Improvements in High Tension Electric Fusible Cut-outs.
Year: 1896

page_text: Date of Application, 12th Dec., 1896
Complete Specification Left, 6th Oct., 1897-Accepted, 6th Nov., 1897
PROVISIONAL SPECIFICATION.
Improvements in High Tension Electric Fusible Cut-outs.
ALFRED STILL, Civil Engineer of Bow Green Farm, Bowdon, Cheshire, and
EDWARD WOODROWE COWAN, Civil Engineer, of Hart Hill, Woodville Road
Dunham Massey, Cheshire do hereby declare the nature of this invention to be
as follows:-
Our improvement consists in a special design of Fusible Cut-out for High
Tension Circuits whereby the formation of a destructive arc at rupture of the fuse
is reduced to a minimum. We construct the improved Fusible Cut-out in the
following way: The terminals are fixed within a tube or channel shaped piece
of glass or porcelain or other similar insulating & incombustible material &
the fusible wire or foil is either completely or partly surrounded by laminations
of asbestos board or some similar insulating and incombustible material, the plane
of the laminations being at right angles to the length of the fuse. The tube or
channel referred to above is provided with perforations or openings. For con-
venience & simplicity in replacing the fusible part of the cut-out we in some
cases obtain mechanical strength by slips of mica or other similar insulating
incombustible material rivetted or screwed or otherwise attached to the copper
terminals to which the fuse wire or foil is connected.
The action of the cut-out is as follows:-When the fuse wire or foil melts the
resulting arc is extinguished partly on account of the effect of the enclosed space
in which it is confined & partly by the rush of the expanded gases at the moment
of rupture, blowing it out. The expanded gases have a free passage between the
laminations of asbestos board or other material of which they may be composed
& the perforations or openings in the incombustible envelope, this relief of
pressure preventing explosion.
Dated this 10th day of December 1896

page_text: Dunham Massey Cheshire 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:-
Our improvement consists in a special design of Fusible Cut out for High
Tension Circuits, whereby, the chances of the formation of a destructive arc at
rupture of the Fuse are reduced to a minimum. We construct the improved
Fusible Cut out in the following way:-The terminals are fixed within a tube
or channel shaped piece of glass or porcelain, or other similar insulating and
incombustible material, & the fusible wire or foil is either completely, or partly,
surrounded by laminations, of asbestos board or scene similar insulating and
incombustible material; the plane of the laminations being at right angles to the
length of the fuse. The tube or channel referred to above is provided with per-
forations or openings. For convenience and simplicity in replacing the fusible
part of the cutout, we, in some cases, obtain mechanical strength by slips of Mica,
or other similar insulating & incombustible material rivetted or screwed, or
otherwise attached to the copper terminals to which the fuse wire or foil is
connected. The Action of the Cutout is as follows:-When the fuse wire or foil
melts, the resulting are is extinguished partly on account of the enclosed space
in which it is confined, & partly by the rush of the expanded gases at the moment
of rupture blowing it out. The expanded gases have a free passage between
the laminations of asbestos board or other material of which they may be composed
and the perforations or openings in the incombustible envelope; this relief of
pressure preventing explosion. In Figs. I & II of the accompanying drawings,
one form of fusible cutout, made in accordance with our invention is shown. In
the drawing A is a channel shaped carrier made of porcelain or other suitable
insulating and incombustible material. O are openings in the sides, T is one of
the terminals mounted on this base, C is one of the flexible copper contacts into
which the terminals T are inserted, L L are laminations of asbestos, or other suit-
able insulating and incombustible material; HH are handles made of ebonite
or other suitable substance. W is the fusible wire, M M are mica slips; the slip
lying next the opening K being of transparent mica, so that the fusible wire can
be inspected. Some of the laminations above referred to are cut away as shown
in Fig. III to allow of inspection of the fusible wire through the opening K. When
the fuse blows, the expanded gases escape through the spaces between the lamina-
tions and the openings in the channel shaped carrier marked 00. The fusible
wire, with the faminations, mica slips and ends of sheet copper or other suitable
material form a removeable portion which is attached by means of small screws
to the terminals T.
Figs. IV, V, & VI show another form of fusible cutout made in accordance with
our invention. In this drawing A is a tube of glass, porcelain or other suitable
insulating and incombustible material which is provided with an opening 0, or
with perforations. LLL are the laminations of asbestos board or other suitable
insulating and incombustible material. TT are terminals of metal, to which the
fusible wire is attached by soldering or other means; they can be of any shape.
The form of terminal shown is suitable for being clipped by flexible contacts of
copper or other suitable material.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we hereby declare that
what we claim is :--
I. The construction of an Electric Fusible Cut-out with the fusible portion
thereof enclosed, or partially enclosed, within laminations of asbestos board or
other suitable insulating and incombustible material, the plane of which lamina-
tions are at right angles to the direction of the length of the fusible portion.
II. The construction of an Electric Fusible Cut-out, substantially as herein-
before described and shown on the accompanying drawing Figuros I, II & III.

page_text: III. The construction of an Electric Fusible Cut-out substantially as herein-
before described and shown on accompanying drawing Figures IV V and VI.
Dated this 5th day of October 1897.
EDW. W. COWAN.
A. STILL.