Improvements in Electric Cut-outs and in Electric Switch Devices, applicable to and serving as Holders therefor.
Year: 1899

page_text: Date of Application, 24th Oct,, 1899-Accepted, 13th Jan., 1900
Improvements in Electric Cut-outs and in Electric Switch Devices,
applicable to and serving as Holders therefor.
I, JOSEPHI SACHS, residing at No. 220, Collins Street, Hartford, in the County
of Hartford, in the State of Connecticut, United States of America, 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:-
-
In the construction of safety fuse cut-outs, lead tin and alloys of various metals
have been used in the form of wires or strips connected with the electric wires
so as to be fused or disrupted by abnormal currents and thereby protecting the
circuit and the transmitting devices therein.
Where these cut-outs or fuses are left open and unprotected they are objection-
able, especially because they are liable to sudden and violent disruption, and
sometimes personal injury or fire results. To obviate this the fuse had been
placed in an enclosure.
Where the metal is of such a character that an oxide or similar formation
occurs on its surface, it has been found that the metal may be brought to a molten
condition and held within the enclosing envelope of oxide or similar material
and the point of disruption is rendered uncertain, and this occurs, especially
where lead, and its alloys are made use of.
Where the fusible strip or wire is closely surrounded by an enclosing material,
the metal may be retained in a melted condition by such enclosure, and the
circuit will not be broken until the electric current is much greater than anti-
cipated, hence it is impossible to rely upon the accuracy of the cut-out.
Where the wire or strip has been closely enclosed in a surrounding jacket, it
is often difficult to produce a proper rating, because where the material surround-
ing the fuse wire is large in proportion to the wire and has a good heat capacity,
the enclosure will absorb heat and it will take much more current to disrupt
the fuse when the material is cold than when the enclosure has become heated,
especially when the current has been near the maximum and the enclosure has
become heated throughout. The carrying capacity of a certain size of fuse wire
is materially increased by its enclosing material over the carrying capacity of
the same size of fuse wire when exposed to the atmosphere.
Fuse wires that are open and suspended in the air are particularly objection-
able in consequence of the current arcing and flashing when the cut-out melts,
particularly when the current is short-circuited and high potential currents are
employed, and where the safety-strip is enclosed, this action frequently takes
the form of an explosion, and being in a confined space, the surrounding jacket
or enclosure is often ruptured.
It has often been found that although a jacket or mass surrounds the fuse
wire or strip that will protect it from its injurious effects yet, if it is intended
to carry a current that is close to that at which the fuse will be ruptured. the

page_text: temperature of the surrounding mass will be brought up closely to that of the
fuse strip, which is in all cases very objectionable.
The objects of this invention are to eliminate the before-named objection-
able features and to provide a cut-out which will operate accurately at a pre-
determined current and without holding the melted metal in suspension after
the contemplated maximum current has been reached; and in the present
improvement the melting or disruption of the fuse wire is effected without arcing
or flashing whether operated by an overload of current or by a short circuit,
and a low temperature will be maintained and the point at which the fuse will
disrupt or melt varies but little when the surrounding envelope may be either
hot or cold.
I also provide means whereby the safety cut-out is rendered non-interchange-
able in the receptacle or blocks, because the terminals are so constructed that a
safety fuse adapted to a high current cannot be inserted into the hole or block
intended for a lower current.
In carrying out this invention, I provide a material that surrounds or is in
contact with the fuse wire or strip and which will act as a flux for destroying
any enclosing envelope of oxide or other formation which would hold the metal
in a melted or other condition, and with this flux or similar agent around the
wire, other materials may be mixed so as to combine or mix with the safety
strip as the same is disrupted, or a non-conducting substance may be formed by
the heat of the safety strip, causing the same either to combine with or diffuse
into the surrounding material. This surrounding material acts upon the oxide
or upon the metal itself when a certain heat is reached.
This surrounding material is sometimes applied directly to the surface of the
safety strip or wire in the form of a paste that will harden and form a surround-
ing cylinder of greater or less size, but it is generally preferable to introduce
this flux or similar material into a tube, preferably small and of glass, through
which the safety strip passes.
The character of this fluxing, deoxidizing or combining material will vary
according to the material of which the safety strip is composed. I have found
that borax or sal-ammoniac is well adapted for this purpose, especially when the
safety strip is of lead or its alloys.
The safety strip or wire is supported in an exterior case, so that an air space
is left inside the case and around the wire, and this outer casing is preferably
of insulating material in the form of a tube, and the ends of the shell or tube
are closed by heads that are advantageously held in place by pin terminals pass-
ing through the tube and projecting for some distance either on one or both
sides of the case, and a disk or washer is generally employed close to the pin
terminals and within the case, and the ends of the case are advantageously sealed
with wax or other cement or covered with metal or paper caps. These pins are
advantageously used as the terminals for the safety cut-out strip which extends
between such pin terminals or is connected to them by short pieces of wire.
It is generally advantageous to connect the fuse wire or strip with copper or
other wires and to have the safety strip shorter than the distance between the
washers, but I do not limit myself in this particular; and I usually employ
within the case and near each end or head a filling preferably of yielding material
around the fuse strip or wire terminals beyond the ends of the inner tube, so
that in case there is a sudden disruption or explosion within the case, direct
pressure upon the heads is relieved by the yielding material at the ends of the
air space in the central portion of the case.
My improved safety cut-out or a modification of the same, can be advan-
tageously employed within a switch for controlling two or more electric circuits,
and the construction is such that the cut-out and switch blade portions are
separate from the carrier to which they are removably secured so that when a
cut-out is disrupted it can be detached and a new one inserted. The parts of
the switch comprise a suitable base, with clip or fork connections mounted thereon,

