Improvements in Fuses for Mining and similar Purposes.
Year: 1893

page_text: Date of Application, 30th Oct., 1893
Complete Specification Left, 25th Aug., 1894-Accepted, 13th Oct., 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by ALFRED NOBEL, of 59, Avenue Malakoff, Paris,
in the Republic of France, Engineer.]
Improvements in Fuses for Mining and similar Purposes.
I PHILIP ARTHUR NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
The present invention has for its object the production of a fuse having no great
sensitiveness to concussion or percussion, which would be a source of danger in the
employment thereof, and a bar to any practical success.
The composition which will now be described will combine all the conditions
requisite to constitute a good fuse with perfect safety. That result is arrived at
by incorporating with nitro cellulose, or hydronitrocellulose, or oxynitrocellulose,
solvents and oxidisers of such nature as to obtain a product not more sensitive to
concussion or percussion than will be consistent with reliable safety.
In order to obtain such a product, nitrocellulose, or its aforesaid equivalent, is
dissolved in nitroglycerine or nitro sugar, to which has been added such quantity
of another non-volatile and non-explosive, or not easily explosive, substance, as
will secure, and lastingly maintain, in the final product hereinafter described, the
degree of insensitiveness to concussion or percussion needed to constitute a good
fuse.
Such substances are the various nitronaphthalenes, nitrocymenes, nitrotolulols,
nitrobenzols, acetine, diacetine, triacetine, heavy camphor oil, camphoric acid,
castor oil mixed with triacetine or other solvent.
It should be borne in mind that it suffices for the aforesaid purpose, that the
solvent destined to temper the sensitiveness of the afore-mentioned highly explosive
substances, should not be volatile in a practically appreciable degree, and not be
of an explosive, or only of a faintly explosive, nature.
The aforesaid fuse is prepared as follows :-Nitrocellulose, wet or dry, is
dissolved in a mixture of nitroglycerine or nitro sugar, with a tempering substance
of the class hereinbefore described, the proportion of nitrocellulose, or its aforesaid
equivalent, being such as to produce a compound of sufficient consistency, and
capable of being squeezed out into continuous strings or cords, in manner described
in the Specification of the Patent of 31st January 1888, No. 1470, granted to
Alfred Vincent Newton. Activating oxidisers and combustibles, finely powdered,
are then, by malaxation, incorporated with said compound in such proportion as
to give the requisite activity of combustion to the fuse.
The nitrocellulose, or its aforesaid equivalent, to be employed, should be of
such nature as to be soluble in the aforesaid solvents, or in such of those as may
conveniently be adopted for use.
In order to facilitate the dissolving and string-drawing operation herein indicated,
a volatile solvent, such as acetone, acetate of ethyle, may be added in such
proportion as to produce the plasticity needed, which solvent afterwards readily
evaporates from the strings or cords made.
A very good composition for a fuse is obtained by dissolving 2 parts, by weight,
of nitrocellulose in a mixture of 1 part of nitroglycerine and 1 part of mononitro-
naphthalene (part being here and hereafter understood to mean part by weight),
heated in a water bath, to facilitate the dissolving action. 14 parts of chromate
of potash, and part of ferricyanide of potassium, very finely powdered, are then,

