Electric Circuits.
Year: 1885

page_text: Electric Circuits.
I PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County of
Middlesex, Fellow of the Institute of Patent Agents do hereby declare the nature
of this invention to be as follows:-
The object of the present invention is to protect in a more perfect manner than
has heretofore been done, electrical circuits, the integrity of which is liable to be
impaired or destroyed by excessive electrical charges. Among such circuits are
those containing telephones, relays, or other delicate electrical instruments, or those
which are partially subterranean or sub-aqueous, and in which the insulation of the
buried portions of the line is often injured or entirely destroyed by the passage of
abnormal electrical currents.
Though applicable generally to electric circuits, the devices which form the
subject of this invention are designed more particularly for the protection of
subterranean or sub-aqueous lines, and they will therefore be described as applied
to this purpose. Said devices are composed mainly of a current arrester; separated,
corrugated plates, a flexible safety conductor and an electro-magnetic cut-out
combined and arranged in certain relations and with modifications thereof, as will
be more fully hereinafter explained.
Two plates of metal placed one above the other are set in or secured to the side
of a support and have their contiguous edges corrugated. A strip or wire of a
metal having a higher specific resistance than the remainder of the conductors and
constituting a fusible safety strip, such as has been commonly employed heretofore,
extends from the upper plate to a standard set in or secured to the side of the
support of the instrument, on which is also an electro-magnet the coils being in a
circuit running from the upper plate to which one terminal of the line is connected
through the safety strip before described, and then through wire forming or
connected with the coils of the magnet, and carried to a metal arm attached to a
weighted lever of insulating material carrying an armature in face of the pole or
poles of the magnet, and pivoted to a suitable support or standard.
This lever is connected by a spiral spring with the safety strip, the tendency of
the strip being to draw the armature away from the poles of the magnet.
The end of the lever is connected by a link with a contact arm pivoted to the
upper plate, and adapted to be brought into contact with the lower plate, by the
lowering of the lever. A swinging arm to which is connected a spring arranged

page_text: to press it down when released is turned back until it engages with a lug on the
under side of a second arm connected with the weighted lever, and this holds it in
a vertical position, its movement beyond this point being prevented by a pin or
stop. To the end of this second arm is pivoted a catch, that falls into contact with
the pin when the arm is raised, and the swinging arm released. By this means the
second arm is held in an elevated position until released by hand. The action of
this device is as follows. When, from any cause, the line receives an abnormal
charge, the instruments and the line may be saved from damage, by the current
leaping across from the upper to the lower plate, and going direct to earth.
If this does not take place the safety strip will either be fused, or the magnet
energized sufficiently to draw down the armature opposite to its poles.
In either of the latter events the movement of the armature lever brings the
lever or contact arm before referred to into contact with the lower plate thus
establishing a shunt to earth, releases the swinging arm and lets fall the catch
which locks the lever and keeps the shunt closed, and the circuit open.
No injury
can then be caused by the excess of current to the line or to the instruments therein.
A modification of this arrangement may be employed where the only abnormal
currents from which danger can accrue are those resulting from natural causes,
while that bereinbefore described provides against artificial dangers also. In safety
devices of that class it is essential not only that a path for the current be provided
around the magnet but that at the same time the portion of the circuit in which
the magnet is included, be entirely and continuously interrupted until the accidental
contact which had produced the abnormal condition, was broken, but when the
abnormal condition is due to natural causes, the circuit need be only momentarily
broken and the shunt brought into use because the short circuit by the shunt to
earth will bring about a discharge of that abnormal current and then the line is
again ready for its usual duty.
These devices relate entirely to that portion of the apparatus denominated the
cut-out, all the other parts being exactly alike in both. For instance the contact
arm attached to the weighted lever may be omitted and instead of it the lever
itself may be prolonged sufficiently to be formed into an eye through which a pin
secures it to a short link by means of which a pivoted contact arm may be secured
to the weighted lever.
The circuit is then completed through this arm. When the shunt circuit is
completed by the lever or contact arm coming into contact with the lower plate
the short link has lifted the pivoted contact arın, and the upright or swinging arm
rests against a pin which prevents it from being pressed down by its spring. The
closing of the shunt circuit having facilitated the discharge of the abnormal charge,
the contact arm resumes its position, and the circuit is again ready to perform its
usual duty. The operation can be repeated as often as the exposed portion of the
circuit raises the potential of the line abnormally to a sufficient extent to cause the
armature to be attracted by the magnet. The apparatus herein before described is
constructed in the following manner. Such portions of the apparatus as are used for
the supports or connections for the operative parts are inserted in recesses or
receptacles in one part of a mould; these portions may be simple pins, screws nuts
or plates. The matrix of the mould is then supplied with some plastic material,
such as hard rubber, artificial stone compounds, or the like, which is compressed in
the mould, and allowed to harden. The supports and the like are by this means
embedded in the block thus formed, and are securely held in place, and insulated.
To them any parts required for the ornamentation or proper working of the
instrument are then secured.

