Improvements in Electrical Cut Outs.
Year: 1896

page_text: Date of Application, 31st Jan., 1896
Complete Specification Left, 28th Oct., 1896-Accepted, 16th Jan., 1897
Improvements in Electrical Cut Outs.
1, HUGO HIRST of 71 Queen Victoria Street in the City and County of London,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in electrical cut outs and has for its object
the prevention of the formation of an electrical arc when the fuse is ruptured and
injury to the adjacent parts resulting therefrom.
In carrying my invention into effect I construct a cut out with a dividing bridge
of an insulating and non-inflammable substance, this division or bridge is provided
with a hole or slot through which the fuse is led in a zig-zag or indirect course in
such a manner as to interpose between the fuse terminals the isolating division aud
thus break down or prevent the formation of an are between the terminals when the
fuse is melted by an excess of current.
100
FREDK. WALKER,
Fellow of the Society of Patent Agents,
88 Queen Victoria Street, Agent for the Applicant.
1, HUGO HIRST of 71 Queen Victoria Street, in the City and County of
London, Electrical Engineer, 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 :-
My invention relates to certain improvements in electrical cut outs, and has for
its object the prevention of the formation of an electrical arc when the fuse is
ruptured and the injury to the adjacent parts resulting therefrom.
In order that my invention may be the better understood I have appended the
accompanying 4 sheets of drawings, in which
Figure 1 Sheet 1 is a plan view of a cut out, with the cover removed, and
Figure 2 is a sectional elevation thereof, showing the cover in situ.
Figure 3 is a plan view of a modification, and Figure 4 a sectional elevation
thereof. This modification is especially designed with a view to perfectly ventilate
the cut out, and dissipate any heat generated therein.
Figures 5. 6. and 7 are plan views of other modifications.
Figure 8 is a plan view of another modification, with a ventilating device.
Figure 9 Sheet 2, is a plan view of another modification, and Figure 10 a plan
of a modification including a ventilating device, and Figure 11 is a sectional
elevation thereof upon the line A B.

page_text: Figure 12 is a plan view of a further modification, as also are Figures 13, 14,
and 15 upon the same sheet.
Figures 16, 17, 18 and 19, Sheet 3 are also modifications.
Figures 20, 21, 22 and 23 are modifications of multiple circuit single pole cut outs
and
Figure 24, Sheet 4 is a four circuit double pole cut out combination all of which
are upon the same principle, based upon the essential features embodied in my
said invention.
Similar letters of reference indicate corresponding parts throughout the several
views, and for the most part the plan views are merely diagrammatic, the points in
detail being omitted for the sake of clearer enunciation.
In carrying my invention into effect I employ an insulating base of china,
porcelain, slate or the like A Figures 1 and 2, Sheet 1, upon which two terminal
plates are oppositely disposed, each carrying a fuse terminals s' and a lead
terminal tt. A dividing wall B is formed upon or attached to the base A and the
fuse or fusible conductor f is carried through a slit or hole in B from one terminal s
to the other terminal s. Now, in the event of the fuse melting by increase of
current it is impossible, by reason of the interposed wall B, for an are to be formed,
nor the terminals s ' t t to be short circuited by pieces of melted metal. It is a
desirable feature in the construction of this type of cut out, according to my said
invention, that the cover or cap C should fit closely upon the wall B when screwed
or otherwise fixed in its closed position. Referring now to Figures 3 and 4, I have
modified the construction so as to divert the path of the fuse f by passing it round
a central projection forming part of the wall B, said projection having a central
orifice h open to the air through an orifice in the cover C, Figure 4. Transverse
ventilating holes are also provided to ventilate the interior of the cut out. In
the diagram Figure 5, the wall B is cruciform and the terminals ss' t t are divided
by one member of the wall, and the fuse is diverted by being passed through slits
or holes in the other three members. Figure 6 illustrates a modification as to
shape. Figure 7 is a diagram showing a Twall B, which is slightly hollowed to
allow of a free passage of air around the fuse f. Figure 8 shows a wall B of
different shape, with a ventilating hole h with transverse holes opening into it as
shown by the dotted outlines v. In this case the cover is provided with a hole
communicating with the hole h. Figure 9 is a diagram showing a modification of
the arrangement shown by Figure 7, which admits of ventilation by a central hole h
and transverse holes v. Figures 10 and 11 show a modification based upon the
lines of Figure 5 Sheet 1, with a central ventilating hole h and transverse holes v.
The cover C in this case is not screwed upon the base at its outer diameter but
upon a boss formed upon the wall B, or by any other suitable device, a circular
groove g in the base A receiving the lower edge of said cover C. This kind of
cover may be adapted to each modification herein specified. Figure 12 is a
modification in which the base A is provided with projections or walls B B¹
through which the fuse f passes. A central wall of the cover C passes between
the insulating walls B B₁ thus affording a further protection against the formation
of an arc.
Figure 13 is a modification of Figure 1 Sheet 1, with a central ventilating hole h
and a transverse hole opening therein from the case. Figure 14 is a diagram
showing a diverted path in which the fuse f is carried by blocks or walls B with
interspaces for ventilation. Figure 15 upon the same sheet is a modification
thereof. Figures 16 and 17 Sheet 3 show alternative devices or adaptations.
Figure 18 is a diagram showing a device which is a modification of that shown by
Figure 12, the base having a wall B bifurcated at each end, the cover C being
shaped to fit over it. A central screw t may be used to hold the cover C in
position, or any equivalent means. Figure 19 is a diagram showing an arrangement
with two walls B B upon the base A, the fuse being diverted as shown.
Figure 20, Sheet 4, shows the adaptation of my invention to groups of single pole
cut outs in which the attachments s and the fuses fare sunk beneath the surface of

page_text: the base A, so that perfect isolating walls divide the attachments S and also the
separate fuses. Figure 21 shows a modification with two raised walls B B' upon
the base A through which the fuses f pass. Figure 22 is a modification with a
single wall B, and Figure 23 is a modification of Figure 20 with open central
interspaces and the two lower fuses F. F shown as strips with suitable
terminals S S'. In Figures 20, 21, and 23 the terminal connections are arranged
at the back of the base A, but any equivalent method or means for conveniently
placing said connections may be employed. Figure 24, upon the same sheet shows
a four-circuit double pole cut out, in which the fuses f are carried through dividing
walls or partitions B in an irregular direction as shown. I may, in carrying out
my invention, adapt these cut outs to any number of poles or circuits.
Having now 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 :-
First. In electrical cut outs the provision of an isolating division between the
terminals under, over or through which division the fuses pass to prevent the
formation of an arc substantially as herein described, with reference to the appended
drawings.
Second. In electrical cut outs, the method of and means for diverting the path
of the fusible conductor, and the interposition of a wall, walls, or dividing media
of insulating material or substance to prevent short circuiting or the formation of
an arc, substantially as herein described with reference to the appended drawings.
Third. In electrical cut outs the combination of a base A, terminals ss¹tt
fusible conductor f with a dividing or isolating wall B substantially as and for the
purposes herein described with reference to the appended drawings.
Fourth. In electrical cut outs as referred to in the preceding claims, the method
of and means for ventilating the interior by a hole h and transverse holes or orifices v
substantially as herein described with reference to the drawings.
Dated this 12th dox of October 1896
FREDK.
WALKER,
73, St. Stephen's Road, Upton Park, E.,
Late of 88 Queen Victoria Street, E.C.,
Agent for the Applicant.