Improvements in Door Closing Apparatus and Door Checks.
Year: 1895

page_text: Date of Application, 1st Oct., 1895-Accepted, 21st Mar., 1896
COMPLETE SPECIFICATION.
Improvements in Door Closing Apparatus and Door Checks.
I, FERDINAND THEODOR FRANKE of Dessau, Germany, Manufacturer, 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 improvements in self closing devices for doors forming the subject matter
of this invention relate to mechanism which not only allows of adjustment of the
spring enclosed in the air cylinder being effected from the outside and of the
opening of the door being facilitated by the air in front of the piston being
allowed to pass freely to the back of it, but renders the door spring effective, even
when, owing to local circumstances the fixing block or base cannot be placed in one
plane, by reason of the bearing of the pull rod as well as of the rod itself being
rendered adjustable, both the pull rod and piston rod engaging with a common beli
crank arranged to turn on the door frame. The spring is adjusted from the
outside as already stated by the aid of a bearing plate moved by a suitable nut.
The passage of air from the front of the piston to the back is facilitated by loosely
connecting the piston to its rod by means of a conical joint.
In the accompanying drawings, which illustrate the new door spring,
Fig. 1 is a section of the spring as it appears when the door is closed, while
Fig. 2 is a similar view as it appears when the door is ajar.
Fig. 3 is a plan of Fig. 1 and
Fig. 4 shows in cross and longitudinal sections respectively the adjustable
bearing of the pull rod.
Figs. 5 and 6 show in elevation and section respectively the adjustable bearings
for the piston spring.
Figs. 7 and 8 show the new door spring as it appears in action, the positions
corresponding to Figs. 1 and 2.
Fig. 9 is a diagram showing the lines of motion of the pull rod and of the
piston rod with the bell crank and the air cylinder.
In the air cylinder A, which is secured to the door frame a in the ordinary
way ie, by means of a bearing b upon which it turns, works the piston c having
its piston rod d jointed to the bell crank which is pivotted to the bearing e fixed
to the door frame a; while the spring , likewise enclosed in the air cylinder A,
bears against a plate i baving a screw threaded extension (see Figs. 5 and 6) on
which is screwed a nut k whereby the tension of the spring can be properly
adjusted. The piston rod d is loosely connected by the cone d¹ to the piston c and
is held in such a manner that when the door a is opened, as shown in Fig. 2, the
pin c allows the cone d¹ to move sufficiently within the piston to leave an opening
for the passage of air from the frout to the back of the piston, but when the door
is closed, the air locked in at the back of the piston retards its movement and the
cone d' of the rod d moved by the back swing of the door closes the piston c
tightly or nearly so (as shown at Fig. 1).
To transmit the motion to the door the pull rod is used, being secured to the
door by a forked bearing m (see Fig. 4) the sliding foot or pedestal m' of which
encloses an adjusting screw o secured in a frame n; this arrangement is devised for
the purpose of rendering the pull rod adjustable at the same time as it allows the
door spring to be fitted to whatever kind of bearing may be had in the locality.
By turning the screw o the foot m¹ can be moved back and forward as desired.
The rod is made in two parts connected by a screw coupling so that it can be
shortened or lengthened as desired.

page_text: The pull rod is bent down at its upper end and is secured to the bell crank f,
on which it can turn, at p. The adjustability of the bearing m and that of the
pull rod in connection with the crank allows the new door spring to be readily
fitted to any door, while its operation may be varied at will.
It will be readily seen with reference to Figs. 7 to 9 which show diagrammatically
the action of the new device, how easily it can be adapted, in consequence of the
adjustability of the bearing m of the pull rod to any kind of door no matter how
it is suspended or whether the door frame and the door are in the same plane or
not, while the different heights of the pull rod bearing and of the bearings b and e
of the air cylinder and the crank and the positions of these bearings can be
adjusted and regulated by adjusting the pull rod bearing m and the pull rod 1 so
that the new device can be fixed in position under whatever circumstances and
conditions may obtain at the time.
Furthermore the adjustability of the piston rod / permits of door springs of the
same size being utilized within certain limits for doors of various sizes and hence
for various weights whereby the wholesale manufacture of door springs is con-
siderably simplified. The spring is adjusted by turning, to a suitable extent, the
nut whereby the bearing piece i can be moved nearer to cr farther from the
piston c.
د
The opening of a door furnished with a closing device of this improved con-
struction is greatly facilitated by the fact that the piston c is loosely connected to
the piston rod d by means of the cone d¹ and the pivot or pin c' this being done in
such a manner that, as before mentioned, there is formed whenever the door is
opened (owing to the looseness of the joint between the conical piece d' of the
piston rod d and the piston c) a comparatively large opening for the air to pass
from the front of the piston to the back. The chief point therefore in regulating
the closing of the door by its own motion is to properly adjust the spring h.
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
consider novel and desire to claim is :-
1. A door closing device having its piston rod connected by a bell crank with a
pull rod which is variable in length and whose fixed end is held in an adjustable
bearing for the purpose of enabling the door spring to be adjusted to different
actions and also to adapt it to all kinds of bearings, substantially as hereinbefore
described with reference to the drawings annexed.
2. The application and use of a bearing plate for the piston spring capable of
being adjusted from outside the cylinder, substantially as and for the purpose
set forth.
3. The loose cone joint by which the piston rod is connected to the piston 80
that whenever the door is opened and the piston rod pulled a circular passage way
is left between the piston and its rod and whenever the door is shut this passage
way is closed by the insertion of the conic plug-end of the rod into the piston,
substantially as herein before described with reference to the drawings annexed.
Dated this 27th day of September 1895.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow, Agent.