IMPROVEMENTS IN ELLIPTIC SPRINGS
Year: 1874

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "IMPROVEMENTS IN ELLIPTIC SPRINGS."-A communi-
cation from abroad by Edward Cliff and Richard Vose, both of the
Citre and State of Nowe Vark Tinited States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 5th August 1874, 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 Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
1

page_text: my exccutors, administrators, and assigns, Her Royal Lotters Patent
for the same, and have made solemn Declaration that it has been
communicated to me from abroad by Edward Cliff and Richard Vose,
both of the City and State of New York, United States of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
scal, 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:-
This Invention relates to an elliptic spring composed of an entire
or endless elliptical hoop with auxiliary V or U shaped leaves placed
interiorly at the ends of the ellipse, and there secured by suitablo
clamping devices either with or without auxiliary leaves arranged
exteriorly midway between the ends. Also to a provision against the
breaking of such interior auxiliary leaves by the peculiar form hercin-
after particularly described given to the interior surface of the said
leaves at their central bend or angle, and a corresponding form given to
the binding bar which fits into such angle or bend.
1

page_text: cllipse. For light loads this elliptic endless bar alone forms a superior
spring; but it is preferably combined with auxiliary leaves, or bars
placed at the ends or in the centre of the ellipse. For this purpose the
auxiliary leaves or bars shown in the Drawing will be found efficient and
5 readily applied. Any other form, number, or arrangement of these
supporting. auxiliary leaves or bars may be employed that may, ho
-thought suitable or desirable. B, C, and D, and B'; O', and D', are such
auxiliary V or U shaped leaves formed of steel bars of different lengths
bont to fit into cach other, as shown, and preferably diminishing in
thickness from the central bend to the ends. These are placed interiorly
at the ends of the principal spring A, and are clamped firmly to the
latter, as represented. I place an auxiliary leaf E, F, or more than one
of such leaves centrally on the exterior of the spring A, the samo being
clamped in the ordinary manner. The several leaves with the principal
spring A ȧro bound firmly together at the ends of the ellipse by the
exterior concave clamp plate a, the binding bar b, and the clip bolts c.
'
It has been found in practise that when the interior surface of the
auxiliary leaf D has the circular form in the centre giving it the U shapo
instead of an angular or V form, and a round binding bolt or bar arranged
in the bend is employed to clamp the leaves together this interior leaf
is very liable to be broken by any considerable compression of the spring.
To obviate this result I give to this .inner leaf the form shown plainly
by Figure 4. As will be seen the interior surface approaches very nearly
to an acute-angle, while the exterior surface is a circular curve. This
form permits the use of the elliptical shaped binding bar herein-after
described fitted into the interior angle of the said leaf, while the exterior
surface of the said leaf corresponds with the curved interior surface of
tho next exterior leaf O.
The form of the binding bar 6 is plainly shown in Figure 4. As will
be seen its cross section presents the form of a wedge with slightly
curved sides united to a half circle. The wedge is formed to fit into tho
interior angle of the leaf D, but does not quité fill the space between the
opposite sides of the leaf. It is evident that when this leaf is compressed
its two arms from the centre of the bend to their extremities will act as
levers, the bar 6 being the fulcrum, and the point of weight being the
centro of the bond, tho fulcrum line shifting-away from the point of
weight in proportion as the levers are caused to approach. It is farther

page_text: ovident that the next exterior leaf fitting closely over the leaf D acts to
resist the strain exerted at the centre of the bend in the leaf D, tending
to break or separate the same at that point, and that the effectiveness of
this resistance of the exterior leaf to prevent the breaking of the leaf D
increases in proportion as the fulcrum line recedes from the inner edge 5
of the bar by the compression of the spring, the length of the short arm
of the levĕrs increasing as the spring is compressed and the strain being
augmented, while the binding action of the external leaf C remains tho
samo and continues to be exerted at the same point. Although it is not
essential it is advisable to make the outer edge of the binding bar 6 1
round, as shown, to fit correspondingly shaped eyes in the clip bolts d, as
with this form they have greater strength, and are more conveniently
'made than with any other form.
. Figure 2 represents three of these springs placed side by side, and
clamped together at the ends, the clamping plate a and the binding bar & 1
extending across and embracing the whole. Two, three, or more of
these springs may thus be combined to be used upon railway carriages,
or in other cases where great bearing power is needed.
An elliptical spring constructed as above described has more combined
bearing power and clasticity, and greater clasticity than the samo
quantity of steel will yield in any other form of elliptical spring with
which I am acquainted.
Having thus fully described the said Invention as communicated to
me by my foreign correspondents, and the manner of performing the same,
I wish it understood that I claim,-
First. An elliptical spring composed of an endless bar, and the auxiliary
leaf or leaves placed interiorily at cach end of the spring and bound
together by suitablo clamping devices, all combined and operating as
herein set forth and for the purpose specified.
Second. An elliptical spring composed of an endless bar and the g
auxiliary leaf or leaves at each end of the spring with centro auxiliary
leaves bound together by suitable clamping devices, all combined and
operating as herein set forth and for the purpose specified.
Third. The combination in an elliptical spring with an endless bar of
the auxiliary leaves at tho ends and the wedge shaped binding bar b,. §

page_text: the interior surface of the said leaves being found to ſit and act upon the
said bar & as and for the purpose described..
In witness whereof, I, the said William Robert Lake, have licrc-
unto set my hand and seal, this Fifth day of August, in the year
of our Lord One thousand eight hundred and seventy-four:
Witness,
H. J. NOONE,
8,.Southampton Buildings,
London.
W. ROBT. LAKE. (L.S.)