Improvements in Portable Alarm Fastenings for Doors, Windows, and the like.
Year: 1894

page_text: Date of Application, 10th Mar., 1894-Accepted, 14th Apr., 1894
COMPLETE DIUIFICATION.
Improvements in Portable Alarm Fastenings for Doors, Windows,
and the like.
I, THOMAS WOODARD of 29 Newman Street Oxford Street in the County of
London Jeweller, 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 in the portable alarm fastenings for doors,
windows and the like for which Letters Patent were granted to G. J. Bellingham,.
dated September 1st 1888 No. 12583.
In the Specification of the said former Letters Patent there is described a spring.
hammer hinged to a wedge shaped supporting block and provided with a spring-
adjusting lever.
In carrying out my invention I dispense with the said adjusting lever and substitute-
therefor a plate hinged at the point of the wedge shaped supporting block and
adapted to be lifted into such a position by the hammer when cocked that upon the-
door, window or the like to which the alarm applied being opened, it will impinge-
against the said plate and move it so as to force down the hammer.
In order that metal percussion caps may be used with the alarm as well as paper ones.
I provide the hammer with a cylindrical striker or projection onto which the said
metal caps can be placed.
I also arrange in conjunction with the hammer spring a pin against which the-
said spring bears when deflected by the cocking of the hammer.
In order that the invention may be clearly understood reference is had to the.
accompanying drawing, in which
Figure 1 is a plan of a portable alarm fastening for doors, windows and the like.
constructed according to my invention.
Figure 2 is a longitudinal central section of the same shewing the hammer in its
fired position and Figure 3 is a similar view to Figure 2 but shewing the hammer-
in its cocked position.
a is the wedge shaped block, b the hammer, c the spring thereof and d the anvil
upon which the hammer strikes, all of which parts are similar to those described in:
the Specification of the said former Letters Patent.
e is the plate which I employ according to my invention for operating the hammer
when cocked, the said plate being advantageously hinged by means of rivets ƒ ƒ in,
the said plate engaging loosely with holes in the block a. The said plate as shewn
in Figure 2 is arranged to lie upon the upper surface of the block a when the
hammer is in its fired position, but when the hammer is cocked, as shewn in
Figure 3, the said plate is raised by the said hammer into the position shewn. If,.
now, the door, window or the like to which the fasteuing is applied be opened,
it will impinge against the plate e which will force down the hammer onto the
anvil d.
g is the cylindrical striker or projection on the hammer for the reception of
metallic percussion caps, the said projection also serving to fire off paper caps.
placed upon the anvil d.
h is the pin against which the spring c bears when deflected by the cocking of
the hammer whereby the strain due to such deflection is relieved at the point
where the said spring is rivetted to the block a and by placing the said pin in the
position shewn, that is to say, hetween such rivetting and the free end of the spring,.
the latter is stiffened and consequently causes the hammer to strike a sharper blow
than when arranged as in the said former Specification.

page_text: 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. In a portable alarm fastening for doors, windows and the like of the kind
herein described the employment of a plate such as e arranged and operating
substantially as described and for the purpose set forth.
2. In a portable alarm fastening of the kind herein-described providing the
hammer with a cylindrical striker or projection substantially as and for the purpose
set forth.
3. In a portable alarm fastening of the kind herein-described the combination
with the hammer spring of a pin such as h substantially as and for the purpose set
forth.
4. The improved portable alarm fastening for doors windows and the like herein-
before described and illustrated in the accompanying drawing.
Dated this 9th day of March 1894.
THOMAS WOODARD.