Improvements in and Relating to Apparatus for Protecting Electric Circuits and Instruments therein from Injury
Year: 1884

page_text: Improvements in and Relating to Apparatus for Protecting
Electric Circuits and Instruments therein from Injury by
I HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co Patent
Agents, Southampton Buildings, London, in the County of Middlesex do hereby
declare the nature of said invention for IMPROVEMENTS IN AND RELATING TO
APPARATUS FOR PROTECTING ELECTRIC CIRCUITS AND INSTRUMENTS THEREIN
FROM INJURY BY EXCESSIVE CHARGES PRODUCED BY LIGHTNING OR OTHERWISE "
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 invention is to form a compact, durable and cheap instrument
adapted to the requirements of telephone circuits, telegraph lines and cables or
any electrical circuit in which instruments of considerable resistance are located,
whereby the instruments in the said lines or cables shall be protected from the
risk of being burned when the said lines are overcharged with electrical currents
of high tension or great quantity or both, such as those produced by lightning or
by dynamo-electric machines.
In the accompanying drawing
Figure 1 is a plan of my improved electric circuit protector.
Figure 2 is a sectional elevation of the same on line x, x Figure 1 and
Figure 3 shows the attachment of the said protector to a submarine cable.
A represents the base-plate, and B a compound electro-magnet in which the
cores are surrounded with coils C of high resistance, and with coils D of low
resistance. As shown, these coils are separate and on different portions of the core,
but it is evident that the fine and coarse wires may be coiled one above the other
like an induction coil.
The line wire enters the binding post R and the current passes by the wire. V
through the fine wire coil C, and is connected by the wire V with the armature
lever F which is provided with the soft iron armature E, and, a.contact
bar I, arranged on opposite ends of the fulcrum G, supported by standards H.
Drine G21

page_text: L
.
J, J1 are two standards provided with spring-brushes K, which, when the
armature E is drawn away from the magnet. B by the spring P made adjustable
by the tension shaft Q, remain equidistant between the said posts J J' and bar I
as shown.
One end of the coarse wire of the coil D is connected with the wire V or
binding post R. by the wire V7, and the other end is connected with one of the
posts or standards J, and the other post or standard J¹ is connected with the
binding post T by wire V5, which, in turn, is connected with the ground or line
wire binding post U by the wire V*. If desired, the post T may be considered the
ground binding.post.
.
The armature lever F is provided on the back with a spring contact O, which,
when the armature is away from the magnet B, presses against the contact
screw M, carried in the standard L and prevented from rotating by the
set-screw N. This post L is connected with the binding post S by the wire Vs.
If the instrument is used for telephony, the telephone circuit W is looped in
between the binding posts S and T, and contains the telephone apparatus X.
The action is as follows, that is to say:-The ordinary electric current passes
through the wire V, coils C, C, wire V, armature lever F, spring O, screw M,
post L, wire V³, binding post S, wire W, telephone apparatus X, wire W,
binding post T, wire V4, binding post U, and to ground without attracting the
armature.
Now should the line-wire- become overcharged by lightning, and the electric
charge have considerable tension but small quantity, then the coils C, C of the
magnet B magnetize the core and cause the armature to be attracted. This action
causes the contact-bar I to touch the two brushes K, K, grounding the line through
the coils C and D and shunting the telephone apparatus X, As the armature is
still further drawn over, and by the combined magnetic effect produced by both
high resistance coils C and low resistance coils D, the spring O leaves the contact
screw M, (thereby opening one end of the telephone circuit W) and pressing the
brushes K K over against the standards J J₁, making a positive connection.
Now the current passes in through both coils C and D, bar I, standard J' to
ground.
If the excessive current be only momentary, then the armature will fall back
again and automatically switch in the telephone and break the ground connection
of the coarse. wire coils D, so that all of the current once more passes through the
fine wire coils C.
If a current from a dynamo-electric machine passes into the line wire then. the
instrument acts as before, and the main current passing over the coarse wire of
the coils D prevents the fine wire insulation from burning, and holds the
armature up until the excessive current is removed. In practice the instrument is
found to work instantaneously.
In the case of marine cables the cable is secured to the post S and preferably the
screw M screwed up so that the contact with the spring O will never be broken.
Now when an overcharge of electricity gets into the air line it is automatically
passed to ground. by the armature, and the terminal of the cable is. also
automatically grounded through the screw M, spring O, lever F, bar I, standard J¹,
wire Vs, post T, wire V', post U and ground wire, and thereby the static charge or
return current is allowed to pass off into the ground also. While I prefer to
ground the cable terminal, it is evident that by leaving the screw M set as in the
case of telephony, the cable terminal would be left open when the air line was
grounded.
While I do not limit myself to any particular resistance for the coils C and D,
for all practical purposes the resistance of the coils C may vary from 5 to 15 ohms
and of the coils D from 1 to 1%, ohms.
If desired a single leg magnet may be used and the apparatus modified in
various ways without departing from my invention.

