Improvements in Door Springs.
Year: 1894

page_text: Date of Application, 4th June, 1894
Complete Specification Left, 4th Mar., 1595-Accepted, 6th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Door Springs.
I, PETER KNOBEL, of Flums, Switzerland, Manufacturer, do hereby declare
the nature of this invention to be as follows :-
This invention has reference to an improved construction of door-closing spring
in which the spring is formed by coiling a strip of steel preferably of the peculiar
shape in cross section hereinafter referred to into a spiral form, one end being
adapted to be fastened to a door, and the other end to a door frame, in such a
manner that the geometrical axis of the spring shall cross the imaginary axis of
rotation of the door at an angle as acute as possible. In this position, the spring
becomes twisted by the opening of the door and a strain is produced in the spring
which imparts to the spring a tendency to close the door. The spring is preferably
fastened with a slight twist, that is to say with an initial strain, with the object of
imparting to it the requisite power for closing the door completely.
By making the spring of a strip having a corrugated, curved or irregular
external contour or profile instead of flat, a pleasing appearance is imparted to it.
The accompanying drawings illustrate two arrangements of door spring
according to this invention,
Fig. 1 being a side elevation of a construction in which the spring is made of a
flat strip of metal,
Fig. 2 a front elevation of one of the heads for holding the ends of the spring,
Fig. 3 an elevation of a construction of spring made of a bar or strip of doubly
channelled form in cross section; and
Fig. 4 a cross section thereof;
Fig. 5 illustrates how the spring is applied to a door.
The ends of the spring, which in Fig. 1 is made of flat metal, are respectively
fixed to the door and to the door-frame by means of screws a which pass through
transverse holes in the heads b (which latter hold the ends of the spring and are
fixed thereto) and are screwed into metal plates c which serve as nuts for the
screws a and are previously fixed to the door and door-frame by screws d.
Each of the heads is provided with a number of transverse through perfora-
tions (two arranged at 90° to each other are shown in the drawings), of which that
one which is brought by the initial twist imparted to the spring into a position
perpendicular to the plate c, is used for the insertion of the screw a.
The distance between the spring and the door or door-frame is adjusted by
interposing one or any other suitable number of washers e between the heads b and
the plates c.
The spring strip employed in the construction shown in Fig. 3, is of ornamental
appearance externally being formed with channel-shaped beadings at its longi-
tudinal edges, as shown in Fig. 4.
In the case of a heavy door more than one of the improved door springs may
be applied thereto.
Dated this 4th day of June 1894

page_text: I, PETER KNOBEL, of Flums, Switzerland, 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 :-
This invention has reference to an improved construction of 'door-closing spring
in which the spring is formed by coiling into-a spiral form a strip of steel preferably
of the peculiar shape in cross section hereinafter referred to, one end being
adapted to be fastened to a door and the other end to a door frame in such a
manner that the geometrical axis of the spring shall cross the imaginary axis of
rotation of the door at an angle as acute as possible. In this position, the spring
becomes twisted by the opening of the door and a strain is produced in the spring
which imparts to the spring a tendency to close the door. The spring is preferably
fastened with a slight twist, that is to say with an initial strain, with the object of
imparting to it the requisite power for closing the door completely.
By making the spring of a strip having a corrugated, curved, or irregular
external contour or profile instead of flat, a pleasing appearance is imparted to it.
The drawings filed with my Provisional Specification illustrate two arrangements
of door spring according to this invention,
Fig. 1 being a side elevation of a construction in which the spring is made of a
flat strip of metal ;
Fig. 2.a front.elevation of one of the heads for holding the ends of the spring;
Fig. 3 an elevation of a construction of spring made of a bar or strip of
doubly channelled form in cross section, and
Fig. 4 a cross section thereof;
Fig. 5 illustrates how the spring is applied to a door.
The spring shown in Fig. 1 is made of a strip of flat metal, so bent and arranged
that the longitudinal dimensions of the cross section of the said strip will be
approximately vertical when the spring is secured in place on a door as shown.
The ends of this spring are respectively fixed to the door and to the door-frame
by means of screws a, which pass through transverse holes in the heads b
which hold the ends of the spring f and are fixed thereto, the said screws a being
screwed into metal plates c which serve as nuts for the screws a and are previously
fixed to the door and door frame by screws d.
..
'
Each of the heads 6 is provided with a number of transverse perforations (two
arranged at 90° to each other are shown in the drawings), of which the one that is
brought, by the initial twist imparted to the spring, into a position perpendicular
to the plate c, is used for the insertion of the screw a.
The distance between the spring and the door or door-frame is adjusted by
interposing one or any other suitable number of washers e between the heads b and
the plates c.
The spring strip employed in 'the construction shown in Fig. 3 is of ornamental
appearance externally being formed with channel-shaped beadings at its longi-
tudinal edges, as shown in Fig. 4.
Whilst a very sensitive spring of considerable elasticity can be produced from a
flat strip of metal (see Fig. 1), a spring of. greaterntorsional force can be made
from a strip having an irregular external contour or profile as for example that
shown in Fig. 3.
In the case of a heavy.door.more than one of the improved door springs may
be applied thereto.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
My improved door-springs constructed arranged and operating substantially
as hereinbefore described with reference respectively to and shown in Figs. 1 and 2
and in Figs. 3 and 4 respectively of the drawings referred to herein.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent