An Improved Self Acting Closer for Doors.
Year: 1893

page_text: Date of Application, 7th Apr., 1893-Accepted, 2nd June, 1893
COMPLETE SPECIFICATION.
An Improved Self Acting Closer for Doors.
J JOHANN CHARLES LUDWIG of 5 Deichstrasse, Hamburg, in the Empire of
Germany, Merchant, 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:-
The object of the present invention is the production of a self-acting closing
apparatus for doors in which the working of the essential parts is effected by the
use of rolling or cylinder pressure and the action of a spiral spring (which enables
the door to close automatically) through a circular segment arranged eccentrically
to the axis of rotation of the door and fixed to the door frame.
The apparatus is equally suitable for single or double doors. In no case do the
latter require, when in a fully open position, any further means of fixing than is
offered by the present construction. In consequence of the little friction of the
surfaces working on each other their wear is scarcely worth mentioning, and the
movement is quite regular and without jar. The required spring in each position
of the door exerts its pressure at right angles to the axis of rotation, so that it has
almost unlimited duration. As, after the apparatus is fixed, so little of it is visible,
and as it can be fixed equally well above or below the door, it does not take up
useless space, nor does it require a varied style of construction..
In Figures 1 and 2 of the annexed drawings the apparatus is shown as fitted to
a double door closing from each side.
Figures 3 and 4 show a side elevation and plan of the apparatus to a larger
scale, which in Figure 3 is partly laid open.
S represents in the said drawings a metal plate in the form of a circular segment
with circular depressions » v2 in the curved surface and which is fixed horizontal
by the screws to the top piece T of the door frame. Eccentrically to the
central point of its circular curve is arranged the rotating pin z of one of the doors
fixed in the metal plates s thereof, which is connected to an adjustable bolt b by
means of the guide piece u between which, and a shoulder t of the bolt, is a spiral
spring f. The right hand side of the bolt is connected to a friction roller " on the
top side of the plate by means of the pin 62 working in the slot a of the plates.
The friction roller can rotate on the pin 6 and is pressed against the segment
plate S by the spring f. The plate s-with-the-connected-portions is let into the
wood. The roller r is free to move sideways in a cut away portion p of the door
frame T.
The action of the apparatus is as follows:-
When the door is moved out of the central position (Figure 4) on one side or
the other the roller r, in consequence of the giving way of its axis, is pushed out
of the depression v, and the spring f is slightly compressed. With the continued
movement of the door the roller turns along the curved surface of the plate S
whereby a continually increasing compression of the spring takes place corre-
ponding to the increase of distance between each point of the periphery of the
curve and the axis of rotation z of the door. If one of the end positions of the
loor is reached the roller r is forced into one of the depressions v² or v³ by
he reaction of the spring, whereby the door is held in the open position
Figure 2).
Having now particularly described and ascertained the nature of my said inven-
ion and in what manner the same is to be performed, I declare that what I
laim is
1. In a self acting door closer: a segment fixed eccentrically to the axis of

page_text: and for
rotation of the door.in combination with a roller traversing the periphery of the
said segment and pressed against it by a spring substantially as descri
the purpose set forth.
2. A self acting door-closer in which one end of a bolt 6 let into the door and
acted upon by a spring presses by means of a friction roller r, whose pin 62 is
fixed to the said bolt and works in a slot a of a plate s on the curved surface of a
segment plate "S" arranged eccentrically to the pivot z of the door and fitted to
the door frame, and rolls on the segment, which is provided with depressions v² v
at the centre and ends in such manner that the separate points of the said circular
curved plate increase in distance from the rotating point of the door as it is opened
inducing the compression of the spring, the reaction of which closes the door sub-
stantially as described.
3. The arrangement and construction of a self acting door closer substantially
as described with reference to the drawings.
Dated this 7th day of April 1893.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.