A SPRING FOR CLOSING DOORS
Year: 1876

page_text: LETTERS PATENT to Gottfried Stierlin, of Schaffhouse, in the Republic of
Switzerland, Patent Hinge Manufacturer, for the Invention of "A SPRING FOR
CLOSING DOORS."
Sealed the 15th August 1876, and dated the 3rd March 1876.
PROVISIONAL SPECIFICATION left by the said Gottfried Stierlin at the
Office of the Commissioners of Patents on the 3rd March 1876.
GOTTFRIED STIERLIN, of Schaffhouse, in the Republic of Switzerland, Patent
Hinge Manufacturer. "A SPRING FOR CLOSING DOORS."
The spring is composed of hardened cast steel bands; these bands are bound by
two rings of compo and fixed at the top into a four cornered slot or hole with an
arm projecting on to the door. The bottom part of the spring is fixed into another.
slot, which has a cog wheel and ball, such ball having four holes for the
purpose of
being wound up by a pin for the purpose of increasing, decreasing, or entirely
suspending the strength of the spring without removing the same from the door.
The bands are placed in an iron tube, which is screwed on to a plate which is fixed
on to the side of the door. There is a roller running on to the door, which is fixed to
the arm projecting on to the door above mentioned.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gottfried Stierlin, in the Great Seal Patent Office on the 26th August
1876.
GOTTFRIED STIERLIN, of Schaffhouse, in the Republic of Switzerland, Patent
Hinge Manufacturer. "A SPRING FOR CLOSING DOORS."
This Invention relates to door springs, and has for its object effecting the closing
of doors automatically with a minimum amount of noise.
In carrying out this Invention the torsional power of a blade spring or com-
bination of blade springs is caused to act upon a lever in such a manner as to
impart to the door when open an impulse of just sufficient power to close it without
[Price 6d.]

page_text: hanging, the lever being of such a shape as that when the door is nearly closed it
will act as a brake to prevent the door from closing too suddenly.
The power of the spring may be regulated by means of a ratchet wheel and
detent (or their equivalent) so as to render the spring suitable for doors of different
weights.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Sheet of Drawings is a perspective view of a door
spring constructed according to this Invention shewing the spring lever in the
position which it assumes when the door is closed.
Figure 2 is a sectional view of the same spring shewing the position of the
spring lever when the door is open.
Figure 3 is an elevation of a door shewing the spring applied, and the remaining
Figures are details, which will be herein-after referred to.
A is a metal plate secured by screws or otherwise to the door post and carrying
two rings or lugs B, C, shewn detached respectively at Figures 4 and 5,) between
which extends a tube D surrounding a spring E. This spring, (shewn in detail at
Figure 6,) is composed by preference of a number of flat steel blades arranged one
upon another, and connected together by metal bands or rings F situate at suitable
intervals along the plates. The upper end of the spring is passed through a square
hole G provided in the arbor H of a lever I, (shewn detached at Figure 7,) in order
that when the lever I is turned on its arbor by the opening of the door it shall
cause the spring to be twisted or turned, and thereby impart to the spring a
torsional strain or power, having a tendency to close the door, and which may be
regulated to any required extent in the manner next herein-after described,) so as to
cause the door to close gently and with the least possible noise.
The lower end of the spring is fitted into a recess K in the cylindrical portion L
of a knob or projection M, (shewn in detail at Figure 8,) connected to the lug B by
the screw, which fixes the said lug to the plate A, the point of which screw enters
an annular groove or recess N formed in the knob M, thereby preventing the
longitudinal displacement of the spring, but admitting of the rotation of the
knob M, and with it the spring in the lug B when it is required to increase or
diminish the power of the spring.
In order to adjust the power of the spring to suit doors of different weights the
knob M is fitted or formed with a ratchet wheel O, (see Figure 8,) engaging with a
detent P, (shewn detached at Figure 9,) carried by a pin on the lug B, so that upon
turning the knob M by means of a lever inserted in the holes Q provided for the
purpose the spring may be twisted or adjusted to any desired extent, after which
it is retained in its adjusted position by the detent P engaging with the teeth of
the ratchet wheel O. The outer end of the lever I, which works in contact with a
friction roller R attached to the inner side of the door, is made by preference of a
wedge shape, as shewn in Figures 1, 2, and 7, in order that when the door is
clearly closed the portion or surface a by acting as a brake upon the pulley R shall
cause the door to close gently and without banging.
In lieu of fixing the friction pulley R to the door as last described the pulley
may be carried on the end of the lever I, (as shewn at Figure 10,) and caused to
bear upon a plate attached to the door in the usual manner.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
First. The application and use of the torsional power of a spring for automatically
closing a door when such spring is constructed and arranged substantially in the
manner herein-before described and illustrated by the Drawing annexed.

page_text: 2. Regulating or adjusting the power of the spring, substantially in the manner
herein-before described and illustrated by the Drawing.
In witness whereof, I, the said Gottfried Stierlin, have to this my Specification
set my hand and seal, the Twenty-fifth day of August One thousand eight
hundred and seventy-six.
GOTTFRIED STIERLIN. (L.S.)