IMPROVEMENTS IN RELATION TO ELECTRIC CIRCUITS AND IN APPARATUS FOR PROTECTING BUILDINGS, SAFES, VAULTS AND OTHER STRUCTURES FROM BURGLARS
Year: 1882

page_text: [E
LETTERS PATENT to William Phillips Thompson of the Agency for foreign
Patent Solicitors 6 Lord Street Liverpool in the County of Lancaster and
323 High Holborn in the County of Middlesex Civil Engineer for an
invention of IMPROVEMENTS IN RELATION TO ELECTRIC CIRCUITS AND IN
APPARATUS FOR PROTECTING BUILDINGS, SAFES, VAULTS AND OTHER
STRUCTURES FROM BURGLARS"-A communication from abroad from Marion
H Kerner of New York in the State of New York one of the United States
of America
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 11th March 1882.
TO
WILLIAM PHILLIPS THOMPSON of the Agency for Foreign Patent Solicitors
6 Lord Street Liverpool in the County of Lancaster and 323 High Holborn in
the County of Middlesex Civil Engineer IMPROVEMENTS IN RELATION
ELECTRIC CIRCUITS AND IN APPARATUS FOR PROTECTING BUILDINGS, SAFES,
VAULTS, AND OTHER STRUCTURES FROM BURGLARS. A communication from
abroad by Marion H. Kerner, of New York, in the State of New York one of the
United States of America.
This invention relates especially to that class of electric burglar alarms in which
a normally closed electric circuit extends through the building, safe, vault or other
structure which is required to be protected from unauthorized entrance, and which
circuit is also connected with a station where an operator, watchman or other
proper attendant remains constantly on duty, so that the opening of a window or
door or the effecting of an entrance in any manner into any part of the protected
structure, by an unauthorized person, will cause the strength of an electric
current traversing the closed circuit to be either increased or diminished so as
to instantly produce a signal or alarm at the station, and thus notify the
attendant.
The object of this invention is to furnish an apparatus which is more certain in
its operation, and more easily maintained in its proper working condition, than
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page_text: the apparatus heretofore employed for this purpose, and moreover to provide
means whereby the circuit is subjected to a continuous test, so that, by the aid of
suitable indicating apparatus at the principal station, the exact condition of the
entire system may be known by inspection at any moment either during the day
or night, so that, in case of any interference or interruption, immediate measures
may be taken to remedy the same.
The invention consists in employing in connection with an electric circuit
traversing the building, vault or other structure to be protected, suitable circuit-
closers for shunting a portion of the main line when any attempt is made to effect
an unauthorized entrance, two independent relays one of which is adapted to
respond to an increase, and the other to a decrease in the normal strength of the
current traversing the main line, and of suitable signaling apparatus included in
independent local circuits and capable of being actuated by either of the relays:
also in the employment in connection therewith of a rheostat included in the main
line circuit and adapted to be shunted or cut out of circuit by the operation of
any one of the circuit-closers; also in the employment of a second rheostat placed
in a branch circuit and having a resistance either greater or less than that of the
first rheostat, of a switch which may be brought into action by some authorized
person to change its position so that the resistance of either one of the rheostats
may be removed from the main circuit, whereby the devices within the building
by means of which the alarm is transmitted to the central office, may be rendered
temporarily inoperative, and a galvanometer or detector in the circuit of the main
line for indicating the strength of current upon that line, whereby it may be
determined which one of the two rheostats is in circuit; also in constructing the
coils of one of the two relays included in the main line circuit of thinner wire,
and thereby causing them to contain a much greater number of convolutions than
the coils of the other relay, in consequence of which an electric current of given
strength traversing the coils of both magnets will cause one relay to respond to a
decrease and the other to an increase in the normal strength in the current
traversing the main line.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Phillips Thompson in the Great Seal Patent Office on
the 9th September 1882.
