Improvements relating to Locks.
Year: 1896

page_text: Date of Application, 4th Nov., 1896-Accepted, 9th Jan., 1897
Improvements relating to Locks.
I, JAKOB DIEHL, Manufacturer of Chased Work, of 51 Blasewitzerstrasse,
Dresden, in the Empire of Germany, 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 improvements having for their object to prevent the
surreptitious opening of a door window or the like.
The accompanying drawings illustrate a door lock applied with my improve-.
ments, such lock being illustrated in two different positions.
In carrying my invention into effect as applied to a door I arrange a lock a upon.
the door having a bolt b, which acts when closed to force out the lower end of a
lever c, so that the head d, of the other end of the lever which is provided with a.
nose d' moves forward and enters the recess in the door frame e, as indicated in
Figure 2. By this means a double closure is effected while at the same time-
contact is broken at f, f', which contact otherwise serves to close the electrical
alarm circuit i.
As soon as the bolt b, is moved back as in unlocking or opening the door,.
(Figure 1) the spring g, forces the lower arm of the lever c, forward draws back
the head d and nose d, and closes the contact f, f', thereby setting the alarm bell
in operation.
A cut-out device or switch may be provided to prevent the alarm from being
given when it is not required.
For the purpose of affording further security, there may be employed in addition
the pawl or stop h, shown in the drawing. This pawl is forced by a spring k, into.
a notch in the lever c, and acts to keep the lever c, in its closed position even when
opening the door until the pawl h, is rotated by means of a key or the like; the
arrangement being such as also to allow of making contact at ff by means of the-
rearward extension h' of the pawl h.
The two notches in the lever c, correspond to single and double locking of the-
bolt 6. Contact is broken at f, f, only when the bolt has moved into double-
locking position, whereby the pawl h, is enabled to fall into the last notch.
Having now particularly described and ascertained the nature of my said inven--
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
(1.) A safety lock with electrical alarm apparatus, the arrangement being such
that by the movement of the bolt b, a spring catch lever c, which is arranged on
the mortice or bolt plate or recess may be caused to rotate into the closed position,.
but which after the rearward movement of the bolt b, is forced back again by
means of a spring 9, and closes the contact or circuit of the electric alarm i,.
substantially as and for the purpose described.
(2.) In combination with the apparatus specified in Claim 1, a pawl or stop h,.
which even after the return movement of the bolt b, allows only of the door being
opened when the stop or pawl is rotated or disengaged by means of a key or the
like substantially as described.

page_text: (3.) A safety lock substantially as and for the purpose herein before described
and illustrated.
Dated this 4th day of November 1896.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.