AN IMPROVED ALARM APPARATUS
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
23rd February 1870.-A communication from abroad by Eugene
Victor Achille Loiseau, of Paris, in the Empire of France, Electrical
Engineer.
.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,".
Southampton Buildings, London, Consulting Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED ALARM
APPARATUS," a communication, to be as follows :—
My Invention relates to an alarm apparatus, to which I give the name
of "Paravol." This alarm apparatus has a bell, of which the hammer or
striker is set in motion by clockwork in such a manner as to obtain for
any desired time a prolonged ringing.
The especial characteristic of my said Invention is, that this: alarm is
of small dimensions so that it may be easily placed in the pocket, and
may be instantaneously adapted without previous preparation to any
object, whether it be the door of an apartment, a window, or a drawer.
The said apparatus differs essentially from the door bells employed up

page_text: to the present time in the following particulars :-The latter require to
be adapted for fixing by a locksmith; they are immoveable, and only
strike one blow; whilst my alarm apparatus is detachable and portable.
It may be placed on a door, window, or other object or article with
facility and promptitude. It may be fixed temporarily or permanently
at will. By the opening of the door, window, or other object upon which
it is fixed a detaching or releasing device conveniently arranged releases
the striker, which acts upon the bell and produces a prolonged sound
similar to that of an alarum clock.
This apparatus will be particularly appreciated by travellers, who for
their personal security or for the safety of their luggage may adapt it
either to the door or to one or more of the windows of their chamber in
a hotel or lodging house. The said apparatus_is_composed of two distinct_
parts, first, the bell or alarm apparatus properly so called, and, second,
the escapement in connection with the clockwork, which is set in motion
by the opening of the door, window, or other object.
The apparatus may be fixed above or on the framework of the door or
other object, or even upon the door, window, or other object itself
according as the same is opened inward or outward, but in every case the
apparatus must be so placed that the movement of the door, window, or
other object itself will actuate the disengaging device and liberate the
clockwork, which will set in motion the striker of the bell. The fixing
of the apparatus may be effected by a simple peg or screw, or by
atmospheric pressure like the so called pneumatic pegs, or by any other
means which are prompt, easy, and within the reach of everybody.
In order that my Invention may be more clearly understood, I have
given an example thereof in the accompanying Drawing, in which Figure
1 is a front view of my alarm apparatus shewing the face behind the bell;
Figure 2 is a profile view of the same, the bell being in section.
In
these two Figures the disengaging device is in its stationary position.
Figure 3 is a profile view of the apparatus, the disengaging device being
in the position which it occupies when the apparatus is in action;
Figure 4 is a detached profile view of a screw socket which is used to
fix the apparatus; Figure 5 is a plan view of the same. In all of thesc
Figures the same letters refer to like parts.
a, b, are flat plates fastened together by cross pins; they form the case
of the clockwork, and serve to support the different parts of the
apparatus. c is the bell fixed upon a pivot d on the plate a. It will be

page_text: seen that the clockwork arrangement is enclosed in the bell c, and this
renders it casy to place the apparatus in the pocket of any article of
dress.
e is the spring box of the clockwork, whose shaft is furnished
with a ratchet wheel and retaining pawl; fis for winding up the spring;
g is the escapement wheel, which receives its motion from the spring
box through the medium of a pinion h. This escapement wheel is in
connection with an anchor escapement i, which being mounted upon
the oscillating axis of the hammer j communicates to the latter a
continuous oscillating motion so that it acts upon the bell c; k is a
spring blade fixed upon the exterior face of the plate b; is a pin or
catch fixed in the spring which traverses the plate b, and engages with
the teeth of the escapement wheel g in such a manner as to arrest its
motion; m is a disengaging device, which is jointed at n to a piece p
fixed on the plate b. The free end of the spring k rests upon the heel m¹
of the disengaging device in such a manner as to keep it in a vertical
position. is a hinged pin fixed on the plate b. To fix the apparatus
it is only necessary to secure the screw socket 8, Figures 4 and 5, in any
required position and insert therein the hinged pin 1. The socket s is to
be arranged in such a manner that the disengaging device will be in the
way of the door or window when the same is opened, the lever or
rod m being approached in the direction indicated by the arrow, Figure 3.
It will be seen that in taking this position the heel m¹ of the disen-
gaging device will push the spring in such manner that the pin
moves backward and liberates the escapement wheel; this wheel being
then no longer restrained yields to the action of the spring box, and the
striking gear is set in motion. To render the apparatus more portable the
rod m may be pivotted at t, so that it may be turned back upon the
plate b. The said rod may also, as shown, be made of a number of tubes
arranged telescopically one within the other so that the length of the
disengaging device may be increased in some cases. It will be readily
understood that instead of the sockets for holding the apparatus I may
employ other convenient and suitable means.
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