page_text: and a switch body having longitudinal edge grooves to receive the cut-outs and
a handle for operating the same, all of which are hereinafter more particularly
described.
In the drawing, Figure 1 is a vertical section of the safety fuse as applied to
the receiving sockets. Fig. 2 is a similar view of smaller sized safety fuses in
multiple arc. Fig. 3 is a cross section at the line 3, 3. Fig. 4 is a plan view
partially in section representing a combined safety cut-out and switch device.
Fig. is an end view of the same partially in section, and Fig. 6 is a side
elevation of the same.
The case a is tubular and preferably of insulating material such as vulcanized
fiber, and the ends are closed by heads which may be in the form of vulcanized
fiber bor cement at b', and the crossing pins c pass through the case and heads
and secure the parts in position and hold them firmly against the pressure which
may result from the sudden disruption of the fusible strip or wire d, and said
pins project outside the case to connect the cut-out to a supporting device.
This fusible strip or wire d is of the desired diameter and length and is con-
nected to the crossing pins c and it is advantageous to apply the metal disks f
within the case and adjacent to the heads so as to aid in properly supporting
such heads against any internal pressure; and where there is risk of sudden
internal pressure 1 apply loose, porous or elastic materials at 9 such as asbestos
or mineral wool adjacent to the inner sides of the heads or ends so as to lessen
the concussion of force of explosion.
The fusible strip d is protected from external influences by being within the
case a, and usually it is advantageous to surround the same with a layer of
material that will combine with the metal or act as a flux, such for instance as
borax, and this may be applied in a pasty condition with or without other
materials, and form a surrounding cylinder, or it may be within a tube i, which
is advantageously of glass, the fluxing or combining material being packed
around the fusible strip so as to act in connection with the heat developed in
the strip to reduce any oxide or to otherwise combine with the material of the
strip in effecting its disruption or destruction at the proper temperature as such
temperature may be developed by the passing electric current.
The crossing pins c are advantageously made to project at one or both sides
of the case so as to form pin terminals or contacts adapted to be received into
sockets to which the circuit wires are connected. These sockets may be of
any desired character, such as spring sockets or clamp sockets for receiving the
pin terminals, and by making these pin terminals of different sizes and the
sockets of corresponding sizes and in proportion to the current to which the
safety fuse is adapted, the pin terminal of the safety fuse for a heavy current
cannot be inserted into the socket that is smaller and adapted to a less electric
current, hence there is no risk of a safety fuse of too high a capacity being
applied where a safety fuse of a lower current is required. In Fig. 2 1
have shown three safety fuses upon the pin terminals c', such pin terminals
being in the form of wires sufficiently long to receive between them the safety
fuses in multiple arc and any desired number of these cases and their contained
safety fuses may be employed in this manner upon the parallel pin terminals,
and it is generally advantageous to taper the ends of the pin terminals so that
they will pass into the sockets with freedom. By this arrangement uniformity
in the volume, capacity of action of the safety fuse is provided and the safety
fuses are very strong and there is no risk of fire or external injury when sudden
and heavy disruptive currents and arcs are formed by the destruction of the
fusible strip or wire.
At e, Fig. 2, I have shown terminals that project from the ends of the case
and through which the crossing wires may pass for securing the terminals in
position, and these terminals may be slotted or hook-ended according to the
places where they are to be used; and where terminals are provided, as shown

