Year: 1887

page_text: Date of Application, 7th Sept., 1887
Complete Left, 7th June, 1888
Complete Accepted, 13th July, 1888
J
.ש
DIESSTS. DICKford,
Smith & Co., Tucking Mill, Cornwall.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for Foreign Patent
Solicitors 6, Lord Street, Liverpool in the County of Lancaster and 323 High Holborn
in the County of Middlesex, Civil Engineer do hereby declare the nature of this
invention to be as follows:-
.
The object of the present invention is to avoid the failures which often occur in
blasting bore-holes.
The invention consists in an improved construction and arrangement of electrically
fixed cartridges, used in preference to others, which will be hereafter described, and
also in the application on the platinum wire (which unites the conducting wires of the
fuse) of an impervious varnish, exploding under a low temperature. The use of the
said varnish presents the following advantages:
1st. Owing to its imperviousness, this varnish, enveloping completely the buckle of
platinum as well as the extremities of the conducting wires adapted thereto, preserves
the contacts from oxidization, which the proximity of the powder might produce in
course of time, and insures thus indefinitely the perfect conductibility of the wires.
2nd. The varnish being itself an explosive which takes fire at a temperature of about
240 degrees centigrade, it will be readily understood that it is no longer necessary
that the platinum wire should be raised to red heat and that consequently the sensi-
bility of the fuse is considerably increased.
The varnish which is used in preference for the purpose, is collodion, into which it
is sufficient to dip for a moment the platinum buckle and the bare parts of the wires,
but any other varnish or chemical compound, possessing equivalent chemical and
physical properties, may be used.
The result obtained can even be improved, by rolling the parts covered with the still
moist varnish, in priming powder or other explosive substance, which adhers firmly to

page_text: it and which promotes, at the moment the collodion is in combustion, an energetic
vibratory motion, and produces very hot sparks, which pass through the neighbouring
powder and do not fail to light it.
The cartridge is provided with two insulated conducting wires, twisted together and
cut to the required length; they are separated from each other at their upper
extremities; where the insulating substance or envelope is removed. These ends are
then slightly flattened and are bent in the form of hooks. A platinum wire connects
the two ends of the conducting wires, and is secured thereto by simply bending the
ends and introducing them into the aforesaid hooks; the hooks are then turned down.
The platinum wire is dipped along with the ends of the conducting wires into the
explosive varnish which can be coloured variously if this be deemed necessary from a
commercial point of view.
It is at this moment that the varnish (not being yet dry) can be rolled in some
priming powder or any other suitable explosive substance which will adhere firmly to it.
At the upper part of the electric conductors, preferably just below where they are
separated, a sort of ligature is provided, made of hemp or string coated over with wax
or any other similar matter, which is then introduced into a cartridge case made of
paper or paste board; so that the said ligature acts as a tight plug at the lower part
of the cartridge which is afterwards filled up with powder in the usual manner and
closed with a small paper plug over which the extremities of the tube are simply
turned down.
When the fuse is to be used for firing dynamite or other similar cartridges, a copper
cap containing a charge of fulminate of mercury, and constituting the detonator, is
secured in its place by a slight setting or compression of the metal which fits into a
corresponding groove in the aforesaid case or cartouche.
Lastly, when the fuse is finished, it is dipped into an impervious varnish, made
preferably of collodion, because this substance contracts very much as it dries, and
thereby increases the solidity of the fuse, and at the same time protects it entirely
against the effects of dampness. It also closes completely the bottom of the cartridge
at the place where the conducting wires penetrate into it.
Dated this 6th day of September 1887.

