IMPROVEMENTS IN THE MANUFACTURE OF PROJECTILES
Year: 1859

page_text: LETTERS PATENT to John Chatterton, of 19, Wharf Road, City Road, in
the County of Middlesex, Lead Manufacturer, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF PROJECTILES."
Sealed the 1st June 1860, and dated the 10th December 1859.
PROVISIONAL SPECIFICATION left by the said John Chatterton at the
Office of the Commissioners of Patents, with his Petition, on the 10th
December 1859.
I, JOHN CHATTERTON, of 19, Wharf Road, City Road, in the County of
Middlesex, Lead Manufacturer, do hereby declare the nature of the In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF PROJECTILES," to be as
follows:-
This Invention has for its object improvements in the manufacture of pro-
jectiles, and is applicable, in the first place, to the manufacture of those descrip-
tions of projectiles which are caused to revolve during their flight by the
resistance of the air through which they pass, the projectile having a passage
through it from end to end with inclined ridges or projections on the sides of
the passage on which the air impinges. Such projectiles have heretofore been
manufactured by casting in a mould. Now this Invention consists in pro-
ducing them by pressing or drawing the lead or other metal for forming the
projectiles through a die as in the manufacture of lead pipe, except that the

page_text: mandril has inclined grooves or notches formed in it, which produce corre-
sponding inclined ridges or projections within the pipe. The pipe so produced
is cut off in lengths each suitable to form a projectile, and the projectile may
subsequently be finished by shaping the end or ends, and providing it with a
suitable wad for closing the passage through it, until it has escaped from the
gun as heretofore.
This Invention is also applicable to the manufacture of projectiles which
have exterior wings or projections to enter the grooves of a rifle. In pro-
ducing such projectiles I press or draw the lead or other metal through a die
of suitable size and form, having notches in it corresponding in form and incli-
nation to the rifle grooves of the arm with which the projectile is to be
employed. In this manner I produce a continuous bar having wings or
projections running spirally around it from which lengths are cut, each
suitable to form a projectile, and they are finished at the ends by subsequent
processes. Projectiles of a polygonal section may conveniently be manu-
factured in this manner.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Chatterton in the Great Seal Patent Office on the
9th June 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Jonn
CHATTERTON, of 19, Wharf Road, City Road, in the County of Middlesex, Lead
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of December, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Chatterton, Her special licence that I, the said John Chat-
terton, my executors, administrators, and assigns, or such others as I, the said
John Chatterton, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF PROJECTILES," upon the condition (amongst
others) that I, the said John Chatterton, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and seals,

page_text: should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Chatterton, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
This Invention has for its object improvements in the manufacture of
projectiles and is applicable, in the first place, to the manufacture of those
descriptions of projectiles which are caused to revolve during their flight by the
resistance of the air, through they pass; the projectile having a passage
through it from end to end with inclined ridges or projections on the sides of
the passage on which the air impinges. Such projectiles have heretofore
been manufactured by casting in a mould.
Now this Invention consists in producing them by pressing or drawing the
lead or other metal for forming the projectiles through a die, as in the
manufacture of lead pipe, except that the mandril has inclined grooves, or
notches, formed in it which produce corresponding inclined ridges or
projections within the pipe, the pipe so produced is cut off in lengths each
suitable to form a projectile, and the projectile may subsequently be finished
by shaping the end or ends, and providing it with a suitable wad for closing
the passage through it until it has escaped from the gun as heretofore.
The apparatus which I prefer to employ is that commonly employed in
making lead pipe, and in which the lead in a heated state is placed in a
vessel with a die at one end and a piston working in the vessel forces the
lead with sufficient pressure to squeeze it out through the die. For a
projectile of the present government guage viz. of an inch in diameter I
make a tube of corresponding size and by preference 1 of an inch in
thickness. The notches formed on the mandril of the die I make three in
number and of such a form as to produce within the tube ridges projecting
about of an inch from the interior surface thereof with a thickness at the
base equal to their height and rounded at the top, and I give the notches such
an inclination that the ridges they produce may make one complete turn
round the interior of the tube in six inches of length. The tube so formed
I cut off in lengths of about one inch and a half, each to form a projectile
which is finished by presenting its front end to a conical or rose cutter
revolving in a lathe, which, by cutting away a small quantity of metal at the
interior of the tube, make the end of the projectile which was previously flat

page_text: to incline inwards; thus it is rendered better able to divide the air, and the
form given to it also tends to increase the quantity of air passing through it.
When the projectile is placed in the gun from which it is to be fired a wad
of boxwood about a quarter of an inch thick is placed between it and the
powder, to prevent the force of the explosion being expended through the
passage in the projectile. As soon as the projectile leaves the gun the wad
falls from it and the current of air which immediately passes through it gives to
it a rotary motion which keeps it steady during its flight. In place of
forming spiral ridges within a cylindrical passage through the projectile a
polygonal passage, or a passage of other suitable form with the requisite
twist upon it, may be produced in a similar manner.
This Invention is also applicable to the manufacture of projectiles which
have exterior wings or projections to enter the grooves of a rifle; in producing
such projectiles I press or draw the lead or other metal through a die of
suitable size and form having notches in it corresponding in form and
inclination to the rifle grooves of the arm with which the projectile is to be
employed. In this manner I produce a continuous bar having wings or
projections running spirally around it from which lengths are cut, each
suitable to form a projectile, and they are finished at the ends by subsequent
processes. To produce such projectiles I employ the apparatus already
described, but without a mandril, and I make notches in the die itself
corresponding in form and inclination with the rifle grooves of the piece from
which the projectiles are to be fired; thus a continuous bar with the required
projections is produced; this bar I cut to lengths each suitable for a projectile
and I subsequently form its ends as may be required by turning in a lathe.
Projectiles of a polygonal section may conveniently be manufactured in the
manner above described.
In witness whereof, I, the said John Chatterton, have hereunto set
my hand and seal, on this Ninth day of June in the year of our
Lord One thousand eight hundred and sixty.
JOHN CHATTERION. (V.D.)