Improvements in Door-closing Apparatus.
Year: 1897

page_text: Date of Application, 28th July, 1897-Accepted, 9th Oct., 1897
Improvements in Door-closing Apparatus.
We, HERMANN FRIEDRICH BRAUN of 14 Goethestrasse, Düsseldorf, and RUDOLF
GROSS, of 12, Uhlandstrasse, Dusseldorf, Manufacturers, 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 spring devices for closing doors automatically and with
little or no noise.
The present invention includes a brake, which only releases the door after it has
been nearly closed by the spring, so that sufficient pressure is left to close the door
completely and with certainty.
In the accompanying drawings, Fig. 1 is a horizontal section of a door closing
device embodying our invention; Fig. 2 is the same in a different position; Fig. 3
is a face view, and Fig. 4 a back-view.
The closing apparatus chiefly comprises a helical spring f enclosed in a telescopic
casing 6, 6, one half of which is pivoted to the door and the other to the door
frame.
When the door is closed, as represented by Fig. 1, the casing b, b¹ has its maxi-
mum length and the spring f is in its natural condition, that is, without artificial
strain. By opening the door until it occupies the position represented by Fig. 2,
the telescopic tube b, b' is shortened and the spring compressed.
A rails situated in the axis of the casing b, b', is fixed at one end to the bottom
cr the tube b¹, while the opposite extremity extends through the bottom of the
tube 6 and is adapted to slide therein. The said rail or rod has a ledge s¹ adapted
to meet a brake block or roller r and slide over the same during the motion of the
door, said roller being held in a lever h secured to the tube b.
The opposite arm of the lever h is forked or slotted for the reception of a screw a
attached to a flange of the tube 6 and surrounded with a helical spring c. The
spring c presses the roller r against the rails, as far as the head of the screw a
will allow it.
If the door is being opened, the ledge s¹ comes in contact with the roller r, but
as the spring c allows the lever h to turn on its fulcrum, the roiler offers little or
no resistance to the opening of the door.
If, however, the door is being closed, the head of the screw a prevents the lever h
from turning, consequently the roller r presses against the projection or ledge s¹,
thus preventing the rapid motion of the rail s, the rapid expansion of the spring,
and the violent closing of the door. When the door has been nearly closed, the
rails is disengaged from the brake roller r, owing to the shortness of the ledge s',
and the door falls into its lock without much noise. By slackening or tightening
the screw c, the brake pressure can be easily increased or reduced.
Other kinds of springs may be substituted for the helical spring c, in which case
the spring would, of course, be applied or mounted in a different manner, and
instead of the lever h, other suitable mechanism may be employed to hold the
brake block or brake roller.

page_text: Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. An automatic door closing device comprising in its construction a brake block
or brake roller and a brake rod s adapted to slide longitudinally in the act of
opening or closing the door, the said rod having a lateral projection or ledge s
adapted to come in contact with the said brake roller and made of such a length
that the rods will be released from the pressure of the brake when the door has
nearly reached its closing position, substantially as described.
2. In an automatic door closing, device having a brake roller or block and a
brake rod s adapted to operate as described, a brake lever h held on one side by a
spring and abutting on the other side against the head of a screw c or another
adjustable stop, in order that the door may be opened without hindrance from the
brake, and that the pressure of the latter may be regulated...
coul 1
.....
100%
FAIRFAX & WETTER,
37 and 39, Essex Street, Strand, London, Agents.
FAIRFAX & WETTER,
37 and 39, Essex Street, Strand, London, Agents.