Improved Burglar Alarm Devices and the like.
Year: 1892

page_text: Date of Application, 16th Apr., 1892-Accepted, 18th Feb., 1893
COMPLETE SPECIFICATION.
Improved Burglar Alarm Devices and the like.
We, WILLIAM SHIRKEY HULL, Electrician, Sheffield, Alabama, United States
of America, CHARLES HENRY SPARKS, Gentleman, La Clide Hotel, St. Louis,
Missouri, United States of America and AIDEN STEVENS BENEDICT Actor,
1164 Broadway, New York City United States of America 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 :-
This invention relates to plates, walls, lattices and the like designed for jails
banks, vaults, safety-deposit walls, burial vaults, and any and all structures and
places where it is desirable to prevent entrance and egress. By the employment of
the invention any attempt to saw a bar or drill a plate or a portion of a wall
constructed in accordance with the invention will result in the sounding of an
alarm.
In the accompanying drawing I have illustrated a variety of ways of carrying
out the invention.
Fig. 1 shows its application, in a reduced form, to bank and jail windows
or cells.
Fig. 2 shows a tubular modification.
Fig. 3 shows the invention in connection with a safe.
Fig. 4 is an enlarged sectional view of a multiple plate and electrical con-
nections.
Fig. 5 is a diagram showing the electrical connections for operating on a closed
circuit.
Fig. 5 is a similar diagram for operating on an open circuit.
In its generic form the invention consists in a plurality of plates or rods, the
inner plate or plates being wholly insulated from the outer ones and an inner and an
outer plate connected with a sounding device.
In its application as seen in Fig. 3 there is an outer wall or plate A, an inner
wall or plate B, and an intermediate plate C, with insulating material upon both
sides of the intermediate plate to wholly insulate the same from the outer ones.
When the intermediate plate is not continuous the portions are connected electrically
by the wire a, as seen at the upper right hand corner of the safe shown in Fig. 3,
and also in Figs. 5 and 5. In Fig. 4 is shown a section of these plates and in this
view the insulation b, is clearly shown. The plates may be clamped or held
together by a bolt or rivet D, the opening in the intermediate plate being larger
than the bolt as seen in Fig. 4. One of the outside plates is connected by wire c
to the ground. The intermediate plate is connected by wire d with a sounding
device E and through a battery F with the ground. When employed in connection
with a safe there may be a filling between the inner plate B and the lining B' of the
safe as seen in Fig. 3.
In Fig. I have shown the invention applied as in a structure where it is desired
to provide light and ventilation as in windows of jails, cells, banks and the like, the
principle is the same, but the details of construction differ; in this form the plates
are as shown in Fig. 5, one A being a channel plate or bar and the other B fitted
between the flanges or smaller sides thereof; the interior plate C is insulated as
before and a filling C¹ may be employed; the interior plate may be in one
continuous piece as shown by Fig. 5 or a plurality of pieces. In this form the
various compound plates A, B, C, are arranged in lattice form and the interior,
plates are connected by wires H, as seen in Fig. 1 or in other continuous manner.
The outer plates or channels, or pipes are connected by metallic electric contact at
the intersections. The interior plates are connected by a wire H', with the

page_text: battery F, and the plates A, B, are connected by a wire H³, with an automatic
drop or relay 1, of any well known or usual construction which drop is connected by
a shunt wire J, including a bell K, with the battery F and by another wire J', con-
stituting a part of the main circuit in which is located a switch L.
There are illustrated three forms of circuits, a simple ground open circuit in
Fig. 4, a metallic open circuit in Fig. 5 and a metallic closed circuit in Fig. 5.
The circuit shown in Fig. 1 may be either open or closed depending upon which
one of the drops shown in Figs. 5 and 5ª is used.
The operation of these circuits is as follows-When a drill or other metallic
instrument makes contact with an outer plate A or B and with an interior insulated
plate C an alarm will be sounded in the open circuit method, the circuit going to
ground and from thence to alarm in Fig. 4. In Figs. 1 and 5* in the open circuit
arrangement provision is made to continue the alarm even if the drill or instrument
is immediately removed from contact with both plates. This is accomplished by
the automatic drop or relay I, which, as is well known, has a pivoted armature m
held by a spring or gravity or friction away from the magnet in an open circuit
which armature when attracted by the action of closing the circuit by contact of
inner and outer plate releases the drop and establishes a new circuit through the
bell. This causes a continuous ringing of the alarm until the switch L is operated.
The circuit employed may be of any suitable arrangement and to operate any
desired system of alarms. The automatic drop used for the closed circuit will be
the reverse of the open circuit. That is the armature or drop is held in place
by the attraction of the magnet until the circuit is broken when the magnet
releases the armature and establishes a new circuit through the bell as seen in
Fig. 5.
While in lattice work, flat bars are preferably used still in some instances round
bars may be desired in which case the pipe A is employed and the plate or rod C
serving as a conductor is entirely surrounded with the insulating material 6 all as
clearly shown in Fig. 2.
In either flat bar or pipe construction an insulated wire for the closed circuit may
be laid alongside the interiorly insulated plate or rod serving as conductor in the
open circuit. Various changes in the electrical connections may be made.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is.-
The electrical wall or grating herein shown and described for the purposes set
forth.
Daind this Kaundaonth day of Anvil 1000
Anvil 1000
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.