IMPROVEMENTS IN PRO- JECTILES FOR BREECH LOADING CANNON
Year: 1879

page_text: LETTERS PATENT to Charles Ambrose McEvoy, of 18, Adam Street, Adelphi,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN PRO-
JECTILES FOR BREECH LOADING CANNON."
Sealed the 24th October 1879, and dated the 12th June 1879.
PROVISIONAL SPECIFICATION left by the said Charles Ambrose McEvoy at
the Office of the Commissioners of Patents on the 12th June 1879.
CHARLES AMBROSE MCEVOY, of 18, Adam Street, Adelphi, in the County of
Middlesex. "IMPROVEMENTS IN PROJECTILES FOR BREECH LOADING CANNON."
At the present time projectiles for breech loading cannon are commonly formed
with grooves around their circumference, into which wires of copper or other com-
paratively soft metal are introduced so as to project beyond the circumference of
the projectile to engage with the rifling and give to the projectile a revolving
motion when it is fired from the cannon. In other cases the projectiles are fitted
with studs to engage with the rifling, or the projectile has fitted to its base an
expanding cup, which is to engage with the rifling, and so give rotation to the pro-
jectile. According to my Invention I form cast iron or steel projectiles for breech
loading cannon with rings around them of slightly greater diameter than the bore
of the gun.
When projectiles formed in this manner are introduced into the breech end of
the cannon the ring will form a stop to limit the distance that the projectile is
allowed to extend from the breech chamber into the bore. Around the exterior of
the rings on the projectiles I form grooves in such a manner that the outer circum-
ference of the rings is reduced to a few narrow edges. When the projectile is fired
from the cannon these edges, where they first come against the projections of the
rifling, break off or yield, leaving intact proportions opposite the grooves of the
rifling, and these remaining portions so engaging with the rifling give to the pro-
jectile the revolving motion as the projectile passes along the bore.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Ambrose McEvoy in the Great Seal Patent Office on the 11th
December 1879.
CHARLES AMBROSE MOEVOY, of 18, Adam Street, Adelphi, in the County of
Middlesex. "IMPROVEMENTS IN PROJECTILES FOR BREECH LOADING CANNON."
At the present time projectiles for breech loading cannon are commonly formed
with grooves around their circumference, into which wires of copper or other com-
paratively soft metal are introduced so as to project beyond the circumference of
the projectile to engage with the rifling and give to the projectile a revolving
motion when it is fired from the cannon. In other cases the projectiles are fitted
with studs to engage with the rifling, or the projectile has fitted to its base an
expanding cup, which is to engage with the rifling, and so give rotation to the pro-
jectile. According to my Invention I form cast iron, or iron, or steel projectiles for
breech loading cannon with rings around them of slightly greater diameter than the
bore of the gun.
When projectiles formed in this manner are introduced into the breech end of
the cannon the ring will form a stop to limit the distance that the projectile is
allowed to extend from the breech chamber into the bore. Around the exterior of
the rings on the projectiles I form grooves in such a manner that the outer circum-
ference of the rings is reduced to a few narrow edges. When the projectile is tired
from the cannon those edges, where they first come against the projections of the
rifling, break off or yield, leaving intact the portions opposite the grooves of the
rifling, and these remaining portions so engaging with the rifling give to the pro-
jectile the revolving motion as the projectile passes along the bore.
The Drawings hereunto annexed shew a projectile formed as above described.
Figure 1 shews a side view of the projectile as cast or formed with a ring around
it near its base; Figure 2 shews the same projectile after that grooves have been
cut around the ring, and its outer circumference reduced to a few narrow edges
the cutting of the grooves is effected by turning the projectile in a lathe.
The projectile shewn in the Drawing is cast or formed with one ring only around
it near its base; it might however if desired be in addition cast or formed with a
similar ring around it near its fore end, and this ring may similarly have grooves
cut in it to reduce its circumference to narrow edges; or it may be cast or formed
with a still greater number of rings; or if cast or formed with a single ring only
such ring may be at the centre of the length of the projectile, or in other desired
position.
After the projectiles have been cast or formed and finished in a lathe I in some
cases coat them with zinc, or it might be other comparatively soft metal, by the
galvanizing process. The zinc not only serves to give a protecting coating to the
surface of the cast iron or steel projectile, but also softens the thin edges projecting
from its circumference, and renders them able to yield and conform more readily to
the rifling of a gun.
Having thus described the nature of my Invention and the manner of performing
the same,
I would have it understood that I claim,-
First. The manufacture of projectiles of cast iron, or iron, or steel with narrow
edges projecting from them around their circumference to engage with the rifling
of the gun from which they are to be fired, substantially as herein before
described.

page_text: Second. The manufacture of projectiles of cast iron, or iron or steel with narrow
edges projecting from them around their circumference, and with their surface
coated with a soft metal, substantially as herein before described.
In witness whereof, I, the said Charles Ambrose McEvoy, have hereunto set my
hand and seal, this Tenth day of December, in the year of our Lord One
thousand eight hundred and seventy nine.
C. A. M°EVOY. (L.S.)