AN IMPROVED ALARM-APPARATUS CHIEFLY DESIGNED FOR INDICATING THE OPENING OF DOORS OR WINDOWS, ALSO APPLI- CABLE AS A RAILWAY-SIGNAL
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 25th March 1881. A communi-
cation from abroad by Charles Haas, of Paris, France.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED ALARM-APPARATUS CHIEFLY
DESIGNED FOR INDICATING THE OPENING OF DOORS OR WINDOWS, ALSO APPLI-
CABLE AS A RAILWAY-SIGNAL." A communication from abroad by Charles Haas,
of Paris, France.
This Invention relates to a portable alarm instrument or apparatus so constructed
that when placed against or in connection with a door or window a bell or gong
forming part of the apparatus will be sounded should any one open the said door
or window, and thus give warning thereof.
The said apparatus will be very useful for commercial travellers and others who
have frequently when in charge of money or valuable goods to sleep at hotels, the
rooms of which are closed by doors and windows having very insecure fastenings.
The said apparatus may also be used for many other purposes, for instance, it
may be employed upon railways for indicating the passage of trains over crossings
and the like.
An apparatus embodying the present Invention is constructed as follows, that
is to say-I provide a spring which is fastened at one end to the frame of the
apparatus, and at the other end to a spindle, which, has at its outside extremity a
thumb-piece or key for winding up the spring. The said spindle carries a toothed
wheel, which transmits motion to a hammer or striker. A ratchet-wheel on the
said spindle is in connection with a spring-pawl, which is pivotted to the face of
the aforesaid toothed wheel. The latter gears with a pinion, upon whose axis
there is an escapement-wheel, the teeth of which act upon an escapement firmly
fixed to the spindle to which the hammer or striker is attached. Therefore
whenever the spring is unwinding the said striker is kept in motion. There is an
arm secured to the same spindle extending out from the latter at about a right
angle to the striker-arm, and the latter is kept from moving whenever this second
arm is not free to oscillate. The latter is arranged to be held by an enlargement
at one end of a rod, at whose other or outer end there is an adjustable head having
Pine I

page_text: pointed extremities. There is a spiral spring around the rod, which spring tends
to keep the head and the rod pressed in an outward direction, but if the points of
the head are pressed upon, for example, by a door, against which the said points
may rest, the aforesaid enlargement on the internal end of the rod is pushed away
from the end of the second arm, so that the hammer or striker is free to oscillate,
and vibrates under the action of the main spring, thus causing a suitably arranged
gong or bell to be sounded as long as the pressure continues to be exerted on the
points aforesaid. The said apparatus is designed to be placed against a door or
the like in an oblique position, the pointed head resting against the door and the
other end upon the floor. A cap may be provided to cover the points when
the apparatus is not in use. The main spring may be enclosed in a barrel if
desired.