Improvements in High and Low Tension Electric Fuses.
Year: 1894

page_text: Date of Application, 16th Jan., 1894
Complete Specification Left, 16th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in High and Low Tension Electric Fuses.
BENJAMIN DEAKIN Electrical Engineer 2 Raeburn Street The Avenue Brixton
S.W. do hereby declare the nature of this invention to be as follows:-
The improvement of high and low tension fuses composed of a single or several
wires and led through a straight passage formed in a handle or block of insulating
and incombustable material such as described in the Specification of British Patent
No. 2703, 1893 for improvement in fuses granted to Darwin Bates. It being found
in practice that when such fuses are blown with an electric current the action that
takes place inside the aforesaid passage has the effect of depositing a film or
coating of copper (or such other metal of which the fuses is composed) inside or on
the inner surface of the said passage thus rendering the said passage and handle a
conductor in itself. Since it is no longer a non-conductor it follows that the cost
of renewals and the necessity of stocking them must be comparatively an expensive
item in any lighting station or installation of reasonable proportion.
In carrying my invention into practice, in order to increase the efficiency and to
avoid the frequent renewals of the handle or block of incombustable insulating
material (hereinafter called the handle) when effected by the copper or other
metallic deposit (as hereinbefore mentioned) I provide the handle with a movable
passage or part (arranged for the passage of the fuse wire or wires, and for the
reception of the aforesaid metallic deposit) preferably in the form of a renewable
incombustable and insulating tube (hereinafter called the tube) which passes through
a passage formed in the handle and is connected preferably at each end of the said
handle or passage and in order to make a further provision for cooling the tube
in addition to the air that may pass centrally through it I form a recess in the
interior of the aforesaid passage through the handle so as to leave an air space
around the tube when it is in position, the said recess terminating at or as near the
ends of the handle as may be necessary or desirable for leaving sufficient substance
for connecting or supporting the tube. This additional air or cooling space between
the outer surface of the movable tube and the inner surface of the passage through
the handle has the advantage of admitting of the employment of smaller fusiable
conductors.
Instead of recessing the passage through the handle, an air space may be
formed by making the tube of a smaller size or diameter (than the said passage)
between the spaces or part at its ends, by which its connection with the handle is
formed so as to leave an air space around such reduced part of the tube, and to
provide for the admission and passage of air into and through the aforesaid air
spaces, the ends or other suitable part of the tube or of the handle are arranged
with suitable grooves or apertures opening into the said spaces surrounding the
tube which is connected with the handle by one end fitting a parallel hole and the
other end tapered to fit a taper hole in the other end of the said handle so as to be
forced into it and held by compression or it may be formed so as to be held to the
handle by a screw or other suitable holding or retaining device admitting of its
ready withdrawal or disconnection from the handle for renewal.
The movable tube may be moulded, formed or composed of any suitable
incombustable insulating material such as plaster of Paris, manufactured asbestos,
unglazed pottery, ground and compressed pumice stone, mica, etc.
16th January 1894.

page_text: COMPLETE SPECIFICATION.
Improvements in High and Low Tension Electric Fuses.
BENJAMIN DEAKIN Electrical Engineer 4 Farm Avenue Streatham S.W. 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 :-
The improvement of high and low tension fuses composed of a single or several
wires and led through a straight passage formed in a haudle or block of insulating
and incombustable material, such as described in the Specification of British Patent
No. 2703, 1893 for improvement in fuses granted to Darwin Bates. It being found
in practice that when such fuses are blown with an electric current the action that
takes place inside the aforesaid passage has the effect of depositing a film or coating
of copper (or such other metal of which the fuses is composed) inside or on the
inner surface of the said passage thus rendering the said passage and handle a
conductor in itself, since it is no longer a non-conductor it follows that the cost
of renewals and the necessity of stocking them must be comparatively an expensive
item in any lighting station or installation of reasonable proportion.
In carrying my invention into practice in order to increase the efficiency
and to avoid the frequent renewals of the whole handle or block of incom-
bustable insulating material (hereinafter called the handle) when coated by the
copper or other metallic deposit (as hereinbefore mentioned) I provide the handle
with a movable passage or part (arranged for the passage of the fuse wire, wires,
or conductors and for the reception of the aforesaid metallic deposit) preferable in
the form of a renewable incombustable and insulating tube (hereinafter called the
tube) which passes through a passage formed in the handle and is connected
preferably at each end of the said handle or passage, and in order to make a
further provision for cooling the fuse and tube in addition to the air that may pass
centrally through it, I form a recess in the interior of the aforesaid passage through
the handle so as to leave an air space around the tube when it is in position,
the said recess has one end increased as or as near the end of the handle as
may be necessary or desirable for sufficient substance for connecting or supporting
.the tube.
This additional air or cooling space between the outer surface of the movable
tube and the inner surface of the passage through the handle, has the advantage of
the employment of smaller fusiable conductors. Instead of recessing the passage
through the handle an air space may be formed by making the tube of a smaller
size or diameter (than the said passage) between the spaces or part at its ends, by
which its connection with the handle is formed so as to leave an air space around
such reduced part of the tube, or the two methods may be combined, and to provide
for the admission and passage of air into and through the aforesaid air spaces, the
ends or other suitable part of the tube or of the handle are arranged with suitable
grooves or apertures opening into the said spaces surrounding the tube which is
connected with the handle by one end fitting a parallel hole and the other end
tapered to fit a taper hole in the said handle, so as to fit into and held by compression,
or it may be formed so as to be held in the handle by a screw or other suitable
holding or retaining device admitting of its ready withdrawal or disconnection from
the handle for renewals.
The movable tube may be moulded, formed or composed of any suitable
incombustable insulating material such as plaster of Paris, manufactured asbestos,
unglazed pottery, ground and compressed pumice stone & etc. etc.

page_text: Fig. 3. shows the tube detached from the handle.
Fig. 4. shows taper end showing grooves for air passages.
Fig. 5. shows parallel end showing grooves for air passage.
A. shows the handle arranged with tube B. having grooves, a, leading into air
space a'. C shows the arrangement of the fuse through the tube.
Having particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
I claim the arrangement and combination of the tube and air space passage or
passages with the fuse and handle substantially in the manner and for the purpose
herein described and shown by Figs. 1. 2. 3. 4 & 5 of the drawing hereto annexed.
October 16th 1894.
BENJAMIN DEAKIN.