An Improved Door Spring.
Year: 1890

page_text: Date of Application, 16th June, 1890
Complete Specification Left. 6th Feb., 1891-Accepted, 14th Mar., 891
PROVISIONAL SPECIFICATION
An Improved Door Spring.
I, CARL WILHELM FRIEDRICH THODE, of Neustadter Fuhlentwiete, 56, Ham-
burg, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved door spring for swing doors whereby
greater effective length of spring is obtained and less liability of breakage than
with other springs of the kind. The spring is of the spiral form and is coiled
about a guide rod curved concentrically with the pivotal axis of the door and is
confined between abutments by which the guide rod is held. Upon this rod play
arms carried by a socket working on a pivot in the spring box and turning with the
door, the said arms bearing against the opposite ends of the spring.
When the door is swung in the one direction the one arm bears against the one
end of the spring whose abutment is for the time being at the opposite end, and
vice versa when the door is swung in the opposite direction.
Dated this 16th day of Lune 1900
C. W. F. THODE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
An Improved Door Spring.
I, CARL WILHELM FRIEDRICH THODE, of Neustädter Fullentwiete, 56, Ham-
burg, 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 relates to an improved door spring for swing doors, whereby
greater effective length of spring is obtained and less liability of breakage than
with other springs of the kind.
Reference is to be had to the accompanying drawings, forming part of this
Specification, wherein
Figure 1 is a plan of the spring box, with the cover removed, and
Figure 2 is a vertical axial section, the heel of the door being represented in
dotted lines in both figures.
The same letters of reference denote like parts in both figures.
The spring box a, which is let into the door sill, has fixed in the bottom a stout
pivot on which the socket c oscillates. The upper flattened end c¹ of the socket
fits in a corresponding hole in the heel plate of the door A so that the door and
socket swing together as one.
The spring is of the spiral form and is coiled about a guide rod e curved con-
centrically with the pivotal axis b of the door A and fixed by its ends to posts d¹ ď²
fixed to the bottom of the box a and forming abutments between which the spring
is confined. Upon this rod e play the arins g g of a sector-shaped frame 91 92 93
carried by the socket c, the said arms g¹g having notches g' embracing the rod e
and passing clear of the posts d' d', the arms bearing against the opposite ends of
the spring f
When the door is swung in the one direction, the one arm g¹ or g² bears against
the one end of the spring whose abutment is for the time being the post d'or d'at
the opposite end, and vice versa when the door is swung in the opposite direction.
[ Ꭰ ᎪᏗ

page_text: When the door is released it is returned by the elastic force of the spring to its
position of rest, the whole length of the spring being effective, whichever way the
door is swung, whereby liability of breakage is diminished.
The pivot at the top of the door is of the ordinary kind.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
The herein described swing door spring, consisting in the combination, with the
door pivot and its abutment arms, of a spiral spring coiled upon a concentric guide
rod and compressed between the one arm of the socket and a fixed abutment at the
opposite end whichever way the door is swung, so that the whole length of the
spring is rendered effective, substantially as herein specified.
Dated L
C. W. F. THODE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
C. W. F. THODE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.