page_text: in Fig. 2, they may lead to branch circuits, and any desired number of such
branch circuits may be provided.
The cut-out or safety fuse before described, is especially adapted to use with
the switch shown in Figs. 4, 5, 6 by the addition of terminals projecting from
the ends of the fuse case. Said terminals or contacts are preferably in the
form of plates or blades / extending sufficiently into the case a to be permanently
secured thereto and projecting so as to pass into stationary clips, and the fusible
strip or wire d is connected with the terminals and is of the proper size and
character to be melted or disrupted when the current reaches the maximum
value. The terminals are held in the case by the pins 2 which also pass through
the case a and through the terminals so as to secure the parts very firmly
together, and the contacts or terminal plates are advantageously cemented into
the ends of the case or held by divided plugs b¹ b¹.
Two, three or more of these cut-outs are made use of according to the number
of circuits that are operated in one switch: I have represented two of these
fusible cut-outs, one at each side of the switch body m and the edges of this
body are grooved so as to receive the sides of the cases a and the cross pins 2
project from the cases, and there are holes or recesses in the body m for the
reception of the ends of these cross-pins, so that the cases and fusible cut-outs
are prevented from moving longitudinally of the body, and a suitable handle n
is connected with or formed upon the body m, and there are clips o, preferably
made with segmental ends, that are applied at each side of the body m and are
drawn together by a screw or bolt so that the clips firmly enbrace and hold
the case of the fusible cut-outs and the contacts or terminals are in parallel
planes.
The clips or forks yr of the external circuit connections are upon a suitable
bases of insulating material, and these clips are each in the form of two plates
adapted to receive between them one of the plate terminals 1, and the parts are
brought together by a turning or sliding movement which ensures the intimate
metallic contact of the terminals with the clips, and one set of forked clips
should form pivots for the switch.
It is advantageous to perforate the terminals as shown at 3, and the set of
fcrked clips q are formed with inward projections or teats 4 upon the inner
faces of the blades, and these projections are in such a position that when the
terminals are pressed in between the plates forming the clips q. such clips are
sprung apart and the projections 4 enter the holes 3 to form pivots upon which
the switch can be swung up or down in opening or closing the circuit.
remark that by perforating all the terminals 1, the switch can be entered in
either direction into the forked clips of the external circuit.
I
It will be observed that each cut-out is complete in itself, containing end
terminals, a fusible strip and a case for firmly holding all the parts, and that
one cut-out can be removed and another substituted very quickly in case of
injury or the blowing out of the fuse.
In connection with the electric switch composed of safety cut-outs having a
fusible strip and a permanently connected support and metallic terminals con-
nected to the fusible strip and means for holding the safety cut-out and for
moving the same, I do not limit myself to the character of the said terminals
or to the switch clips to which they are electrically connected or to the character
of the particular means for holding the safety-cut-out and moving the same.
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
First The combination with the tubular case having heads within the end
portions and a fusible strip, of metallic terminals connected with the strip and
passing across through the case and the end heads thereof so as to hold the
said heads within the tubular case, substantially as set forth.

page_text: Second: The combination with the safety fuses, each having a case and
fusible strip, of metallic terminals that are parallel and pass across through
the two or more cases and connect the fusible strips in multiple arc, and sockets
or clips for receiving the projecting ends of the terminals, substantially as set
forth.
Third: In a safely fuse having an enclosing case and a smaller internal
tube around the fusible strip and an air space between the tubes, borax or
similar material around and in intimate contact with the fusible strip and within
the smaller tube, substantially as specified.
Fourth In a safety fuse having an enclosing case, and a smaller internal
tube around the fusible strip and an air space between the tubes, heads at the
ends of the case and yielding material around the terminals and close to the
inner sides of the head, substantially as set forth.
Fifth The combination with the enclosing case and metallic terminals
passing across through the same, of a fusible strip within the case, a small tube
surrounding the fusible strip and material such as borax within the small tube
and around the fusible strip and acting as a flux when the fusible strip melts,
substantially as set forth.
Sixth-The combination with an enclosing case and metallic terminals eros-
sing through the case near the ends thereof, of a fusible strip connected with the
metallic terminals, a small tube surrounding the fusible strip and material such
as borax, within the small tube to act as a flux when the fusible strip is heated,
substantially as set forth.
Seventh The combination with an enclosing case and heads within the case,
and metallic terminals crossing through the case near the ends thereof, of a
fusible strip connected with the metallic terminals, a small tube surrounding
the fusible strip and material such as borax within the small tube, to act as a
flux when the fusible strip is heated, substantially as set forth.
Eighth The combination with a tubular case of insulating material, of
terminals passing across through the case near the ends thereof, a fusible strip
connected between the terminals and within the case, heads near the ends of
the case and sealing material for closing the case air-tight and a fluxing material
such as borax, around the fusible strip and within the case, substantially as set
forth.
:
Ninth The combination with a tubular case of insulating material, of
terminals passing across through the case near the ends thereof, a fusible strip
connected between the terminals and within the case, heads near the ends of the
case and sealing material for closing the case air-tight, and a fluxing material
such as borax around the fusible strip and within the case, the fluxing material
being in a layer around the wire so that there is an air space between the same
and the interior of the case, substantially as set forth.
:
Tenth A cut-out conductor and a surrounding mixture containing borax
or similar material, a tube for surrounding and holding such material and the
cut-out conductor, a case for holding the conductor and tube, a heat insulator
between the inner tube and the outer tube, and terminals projecting from the
outer case near its ends and a connection therefrom to the cut-out conductor,
substantially as set forth.
Eleventh-The combination with a tubular case of insulating material, of
terminals connected thereto and a fusible strip attached between the terminals
and within the case, heads near the ends of the case and a fluxing material such
as borax, around the fusible strip and forming a layer to such strip so that there
is an air space between the same and the interior of the case, substantially as
set forth.
Twelfth The combination with the safety fuse, of the containing case, the
heads fitting therein at the ends, the cross pins passing through the case and
projecting therefrom, the terminals extending from the ends of the case and

