Year: 1889

page_text: I, ELMER AMBROSE SPERRY, of 1007 Opera House Block, Chicago, Illinois, United
States of America, Mechanical 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 devices for grounding closed circuits and has for its
object to provide means whereby closed circuits may be grounded when broken so
as to continue the service over the same.
:
This object I accomplish by means of the mechanism shown in the accompanying
diagrammatic view A, supposed to represent the central station; B, a gong
therein;
C, C, are indicators or chemical registers; E, E, are batteries joined at the centre
by the wires F, F, and the switch. The switch is composed of the bar G, spiral
spring G, guides G², G2, and the switch bars G³, G³, pivoted to but insulated from
the bar G. G, G', are contact buttons and G a wire connecting them. G', G', are
contact buttons; from the latter leads the wire G8, to the ground G, and from the
former leads the wire Go, to the chemical register C. From this register in turn,
passes the conductor G", to the ground G; thus the connection between the two
batteries E, E, is always complete when the switch pieces G³, G³, rest upon the
buttons G, G, or upon the buttons G, G7, though in the latter case the circuit is
also made to the ground and includes the chemical register C. H, is a line conductor
which passes into the chemical register C, and J, is the wire passing thence to the
coil J. The conductor is then connected with the supporting bar J2, whence passes the
wire J, to the battery. K, is a pivoted armature lever free to move vertically
beneath the core of the magnet coil J, and provided with the retarding mechanism K.
K', is a contact piece engaged by this pivoted lever when it descends and from this
latter passes the conductor K³ to the gong B. From such gong passes the con-
ductor K, to the magnet coil K, from which it passes by wire K', to the wire which
connects the cells of the battery so as to make the first cell or cells develop
the E, M, F, for the subsidary circuit K', is a pivoted weighted lock lever free to
move slightly beneath the magnet coil K, and provided at its outer extremity with
the pin K, adapted to engage the notch K, in the end of the bar G. L. is a line

page_text: onductor passing from the battery E¹, onto the line, M, is a combined call box
and line grounding device M¹, being the line wire passing between such boxes
nd M², the wire passing therefrom to the ground M. N is a call box contained
within the mechanism M. O, O¹, are magnet coils; P. P¹, are their supported
metallic frames; Q, Q', are pivoted weighted levers beneath the cores of the
coils O, O' R R are motion retarding devices on the ends of such levers S, S¹, are
wires passing from such call box N to the frame pieces P, P₁. These latter are con-
nected with the wire on the coils O O¹; T T are contact plates in the path of the
levers QQ U, U, are the wires leading thence to the wires M2, and thence to
the ground M³.
The gong B, may be ommitted without interfering with the spirit of the invention.
The use and operation of my invention are as follows
Any number of the combined call boxes and grounding devices indicated by M, M,
are placed in the line as desired.
Then while the current is passing over the line conductors, as indicated by the
arrows, it will pass through each of these combined call boxes and grounding devices M, M,
as follows; first into the spool O, thence into the frame P thence through the wire S,
box N, wire S¹, frame piece P¹, coil O' wire H, to the central station; at the central
station it will pass through the chemical register C, wire J, coil J; frame piece J²
wire J³, battery E, wire F, switch piece G³, button G, wire Gs, button G, switch
piece G³, wire F, battery ¹, and on to the line wire L, thus making a complete
and continous circuit through the line and all the devices thereon capable of giving
or registering the calls which may be turned in from the boxes on the line by means
of the chemical register C. The calls as they are turned in break the current but
this is for a very brief space of time and not sufficient to permit the levers Q, Q¹,
and K, to descend from the energized cores of the magnet coils. If, now, the lines
be cut and broken at the point X, so that the current is necessarily discontinued for a
considerable portion of time the levers Q, Q', and K, will descend upon their
respective contact plates the course of the current will be as follows; commencing
with battery E¹, passing through line L, sundry combinations M, M, and line
wire M, M, into the spool O, which it energizes, restoring the lever Q to its original
position thence through the frame P wire S, call box N, wire S', frame piece P¹,
lever Q, contact plate T, line U¹, wire M² into the ground M³ thence through the
ground to the ground G, along wire G", through chemical register, along wire G10,
button Go, switch piece G³, wire F and thence into the battery E. As hereinafter
explained the interruption of the current as above referred to causes all the levers to
descend, the lever K, descending upon its contact plate K², establishes a current
through the wire K³, gong B, wire K* magnet coil K, wire K, to the battery E,
by this means the coil K, is energized, the lever K7, is drawn upward and the
bar G released so that the spring G, will draw it to one side to move the switch
pieces G³, G³, on to the buttons G G7. As soon as the automatic grounding takes
place a circuit is established between the ground which is between the central station
and the point X, and the ground which circuit includes the magnet J', and battery E.
and chemical register C. In this matter the circuit is as it were divided into two
parts and each is operated. In each house or place to be protected is placed one
of the combined boxes and grounding devices M consisting substantially of the
devices shown; the box M; placed between two grounding devices so that if the line
be cut upon either side of such box, the operation just described will take place and
the mechanical gong will be started ringing in the station thus awakening or calling
the attention of the operator; immediately thereafter the two circuits are established
from the two grounds M³, M³, adjacent to each other, to the ground G³, one of such
circuits including the battery E, and the other the battery E. The motion retarding
devices K, R, and R', are so timed and adjusted as to retard the motion of the
pivoted armature cri pivoted lever, in the event of any short or temporary
interruption of the current, and thus prevent the lever from reaching the ground
contact piece; when, the line is broken for a considerable period of time ;. these
levers as above described will all drop to their contact pieces and the current when

