IMPROVEMENTS IN PROJECTILES AND CARTRIDGES FOR ORDNANCE AND. FIRE-ARMS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by John Webster Cochran at the Office
of the Commissioners of Patents, with his Petition, on the 20th June
1867.
I, JOHN WEBSTER COCHRAN, of the City, County, and State of New York;
United States of America, now of No. 8, Southampton Buildings, Chancery
Lane, in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PROJECTILES AND CARTRIDGES FOR ORDNANCE AND.
FIRE-ARMS," to be as follows:-
The said improvements consist, first, in forming the exterior of a hollow
projectile or shell of a metal tube of equal thickness on all sides, whereby the
weight is equally distributed around the axis of the shell.
Second, in the employment of rings formed with lateral teeth or corrugations:
and fitted or packed closely together within the outer case or tube, which rings.
break and scatter when the shell explodes.
Third, in the employment of a central fixed tube to keep the rings in
place.
Fourth, in the arrangement of an inner tube or case for containing the charge,
which tube slides forward and explodes the percussion fuse when the projectile
strikes an object.
Fifth, in the combination with the said sliding tube of a percussion fuse
consisting of a nipple attached to the said tube, which nipple is provided
with fulminate and arranged to strike a projection on the plug or stopper, of
the nose piece.

page_text: Sixth, in the novel construction of a time fuse employed in combination
with the sliding tube, which fuse consists of a small tube perforated at certain
intervals or provided with a longitudinal aperture and filled with ordinary fuse
powder. This tube is covered with thin sheet brass or paper, which is perforated
to correspond with either of the perforations or portion of the aperture in the
tube according to the time fixed for the explosion.
Seventh, in covering parts of projectiles and cartridge with a thin coat of
tin to prevent corrosion or other injury to the same.
The outer case of the projectile is by preference formed of a wrought-iron
tube of any suitable diameter and thickness; this tube is faced at each end
to form a true surface for the shoulders of the nose piece and base of the shell,
which are constructed of cast iron or other suitable metal, and provided with
a screw thread which fits a corresponding screw thread cut inside each end
of the wrought-iron tube. The base is provided with an extension for carrying
a metallic expansion ring. which fits the grooves in the bore of the piece.
The rings with which the projectile is filled are constructed to fit concentrically
inside the wrought-iron tube, and may be advantageously made of a thickness
of about half an inch. The said rings are constructed with teeth or projections
on one side, and the teeth of one ring fit into the spaces of the adjacent ring;
the solid portion of the ring at the root of the teeth is chilled, and when the
explosion takes place the rings will: break across these chilled portions and
divide into a number of short segments with jagged edges. The interior of
the shell is divided by thin-sheet-iron plates into several compartments which
serve to keep the rings in place if the same should be broken; the inner rings
fit around a tube of wrought iron or other suitable metal which extends from
end to end of the projectile in the centre of the same; the ends of the said
tube are faced, and the rear end fits against a lead disc or cushion which lies
against the base of the shell; the forward end of the central tube fits against
the interior of the nose piece, and when the latter is screwed into the outer
case the central tube is pressed tightly against the lead cushion at the base.
Within the said tube another tube of brass or other metal is fitted which
contains the charge of powder or other explosive substance for bursting the
shell this tube after being filled is, closed at each end with a metal disc or
stopper. The said tube is shorter than the fixed tube in which it is enclosed,
and is fitted to slide endwise in the latter. The disc which closes the forward
end of the sliding tube is perforated to receive the nipple of the percussion
fuse, whose end carries a detonating cap or other fulminate, and is arranged
opposite to a projection on the plug or stopper of the nose piece; this projection
and nipple are surrounded by a spiral spring which keeps the sliding tube

page_text: back till the projectile strikes an object, but then gives way, allowing the
sliding tube to be thrown forward and bring the nipple into contact with the
projection. The latter explodes the cap, the flame from which passes through
the nipple to the charge in, the sliding tube and ignites the same. The tube
of the time fuse is passed through the centre of the plug of the nose piece
and also through the disc which closes the end of the sliding tube and carries
the nipple of the percussion fuse. The said tube which may extend for
any required length within the sliding tube is perforated with small holes
at certain distances, which correspond with certain intervals of time; the
thin metal or paper envelope which surrounds this tube prevents the com-
munication of the fire from the fuse powder with the charge until the said
powder has burnt to a perforation formed in the said envelope opposite one
of the perforations in the tube containing the fuse powder. Instead of the
perforations at certain intervals the tube may be formed with a slot from
end to end. The metal or paper envelope is marked with rings to indicate
the intervals of time. The fire from the burning fuse powder passes through
the perforation formed in the exterior envelope and ignites the charge in
the sliding tube. The said tube, as well as the fuses, may be kept separate
from the shell till the same is to be fired, and can then be readily and
conveniently inserted through the aperture in the nose piece. The interior
of the tube which contains the powder, gun cotton, or other explosive
material is covered or coated with tin to exclude moisture and prevent
the charge being otherwise injured. In constructing metallic cartridges for
fire-arms the shells of the same are also coated with tin on both the inside
and outside. When the said shells are made of brass the coating on the
interior surface prevents injury to the charge and the fulminating compound
for igniting the same, which would be deteriorated by the effect of the zinc
in the brass upon some of the ingredients of the said fulminate and charge;
the coating of tin on the exterior of the said shells or cases keeps them clean
and free from the verdigris produced in the oxidation of copper or brass.