IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by John Barnett at the Office of
the Commissioners of Patents, with his Petition, on the 13th July
1869. A communication from abroad by Albert Bernard Zieschang
and Frederick Louis Hugo Schmidt, both of Breslau, in the Kingdom
of Prussia.
I, JOHN BARNETT, of No. 134, Minories, in the City of London, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
BREECH-LOADING FIRE-ARMS," to be as follows:-
This Invention has for its object improvements in breech-loading
fire-arms.
In constructing breech-loading fire-arms I form or fix at the breech
end of the barrel a shoe of a trough-like form, open by preference at the
top, but it might be on one side. This shoe or trough carries a pin or
axis on one side of but parallel with the bore of the piece. On this axis
a breech block is mounted so as to be able to turn into and out from the
shoe or trough; when in the shoe or trough it closes the bore of the
piece at its rear end, and when out of the shoe or trough it leaves the
bore open for the insertion of a cartridge. At the back of the breech

page_text: block a screw is formed which enters a tube with a corresponding thread
within it. On this tube there is a handle on one side, and the tube has
also a collar upon it, which when the breech is closed is received into a
recess in the bottom of the shoe or trough, and the breech block is
firmly locked in its place by turning down the lever to one side, thus
rotating the tube partially and unscrewing it to the amount of a portion
of a turn of the screw from the breech block. In this way the distance
between the face of the breech block and the back of the collar on the
tube is somewhat increased; and as both of these parts abut on the shoe
or trough, the one at its forward end and the other on the groove in its
bottom, as already mentioned, the breech block is in this way firmly
held in its place, closing the breech of the barrel. When the lever is
turned back for opening the breech it screws the breech block and the
tube behind it more closely together, and so relieves the end pressure on
the breech block, and frees it so that it can easily by the further motion
of the lever be turned back out of the way. The lever and the side of
the shoe or trough are so formed that the lever can only turn when the
breech block is closing the breech. The extractor for withdrawing the
cartridge case after firing is a piece of a semi-cylindrical form working in
a corresponding recess in the side of the shoe or trough; its inner end
enters under the flange of the cartridge case in the usual manner, and
its outer end is operated on by an incline on the breech block, which
when the breech is opened causes it partially to rotate in its recess, and
similarly the closing the breech causes it to turn back to its original
position. The notch or recess in which the extractor works does not, as is
usual, extend into the chamber of the gun, but terminates in the circular
groove which receives, the flange of the cartridge. This arrangement
removes all liability of the extractor being set fast by dirt entering
behind it. The face of the breech block is bevelled around the edge so
as to aid in pushing the cartridge home, and to give a freer escape to any
gas which may issue from a faulty cartridge.
The breech-loading arrangement above described may be used with an
outside lock, but I prefer to arrange a needle or striker to pass through
the centre of the breech block, as is usual when central-fire cartridges
are employed. The needle or striker is carried by a stem within the
lever tube, and a coiled spring presses it constantly forward. There is,
however, on the back of the breech block an incline, which when the
lever tube with the striker within it is rotated in opening the breech acts

page_text: against a projection on the stem of the striker and forces it back to full
cock, where it is retained by a sear jointed to it, the extremity of which
drops into an opening in the side of the lever tube and is there retained.
The coiled mainspring presses on the tail of the sear, and so gives to its
other extremity a tendency to move outwards, and thus the one spring
serves both as sear and mainspring; or two separate coiled springs may
be used, the one within the other, the inner spring acting as the sear
spring and the outer as the mainspring. When the breech is closed
the opening into which the sear catches is brought to coincide with an
opening in the bottom of the shoe or trough, and in firing the piece the
pressure on the trigger causes an instrument to project up through this
opening and eject the end of the sear from the opening in the lever tube,
and the striker then immediately flies forward by the action of the coiled
spring upon it and so discharges the cartridge..
In rifling breech-loading fire-arms I employ by preference six grooves,"
which I cut each with one side forming a tangent to the original
cylindrical bore, and the other side of each groove is at right angles to
the tangential side. The lands and the grooves I make of equal width.