An Indicator and Locking Device for House Doors.
Year: 1890

page_text: Date of Application, 21st Nov., 1890-Accepted, 27th Dec., 1890
COMPLETE SPECIFICATION.
An Indicator and Locking Device for House Doors.
L, FRANZ LUDEWIG, Manufacturer, of Düsseldorf, do hereby declare the nature of
my invention and in what manner the saine is to be performed to be particularly
described and ascertained in and by the following statement :-
In the case of houses which are inhabited by several families, the door is frequently
provided with a safety chain, to be fastened only after the last person has entered.
Consequently, persons arriving late at night wish to possess a ready means of ascor-
taining whether all other inhabitants have already entered.
To supply this want is one of the objects of the apparatus illustrated by the accom-
panying drawings, in which
Fig. 1 is a front view and Fig. 2 a plan of an apparatus in the closing position,
while Fig. 3 is a front view and Fig. 4 a horizontal section of the same in the open
position and Fig. 5 a partial view of a door provided with my invention.
The apparatus chiefly comprises a frame which contains as many slidos a, as there
are flats or dwellings in the house, each slide bearing the number of the corresponding
floor (I, II, III, etc.) or the name of the occupant. If the slide is drawn out, it
indicates that the corresponding family or occupant is not at home.
"
The face of the frame may be provided with slots, through which the words "in"
or out," can be seen at certain positions of the slides. As far as described, the
apparatus simply serves to indicate which of the inhabitants are in and which are out;
but it may be combined with a device which prevents the person who enters from
closing the safety chain, as long as one or more slides remain drawn out.
This device chiefly comprises a lever or slide b, to which the safety chain is attached,
a spring c which presses the said lever towards the indicator frame, and a series of
angular levers d, one for each slide a. Each lever d is pivoted to the frame or base
plate and connected at one end with the slide a by means of a pin and slot, while the
other end is parallel with the slide a and abuts against the lever b, so as to push the
latter back, when the slide a is being drawn out.
The position of the lever b and the length of the chain are arranged in such a
manner, that the chain will no longer reach the hook e, when one of the slides a is
drawn out; consequently, the chain cannot be fastened, until all the slides a have
been pushed back.
Each of the slides may be provided with a lock and a key, so that it can only be
moved by the person who possesses the key.
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. An indicator for house-doors, consisting of a slotted frame and slides adapted
to show by their position, which of the inhabitants are in and which are out, sub-
stantially as described.
2. The combination of a door chain, with controlling apparatus comprising
slides a, a lever b, actuated by a spring and angle levers d, substantially as
described.
Dated this 20th day of November 1890.
144NN112
FRANZ LUDEWIG.
By Fairfax & Wetter,
433, Strand, London, Agents.