Year: 1886

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention (a communication to me
from abroad by Henry Julius Smith of Mountain View, Passaic County, State of
New Jersey, United States of America) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This Invention relates to electric fuses used in connection with an electric
generator and circuit for igniting fireworks from a distance.
The object of the Invention is to provide means for holding the electric wires
rigidly in place in the fuse casing, and for retaining the explosive charge in the
fuse casing without the employment of a metallic head to the case.
The Invention consists in the combination with the casing, of electric wires held
rigidly in proper relation to each other by a metallic clamp and secured in the
casing by means of cement; a fine wire of high resistance connecting the inner
ends of the electric wires, a filling of explosive material packed around the electric
wires and in contact with the fine wire and a plug or cap of compressed explosive
or combustible material secured in the end of the fuse case for retaining the
granulated powder or other explosive in the fuse case.
Reference is to be had to the annexed drawings forming a part of this
specification in which figure 1 is a side view partly in section of a fuse made
according to this improvement; figure 2 is a longitudinal section Figure 3 is a
perspective view of the clamp and wires detached from the case; figure 4 is a
transverse section taken on line x in figure 1. Similar letters of reference
indicate corresponding parts in the different figures of the drawings.
The casing A which contains or supports the other parts of the fuse is preferably
made cylindrical in form and provided with a bead a near one end for holding the
cement or packing in place. A clamp B formed of a strip of sheet metal bent over
or returned upon itself and embracing the insulated wires b holds the insulated
wires parallel with each other. The clamp B fits snugly into the casing A and
supports the wires in proper relation to each other and to the casing so that they

page_text: cannot accidentally come in contact with each other within the casing. The
inner ends of the wires b are stripped of their insulating covering and rendered
unoxidable by a coating of tin or otherwise, and their extremities are bent toward
each other and connected by a fine wire o of high resistance, the wire being
preferably made of platinum. Opposite ends of the wires b project beyond the 5
casing A and are securely fastened in the casing by a quantity of insulating
cement & poured into the casing around the wires b, melted sulphur being preferred
as a cement for securing the wires in the case. The case A, between the cement
and the opposite end, is nearly filled with granulated powder or other suitable
explosive closely packed around the wires b and around the fine platinum wire o
and the explosive charge contained by the casing is secured therein by a disc or
plug C of meal powder or analogous material forced into the open end of the
casing A and into contact with the explosive contained by the case.
electric current having the proper quantity and intensity is sent through the
wires bb the resistance offered by the fine wire c causes it to be heated igniting 1
the powder contained by the casing, causing it to explode and force out the
combustible plug C which becomes ignited and also explodes, thereby freely
communicating fire to the explosive contained by the fire-works in connection
with which the fuse is used. By employing a combustible or explosive plug C for
closing the end of the case A, the uncertainty common to fuses closed by a metallic
cap is avoided, and the destructive explosion of the fire works is also obviated.
When an
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is ;-
1. In an electric fuse, the combination of separated insulated wires connected at:
their inner ends by a fine wire of high resistance, the sheet metal clamp folded
over the fuse-wires, and the casing enclosing the clamp, the ends of the wire
conductors, the fine wire and an explosive, substantially as herein shown and
described.
2. In an electric fuse, the combination of the cylindrical casing A for holding
the electric wires and the explosive charge in proper relation to each other, the
insulated wires bb the clamp B embracing the wires, the fine wire c of high
resistance joining the ends of the wires b and an explosive contained by the
casing A and surrounding the ends of the wires bb and the fine wire c sub-
stantially as herein shown and described.
3. In an electric fuse, the combination of the cylindrical casing A for holding the
electric wires and the explosive charge in proper relation to each other, the
insulated wires b b, the clamp B embracing the wires, the fine wire c of high
resistance joining the ends of the wires b, the cement d filling the end of the
cylinder and surrounding the wires 6 and an explosive contained by the casing A
and surrounding the ends of the wires b b and the fine wire c substantially as
described.
4. The combination with the casing A containing coarse and fine wire conductors
surrounded by an explosive as described of a combustible plug or disc inserted in
the end of the case for retaining the explosive charge in the case, substantially as
described.