page_text: through which the cross pins pass, the switch body receiving the case, a support-
ing base, electrical supporting connections therefrom for the terminals and means
for operating the switch, substantially as set forth.
Thirteenth-The combination with the safety fuse, of the containing case,
the heads fitting therein at the ends, the cross pins passing through the case
and projecting therefrom, the terminals extending from the ends of the case and
through which the cross pins pass, the switch body with edge grooves receiving
the case and having holes for the cross pins, a supporting base, electrical support-
ing connections therefrom for the terminals and a handle for operating the
switch, substantially as set forth.
Fourteenth: The combination with the safety fuse, of the containing case,
the heads fitting tightly therein at the ends, the cross pins passing through the
case, and projecting therefrom, the terminals passing through the heads and
extending from the ends of the case and through which the cross pins pass, the
switch body receiving the case, a supporting base, clips and forks and electrical
supporting connections therefrom for the terminals, and means for operating
the switch, one set of forked clips forming pivots for the switch, substantially
as set forth.
:-
Fifteenth The combination with the safety fuse, of the containing case,
the heads fitting tightly therein at the ends, the cross pins passing through the
case, and projecting therefrom, the terminals passing through the heads and
extending from the ends of the case and through which the cross pins pass, the
switch body with edge grooves receiving the case and having holes for the cross
pins, a supporting base, clips and forks and electrical supporting connections there-
from for the terminals and a handle for operating the switch, one set of forked
clips forming pivots for the switch, substantially as set forth.
Sixteenth: The combination with the safety fuse, of the containing case,
the heads fitting tightly therein at the ends, the cross pins passing through the
case, and projecting therefrom, the terminals passing through the heads and
extending from the ends of the case and through which the cross pins pass, the
switch body with edge grooves receiving the case and having holes for the cross
pins, a supporting base, clips and forks and electrical supporting connections there-
from for the terminals and a handle for operating the switch, one set of forked
clips forming pivots for the switch, and clips having segmental ends applied at
each side of the body, one embracing the cut-outs and a screw or bolt for drawing
the same together, substantially as set forth.
Seventeenth: The combination with the enclosing case, of a fusible strip
within the case, terminals at the ends of the case and to which the ends of the
fusible strip are connected and borax or similar material around and in intimate
contact with the fusible strip, substantially as specified.
Eighteenth: The combination with the enclosing case, of a fusible strip within
the case, heads at the ends of the case to which the ends of the fusible strip
are connected, and borax or similar material around and in intimate contact
with the fusible strip and acting as a flux when the fusible strip melts, sub-
stantially as specified.
Nineteenth-The combination with the enclosing case, of a fusible strip
within the case and means at the ends of the case and connected to the fusible
strip for supporting the same within the case, fillings within the ends of the
case surrounding the fusible strip and an intermediate filling around the fusible
strip of small diameter and leaving an air space between the same and the case,
substantially as specified.
Twentieth-The combination with the switch clips or terminals, of a safety
cut-out having a fusible strip and a permanently connected support, metallic
terminals permanently connected with the fusible strip and means for removably
holding the safety cut-out and for moving the same bodily to connect or dis-
connect the terminals thereof with the clips, substantially as set forth.

page_text: Twenty-first:-The combination in an electric switch having stationary clips,
of two safety fuses and their supporting cases and permanently attached metallic
terminals, a clamp and switch body for removably holding the safety fuses
together and allowing the metallic terminals to be connected to or disconnected
from the clips, substantially as set forth.
1000
HARRIS & MILLS,
Agents for the Applicant, 23, Southampton Buildings, London.