IMPROVEMENTS IN THE CONSTRUCTION OF CANNON AND OTHER ORDNANCE
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at
the Office of the Commissioners of Patents, with his Petition, on the
22nd July 1864.-A communication from abroad by Francis Sorrel
Claxton, of Ruelle, France.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF CANNON AND OTHER ORDNANCE," to be
as follows:-
This Invention consists of the improvements herein-after explained for
casting iron or bronze over and around steel or wrought-iron rings set upon
or suspended about a core barrel, and over and around hollow cylinders of
steel or wrought iron, such cylinders being reinforced exteriorly by steel or
wrought-iron rings.
The said Invention further consists in reinforcing the cannon or cylinder
thus cast and after cooling by shrinking on to the exterior steel or wrought-
iron hoops or sleeves, such hoops having heels or projections, which are
destined to enter into corresponding grooves, turned on the breech and rein-
force of the gun or on the face of the cylinder.
The manner in which I carry out this Invention is as follows:-
First, I take a cylinder of wrought iron or other metal, such as a gas pipe.
closed at one end, and of sufficient thickness to permit of cutting four, six, or-
more longitudinal grooves throughout its length of about 1th of an inch in
depth; the length of the tube is such that it will project beyond the mould
or the gun head a part, and in some cases the whole of said tube must be

page_text: slightly tapering to admit of its being withdrawn from the casting when
desired; upon it I fix or drive on rings, or they or a steel cylinder may be
suspended around it, but not in contact, their interior diameter in this last
case being such that the metal in fusion shall entirely surround them, their
number and relative disposition being determined by the probable bursting
strain to which the casting will be ultimately subjected. The section of the
rings may be modified, care being had that the metal in fusion shall pass
between them, and in cooling form a dovetail or key. The rings having been
attached to the tube and in contact with it its exterior must be furnished
with the usual dressing, and in the usual manner as for a core for a cast-iron
pipe, the thickness of the dressing being such that the exterior diameter of the
core shall be from 15 to 20 less than the proposed bore of the gun or casting,
this difference being made to cover any excentricity in the centering of the
core in the mould. The core being thus prepared is set in the mould, and
either suspended from above, or sustained by a rod set in the bottom or in the
cascable; the melted metal is let into the mould through a syphon attached
near the bottom; when it is filled or nearly so a current of water or air is
turned on through a pipe, and after filling the core barrel is allowed to waste
through another pipe set into the core barrel, either above the casting or
traversing the gun head; this current is maintained until the casting has
partially cooled, when the core is removed, and the current renewed in the
bore of the casting until the mass has cooled; the bore, as also the projecting
portions of the rings, are then turned or bored out to the desired dimensions.
Secondly, to reinforce the bottom of the casting or the breech of the gun,
steel or wrought-iron rings provided with two or more interior projections are
then shrunk on the projections, or heels are made to fit corresponding circular
grooves cut upon the exterior of the casting or gun; their depth must vary
according to the diameter of the casting from 3nd to eth of an inch, and
their length according to the maximum longitudinal strain to which the gun
may be subjected; for large guns two rows of hoops or rings may be used,
breaking joint and let into each other.
The same system may be applied and used for repairing any gun which has
broken traversely, care being had to turn closely fitting shoulders in each
part, to insert in the joint a thin plate of soft metal and to mechanically press
the two parts violently together during the cooling of the exterior bands
referred to.
Thirdly, when it may be desired to line the bore of a gun with an interior
tube of steel or other metal, the tube must be reinforced partially or through-
out its length by rings; this tube serves as the core to the mould, is centered

page_text: as before described, and the enveloping metal, cast iron or bronze, is let into
the mould from below by a syphon, a portion of this metal after passing up
through the mould, and after heating the tube to near red heat, is allowed to
run out into a vessel prepared to receive it through a runner set in the gun
head; gas blows are thereby prevented.
As soon as the steel tube has attained a welding heat, a strong current of
air is introduced and maintained until the mass has cooled. The tube may
be heated before being placed in the mould, and powdered borax or ground
glass sprinkled thickly over it; or in the case of a brass envelope, the steel tube
may be tinned or coated with spelter to assist the union of the two metals.
The flasks used in either of the cases herein-before described must be covered
exteriorly with a non-conducting substance, or the temperature of the pit in
which the casting is made must be raised to a high temperature.
Guns or cylinders lined as just described may be reinforced exteriorly with
hoops or sleeves in manner herein-before explained.