page_text: Electric Circuits.
I, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County of
Middlesex, Fellow of the Institute of Patent Agents, do hereby declare the nature
of this invention (a communication to me from abroad by Henry Curtis Spalding
of Boston, Massachusetts, United States of America, Electrician) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—
The object of my present invention is to protect in a more perfect manner than
has heretofore been done, electrical circuits, the integrity of which is liable to be
impaired or destroyed by excessive electrical charges.
Among such circuits are those containing telephones relays or other delicate
electrical instruments or those which are partially subterranean or subaqueous, and
in which the insulation of the buried portions of the line is often injured or entirely
destroyed by the passage of abnormal electrical currents.
Though applicable generally to electric circuits, the devices which form the
subject of this invention are designed more particularly for the protection of
subterranean or subaqueous lines, and I will therefore describe it as applied to this
purpose. In the drawing annexed, I have illustrated the devices embodying my
invention. Said devices are composed mainly of a lightning arrester, separated,
corrugated plates, a flexible safety conductor and an electric magnetic cut-out,
combined and arranged in certain relations and with modifications thereof, as will
be more fully hereinafter explained. I will now describe my invention by reference
to the accompanying drawings in which-
Fig. 1 is a side elevation of the apparatus complete, in connection with an
underground system, with its parts in one position.
Fig. 2 is a similar view, with the parts in another position.
Fig. 3 is a top view of the device."
Fig. 4 is a side elevation of a modified form thereof which will be hereinafter
more fully explained, and―
Fig. 5 is an elevation of a portion of the same, showing the parts in another
position. Similar letters of reference indicate corresponding parts in the several
figures.
A, E, are plates of metal set in or secured to the side of the support, and having
their contiguous edges corrugated. G. is a strip or wire of a metal having a higher
specific resistance than the remainder of the conductors and constituting a fusible
safety strip, such as has been commonly employed heretofore. It extends from the
plate A, to the standard A¹, set in or secured to the side of the support of the
instrument.
B, is an electro magnet. Its coils are in a circuit indicated by the letters a, a,
and running from the plate A to where one terminal of the line is connected
through the safety strip G, and then through wire forming or connected with the
coils of the magnet B, and carried to a metal arm H, attached to a lever F of

page_text: insulating material carrying an armature in face of pole or poles of magnet B, and
pivoted to a support or standard set in the support L
Lever F, is connected by a spiral spring K with the safety strip G. the tendency
of the strip being to draw the armature away from the poles of magnet B. The
end of lever F is connected by a link C, with a contact arm D, pivoted to plate A,
and adapted to be brought into contact with plate E, by the lowering of the lever.
I, is a sliding weight placed on the long arm of lever F. C, is a swinging arm to
which is connected a spring acting to hold it in the position shown in Fig. 2.
When the device is used in a circuit, the arm C is turned back until it engages
with a lug on the under side of arm H that holds it in a vertical position. Its
movement beyond this point is prevented by a pin or stop.
To the end of arm H is pivoted a catch d that falls into contact with the pin
when the arm H is raised and arm C released. By this means the arm H is held
in an elevated position until released by hand. The action of this device is as
follows Normally the current follows the path indicated by the letters a, a, etc.
and will continue to do so until from any cause the line receives an abnormal
charge. In this event the instruments and the line may be saved from damage by
the current leaping across from the plate A to plate E, and going direct to earth.
If this does not take place the strip G. will either be fused or the magnet B
energized sufficiently to draw down the armature opposed to its poles. In either
of the latter events the movement of the armature lever brings the lever D into
contact with plate E, thus establishing a shunt to earth, as indicated by the
letters b, b, releases the arm C, and lets fall the catch d which locks the lever and
keeps the shunt b closed and the circuit a open. No injury can then be caused by
the excess of current to the line or to the instruments therein. The modifications
before mentioned represented in Figs. 4, 5, are calculated for use where the only
abnormal currents from which danger can accrue are those resulting from natural
causes, while that hereinbefore described provides against artificial dangers also.
In safety devices of that class it is essential not only that a path for the current
be provided around the magnet, but that at the same time the portion of the
circuit in which the magnet is included be entirely and continuously interrupted
until the accidental contact which had produced the abnormal condition, was
broken; but when the abnormal condition is due to natural causes the circuit
need be only momentarily broken and the shunt brought into use because the
short circuit by the shunt to earth will bring about a discharge of that abnormal
current and then the line is again ready for its usual duty. These devices relate
entirely to that portion of the apparatus denominated the cut-out, all the other
parts being exactly alike in both. In Fig. 4 the contact arm H attached to the
lever F is omitted and instead of it the lever F is prolonged sufficiently to be
formed into an eye through which a pin secures it to the link f, by means of which
the pivoted contact arm g is secured to the lever F. The circuit a, a, etc. is then
completed through the arm g.
The operation of this part of my invention is illustrated in Fig. 5. When the
shunt circuit b, b, etc. is completed by the movement of the lever D into contact
with the plate E, the link fhas lifted the contact arm g, and the upright arm C
rests against the pin h which prevents it from assuming the position indicated in
Fig. 2. The closing of the shunt circuit b, b, etc. having facilitated the discharge
of the abnormal charge, the contact arm g resumes the position indicated in Fig. 4,
and the circuit a, a, etc. is again ready to perform its usual duty. The operation
can be repeated as often as the exposed portion of the circuit raises the potential of
the line abnormally to a sufficient extent to cause the armature to be attracted by
the magnet.
The apparatus hereinbefore described is constructed in the following manner―
Such portions of the apparatus as are used for the supports or connections for the
operative parts are inserted in recesses or receptacles in one part of a mould.
These portions may be simple pins, screws, nuts or plates, such as are indicated
at e, e, etc. The matrix of the mould is then supplied with some plastic material

