An Improvement in Electric Fuse Heads for Blasting and for other Purposes.
Year: 1897

page_text: Date of Application, 6th May, 1897
Complete Specification Left, 28th Feb., 1898-Accepted, 2nd Apr.,
1898-
PROVISIONAL SPECIFICATION.
An Improvement in Electric Fuse Heads for Blasting and for other
Purposes.
I, GEORGE PETTINGER, of 98A, Corporation Street, Manchester, in the County.
of Lancashire, Coal Factor and Explosives Merchant, do hereby declare the nature
of this invention to be as follows:
This invention embraces an improvement in electric fuse heads for which a
Patent was granted to me dated June Sth 1895 and numbered 11,283.
The invention forming the subject-matter of my prior application consists of
a fuse head constructed of a tube of wood, porcelain, or other material, having
a tapered bore. In this tube are secured two wires, used for conducting the
firing charge of electricity, by first threading the said wires therethrough and
then bending them at a suitable distance from the ends thereof, so that the
portion between the bend and ends of the wire lies parallel, or nearly so, to the
remainder thereof.
After baring the said wires at or near the bend, and, when desired, connecting
the bared portions thereof by a fine platinum wire, the wires are drawn into the
tube in such a manner that the bent portion thereof eventually jambs in the tube
at or near the middle of the bore, thus leaving a space for the introduction of an
explosive compound. My prior application also embraces a special explosive
compound.
By my present invention I use a fuse head constructed, as before, of a tube
having a tapered bore, and thread the two wires for conducting the firing charge
of electricity through the said tube and then bend them at a suitable distance
from the ends thereof, so that the portion between the bend and ends thereof
lies parallel, or nearly so, to the rest of the wires. I then make a second similar
bend in the same direction in this end of the wires thus forming a double fold
or bend having the end of the wires within it; the ends of the wires, bared of
insulating substance for a sufficient length, are then, in the case of a high tension
fuse head, bent down across the crown of the bend or fold, the bared portions being
separated by a distance of 1/16th inch or thereabouts, so that the necessary spark
for ignition may pass between them. In the case of a low tension fuse head,
the ends of the wires are not bent down across the bend or fold, but simply
united by a suitable bridge of fine platinum wire or the like. The wires are
now drawn into the tube so that the bent or folded portion thereof eventually
jambs at or near the middle of the bore, as in my previous application, leaving
a suitable space for the introduction of the necessary explosive compound. The
fuse head is then secured to the fulminate of mercury tube in the usual manner,
and the whole is ready for use.

page_text: An Improvement in Electric Fuse Heads for Blasting and for other
Purposes.
I, GEORGE PETTINGER, of 98A, Corporation Street, Manchester, in the County
of Lancashire, Coal Factor and Explosives Merchant, 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: ·
This invention embraces an improvement in electric fuse-heads for which a
Patent was granted to me dated June 8th 1895 and numbered 11,283.
The invention forming the subject-matter of my prior application consists of
a fuse-head constructed of a tube of wood, porcelain, or other material, having
a tapered bore. In this tube are secured two wires, used for conducting the
firing charge of electricity, by first threading the said wires therethrough and
then bending them at a suitable distance from the ends thereof, so that the
portion between the bend and ends of the wires lies parallel, or nearly so, to the
remainder thereof.
After baring the said wires at or near the bend, and, when desired, connecting
the bared portions thereof by a fine platinum wire, the wires are drawn into the
tube in such a manner that the bent portion thereof eventually jams in the tube
at or near the middle of the bore, thus leaving a space for the introduction of an
explosive compound. My prior application also embraces a special explosive
compound.
By my present invention I use a fuse-head constructed, as before, of a tube
having a tapered bore, and thread the two wires for conducting the firing charge
of electricity through the said tube and then bend them at a suitable distance
from the ends thereof, so that the portion between the bend and ends thereof
lies parallel, or nearly so, to the rest of the wires. I then make a second similar
bend in the same direction in this end of the wires thus forming a double fold
or bend having the ends of the wires within it; the ends of the wires, bared of
insulating substance for a sufficient length, are then, in the case of a high tension
fuse-head, bent down across the crown of the bend or fold, the bared portions being
separated by a distance of 1/16th inch or thereabouts, so that the necessary spark
for ignition may pass between them. In the case of a low tension fuse-head, the
wires are not bent down across the bend or fold, but simply united by a suitable
bridge of fine platinum wire or the like. The wires are now drawn into the
tube so that the bent or folded portion thereof eventually jams at or near the
middle of the bore, as in my previous application, leaving a suitable space for
the introduction of the necessary explosive compound. The fuse-head is then
secured to the fulminate of mercury tube in the usual manner, and the whole is
ready for use.
I will now proceed to further describe my invention in connection with the
accompanying drawings in which the same letters of reference indicate like parts
in the various figures.
Fig. 1 is an enlarged sectional view of a fuse-head constructed according to
my invention, and
Figs. 2 and are plan views thereof.
The tube has a tapered bore in which is jammed the end of the wires b for
conducting the firing charge of electricity.
This end of the wires is bent so as to form a double fold c as previously
described, and the ends of the wires are stripped of insulation, and such stripped
parts are bent down across the crown of the bend (and have a space of about

page_text: 1/16th of an inch, or thereabouts, between them, as shown in Fig. 2), in the case
of a high tension fuse, but have their ends simply united by a platinum wire or
the like bridge, as shown in Fig. 3, in the case of a low tension fuse.
The explosive d is placed in the tapered tube previously to placing the latter
in the fulminate tube, and exploded, when necessary, in the usual manner.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
(1) Wires, for conducting the firing charge of electricity to high or low tension
fuse-heads, having a double fold in the ends thereof attached to the fuse-head
and having a short stripped length at the extremities of the said ends arranged
for conducting the necessary spark or heat for firing substantially as described.
(2) The method of bending and arranging the ends of the wires for conducting
the firing charge to high or low tension electric fuse-heads substantially as
described.
Dated this 95th day of 1000
CASTLE SMITH,
"Invention" Office, Mitre Court, Fleet Street, London, E.C.,
Agent for the Applicant.