page_text: I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for Foreign
Patent Solicitors 6, Lord Street, Liverpool in the County of Lancaster and 323 High
Holborn in the County of Middlesex, Civil Engineer, 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 :-
The object of the present invention is to avoid the failures which often occur in
blasting bore holes.
The invention consists in an improved construction and arrangement of electrically
fixed cartridges, used in preference to others, which will be hereafter described, and
also in the application to the buckle of platinum (which unites the conducting wires
of the fuse) of an impervious varnish, exploding under a low temperature. The use of
the said varnish presents the following advantages.
1. Owing to its imperviousness, this varnish, enveloping completely the buckle of
platinum as well as the extremities of the conducting wires connected therewith,
preserves the contacts from oxidation, which the proximity of the powder might
produce in course of time, and thus ensures for an indefinite time the perfect con-
ductibility of the wires.
2. The varnish being itself an explosive which ignites at a temperature of about
240 degrees Centigrade, it will be readily understood that it is no longer necessary
that the platinum buckle should be raised to red heat, and consequently the sensibility
of the fuse is considerably increased.
The varnish, which is preferably used for the purpose is collodion, into which it is
sufficient to dip for a moment the platinum buckle and the bare parts of the conducting
wires, but any other varnish or chemical compound, possessing equivalent chemical and
physical properties, may be used.
The result can be improved by rolling the parts covered with the still moist varnish,
in priming powder or other explosive substance, which adheres firmly to it, and which
promotes, at the moment the collodion is in combustion, an energetic vibratory motion,
and produces very hot sparks, which penetrate into the neighbouring powder, and do
not fail to light it.
In order to make the invention more clearly understood, my correspondents have
shown on the annexed drawing the best way known to them of carrying their invention
into practice.
In this drawing:
Figure 1 shows the platinum wire placed between the hooked ends of the conducting
wires, and ready to be clinched thereto at both its ends.
Figure 2 shows the conducting wires and the platinum buckle coated with the
explosive varnish.
Figure 3 shows the conducting wires provided with their plug, and introduced into
the cartridge.
Figure 4 is a view of the finished electric fuse provided with its detonator.

page_text: As shown in Figure 1 the two insulated conducting wires a a previously twisted
together and cut to the required length, are separated from each other at their upper
extremities at which points the insulating substance or envelope is removed. These
ends are then slightly flattened and bent in the form of hooks b. A fine platinum
wire or buckle c connects the two ends of the conducting wires, and is secured thereto
by simply bending the ends and introducing them into the aforesaid hooks; the hooks
are then turned down. The platinum wire is dipped along with the ends of the con-
ducting wires into the explosive varnish, which can be coloured variously, if this be
deemed necessary from a commercial point of view.
The appearance of the extremity of the conducting wire is then very much like that
shown at d in Figure 2.
It is at this moment that the varnish (not being yet dry) can be rolled in some
priming powder or any other suitable explosive substance which will adhere firmly to it.
At the upper part of the electric conductors a preferably just below where they are
separated, a sort of ligature e is provided made of hemp or string, or other similar
substance coated over with wax or any other similar matter, which is then introduced
into a cartridge-case of Figure 3 made of paper or paste board, so that the said
ligature e acts as a tight plug at the lower part of the cartridge case, which is after-
wards filled up with powder in the usual manner and closed with a small paper plug,
over which the extremities of the tube fare simply turned down.
When the fuse is to be used for firing dynamite or other similar cartridges, a copper
cap g Figure 4, is applied to the extremity of the case. This cap contains a charge of
fulminate of mercury, and constitutes the detonator, being secured in its place by a
slight setting or compression h of the metal, which fits into a corresponding groove in
the aforesaid case or cartouche.
Lastly, when the fuse, whether provided or not provided with a detonator is finished,
it is dipped as far as the dotted line in Figure 4 into an impervious varnish, made
preferably of collodion, because this substance contracts very much as it dries, and
thereby increases the solidity of the fuse, and at the same time protects it entirely
against the effects of moisture. It also closes completely the bottom of the cartridge
at the place where the conducting wires penetrate into it.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what
claim is:
1. In electric fuses, for mines the coating of the extremities of the conducting wires
and the platinum buckle connecting the same with an impervious varnish (preferably
collodion) which explodes at a low temperature, the said varnish being preferably
afterwards covered with a light coating of priming powder or other suitable explosive
substance, the whole substantially as and for the purpose described.
2. In electric fuses for mines having the platinum buckle coated with an impervious
varnish the mode of attaching the said buckle by simply clinching it to the extremities
of the conducting wires, as herein described and shown on the annexed drawings.
3. In electric fuses, the application to the finished fuse, whether provided or not
with a detonator charged with fulminate of mercury, of a coating of collodion or its
equivalent extending for a short distance along the insulated conductors, in the manner
described and for the purpose specified.
WM. P. THOMPSON & Co.,
Agents for the Applicant.