page_text: sent through will restore them all to their positions except in the case of this lever
controlled by the magnets between which the break has been made and through
these two the ground connections are established. If the current has been
withdrawn from the line, as during the course of the day, all these levers will fall to
their contact pieces, but as soon as the current is turned on at night they will be
restored to their positions unless the line has been broken and in that event the
operation will be the same as above described, and the gong will cause the alarm to
be rung thus showing that the line has been cut at some point. The entire circuit
is virtually divided into two seperate circuits after the line has been broken; the
local circuit through the gong B, is only operated for a very brief period of time as
the newly established currents immediately energize the magnet J, and take the gong
out of circuit therefore a mechanical gong must be used which will continue to ring
until the operator stops it.
Having now particularly described and ascertained the
Invention and in what manner the same is to be performed
claim is
nature of my said
declare that what I
1. The combination of a main normally closed metallic circuit with an electro-
magnet therein a ground circuit and contact a pivoted armature lever adapted to
move between such contact and such magnet, such armature held to such magnet by
the influence of the current passing over the main line and a motion retarding device
connected with such armature lever which permits the same to leave the magnet and
engage the contact only when the current is discontinued for a considerable period
of time.
2. The combination of a main normally closed metallic circuit with an electro-
magnet therein a ground circuit and contact a pivoted armature lever adapted to
move between such contact and such magnet such armature held to such magnet by
the influence of the current passing over the main line and a retarding device
connected with such armature lever which permits the same to leave the magnet and
engage the contact only when the circuit is discontinued for a considerable period
of time.
3. The combination of a main normally closed metallic circuit with a call box
therein an electric magnet on each side of said call box in the main circuit, a pivoted
armature lever controlled by each of said magnets a ground line and two contacts
one in the path of each of such levers said lever attracted to the magnets by the
influence of the current passing over the main line, and two motion retarding devices
connected with such armature levers which permit the same to leave the magnets and
engage the contact only when the current is discontinued for a considerable period
of time.
4. The combination of a main normally closed metallic circuit with an electro-
magnet therein a local circuit and a contact, a pivoted armature lever adapted to
move between such contact and such magnet such armature held to such magnet,
said local circuit containing an electro magnet in combination with a grounding
switch controlled by said magnet and connected with the battery so as to ground
the same when the main line is broken.
5. The combination of a main normally closed metallic circuit with an electro-
magnet therein a local circuit and a contact, a pivoted armature lever adapted to
move between such contact and such magnet such armature held to such magnet,
said local circuit containing an electro magnet in combination with a grounding
switch controlled by said magnet and connected with the battery so as to ground
the same when the main line is broken, and a second electro magnet in the main
line with a pivoted armature lever and a ground line and a contact point in the
path of said armature lever.
6. The combination of a normally closed metallic circuit with an electro magnet
therein a pivoted armature lever controlled by said magnet a ground line and a
contact point in the path of said lever, a second electro magnet in the main line a
pivoted armature lever controlled thereby a local circuit with contact point in the

page_text: path of said lever an electro magnet in such local circuit a battery in the main circuit
a ground line and a switch controlled by said last mentioned magnet and adapted to
ground the battery so that when the main line is broken it is grounded at the battery
and on the line so as to make a circuit.
7. The combination of a normally closed metallic circuit with an electro magnet
therein a pivoted armature lever controlled by said magnet a ground line and a contact
point in the path of such lever a second electro magnet in the main line a pivoted
armature lever controlled thereby a local circuit containing an alarm with contact
point in the path of said lever an electro-magnet in such local circuit, a battery in the
main circuit a ground line and a switch controlled by said last montioned magnet and
adapted to ground the battery so that when the main line is broken it is grounded at
the battery and on the line so as to make a circuit part ground and part metallic
circuit.
8. The combination of a normally closed metallic circuit. with a series of call
boxes therein an electro magnet on each side of each box a pivotted armature lever
attracted to such magnet by the influence of the current passing therethrough a
ground line and contact point in the path of each of such levers a central station
magnet in such main line with similar armature lever, a local circuit having a contact
point in the path of such lever and containing an electro magnet a ground line
contact point battery and battery grounding switch the latter controlled by the electro
magnet in the local circuit.
9. The combination of a normally closed metallic circuit with a series of call boxes
therein an electro magnet on each side of each box a pivoted armature lever attracted
to such magnet by the influence of the current passing therethrough a ground line
and a contact point in the path of each of such levers a central station magnet in such
main line with similar armature levers, a local circuit containing an alarm and
having a contact point in the path of such lever and containing an electro magnet a
ground line contact point a battery and battery grounding switch the latter controlled
by the electro magnet in the local circuit.
Detail this 76th day of Morab 1880