Improvements in or relating to Safety Fuses and Boxes therefor.
Year: 1889

page_text: Date of Application, 21st Jan., 1889
Complete Specification Left, 17th Oct., 1889-Accepted, 23rd, Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in or relating to Safety Fuses and Boxes therefor.
We, WILLIAM LOWRIE, Engineer, and CHARLES JAMES HALL, Electrician, both of
117 Bishopsgate Street Within, in the City of London, do hereby declare the nature
of this invention to be as follows:-
We construct our improved safety box of earthenware in one piece, usually in the
form of a long narrow cover, semi-circular or square (with one face omitted), in
cross section; and, with the exception of orifices for the circuit connections, the ends
are closed. The open face is adapted to be attached to a board, or placed against the
wall, and the box or cover is provided with flanges, lugs or other means for the
said attachment. On the outer face, two plug holes are made, one near each extremity,
which communicate with each other by means of a long narrow slot. Holes are also
made in the cover for ventilation.
In addition to the above cover, we provide an earthenware base plate, somewhat
smaller in its superficial dimensions than the open space of the box already mentioned.
At each end of the base plate there is formed a short dovetailed groove to receive and
hold a split tube terminal, exactly beneath the plug holes in the cover. The terminals
are also adapted to receive and bind circuit connections, which are inserted into the
terminals at the ends of the box or cover.
The plugs are key shaped having ebonite or other insulated bows or handles,
suitably connected to the metallic barrel or pin, the latter being formed at the lower
end with a projecting web. A small binding screw is tapped into the centre of each
web to receive and hold the safety fuse which is stretched between the two plugs. A
silk cord, or any other suitable insulating connection, is made between the plugs, in
order to limit their distance apart to the corresponding distance when placed in their
terminals. Should a fuse be burnt out, the two key plugs are withdrawn by their
insulated handles, and a new fuse can be re-fitted to the exact length required; the
cord or other insulated connection serving as a gauge for the length of the same. In
addition to this advantage, the plugs, with the attached fuse, can be immediately
replaced within the cover (through the long slot), the cord withstanding any strain
that might, otherwise, be thrown upon the safety fuse.
It will be seen that instead of the terminals being made with a split tube socket fr
each of the solid plugs,the reverse arrangement may be used,and that a rigid insulated
or insulating connection may be made between the two plugs instead of a flexible
one, to limit their distance apart; and that slate, ebonite or other insulating material
inay be used for the cover or box instead of earthenware, without departing from the
nature of our invention.
This 10th
T
1000
COMPLETE SPECIFICATION.
Improvements in or relating to Safety Fuses and Boxes therefor.
We, WILLIAM LOWRIE, Engineer, and CHARLES JAMES HALL, Electrician, both of
117 Bishopsgate Street Within, in the City of London 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:
In the accompanying drawings, Fig. 1 is a longitudinal vertical section through a
safety fuse box constructed according to our invention, showing the safety fuse in
position therein. Fig. 2 is a plan of the said box, the left hand half being shown in
Price 8d.1

page_text: horizontal section, and Fig. 3 is a transverse section of the same. Figs. 4 and 5 are
respectively a sectional elevation, and a plan, through one of the split tube terminals
used, while Fig. 6 is an elevation, and Fig. 7 a plan of one of the key-shaped plugs
making contact with the terminals just mentioned.
Our safety fuse box a, a, is of one piece of earthenware in the form of a rectangular
cover, the lower face of which is omitted, as shown in Fig. 3. The ends are closed
as shown by Fig. 1, with the exception of orifices, b, b, which are left for the circuit
connections to the terminals c, c. Orifices are also made in the sides, or other parts
of the box, as indicated by d, d, for the purpose of ventilation, and a long narrow
slot e, e, terminating at the ends in circular holes for the plugs f, f, extends through
the top of the box a, nearly its whole length.
The lower or open face of the box a is adapted to be attached to a board. or
placed against a wall, or be mounted upon slate or earthenware, as the case may be.
In the drawings a porcelain base is indicated by g, and this is formed with dove-tail
recesses to receive and hold the terminals c, c, exactly in position beneath the holes
for the plugs f, f, as aforesaid The-box or-cover_and_the_base_g, are provided
with suitable flanges, lugs, or other means for securing the whole apparatus in a
desired position.
The plugs f,f, are key-shaped, and have ebonite or other insulated handles suitably
secured to the metal barrel or pin which is adapted to make good spring contact with
the split tube terminals c, c. The projecting web of the key shaped plugs, have
each a small screw f', to receive and hold the safety fuse which is stretched between
the two plugs f, f, as shown in Fig. 1, and a silk cord i, or any other suitable
insulating connection is fastened between the handles or other part of the said plugs,
to limit their distance apart to the corresponding distance occupied when placed in
their respective terminals c, c. Should a fuse be burnt out, the two key shaped
plugs fure withdrawn by their insulated handles, a new fuse is re-fitted in place
to the exact length required, the cord or other insulated connection i, serving as a
gauge for the same. In addition to this advantage, the plugs, with the attached fuse,
can be immediately replaced within the cover-through the long slot-the cord i
withstanding any strain that might otherwise be thrown upon the safety fuse.
It will be seen that instead of the terminals being made with a split tubo socket for
each of the solid plugs, the reverse arrangement may be used, and that a rigid
insulated or insulating connection may be made between the two plugs instead of a
flexible one, to limit their distance apart; and that slate, ebonite, or other insulating
material may be used for the cover or box instead of earthenware, without departing
from the nature of our invention.
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1-A safety fuse box or cover of earthenware or other suitable non-conducting
material having a longitudinal slot in its outer face with a communicating plug hole
at each end of the slot; substantially as and for the purpose described.
2-An earthenware box or cover having two plug holes and a slot comminunicating
therewith, and an open side or face adapted to cover over, receive, or be attached
to, a non-conducting base piece carrying terminals arranged beneath the said plug
holes; substantially as described.
3-The combination of a safety fuse connected at its ends to removeable contact
pieces having insulated handles, a non-conducting connection between the said
contact pieces adapted to limit their distance apart, and two terminals placed and
adapted to make electrical connection with the said contact pieces at the limit of their
distance apart; substantially as described.
4-The combination of a non-conducting base or support for the two terminals fixed
thereon at a certain distance apart; a safety fuse having at its ends plugs or contact
pieces adapted to fit in or upon the said terminals, a non-conducting cord or connection
between the said contact pieces limiting their distance apart, and an enclosing

page_text: earthenware cover having an extended slot permitting the insertion or withdrawal
of the said fuse and its end connections; substantially as described.
5-
-A safety fuse, electrical connections thereto, and a box or cover therefor arranged
and adapted for use substantially in the manner shown by the drawings Figs. 1 to 3,
inclusive.
6-A plug or terminal having a key shaped web, and adapted to receive one end of
a safety fuse, and to make spring contact with electrical connections; substantially as
described.
13
FAIRFAX & WETTER,
433, Strand, London, Agents for the Applicants.