IMPROVEMENTS IN THE MANUFACTURE OF VOLUTE SPRINGS."
Year: 1880

page_text: LETTERS PATENT to Thomas Brown, of Newburn, in the County of Northum-
berland, for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
VOLUTE SPRINGS."
PROVISIONAL SPECIFICATION left by the said Thomas Brown at the Office
of the Commissioners of Patents on the 3rd June 1880.
THOMAS BROWN, of Newburn, in the County of Northumberland. "IMPROVE-
MENTS IN THE MANUFACTURE OF VOLUTE SPRINGS."
My Invention has for its object the manufacture of volute springs in such a
manner as to cause the spring when in use to be more regular in its working or in
its deflection per increment of load, and to obtain a given result with less weight of
material. For this purpose, instead of the spring being rolled as usual from a plate
of the same cross section throughout its length, thereby using unnecessary inaterial
for a given result, or from a plate gradually reduced in thickness, thereby involving
the employment of special and expensive machinery, it is intended that under my
Invention the spring should be made from a plate of the same section or thickness
throughout its length, but tapered in form by being gradually reduced in width.
A plate of the same section throughout its length is tapered as required, either by
slitting, shearing, or other ordinary method, leaving the bar (or portion thus
detached from the plate) of the same thickness throughout its length. The bar is
then prepared and coiled in the usual way.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Brown in the Great Seal Patent Office on the 18th October
1880.
THOMAS BROWN, of Newburn, in the County of Northumberland.
MENTS IN THE MANUFACTURE OF VOLUTE SPRINGS."
"IMPROVE-
My Invention of "Improvements in the Manufacture of Volute Springs" has for
its object the manufacture of volute springs in such a manner as to cause the spring
when in use to be more regular in its working or in its deflection per increment of
load, and to obtain a given result with less weight of material.
For this purpose, instead of the spring being coiled as usual from a plate of the
same cross section throughout its length, thereby using unnecessary material for
a given result, or from a plate gradually reduced in thickness, thereby involving
the employment of special and expensive machinery, it is intended that under my
Invention the spring should be made from a plate of the same section or thickness
throughout its length, but tapered in form and gradually reduced in' width. The
plate may be tapered or curved on one or both edges and at each end, as hereinafter
described.
A plate of the same section throughout its length is tapered as required, either
by slitting, shearing, or other ordinary method, leaving the bar (or portion thus
detached from the plate) of the same thickness throughout its length. The bar is
then prepared and coiled in the usual way.
Having thus stated the nature of the said Invention, I will proceed to describe
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings, in which are represented different modes of tapering
plates.
DESCRIPTION OF THE DRAWINGS.
In Fig. 1 the plate is gradually tapered on one edge a, as shewn.
In Figures 2 and 3 the plates are shewn as gradually curved on one edge a. In
Figures 4, 5, and 6 they are shewn with one or both edges a, b, tapered or curved;
and in Figures 7 and 8 the plates are shewn with one edge tapered and the other :
edge curved.
In all cases the reverse ends of the plates are tapered in the opposite
direction on the edges c, d, as shewn, so as to form a base upon which the spring
shall rest when coiled, and also to act as a guide in the coiling of the spring, as is
usually done.
The plate is to be of the same thickness throughout its length, except at the ends
thereof, which may be gradually drawn down, as in the ordinary method of
manufacture.
The plate may be made of the required form either by means of rolls, shearing
machine, or saw, or by any ordinary method. Volute springs manufactured in the
manner above described, will be thereby rendered capable of working with increased
regularity, that is to say, the deflection of the spring per increment of load will be more
regular, and the same bearing or resisting power obtained with less weight of metal
than in volute springs made in the ordinary way.
Also, by adjusting the taper of the edge of the plate forming the outside coil and
base in relation to the curve or taper of the plate forming the inside coils, the spring 4
can be coiled without over-straining the metal of which it is composed.
And a further advantage resulting from the above described method of manufac-
ture is, that the rubbing surface of the inside coils being thereby diminished in
extent, the liability of the plates rubbing together and influencing the deflection of
the spring by the friction thus induced will be correspondingly lessened.
E

page_text: Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I hereby declare that what I claim as of my Invention
is, the preparation of steel plates to be used in the manufacture of volute springs
by cutting, sawing, or rolling, and thereby tapering the plates on one or both
edges while keeping them of the same thickness throughout their length (except at
their ends as usual), as and for the purpose or purposes hereinbefore described.
In witness whereof, I, the said Thomas Brown, have hereunto set my hand
and seal, the Sixteenth day of October, in the year of our Lord One
thousand eight hundred and eighty.
Witness,
WILLIAM CLAY RITSON,
Newburn on Tyne,
Clerk.
THOMAS BROWN. (L.S.)