received into a
transverse opening in the gun and in which the movement of such block is in an
oblique plane neither vertical nor horizontal, so that on the one hand the weight of
the block is partially supported whilst on the other hand its weight is left partially
available to aid in the extraction and ejection of the cartridge case from the bore
of the gun, substantially as described.