Year: 1887

page_text: Date of Application, 8th Dec., 1887
Complete Specification Left, 6th Sept., 1888
Complete Specification Accepted, 12th Oct., 1888
I, ALFRED VINCENT NEWTON, of the Office for Patents, 6 Bream's Buildings.
Chancery Lane in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of this invention to be as follows:-
Fulminate of Mercury, which is largely used for charging detonators, has the
double disadvantage of being very expensive, and highly dangerous. On that account,
efforts have been made, but hitherto without success, to substitute for the said
fulminate, such explosives as Picrate of Potassium, and Picrate of Lead, in conjunction
with a Chlorate. It has however been found by experiment, that when charging
detonators with such explosives in a granulated state, a very different result is
obtained, the same explosive substance, which is quito unfit for detonators when
charged like fulminate in a powdered state, becoming, when granulated, almost as
violent as fulminate of mercury, and as efficacious when exploded in a detonator.
Various explosives brought to a granulated state can thus be utilized for charging
detonators, such as powder composed of Chlorate of Potassium, carbon, and sulphur,
in well known usual proportions, or mixtures of picrates and chlorates in explosive
proportions, or mixtures of ferrocyanides or ferricyanides with chlorates. The
granulation is effected in the same manner as that of gunpowder, and the ingredients
are to be intimately mixed in a state of very fine powder, and moistened with water, or
with a solution of gum or gelatine, if needed, for giving greater consistency to the
grains.
In order more closely to confine the charge in the detonator, the metallic tube is
subjected to a moulding pressure at the mouth end, so as to give it a form somewhat
resembling that of a bottle. This also provides for the insertion in the detonator of a
large charge of explosive, while its upper end remains small enough to fit the common
safety fuse.

page_text: The filling or charging of detonators with a granulated explosive is of course a very
simple operation, which needs no describing. In order to fix the powder in the
detonator, and prevent its falling out, it may either be slightly compressed therein, or
it may be fixed with a drop of collodion, or by putting in, over the charge, a small
plug of gun-cotton, or by any other suitable means.
Detonators requiring an unusually strong charge, mostly in request for military
uses, may be produced by the use of two tubes or caps, so joined that the outer one is
bottle shaped, as above described, and the inner one shaped as a common detonator
tube or cap, which fits exactly into the mouth part of the outer tube. The outer tube
or bottle is charged with Nitromannite, Picric Acid, or some such sluggish explosive.
which, under the action of a common detonator, explodes with utmost violence. The
inner tube, inserted halfway into the outer one, receives a charge of fulminate of
mercury, and is fixed to the outer tube by slightly squeezing them together. When
the fire from a fuse reaches the fulminate in the said inside cap or tube, the charge
in the outer tube also detonates most violently, producing an offect much greater
than if the entire charge consisted of fulminate of mercury.
Dated 8th day of December 1387
NEWTON & SON,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Detonators.
I ALFRED VINCENT NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Mechanical Draughtsman 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:
Fulminate of mercury, which is largely used for charging detonators, has the
double disadvantage of being very expensive and highly dangerous. On that account,
efforts have not been wanting, but hitherto without success, to substitute for the said
fulminate, such explosives as picrate of potassium and picrate of lead, in conjunction
with a chlorate. On compressing these substances in a detonator tube, in the same
manner as fulminate of mercury is usually compressed, the charge, when ignited,
explodes only partially, and the effect produced is very unsatisfactory. Experiment,
however, has proved that by granulating the aforesaid substances, and similar
explosives, a very different result is obtained, and although, in the ordinary pulverulent
state, this class of explosives is entirely unfit for charging detonators, they become
highly efficacious when made up into minute grains of say 3,000 to 10,000 per
gramme.
A granulated fulminate of very good quality is obtained by mixing intimately 2 parts
by weight of collodion cotton dissolved in 12 parts by weight of acetone, 1 part by
weight of nitroglycerine, 4 parts, also by weight, of picrate of potash, and 8 parts by
weight of chlorate of potash, the latter ingredients very finely powdered. Upon
evaporation of the said acetone, the explosive thus formed is sufficiently brittle to be
easily broken up into grains. It should be understood that the afore specified
composition is not the only one which is suitable, when made up into grains, for
charging detonators, for almost any picrate, when mixed in explosive proportions with
a non-hygroscopic chlorate, will do; also, chlorates mixed with charcoal and sulphur ;
also, nitrate of lead and other non-hygroscopic nitrates mixed with charcoal and
phosphorus, or with a ferrocyanide, or cyanide, in explosive proportions. All such
substances, however, are only fit for charging detonators on being granulated, and it
is the granulation of fulminates to be used for detonators, which is the main feature of
the present invention.
When the compound to be used does not offer sufficient consistency to give the
requisite hardness to the grains, a small quantity of gum, dextrine, or collodion
solution, may be added, in order to obtain such consistency, but the quantity of
dextrine or gum should in no case exceed per cent of the weight of the
compound.
The granulated fulminate wherewith detonators are to be charged, may be secured
in the tube either by compression, in the same manner as granulated gunpowder is
now fixed in the well known compressed-powder cartridges; or the charge may be
rendered adherent by inserting in the detonator a drop of collodion; or the charge

page_text: may be prevented from falling out by applying a small plug of guncotton, or a cap or
cover of nitrated paper.
As the granulated fulminate herein described is very inexpensive, it is desirable
that the charge of detonator tubes should be increased beyond the present limit. For
such purpose, bottle-shaped detonator tubes or cases are used, the same being made of
steel, copper, brass, hardened lead, or other suitable material.
In the accompanying drawing, Fig. 1 shows in longitudinal section a bottle shaped
detonator tube filled with granulated fulminate according to this invention.
The way of producing this novel form of detonator tube is first to manufacture a
metallic tube of the required diameter by the ordinary method of drawing, and then,
by compression, to reduce the diameter of the open end to the bottle neck shape, so
that it may fit the common fuse.
For detonators of exceptional energy, needed chiefly for military purposes, the
arrangement shown in longitudinal section at Fig. 2 is adopted. In this figure, a is
an external bottle shaped tube charged with the granulated explosive b, into which is
inserted a tube c, charged with, say, a gramme of fulminate of mercury. To secure
the tube c in place, pressure may be applied to the neck of the bottle.
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
by my foreign correspondent, I declare that what I claim is :-
1. In the manufacture of detonators, the use of granulated fulminates prepared as
and for the purpose above set forth.
2. The bottle-shaped detonator tube herein described.
3. The double detonator herein described, consisting of a fulminate detonator fixed
into a bottle-shaped detonator charged with another explosive, substantially as herein
described.