IMPROVEMENTS IN AND RELATING TO ELECTRIC ALARM APPARATUS FOR THE DETECTION OF BURGLARS AND FOR SIMILAR PURPOSES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Marion Harrison Kerner at the
Office of the Commissioners of Patents on the 18th October 1882.
MARION HARRISON KERNER, of the City and State of New York, United States
of America, now of Queen Victoria Street, in the City of London, "IMPROVEMENTS
IN AND RELATING TO ELECTRIC ALARM APPARATUS FOR THE DETECTION OF
BURGLARS AND FOR SIMILAR PURPOSES."
My invention relates to electric alarm apparatus for the detection of burglars
and for similar purposes.
According to one part of my invention, I provide, in the walls, doors and windows
of a building, a system of conductors consisting of strips or sheets of tin-foil or
other metal, or of copper or other wires, which extend over the whole area of the
wall or other part and cannot be cut, crossed or grounded without instantly
sounding an alarm.
In carrying this part of my invention into practice in connection with bank vaults
or similar buildings, the interior walls of the vault are arranged with a system of
conductors consisting of strips of tin-foil or sheet metal, or copper or other wire, in
such a manner that any attempt to penetrate them with any kind of tool will
disturb the circuit, that is to say, will increase or diminish the electric current, and
cause an alarm to be sounded at a central station or upon the building itself.
The entrance to the vault is arranged with a duplicate door of any design,
constructed of wood and paper or other suitable material and arranged with
invisible electric conductors and appliances for carrying a current of electricity
through them when closed, so that the door cannot be opened or cut through, nor
any portion of the vault entered without an alarm being instantly given.
In the case of jewellers' or other safes, a cabinet of any desirable design is
constructed to envelop or surround the safe, and this is done in such a manner as
to make it an ornament to the room. This cabinet is constructed as follows, that
is to say: The frame work is of any kind of wood and the panels are either of
wood or paper. The frame work is protected by wires embedded in the wood and
leading to the panels which are lined either with tin-foil or copper or other metal
strips or wires, the latter being electric conductors, so that any attempt to tamper
with the safe immediately sounds an alarm:
'

page_text: In warehouses the walls are arranged with the tin-foil or copper strips or wire,
as the case may require, which are covered with paper or other suitable material.
I construct light wooden screens for covering the windows at night, these screens
as well as the doors I provide with conducting wires inserted below the
surface and extending over the whole area of the door or screen and I arrange the
said wires in combination with any suitable devices for breaking or completing
the circuit, in such a manner that when the door is closed or the screen is in
position the circuit is completed but as soon as the door is opened or the screen.
removed the circuit is either broken or grounded, and if the door or screen is
cut so that the wire is severed the circuit will be broken and an alarm sounded.
According to another part of my invention I arrauge in combination with the
floors, counters, shelves or other movable or stationary parts in a building, springs
for either completing or breaking an electric circuit when the said parts, or any
goods resting upon or against them, are removed and thereby sounding an alarm, so
that in case a burglar secretes himself within a building during the day he can
hardly tamper with any goods without the alarm being sounded.
A system of springs is placed on the counters and shelves and the goods are
placed on these springs so that the moment they are shifted the alarm is sounded.
I prefer to fit these springs to the counter or other part as follows, that is to say,
a recess is formed in the counter in which is fixed a spring or contact piece in
connection with one pole of a battery or other source of electricity, another spring.
being connected to the other pole thereof and fixed in the counter in such a
imanner that it projects slightly above the same and is normally in contact with
the first spring, and the circuit will be broken when the spring is depressed by the
weight of any goods, but when such goods are lifted. the circuit will be completed
and an alarm sounded; or the circuit may be arranged to be broken when the said
goods are lifted or removed from the spring.
Another part of my invention consists in forming a conductor of tin-foil or other
material upon a sheet of glass at or near the edge thereof and connecting the
same with a conductor embedded in the window or other frame in which the glass
is situated, so that if the glass is broken at any part and a crack extends to the
edge the circuit will be broken and an alarm sounded.
According to another part of my invention I provide an improved device for
effecting either the completion or the breaking of a circuit by the opening of a
window or other part of a building. This device consists essentially of a plate to
which is pivotted a double armed lever, the two arms of which project through the
said plate, the said lever is retained in position by a spring and is normally either in
or out of contact with a spring secured to the said plate but insulated therefrom.
This device is chiefly designed to be fixed to the frame of a window preferably in such
a manner that only one side of the said plate and the arms projecting through the
same are exposed, and so that the lower sash when opened will act upon one of the
said arins and the upper sash when opened will act upon the other arm to depress
the lever, either of these operations completing or breaking the circuit by causing
the said lever to make or break contact with the spring as the case may be. This
device can obviously be arranged to be operated by a door or other movable part
of a building.
Another part of my invention consists in attaching a spring or springs to the
wall or floor or other suitable part of a building, and combining with the same a
cord or chain adapted to be stretched across the floor in such a manner that should
the said cord or chain be disturbed it will release the spring or springs and cause
an alarm to be sounded eitlier by breaking or by completing an electric circuit..