IMPROVEMENTS IN THE MANUFACTURE OF CARTRIDGES FOR BLASTING AND PROJECTILE PURPOSES
Year: 1864

page_text: LETTERS PATENT to Richard John Cunnack, of Helston, in the County
of Cornwall, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
CARTRIDGES FOR BLASTING AND PROJECTILE PURPOSES."
Sealed the 29th July 1864, and dated the 9th February 1864.
PROVISIONAL SPECIFICATION left by the said Richard John Cunnack
at the Office of the Commissioners of Patents, with his Petition, on the
9th February 1864.
I, RICHARD JOHN CUNNACK, of Helston, in the County of Cornwall, do
hereby declare the nature of the said Invention. for "IMPROVEMENTS IN THE
MANUFACTURE OF CARTRIDGES FOR BLASTING AND PROJECTILE PURPOSES," to be as
follows:
I proceed to concentrate the charges by exposing the explosive material of
which they are composed to great pressure when making such cartridges,
either by using percussion, or by pressing in screw, hydraulic, or other press,
as to render such cartridges as nearly as possible incapable of further
compression under the circumstances in which they are intended to be used.
And I can enclose hermetically the explosive material of such cartridges in a
flexible metallic tube or case of iron, lead, tin, or other suitable metal or
alloy. And by the admixture with the explosive material previous to its

page_text: formation into cartridges of a resinous, gummy, or other adhesive material, the
use of an external case may be either wholly or partially dispensed with. By
the above-mentioned method of manufacture I obviate the existing objection
to cartridges as ordinarily constructed with the explosive material loosely
packed in cases, which, when used in wet situations, are often rendered
ineffective from their shrinking on being subjected to pressure in tamping,
whereby the water with which they are surrounded has a tendency to become
forced through the case into the charge.
The manner of and proportions for mixing the resinous or other material
with the explosive material are, as I now prefer, as follows:-The resinous or
other adhesive material is to be agitated with the explosive material until
they are thoroughly incorporated. The proportion of the former should be
the smallest possible consistent with procuring the adhesive effect, generally
about from three to five per cent. by weight will be sufficient, but the pro-
portions may be varied.
SPECIFICATION in pursuance of the conditions of the Letters Patent; filed
by the said Richard John Cunnack in the Great Seal Patent Office
on the 8th August 1864.
3
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
JOHN CUNNACK, of Helston, in the County of Cornwall, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of February, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Richard John Cunnack, Her special licence that I, the said
Richard John Cunnack, my executors, administrators, and assigns, or such
others as I, the said Richard John Cunnack, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time
and at all times thereafter 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 Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF CARTRIDGES POR BLASTING AND
PROJECTILE PURPOSES," upon the condition (amongst others) that I, the said
Richard John Cunnack, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what manner

page_text: 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 Richard John Cunnack, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and .by the
following statement thereof, that is to say:―
The object and purpose of my said Invention being the obviating of the
defect in cartridges for blasting as ordinarily constructed (with the explosive
material loosely packed in cases) of being rendered ineffective when used in
wet or damp situations, owing to their shrinking on being subjected to
pressure, particularly as in tamping, when the water by which they are
surrounded has a tendency to become forced through the cases into the
charges, and at the same time to obtain greater efficiency in all cases, whether
applied to blasting or projectile purposes, by the increased charges, contained
in the same bulk as compared with the ordinary form now in use.
I Now, therefore, the nature of my said Invention comprises the fulfilment of
the object and purpose above stated by concentrating the charges or explosive
material with which the cases are filled, by exposing such explosive material,
forming such charges, to great pressure when making the said cartridges
either by using percussion, as hereafter described, or by pressing, in manner
hereafter set forth, by screw, hydraulic, or other press, so as to render such
cartridges as nearly as possible incapable of further compression under the
circumstances in which they are intended to be used; also I can hermetically
enclose the explosive material of such cartridges in a flexible metallic tube or,
case of iron, lead, tin, or other suitable-metal or alloy.. Thus I would take
the explosive material (to which, if it consists of common gunpowder, I prefer
to add any liquid hydrocarbon, such as naphtha or benzole or other suitable
liquid, by sprinkling the same over it to. such an extent as to produce, a slight
cohesion when pressed between the fingers), and would then proceed as
herein-after set forth. Further, by the admixture with the explosive material,
previous to its formation into cartridges, of a resinous, gummy, or other
adhesive material the use of an external case may be either. wholly, or
partially dispensed with.
Having thus particularly described the nature of the said Invention, I now
proceed to describe in what manner the same is to be performed, namely,
"I take the explosive compound and let it fall in successive small quantities,
into the mould, and subject each successive quantity to percussion by the
falling of a weight;, or I take the requisite quantity of the explosive-charge

page_text: and place it in a mould of the proper form, and submit it to the action of a
screw or hydraulic press in the ordinary manner until the requisite com-
pression is obtained, repeating the operation as may be necessary to fill the
case. In these operations the contact of iron with the explosive substance is
to be avoided. In all cases I form the cartridge in a mould of suitable
dimensions and shape, the mould being made to open so as to allow of the
ready removal of the cartridge when filled.
When cases are used, of whatever material they may be made, I prefer to
insert the case into the mould and form the cartridge within it; when for
blasting purposes it is desired to furnish the cartridge with a fuse, I insert
such fuse into the case previous to charging it, poviding a suitable indenta-
tion in or making a proper allowance in the size of the piston pressing the
charge to avoid injury to the fuse during the process of filling.
When I wish to make cartridges in which the use of an external case is
wholly or partially dispensed with, I take a solution of shell-lac, resin, caout-
chouc, or gutta percha, or a mixture of these in wood or mineral naphtha,
turpentine, benzole, or any ordinary solvent (using, by preference, though I
do not confine myself to this, a mixture of one pound of shell-lac dissolved in
one pint of mineral naphtha and one ounce of saturated solution of caoutchouc
in benzole); or, instead of these, gum or glue dissolved in water, and agitate
the solution with the explosive material until the whole is thoroughly incor-
porated. The proportion of the adhesive material will clearly depend upon
the character of the explosive compound operated upon. A sufficient quantity
will be indicated by pressing in the hand, if it has then barely sufficient
coherence to retain an impression of the finger, in this state it is pressed
into the desired shape by either of the modes above indicated, and the
cartridge so formed is dried in a current of warm air. The surface of the
mould should be slightly oiled to prevent adhesion to the sides (and if a fuse
is to be attached, in the case of cartridges for blasting, I prefer to place such
fuse in the mould previous to the addition of the charge).
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I hereby declare
that I claim in regard thereto and as comprised within the scope and effect
of my said Letters Patent,-
(1.) The concentration and compression of the charge in cartridges.
2. The enclosing of the explosive material of the cartridges in a flexible
metallic tube or case of iron, lead, tin, or other suitable metal or alloy of
metal.
3. The admixture with the explosive material, previous to its formation into

page_text: cartridges, of a resinous, gummy, or other adhesive material, whereby the use
of an external case may be wholly or partially dispensed with.
In witness whereof, I, the said Richard John Cunnack, have hereunto
set my hand and seal, this 3rd day of August, in the year of our Lord
One thousand eight hundred and sixty-four.
RICHARD JOHN CUNNACK. (L.S.)
Signed and sealed in the presence
of (witness),
JAMES CUNNACK,
of Helston.