page_text: by malaxation, incorporated therewith, and the material thus obtained is, with or
without the addition of a volatile solvent, as aforesaid, squeezed out, by hydraulic
or other pressure, through a small aperture of such diameter as to obtain a string
of the desired dimension, which in most cases will vary from 1 to 2 millimeters in
diameter.
Of course, the above specified composition can be greatly varied, provided it
fulfils the conditions which constitute the pith of the invention, viz., a perfect
continuity of string, a steady and even burning under all conditions to which
miners' fuses can be subjected, insensitiveness to concussion and percussion, so as
to offer, in practice, every guarantee of safety, and absence of very deleterious
fumes.
Like ordinary Bickford fuses, the fuse herein described ought to be spun round
with a textile material, which protects it from being damaged, but, unlike the
Bickford fuse, it is not deteriorated by water, and it is therefore not needed that
said textile covering should be tarred or otherwise rendered waterproof. Nor is a
covering absolutely necessary, since an uncovered fuse as herein described will
burn even on damp ground; but a protecting covering is always desirable.
Dated this 30th day of October 1893.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Fuses for Mining and similar Purposes.
I PHILIP ARTHUR NEWTON of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
-particularly described and ascertained in and by the following statement :-
Safety fuses have been made from a plastic mass containing nitrocellulose and
nitroglycerine, along with activating oxydisers. Such a fuse is described in the
English Patent of January 31st 1888, No. 1470; but this fuse, owing to its sensi-
tiveness to concussion, has not come into practical use in mines.
The fuse now to be described, and which consists of a new composition of matter
hereinafter described, is entirely free from the aforesaid drawback. It also contains
nitroglycerine, or equivalent material, such as nitro-sugar and nitro-cellulose, or its
equivalents, hydronitrocellulose or oxynitrocellulose, but the sensitive nature of
those explosives is in a very great measure modified by the addition of other
solvents of nitrocellulose, which are neither of a really explosive, or of a volatile
nature, and which are not subject to evaporation, which would render the product
more sensitive to concussion, and more brittle. Amongst such substances may be
mentioned nitronaphthalenes, nitrocymols, nitrobenzols, nitrotoluols nitroxylols,
nitrocumols, acetic ethers of glycerine, and, in general, all substances which are not
volatile, or scarcely volatile, and which dissolve easily nitrocellulose and nitro-
glycerine, or nitrosugar, which is its equivalent for the purpose in view. Such
aforesaid substances as are solid at the ordinary temperature have to be dissolved
in nitroglycerine or its equivalent, for the purpose of incorporating therewith the
nitrocellulose of the product.
:
The following the composition, which gives a very good product, can of course
be greatly varied, but will serve as a type.
In a solvent composed of 100 parts (by parts I understand here and hereafter
parts by weight) of nitroglycerine or nitrosugar, 33 parts of mononitronaphthalene,
33 parts of dinitrobenzol, and 33 parts of di- or trinitrotoluol, I dissolve 200 parts of
⚫ nitrocellulose or its aforesaid equivalent. The solution may be used with either wet
or dry nitrocellulose. In the first case, the incorporation is easily effected by simple
mixing and kneading at, say, 50° C. The greater part of the water contained in

page_text: the mixture is squeezed out by simple pressure, and the surplus is evaporated by
malaxation or kneading, aided by gentle heat. In the second case, the addition of
some volatile solvent, such as acetone, or acetate of ethyle, usefully promotes the
incorporation, but is evaporated, so as not to be contained in the final product.
To 100 parts of the plastic material thus obtained, I add 38 parts of chromate of
potassium and 12 parts of ferricyanide of potassium, both very finely powdered,
and carefully knead them in, so as to obtain a perfectly homogeneous mixture.
The plastic material thus obtained, and which can be rendered as plastic as may
be desired, by incorporating therewith acetone, acetic ether, or other volatile
solvent, serves for the manufacture of lengths of fuse-string by simply pressing out
the compound through an opening in a mould provided with a suitable piston
submitted to mechanical pressure. It is to be understood that the outlet through
which said string emerges, has to be suited to the diameter which it is intended that
the said string should have, and which, in practice, for miners' fuses, will generally
vary from 2 mm., as a maximum, to mm., as a minimum. In the Specification
of the above named English Patent of 1888, No. 1470, the process of squeezing
out strings of the same nature is more fully described; moreover the operation is
very simple, and offers no difficulty if the material is rendered sufficiently plastic.
The aforesaid volatile solvent gradually evaporates, and forms no part of the final
product.
The substances above mentioned as moderating the explosive sensitiveness of
nitroglycerine, nitrosugar, and nitrocellulose, as well as the oxydisers which activate
the combustion, can of course be greatly varied, without departing from their
specific functions herein described, and the substitution of one such substance for
another, simply amounts to the substitution of an equivalent.
The string fuse aforesaid is conveniently covered with a textile coating, in the
same manner as is now practised for the Bickford fuse, but in consideration of its
great resistance to the action of water, the tarring of such textile material, or
otherwise coating it, with a view of making it impermeable, can be entirely dispensed
with; whence results not only considerable economy of manufacture, but also absence
of noxious fumes, on the burning of the fuse in mines. The aforesaid string itself
may be dipped in tar, or equivalent sticky substance, to reinforce its resistance to
the action of water, and also prevent the flame of the burning fuse from leaping
between the string and its coating, and thus causing too rapid combustion of the
fuse to take place.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me from
abroad, I declare that what I claim is :-
The application, in the manufacture of fuses, of a composition of plastic safety
fuse material prepared as and for the purpose above described, such composition
consisting in the combination of nitroglycerine or nitrosugar with nitrocellulose or
hydronitrocellulose, or oxynitrocellulose, and a substance calculated to moderate
the sensitiveness of the compound to concussion (such as nitronaphthalene), and an
oxydiser for securing, in spite of such moderated sensitiveness, the needful regularity
of combustion.
Dated and dox of Aust 1901
NEWTON & SON,
Agents for the Applicant.