IMPROVEMENTS IN ELECTRIC FUSES
Year: 1873

page_text: LETTERS PATENT to Charles Ambroso M. Evoy, of the London
Ordnance Works, Bear Lane, Southwark, in the County of Surrey,
for the Invention of "IMPROVEMENTS IN ELECTRIC FUSES."
PROVISIONAL SPECIFICATION left by the said Charles Ambrose
M. Evoy at the Office of the Commissioners of Patents, with
Petition, on the 28th February 1878,
his
I, CHARLES AMBROSE M° EvOY, of the London Ordnance Works,
Bear Lane, Southwark, in the County of Surrey, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN ELECTRIC FUSES," to
bo as follows:—
This Invention has for its object improvements' in electric fuses. For
this purpose I connect together tho and portions of two metal wires by
casting around them melted sulphur, with which powdered glass, sand,
and plaster of Paris. or such like materials, together with colouring
matters if desired, may be added. Wires are placed at a short distanco
apart, and parallel with one another. The sulphur compound is then
cast around them into a cylindrical or other mould. The ends of the wires

page_text: passing from one end of the casing of sulphur compound, and which are
to be coupled up with a battery, may be coated if necessary with any
suitable insulating material. The ends of the wires projecting from tho
opposite end of the casing may be connected by a fine platina wire,
which will become heated on the passing of a current through it, or the
cnds of the wires may be cut off flush with the end of the sulphur
casing, in order that when the two wires are coupled to a battery sparks
may pass from the end of one wire to the end of the other. Over this
end of the sulphur casing is slipped the open end of a long copper or
other metal cap containing fulminating material, and the joint between
the two may be rendered water-tight by shellac, varnish, or otherwise.
By this means I am enabled to construct an electric fuse with the point
of ignition situated within an ordinary metal cap containing fulminate.
In place of encasing the ends of the wires with a compound of sulphur,
as above described they may be encased with gutta percha or other
material, and the end of such casing be similarly inserted into a drawn
metal cap containing the fulminate.
Melted sulphur or compounds of sulphur with other materials, such as
those herein-before mentioned, may also be employed in the construction
of other forms of electric fuse for connecting together the two wires of
the fuse, and at the same time insulating them from one another, as,
for example, in those fuses where the two wires instead of being placed
side by side are placed end to end, the ends of the two wires may be
embedded in a ring of sulphur or sulphur compound, a thin platina
wire connecting the two being slid across the central space of the
ring.
SPECIFICATION in pursuance of the conditions of the Letters Patent
'
filed by the said Charles Ambroso M°Evoy in the Great Seal Patent
Office on the 28th August 1878.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES 30
AMBROSE M Evor, of the London Ordnance Works, Bear Lane,
Southwark, in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing dato the Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-sixth 35

page_text: year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Charles Ambroso Me Evoy, Her special license
that I, the said Charles Ambrose M Evoy, my executors, administrators,
and assigns, or such others as I, the said Charles Ambrose McEvoy,
my executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for " IMPROVEMENTS
IN ELECTRIC FUSES," upon the condition (amongst others) that I, the
said Charles Ambrose Mª Evoy, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
scals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Charles Ambrose M. Evoy, do
hereby declare the nature of tho said Invention, and in what manner
the same is to be performed, to bo particularly described and ascertained
in and by the following statement thereof, that is to say :-
This Invention has for its object improvements in electric fuses. For
this purpose I connect together the and portions of two metal wires by
casting around them melted sulphur, to which powdered glass, sand,
5 and plaster of Paris or such like materials and coloring matters, such as
vermillion and Prussian bluc if desired, may be added. The wires aro
placed at a short distance apart, and parallel with one another. The
sulphur compound is then cast around them into a cylindrical or other
mould. The ends of the wires passing from one end of the casing of
O sulphur compound, and which are to be coupled up with a battery, may
be conted if necessary with any suitable insulating material. The ends
of the wires projecting from the opposite end of the casing may be con-
nected by a fine platina wire, which will become heated on the passing
of a current through it; or the ends of the wires may be cut off flush
5 with the end of the sulphur casing, in order that when the two wires
are coupled to a battery sparks may pass from the end of one wire to
the end of the other, Over this end of the sulphur casing is slipped the
open end of a long copper or other metal cap containing fulminating
"

page_text: material, and the joint between the two may be rendered water-tight by
shellao, varnish, or otherwise. By this means I am enabled to construct
an electric fuse with the point of ignition situated within an ordinary
metal cap containing fulminate.
In place of encasing the ends of the wires with a compound of sulphur, b
as above described, they may be encased with gutta percha or other
material, and the end of such casing be similarly inserted into a drawn
metal cap containing the fulminate.
Melted sulphur or compounds of sulphur with other materials, such as
those herein-before mentioned, may also be employed in the construction 1
of other forms of electric fuse for connecting together the two wires of
the fuse, and at the same time insulating them from one another, as, for
example, in those fuses where the two wires instead of being placed
side by side are placed end to end. The ends of the two wires may
be embedded in a ring of sulphur or sulphur compound, a thin platina 1
wire connecting the two being led across the central space of the
vince

page_text: platinum wire should in this fuse be fastened by solder. Figure 7 is a
longitudinal section of a similar fuse of another shape, the sulphur
compound being caused to clothe the wires for a considerable distance
to ensure making a joint which will remain water-tight during a long
exposure under a heavy pressure. These fuses may be made of various 5
sizes, but usually about one half of the dimensions of the Drawing will
be found convenient.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I
claim,―
1
1st. The construction of electric fuses, consisting of a plug of insulating
material having a solid drawn metal cap secured on to its end, so as to
be water-tight, and in such manner so that the electrical point of
ignition is within the cap, wires or conductors being passed through the
plug, and brought into contact with the explosive material with which 1
the cap is charged, substantially as described and illustrated by Figures 1
and 2 of the Drawings.
I also claim the use of melted sulphur (by preference mixed with
other materials) in manufacturing fuses, substantially in the manner
described.
In witness whereof, I, the said Charles Ambrose M° Evoy, have
hereunto set my hand and seal, this 27th day of August, in the
year of our Lord One thousand eight hundred and seventy-