WILLIAM PHILLIPS THOMPSON, of the Agency for Foreign Patent Solicitors,
6, Lord Street, Liverpool, in the county of Lancaster, and 323, High Holborn, in
the county of Middlesex, Civil Engineer, " IMPROVEMENTS IN RELATION TO
ELECTRIC CIRCUITS, AND IN APPARATUS FOR PROTECTING BUILDINGS, SAFES,
VAULTS, AND OTHER STRUCTURES FROM BURGLARS."-A communication from
abroad from Marion H. Kerner, of New York, in the state of New York, one of
the United States of America.
This invention relates more especially to that class of electric burglar-alarms in
which a normally-closed electric circuit extends through the building, safe, vault,
or other structure which is required to be protected from unauthorized entrance,
and which circuit is also connected with a station, where an operator, watchman,
or other proper attendant remains constantly on duty, so that the opening of a
window or door, or the effecting of an entrance in any manner into any part of the
protected structure by an unauthorized person, will cause the strength of an
electric current traversing the closed circuit to be either increased or diminished,
so as to instantly produce a signal or alarm at the station, and thus notify the
attendant.
The object of this invention is to furnish an apparatus which is more certain in
its operation, and more easily maintained in proper working condition, than the
apparatus heretofore employed for this purpose, and moreover to provide means
whereby the circuit is subjected to a continuous test, so that by the aid of suitable
indicating apparatus at the principal station the exact condition of the entire
system may be known by inspection at any moment either during the day or
night; so that in case of any interference or interruption immediate measures may
be taken to remedy the same.
In the accompanying drawings, fig: 1 is a diagram representing the organization
of the electric circuits and apparatus of a single protective circuit embodying
the invention and which shows the apparatus as arranged in position for night.
service, and fig: shows the same in the proper position for day service.
Referring to fig. 1, E represents the main battery at the central station, one pole
of which is connected to the earth at G by the wire 1; from the other pole of the
battery a wire 2 extends to the electro-magnet of a relay M and thence the circuit
may be traced by the wire 3 to the electro-magnet of the relay M', thence by the
wire 4, to a detector or indicator D for showing the strength of current in the
circuit, herein shown as an ordinary galvanometer of well known construction;
after passing through the coils of which the circuit extends by the line L to a
greater or less distance and enters the building to be protected as hereinafter
explained.
The drawings show the protective appliances as attached to two windows W.
and W', in order to illustrate the organization and operation of the system; but
I remark that protective appliances of like or equivalent construction may also be..
attached to doors, scuttles, safes and vaults, or to any structure or a portion of a
structure which may for any reason require such protection. The attachment may
consist of any suitable circuit-closer or contact-maker, one form of which is
shown in the drawings, consisting of a metallic spring wwhich is mounted
within a suitable cavity formed in the window-frame, and which is bent so as to
normally project into a slot w3 cut in the edge of the sash. If an attempt is

page_text: made to raise the sash, the spring w is forced into contact with a metallic
plate w 1, normally insulated therefrom, and an electric contact is formed between
them.
The line L after entering the building to be protected is conducted successively
to each window, door or other point to be guarded, and at each of these places is
electrically connected with the insulated spring w, as shown for example at 5 and 6,
after which it is continued by the wire 7 to a rheostat or artificial resistance R,
and from thence by wire 8 to a switch-board S, which is located in some convenient
place within the protected building.
The switch-board S is provided with three metallic switch-levers 81 82 and 83,
which are mounted parallel to each other upon a suitable base of insulating
material, and are mechanically linked together by a non-conducting bar k, which
may be provided with a handle or knob k 1 for convenience in moving the several
levers simultaneously. When the circuits are arranged for night service the
switch-levers are placed in the position shown in fig 1; and the course of the
circuit may then be traced from the wire 8 to the stud 9, and thence by switch-
lever 82 and wire 10, to the contact-points w1 of windows W and W' in succession
as shown at 11 and 12; thence by wire 13, stud 14, switch-lever 83 and wire 15
to the earth at G.
