Improved Fastening for Doors.
Year: 1895

page_text: Date of Application, 3rd Aug., 1895-Accepted, 21st Sept., 1895
COMPLETE SPECIFICATION.
Improved Fastening for Doors.
I, LOUIS GROSSMANN, of I Opernring No. 3, Vienna, Austria, Gentleman, 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 :-
My invention relates to an improved fastening for doors which affords great
security against unauthorised opening. For this purpose the doors are provided
on one or both sides with a covering of sheet steel for preventing the cutting
through of the woodwork. To this sheet steel covering is fixed a locking device
which only permits of the opening of the door to a slight angle; at the same
time an electrical alarm signal is sounded until it is stopped by hand.
For completely opening the door, the hand has to be passed through the narrow
opening formed as above described for the purpose of opening either the safety
locks of the above described locking device, or, in the case of double doors, to open
the bolts, or to effect both the said operations, and thus to open either both parts
or one part only of the door.
In order furthermore to prevent one of the wings of the door from being lifted
off its hinges through the crack, there are provided above the same stops or plates,
that prevent any such unhinging.
The construction of the said fastening will be understood on reference to the
accompanying drawings in which Fig. 1 shews an inside view, and Fig. 2 a cross
section of a door with a single wing, and Figs. 3 and 4 shew the same views of a
double door; Fig. 5 shews an enlarged detail.
The door is provided with a sheet steel covering a and turns upon hinges b;
above the door are angle plates or stops c fixed to the top framing of the
door, which prevent the door from being lifted off its hinges except when quite
open. At the top of the frame is also fixed an electrical contact device of
any suitable known construction, such for instance as that shewn in plan at
Fig. 4A.
The contact spring is in this case kept away from the contact plate by a stud
on the door while this is closed, but when the door is slightly opened, the spring
makes contact so as to close the circuit of an electrical alarm signal.
The door is provided with a safety lock to which access can be gained from
the outside for opening it. On the inner side of the door are guides e between
which is a slide to which is pivotted a link y whose other end is pivotted to a fixed
abutment h.
On turning the door on its hinges, the slide is therefore made to slide to and
fro between the guides e, but it is ordinarily prevented from such motion by bolts
or stops i and thus the opening of the door beyond a small angle x is prevented.
These bolts are connected by means of elbow levers k with rods m that pass into
the safety locks and are there so arranged as to be drawn inwards on unlocking
the lock; by this means the bolts are withdrawn from the path of the slide f,
so that the door can now be completely opened.
This arrangement can also be applied to double doors, as at Figs. 3 and 4, but
in this case means have to be provided for preventing the opening of the ordinary
bolts n when the door has been slightly opened, except through the agency of
safety locks o. All these safety locks and o are only accessible from the inside
and can therefore only be reached after the one wing of the door has been opened
to the above described small angle x.

page_text: During the opening of the safety locks the alarm signal is sounded for a
sufficient length of time to bring assistance to the spot, in case of unauthorised
opening, in addition to the resistance to burglary afforded by the safety locks.
Furthermore, all the screws employed in fastening the parts are constructed
with peculiarly formed heads which cannot be actuated by means of ordinary
screw-drivers, but only by a specially constructed key. The head of the screw
is for this purpose not formed with the usual groove, but with two lateral
notches r, as shewn at Fig. 5, into which fit studs on a specially formed key, for
screwing and unscrewing.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:―
1. A safety fastening for doors wherein the door provided with a sheet steel
covering a and electrical alarm signal contacts d and turning on hinges b, is
prevented from being lifted off its hinges by a plate or stop c above the same, and
is provided with guides e between which a slide f can move to and fro if not
prevented by bolts or stops i, which can only be withdrawn by the agency of safety
locks accessible only from the inside, substantially as described.
2. In combination with the safety fastening referred to in the first claim the
use, in the case of double doors, of bolts n so arranged as only to be actuated by
means of safety locks o accessible only from the inside, substantially as described.
3. The use in combination with the safety fastenings referred to in the first and
second claims, of screws provided with lateral notches in place of the ordinary
groove, so as only to be capable of being actuated by means of a specially formed
key, substantially as described.
Dated this 3rd day of August 1895.
ABEL & IMRAY,
Agents for the Applicant.