IMPROVEMENTS IN COILED OR VOLUTE SPRINGS
Year: 1869

page_text: LETTERS PATENT to William Robert Lake, of the "International
Patent Office," Southampton Buildings, London, Consulting
Engineer, for the Invention of "IMPROVEMENTS IN COILED OR VOLUTE
SPRINGS."A communication from abroad by Joseph Trent, of
Millerton, New York, United States of America, Mechanical
Designer and Engraver.
Sealed the 22nd February 1870, and dated the 29th October 1869.
COMPLETE SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 29th October 1869, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the "International Patent Office," Southampton
Buildings, London, Consulting Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN COILED OR VOLUTE SPRINGS," and have petitioned Her Majesty to grant

page_text: unto me, my executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that it has
been communicated to me from abroad by Joseph Trent, of Millerton,
New York, United States of America, Mechanical Designer and
Engraver.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing forming a
part of this Specification.
These improvements relate to that class of springs which are technically
called volute springs, and which are formed by coiling or rolling up bars
or plates of metal having certain definite forms or shapes, and it may be
here remarked that the quality of the spring depends upon the shape of
the bar or plate used to construct it, hence by a slight change in the
form of the bars or plates I am enabled to produce springs having
independent characteristics and different external appearances, and
possessing different powers.
DESCRIPTION OF THE DRAWING.
Figure 1 is a side elevation of a bar or plate; Figure 2 is a side
elevation of the spring produced by coiling such bar or plate; Figure 3
is a vertical central section of such spring; Figure 4 is a side elevation of
another bar or plate; Figure 5, a side elevation of the spring produced
by coiling such bar or plate; Figure 6 is a vertical central section of
such spring; Figure 7 is a side elevation of another bar or plate in its
first stages; Figure 8 is a side elevation of the same bar when folded
and ready for coiling; Figure 9 is a side elevation of the spring produced
by coiling the bar or plate represented in Figure 8, and Figure 10 is a
vertical central section of such spring. Figure 7 is drawn on a scale
one-quarter, and Figure 8 on a scale one-half that of Figures 9 and 10.
The manner of coiling all of these bars or plates is the same, and it
may be accomplished by machinery especially designed for the purpose,
or by winding the bars or plates around a mandrel.
To avoid confusion the bars or plates and the springs produced
therefrom will be described separately.

page_text: The bar or plate illustrated by Figure 1 is semi-elliptical in shape as
to its main portion a, and has two horizontal legs or arms b, b', one at
each terminus of the semi-elliptical portion. One of these legs bis
represented as of greater length than the other b', and when the plate is
coiled it provides an even base b* for the spring to rest upon, the shorter
leg constituting the core of the spring; but it may be well to remark
here that this shorter leg is not absolutely essential, though it is
preferable to terminate the bar or plate in such way. Such bar or plate
is properly coiled, beginning at the end ', say, around a mandrel, and
when so coiled produces the spring represented in Figure 2, the position
of the coils when the spring is not subjected to pressure being that
shown by Figure 3. When weight is applied to this spring it rests
upon the highest part of the semi-ellipse, and consequently the qualities
of a semi-elliptical spring are combined with those of a coiled or volute
spring, and hence Figure 2 may be properly said to illustrate a semi-
elliptical volute spring.
The bar or plate illustrated by Figure 4 is of a serpentine form, the
convex edges c, c', facing in opposite directions. This bar or plate is also
preferably terminated by legs or arms d, d', and one of these legs (if
not both) is provided with a straight horizontal lower edge, as shown
at *, so that when the bar or plate is coiled it will have an even base to
rest upon, as in the previous example, and in this case the leg d if the
bar be so provided will constitute the core of the spring. With regard
to this serpentine style of bar or plate it is proper here to remark that
such bar or plate may be made longer or shorter and provided with a
number of curves corresponding in a measure to its length, in which
cases the convex and concave edges of the curves would alternate on the
bar. In proportion to the length and the number of the curves the
power of the spring produced from such plate or bar will be increased or
diminished.
By reference to Figures 4 and 6 it will be seen that the two curves
contained in the bar or plate represented by those Figures will give
upon coiling such bar or plate three distinct series of coils running in
alternately opposite directions. For illustration, from the dotted line z
to that z¹ there is a series of coils running in a downward direction, from
the line to that there is a series of coils running in an upward
direction, and from the line to that there is a series of coils running

page_text: in a downward direction; these three series complete the curves of the
bar or plate shown in Figure 5, but if the bar be made longer and be pro-
vided with more curves of course the number of the series of coils will be
increased and they will alternate as above.
A spring (Figure 5) constructed by coiling or rolling up the bar or
plate illustrated in Figure 6 posseses the sustaining power of three single
volute springs in one spring, and hence such spring may be properly
termed a triple volute spring, and when the number of curves of the
plate are increased the power of the spring made therefrom increases,
and the spring becomes a quadruple, quintuple, or sextuple, etc.,
spring.
The bar or plate shewn in Figure 8 is in a condition ready for being.
coiled to produce the spring shown in Figure 9. It will however be
borne in mind that said Figure 8 is drawn on a scale one-half that of
Figure 9. The plate or strip of metal shown in Figure 7 is used to
construct the bar shown in Figure 8, and as to this Figure 7, it will be
borne in mind that it is drawn on a scale one-half that of said Figure 8.
This plate shown in Figure 7 is provided with two semi-ellipses g, g',
the convex edges facing in opposite directions and the two semi-ellipses
connected by a horizontal portion h, and the ends of the plate termi-
nating in horizontal ends i, one of which ends is shown as provided with
a slot and the opposite end with a pin. This plate represented in
Figure 8 is to be folded over, say, on the dotted line z, z, Figure 7,
which being done the bar or plate shown in Figure 8 will be produced.
This bar or plate is of an elliptical form with horizontal legs h and i, and
when coiled or rolled up gives us an elliptical volute spring. In rolling
or coiling it is preferable to commence with the leg i, which will
constitute the core, and terminate with the leg h, which will constitute
the outer or binding coils. The ends i, i, of the plate in Figure 7 may
be soldered together or otherwise united as found desirable. By coiling
the plate shown in Figure 8 the advantages of an elliptical spring added
to that of a coiled spring are obtained and a spring possessing great
sustaining powers. From the form of the plate of which this spring is
made and in view of its mode of operation it may be properly termed an
elliptical volute spring.
It is of course well understood that any of the bars or plates herein-
above described can be easily and quickly cut or stamped out of a plate

page_text: or series of plates of metal by a stamping machine or knives or cutters
suitably arranged for the purpose.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and shewn how the same may be
conveniently and advantageously carried into practice, I claim,―
First. A coiled or volute spring made of a semi-elliptical bar or plate,
substantially as herein described.
Second. A coiled or volute spring made of a serpentine bar or plate,
substantially as herein described.
Third. A coiled or volute spring made of an elliptical bar or plate,
substantially in the manner herein described.
In witness whereof, I, the said William Robert Lake, have hereunto
set my hand and seal, this Twenty-eighth day of October, in
the year of our Lord One thousand eight hundred and sixty-ninc.
WILLIAM ROBERT LAKE. (L.S.)