When the apparatus is in this position a constant current of electricity from the
battery E will traverse the entire circuit, passing through the coils of the relays M
and M and also through the coil of the detector D and through the rheostat R as
shown by the arrow-heads in fig. 1. The resistance of the rheostat R may with
advantage be made equal to or even considerably greater than that of the
remainder of the circuit including the conducting wires, relays and detector.
The armature of the relay M¹ is provided with a suitable counterbalance m 1,
the weight of which is almost sufficient to overcome the attraction of the electro-
magnet due to the normal strength of current, so that any interruption or
diminution thereof will cause the armature, under the influence of the counter-
balance, to fall back on its rear contact-stop cl. The relay M is also provided
with a similar counterbalance m, which is of sufficient weight to retain the
armature against its back stop in opposition to the attraction of the electro-magnet
under the influence of the normal current.
In order to insure greater certainty and reliability in the action of the relays M
and M³ it is preferred to construct the coils of the electro-magnet of the relay M¹
of thinner wire and thereby to cause them to contain a much greater number of
convolutions than the coils of the other relay M. In consequence of this arrange-
ment, an electric current of given strength traversing the coils of both magnets
will produce a much greater magnetic effect upon the cores of the relay M³,
than upon the cores of the relay M; and hence it will require comparatively
little weight in the counterbalance m to overcome the normal attraction of its
electro-magnet.
A represents a signalling apparatus which may be of any suitable character.
The form shown is well adapted for the purpose, consisting of an ordinary drop
annunciator or visual signal, which is actuated by an electro-magnet a; this
electro-magnet is included in the circuit of a local battery e, (shown in dotted lines)
which is connected to the front contact stop c of relay M and to the back contact-
stop c1 of relay M; and also to the armature-levers of both relays. The circuit
of the local battery e will therefore be closed, and the signalling apparatus A set in
action whenever the armature of the relay M is brought in contact with its front
contact stop c or the armature of the relay M' with its rear contact-stop c 1.
The operation of the apparatus is as follows:-
In case an attempt is made by any person to effect an entrance into the protected
structure, as for example by raising the window W, an electric contact will be formed
between the springs wand w1 which will shunt the rheostat R and thereby remove
its resistance from the circuit. The effect of this decrease in the total resistance of the
circuit will be to increase the strength of current in the line L to nearly double its

page_text: normal amount, which abnormal strength of current will instantly be indicated at
the central office, not only by the increased angle of deflection of the detector D,
but by the action of the signalling apparatus A also, inasmuch as the augmented
strength of the current traversing the relay M will overcome the gravity of the
weight m and by its armature-lever close the local circuit of battery e at the
stop c. If any attempt should be made to enter the building unperceived, by first
severing the conducting wire at any point, a similar effect will be produced at
the central station; the circuit of the line L being entirely interrupted, the needle
of the detector or indicator will fall back to zero, and the armatures of both
relays M and M will fall on their back contact-stops, while the contact of the
armature of the relay M¹ with the stop cl will close the circuit of the local
battery and cause the signalling apparatus A to be operated with the same effect
as in the first case.
During that portion of the day that a protected building, such as a bank or
mercantile establishment is open for the ordinary transaction of business, it is
desirable to disconnect or render inoperative the devices within the building by
means of which the alarm is transmitted to the central office. But it is never-
theless important that the attendant at the central station should at all times
during the day or night be advised of the electrical condition of the circuits, and
should also be able to ascertain from an inspection of his apparatus whether or not
the protected building is occupied or opened for business. To this end, there is
provided for day service an auxiliary system of circuits within the protected
building, which is brought into action by some authorized person within the
building, who at the proper hour changes the position of the levers upon the
switch S, placing them in the position shown in fig. 2. When the switch is in
this position the rheostat R is shunted or cut out of circuit, and an independent
rheostat r, of a different and preferably of a smaller resistance is inserted in its
place. The course of the circuit as denoted by the arrow-heads in fig. 2 may now
be traced as follows:-From the line L as before to the points 5 and 6, thence by
wires 7 and 16 to stud 17, thence by switch-lever 81 and wires 18 and 8 to
rheostat r, and thence by the wire 19 to the stud 20, and through switch-lever & 3
and wire 15 to the earth at G.
