Door Closer with Automatic Lubricator.
Year: 1894

page_text: Date of Application, 15th Dec., 1894-Accepted, 2nd M r., 1895
Door Closer with Automatic Lubricator.
I, HEINRICH KÜHN of 63 Gitschiner Strasse Berlin, 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 a door closer in which the lubrication of
the inner cylinder walls is effected either by the arrangement of a hollow piston
rod acting as the oil reservoir or by the employment of a solid piston rod which is
bored through across and dips with this bore into the stuffing box connected to the
oil reservoir, delivering up on its return the oil to the cylinder, in which the latter
is spread evenly over the inner walls by means of the piston movement.
The door closers at present in use all suffer from the same disadvantage that
they must be frequently oiled if they are to fulfil their purpose. If these door-
closers are not freely and frequently oiled they act as a brake on the door instead
of as an assistance to its closing.
To remove this disadvantage is the object of the present invention.
I will now describe the invention with reference to the accompanying drawings
in which
Fig. 1 shows an end view and partial section of the stuffing box of the piston
rod, acting as the oil reservoir.
Fig. 2 shows a section on the line x-x of Fig. 1.
Fig. 3 shows a perspective view of the door-closer with solid piston rod.
Fig. 4 shows a longitudinal section of the hollow piston rod of a door closer, for
one form of lubricating apparatus.
The chamber A shown in Figs. 1 and 2 consists of an upper part a, and lower
part b, filled with oil and in one with the top portion.
Into the lower part & dips a wick c and passes round the upper part a.
The upper part a as well as the lower part b are provided on the inner side
facing the piston rod e, each with a slot-like opening d, through which the wick
projects and comes into contact with the piston rod e. In order to be able to
insert the wick in the upper part a, the removable cover f is fitted to the
front thereof. The fastening of the chamber to the cylinder is effected by means
of the lugs 9, 9.
The under part b, is filled with oil through the opening / as required..
The piston rode of the door closer shown in Fig. 3 is provided at a suitable
point with a small transverse aperture B which at the circumference of the piston
rod is opened out elliptically.
This aperture B, so soon as the piston rod is moved backwards and forwards, on
the opening and closing of the door, passes under the wick filled with oil which
projects slightly through the slot d, and it is filled by this wick with oil which
then drops on to the bottom of the cylinder. On the piston head is fitted a
cup leather or an oil absorbing layer Ċ made of cotton, felt or other suitable
material.
This absorbs the oil and spreads it evenly on the inner surfaces of the
cylinder.
In this manner the arrangement of the chamber A acts in combination with the
aperture B and the oil absorbing layer or cup leather C to produce the automatic
lubrication of the door-closer.

page_text: The elliptical mouth of the aperture B serves to take up dust and prevent it
from becoming clogged.
In order to lead the oil to the inner cylinder the modified arrangement as shewn
in Fig. 4 can be used. The piston rod e¹ is in this case bored and suitably closed
in at the top and bottom.
The hollow space so formed is filled with oil through the opening . The
groove K produced in the position is filled by a wick and the passage i bored into
the hollow space.
In this manner the wick c¹ laying close to the cylinder walls is able to absorb
the oil and spread it over the inner surface of the cylinder.
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 :-
A lubricating arrangement for the pistons of pneumatic doorclosing apparatus
consisting of supplying the pistons with a layer or layers of oil absorbing material
so placed as to lubricate the surface of the cylinder, the oil being fed thereto
from the interior of the piston or from a small aperture as herein described and
set forth.
Deted this 15th day of December 1894.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Agent for Applicant.