page_text: particularly descrivCu ици ascertained the nature or my said
invention and in what manner the same is to be performed I declare that what
I claim is :-
First. In an instrument for protecting electric circuits and their receiving
instruments from damage by lightning or excessive electrical charges generally,
two coils of wire of different resistance carried upon the same core and acting
upon an armature, in combination with a line wire in circuit with the coil of
highest resistance and having receiving instruments thereon, mechanism controlled.
by the armature to first shunt the said receiving instruments and throw the
low-resistance coils into circuit and then break the original line circuit close to the
receiving instruments when the said line becomes over-charged with electricity,
substantially as and for the purpose specified.
Second. The combination of a line circuit with receiving instruments located
therein, coils C and D of different resistances located upon the same core with the
armature E and its lever contact brushes and circuit closing devices actuated by
the said armature to first make contact with the said brushes to complete the line
circuit through the low-resistance coils and then make a solid contact to ensure the
grounding of the line through the said low-resistance coil, substantially as and for
the purpose specified.
Third. The combination of a line circuit having receiving instruments located
therein, coils C and D of different resistances located upon the same core, with an
armature E and its lever, contact brushes and circuit closing devices, actuated by
the said armature to first make contact with the said brushes to complete the line
circuit through the low-resistance coil and shunt the said receiving instruments
and then make a solid contact to ensure the grounding of the line through said
low-resistance coil, substantially as, and for the purpose, specified.
Fourth. The combination of a line circuit having receiving instruments located
therein, coils C and D of different resistance located upon the same core, with an
armature E, and its lever, contact brushes, circuit closing devices actuated by the
said armature to first make contact with the said brushes to complete the line
circuit through the low-resistance coil and shunt the said receiving instruments,
and then make a solid contact to ensure the grounding of the line through the said
low-resistance coil, means for finally breaking the said original line circuit close to
the receiving instruments and devices for regulating the time of the said break,
substantially as and for the purpose specified.
Fifth. In an instrument for protecting electric circuits and their receiving
instruments from damage by lightning or excessive electrical charges generally, two
coils of wire of different resistances carried upon the same core and acting upon an
armature, in combination with a line wire in circuit with the coil of highest
resistance and having receiving instruments thereon, mechanism controlled by the
armature to first shunt the said receiving instruments and throw the low-resistance
coils into circuit, and then break the original line circuit close to the receiving
instruments, when the said line becomes overcharged with electricity, and means
for regulating the time of the said break in the line close to the said receiving
instruments, substantially as, and for, the purpose specified.
Sixth. The combination of the electro-magnet B having the coils C and D of
different resistances the armature lever F, armature E, contact spring O, contact
screw M, means for putting the said coil D in circuit upon moving the said
arinature receiving instruments X and connecting circuits, substantially as shown.
Seventh. The combination of the electro magnet B having the coils C and D of
different resistances, the armature lever F, armature E, contact spring O, contact
screw M, means for putting the said coil D in circuit, the contact bar I, contact
standards J, J' receiving instruments X and connecting circuits substantially as
shown.
Eighth. The combination of the electro magnet B having the coils C and D of
different resistances, the armature lever F, armature E, contact spring O, contact

page_text: screw M means for putting the said coil D in circuit, the contact bar I, contact
standards JJ, brushes K, receiving instruments X, and connecting circuits,
substantially as shown.
Ninth. The combination of an air line, a ground line, and a sub-marine cable
with an electric protector constructed as shown and described whereby the air line 5
and cable terminals are both grounded upon the said air line becoming over
charged with electricity and without breaking either the line or cable circuit.
Dated this 11th day of February 1884.
HASELTINE, LAKE & Co.;
For the Applicant.