The effect of this change is to permit the windows W and W or other protected
openings to be entered without affecting the resistance of the line, and also to
Bubstitute the resistance of the rheostat r. for that of the rheostat R in the main
circuit, which produces a change in the strength of the current, and a corresponding
indication upon the detector D. Thus by a mere inspection of the detector D,
which indicates the strength of current traversing the line L, the attendant at the
central office can determine at any moment which one of the two rheostats R
and is in circuit and can thus know whether the protected building is open
or closed.
The changing of the switch S from one position to the other momentarily
breaks the main circuit and by so doing actuates the signalling apparatus A, thus
giving notice at the central station at the moment the change is effected. The
switch S may be placed in a locked compartment and thus rendered inaccessible
to any other person than the one authorized to take charge of it.
I do not desire to confine myself to the particular form of detector or indicator
which is shown in the drawings, as any device which will measure the strength of
an electric current traversing a circuit can be made to serve the same purpose; so
also the signalling apparatus A may consist either of a visual or an audible signal,
or both. Nor do I restrict myself to any special device for closing a shunt-circuit
by the moving of a door, window or other object, as any well known or proper
mechanism for that purpose may be used in connection with this invention.
Having now described the invention as communicated to me I wish it to be
understood that what I believe to be new and desire to protect under the herein-
before in part recited Letters Patent is :-
1st. The combination, substantially as hereinbefore set forth, of a main line, a

page_text: main battery, one or more circuit-closers adapted to shunt a portion of the main
line, two independent relays included in the main line circuit, one of which
responds to an increase and the other to a decrease in the normal strength
of the current traversing said main line, and a signalling apparatus included
in an independent local circuit and capable of being actuated by either of said
relays.
2nd. The combination, substantially as hereinbefore set forth, of a main line, a
main battery, a rheostat included in the main line circuit, one or more circuit-
closers adapted to shunt the portion of said main line including said rheostat, two
relays included in the main line circuit, one of which responds to an increase and
the other to a decrease in the normal strength of the current traversing said main
line, and a signalling apparatus included in an independent local circuit and
capable of being actuated by either of said relays.
3rd. The combination, substantially as hereinbefore set forth, of a main line, a
main battery, a rheostat included in the main line circuit, one or more circuit-
closers adapted to shunt the portion of the main line including said rheostat, a
second rheostat placed in a branch circuit and having a resistance either greater or
less than that of the first rheostat, a switch for disconnecting the main line from
one rheostat and connecting it with the other, and a detector for indicating the
strength of current traversing the main line.
4th. The combination, substantially as hereinbefore set forth, of a main line, a
main battery, a rheostat included in the main line circuit, one or more circuit-
closers adapted to shunt the portion of the main line including said rheostat, a
second rheostat having a resistance greater or less than that of the first one and
placed in a branch line, a switch for disconnecting the main line from one rheostat
and connecting it with the other, a detector for indicating the strength of current
in the main line circuit, two relays included in the main line circuit, one of which
responds to an increase and the other to a decrease in the normal strength of the
current traversing said main line, and a signalling apparatus under the control of
either of said relays.
5th. The combination, substantially as hereinbefore set forth, of a main line, a
main battery, two rheostats, one or more circuit-closers adapted to shunt one of
said rheostats and not the other, and a switch whereby the resistance of either one
of said rheostats may be removed from the main circuit at pleasure, but not both
at the same time.
6th. The combination, substantially as hereinbefore set forth, of a main line a
main battery, two relays included in the main line circuit, one of which, having a
lesser number of convolutions, responds to an increase, and the other, having a
greater number of convolutions, responds to a decrease, in the normal strength of
the current traversing said main line, and a signalling apparatus under the control
of either of said relays.
In witness whereof I the said William Phillips Thompson have hereunto set
my hand and seal this twenty ninth day of July in the year of our Lord
one thousand eight hundred and eighty two.