page_text: TT
such as hard rubber, artificial stone compounds, or the like, which is compressed in
the mould, and allowed to harden. The supports and the like are by this means
embedded in the block thus formed, and are securely held in place and insulated.
To them any parts required for the ornamentation or proper working of the
instrument are then secured.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is―
1. In an apparatus for the protection of electric circuits, the combination of the
lightning arrester, composed of the separated corrugated plates, one of which is in
permanent connection with the earth, with the fusible wire and devices as described
connected therewith and adapted to operate on the fusion of the wire to establish
an earth connection by means of which the current may be diverted from the line
in the manner set forth.
2. The combination with a main electric circuit of a fusible safety wire included
in said circuit, a normally open branch circuit to earth, and a mechanical circuit
closer connected to the fusible wire by a distensible spring and constructed and
arranged to operate on the fusion of the safety wire, and thereby close the said
branch circuit, as and for the purpose set forth.
3. The combination with a main electric circuit of an electro magnet, a pivoted
armature lever and circuit breaker, a normally open branch circuit to earth, and a
circuit closer connected therewith, a fusible safety wire included in the main
circuit and a spring sustaining the pivoted armature lever connected therewith,
these parts being constructed and arranged for operation substantially in the
manner set forth.
4. In a safety device for electric circuits, the combination with an electro magnet
and pivoted armature lever of a shunting device, and a circuit breaker operated by
the lever and a locking device for preventing reaction of the same substantially as
described.
5. In a safety device for electric circuits, the combination with an electro magnet
and pivoted armature lever of a shunting device operated by the lever, a circuit
breaking arm engaging with the lever and a catch or locking device for preventing
the reaction of the lever when moved substantially as described.
6. In a safety device for electric circuits the combination with an electro magnet
and pivoted armature lever of a circuit breaker and shunting device connected with
the lever, and adapted to be simultaneously operated by the movement of the arm
as set forth.
7. In a safety device for electric circuits the combination with an electro magnet
and pivoted armature lever, of a device for making and breaking the circuit and a
device for shunting the same to earth, both connected with the armature lever in
the manner described, whereby the lever is vibrated and caused to interrupt and
close the circuit, substantially as set forth.
8. In a safety device for electric circuits, the combination with a fusible safety
strip, an electro magnet and a pivoted armature lever connected by a spring with
the safety strip, of a circuit breaker and shunting device connected with the lever
and constructed and arranged for operation in substantially the manner set forth.
9. In a safety device for electric circuits, the combination with a fusible safety
strip, an electro magnet and pivoted armature lever, weighted and connected by a
spring with the safety strip of a circuit breaker and shunting device connected
with the lever, and constructed and arranged for operation in substantially the
manner set forth.
10. In a safety device the combination with an electro magnet and pivoted
armature of a circuit breaker and shunting device, each comprising as the means
for operating them, a pivoted lever, and links connecting the pivoted armature
with said levers whereby a movement of the armature is imparted to the lever
substantially as and for the purpose specified.

page_text: 11. In a safety device for electric circuits, the combination with a safety strip,
an electro magnet and a pivoted armature, connected by a spring with the safety
strip of a circuit breaker and a shunting device, each comprising as the means for
operating them, a pivoted lever and links connecting the pivoted armature with
said levers whereby a movement of the armature is imparted to the levers
substantially as and for the purpose specified.
.
12. The method of constructing instruments of the kind described which consists
in moulding a plastic insulating material in the form of a base or support around
portions of the supports for the operative parts of the instrument, substantially as
described.
13. The combination with a base or support of plastic insulating material, of the
pins, screws, or supports of like nature embedded therein, and the movable or
operative portions of the instrument secured thereto, in the manner described.
1000