IMPROVEMENTS IN GAS CHECKS FOR BREECH LOADING ORDNANCE
Year: 1879

page_text: LETTERS PATENT to William Morgan-Brown, of the Firm of Brandon and
Morgan-Brown, Engineers and Patent Agents, of 38, Southampton Buildings,
London, and 1, Rue Laffitte, Páris, for the Invention of "IMPROVEMENTS IN
GAS CHECKS FOR BREECH LOADING ORDNANCE." A communication from
abroad by Benjamin Berkley Hotchkiss, of New York, United States of
America
Sealed the 23rd May 1879, and dated the 14th March 1879.
COMPLETE SPECIFICATION filed by the said William Morgan-Brown at the
Office of the Commissioners of Patents on the 14th March 1879.
WILLIAM MORGAN-BROWN, of the Firm of Brandon and Morgan-Brown, Engineers
and Patent Agents, of 38, Southampton Buildings, London, and 1, Rue Laffitte,
Paris. "IMPROVEMENTS IN GAS CHECKS FOR BREECH LOADING ORDNANCE."
communication from abroad by Benjamin Berkley. Hotchkiss, of New York, United
States of America.
A
Heretofore gas checks or rings for breech loading ordnance have been commonly
constructed of a single piece of comparatively soft and unyielding material, as
copper, bronze, wrought iron, and low steel, which metal gas check or ring is
susceptible of being expanded by the gases resulting from the exploded charge, so
that it shall press tightly against the walls of the charge chamber and the firmature,
thus forming a perfect gas check. In practice such a gas check so expands after
repeated firings as to prevent the ready movements of the firmature in opening and
closing the breech, thus impairing the efficiency of the gun.
The object of this Invention is to remedy this defective operation, and the
Invention consists in an improved construction of a gas check or ring by forming
the same from two substances, preferably metals having different physical qualities
in hardness, tensile strength, compressibility, and extensibility, whereby the check
or ring has the most suitable construction to form a perfect and close check at its
sides with the seat in the chamber of the gun, and at the same time have its base
portion of a hard and unyielding substance that will prevent any binding or sticking
of the breech firmature in moving to perform its functions.
In order to make these improvements clearly understood I will describe them in
connection with the three Figures of the accompanying Drawing, in which Figure 1
is a longitudinal section of so much of a gun as is necessary to represent the gas
check in its relation to the various other parts.
Figure 2 is a plan of the gas check or ring detached; and
Figure 3 is a section through the gas check on a larger scale.

page_text: 1 represents the back portion of a piece of ordnance; 2, the gun body proper;
3, the breech block; and 4, the obdurator plate.
My improved gas check or ring, seated in the rear of the bore of the gun in
the usual manner, is composed of two sections, viz., the lip portion 6, and the base
portion 5. The front portion or lip 6 is formed out of an extensible and tough
metal, such as copper, and the rear portion or base plate 5 is formed out of a harder
but more elastic and incompressible metal, as steel.
The object accomplished by this structure and disposition of material is as follows:-
First. The more extensible material constituting the lip 6 under the enormous
pressure of the gases is forced into close contact with the gas check seat in the bore
of the gun, thus forming complete obduration at this point. Second. The harder
and less extensible base plate 5 is pressed into close contact with the obdurator
plate 4, and while preventing the escape of gas will not, from its superior hardness,
incompressibility, and elasticity, materially change its shape, and hence prevents
any sticking or other obstruction to a free movement of the firmature in opening
the breech after firing, a difficulty frequently occurring where the gas check or ring
is composed solely of a soft and extensible material, as in former constructions.
It is obvious, especially in guns composed of such material as provides a soft gas
check seat, as copper or any of its alloys, wrought iron, or low steel, &c., that a gas
check, the lip 6 of which is constructed out of a material harmonizing in its physical
qualities with such seats, will in repeated firings go out with or rather enlarge with
the seat, and thus in practice constantly form a close contact therewith so necessary
to constitute a perfect gas check, while the harder, more elastic, and loss com-
pressible base plate 5, which finds its contact with the obdurator plate 4, will so
operate as to avoid the difficulties arising from the binding which results from a
gas check or ring wholly formed out of a comparatively soft and yielding
material.
It is apparent that the lip 6 and base plate 5 composed of two materials differing
in their physical qualities can be united together by casting, screwing, or by any
other mechanical means of union.
Having now fully described the Invention and set forth the merits it possesses, I
claim,―
A gas check or ring having a lip composed of a soft and extensible material
united to a base composed of a hard and elastic material, substantially as
described.
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In witness whereof, I, the said William Morgan-Brown, have hereunto set my
hand and seal, this Fourteenth day of March, in the year of our Lord One
thousand eight hundred and seventy-nine.
WILLIAM MORGAN-BROWN. (L.S.)