An Electric Fuse.
Year: 1898

page_text: TRUVIDIONAL DIMITICATION.
An Electric Fuse.
JOSEPH GERSHOM CHILDS, 33, Myddleton Square, Clerkenwell, E.C., Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-.
An electric fuse arrangement consisting of one or more wires enclosed in
insulating material so that upon the fuse being blown, the ensuing flames &
other products shall be restrained from escaping except at a distance sufficiently
remote from the terminal of supply as to prevent the continuance of an aro
between the terminal of supply and any other conducting material that might
come into circuit. To effect this place the fuse wire within a tube of insulating
material or within a passage through a block of insulating material and close
one end of the said tube or passage. This arrangement constitutes an important
improvement in electrical fuses especially when used in combination with Bates
fuse Patent No. 2703 A.D. 1893.
Dated this 92nd day of tunst 1808
JOSEPH GERSHOM CHILDS.
An Electric Fuse.
I, JOSEPH GERSHOM CHILDS, 33, Myddleton Square, Clerkenwell, E.C., Elec-
trical Engineer, do hereby declare the nature of this invention and in what
manner the same to be performed to be particularly described and ascertained
in and by the following statement:-
My invention relates to an electric fuse device, which is specially suitable for
use on high tension circuits.
The object if my said invention is to construct an improved device which
when the fuse is blown shall prevent the flames and other products of combus-
tion or volatilisation from escaping except at a distance sufficiently remote from
the supply terminal as to prevent the continuance of an arc between such ter-
minal and any conducting material which might be in or come into circuit.
According to my invention I place the fuse wire or wires within a tube of
insulating and incombustible material or within a passage through a block of
such material, one end of said tube or passage being closed. By this arrange-
ment when the fuse blows the flames and products are expelled from one end
of the tube with great violence and rupture the arc which is formed. Further-
more, that end of the tube which is nearest the supply terminal is made the
closed end, so that the flame escapes at a place remote from such terminal,

page_text: My invention will be clearly understood by the following description, refer-
ence being made to the accompanying drawing, in which
Figure 1 is a side elevation partly sectional of my improved fuse, the ter-
minals of the circuit to which it is to be attached not being shewn.
Figure 2 is a section on the line 2-2 Figure 1.
Figure 3 is a section on the line 3-3, Figure 1 and
Figure 4 is a plan of the fuse.
Figures 5 and 6 are sectional views illustrating modifications hereinafter
explained.
A is a tube of insulating an incombustible material such as vulcanised fibre
for example. One end of the tube A is fitted with a metallic plug B a portion
of which is arranged to project through the side of the tube A as shewn. Said
plug has an orifice B₁ through which the fuse wire is passed, said fuse wire,
which is indicated at C, being secured in the piece B by means of a pinching
screw B the pinching screw 132 also serves to secure the plug B in position
in the tube. The other end of the fuse wire is brought outside the tube A
through the open end A¹ thereof and attached to a terminal 1) which may be
secured to the tube A in any suitable manner. For convenience in handling
the fuse and inserting it in position I provide handles E of insulating material,
and the metallic portion of the terminal D is covered with an insulating sheath D¹
as shewn.
After the fuse wire has been secured in position, the orifice through
the part B is closed by a screw plug B³ which however may be dispensed with
if the pinching screw 132 is large enough to fill the orifice through the part B.
In place of securing the fuse wire in the orifice B¹ by means of a screw B2
passing through the side of the part B I may grip the wire between the end of
the plug B3 and a corresponding shoulder in the part B as shewn in Figure 5.
Or I may screw thread the end of the part B externally to receive a cap B
which may be of any suitable material, the end of the fuse wire being held
between the inside of the cap, and the end of the plug as shewn in Figure 6.
Various other methods of holding the fuse wire may be adopted.
The circuit to which the fuse is to be attached will be fitted with terminals
adapted to engage with the parts B and D of the fuse, and prefer to make
said parts of a different shape, B for example taking the form of a plug and D
that of a pair of jaws. The terminals of the circuit will be correspondingly
shaped and that on the supply main is arranged to receive the part B: by this
means I ensure that the fuse shall be placed in proper position, and that the
open end A¹ of the tube shall be as far as possible from the supply terminal.
The operation of my device is very simple. If the fuse blows, the products
of combustion and volatilisation, and in fact everything contained within the
tube A are forced out of the open end A¹ and the other end of the tube being
closed no flames will appear at this part. Consequently any arc which may be
formed between the supply terminal and the walls of the casing containing the
fuse, or any other metallic object, will necessarily pass through the entire length
of the tube A and will be certain to be interrupted owing to the blast at the
orifice A¹ of the tube. With my improved device, the blast which is formed
by the out rush of the gases from the tube is very much stronger than would
be formed if said tube were open at both ends. Furthermore, no flames are
formed at any place near the supply terminal, since the end of the tube to which
such terminal is attached is closed.
It will be understood that I do not limit my invention to the fuse shewn in
the drawings and hereinabove described; it is clear for example that the wire
is not necessarily brought out at the open end of the tube, because the ter-
minal D may be arranged to project into the tulie and be provided with a pinch-
ing screw in the same manner as the part B or the part D may be arranged
to be attached to the supply terminal and the part B to the other terminal, in
which case the end A¹ of the tube will be closed up, the other end being left
open. Furthermore, the use of a tube such as A is not essential to the practice

page_text: of my invention: all that is necessary is that the fuse wire should pass through
a passage in a lock of insulating material which passage is open only at that
end remote from the supply terminal. My improved electric fuse is especially
suitable for use with high tension circuits, but may obviously be arranged in
place of any ordinary description of fuse.
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. An electric fuse, in which the fuse wire is located within a passage formed
in a block of insulating material, said passage being open only at that end which
is remote from the supply terminal of the circuit to which the fuse is to be
connected, for the purpose specified.
2. An electric fuse constructed and operating substantially as herein described.
1000
W. P. THOMPSON & Co.,
322 High Holborn, London, W.C.,
Patent Agents for the Applicant.