IMPROVEMENTS IN SPRINGS
Year: 1885

page_text: I EDWARD SPAULDING, of 43 Exchange Place, in the City and State of New
York, in the United States of America, but at present of 115 St. Vincent Street,
Glasgow, in the County of Lanark, North Britain, Machinist and Engineer do
hereby declare the nature of the said invention for IMPROVEMENTS IN SPRINGS to
be as follows:-
This Invention relates to that class of elliptic springs the plates of which are
made in concavo-convex form in cross section and it consists in making the ends of
the springs for forming the edges for the connecting bolts of the same concavo-
convex form of the plates as that of the rest of the spring instead of the flat
extensions as heretofore, whereby the advantage of the superior strength imparted
to the springs by reason of the said concavo-convex form is available in the eye
part as well as in all other parts of the spring.
Springs made of plates of the form described and the said plates arranged in the
spring.so that the tension is sustained on the middle web of the plates and the
compression on the edges of said plates are found in practice to possess about twice
the power to sustain the load, that springs made of the ordinary flat plates have,
but as such springs have up to this time been made with the main plate flattened
just where the coil for the eye begins, so that in that part they are not stronger
than the flat plate springs are; the great advantage of the concavo-convex form of
the rest of the spring has not hitherto been so far available as is desirable, although
the defect might be remedied by thickening the plates where the shape changes
from the curved to the flat form that is not practicable because in the manufacture
of the plates it is desirable to roll them out in long strips, and cut them into the
short pieces of different lengths required for springs, hence it is desirable to
continue the said curved form of the plates throughout the coil for the eye for the
bolt that connects the two halves of the spring and thus invest the said parts with
the same strength as the rest of the plate.-The ends of the springs are connected
го

page_text: together by bolts which pass through properly coned clamp washers whose edges
are notched to receive the sides of the plates so that when the bolts are tightened
all the parts are held firmly together.
This mode of coupling together the ends of the springs may also be applied to
spring plates in whose ends the concavo-convex form hereinbefore mentioned is not
adopted.
J. H. JOHNSON, DAY & JOHNSON,
Petitioner's Agents,
115, St. Vincent Street, Glasgow.
I, EDWARD SPAULDING of 43 Exchange Place, in the City and State of New
York, in the United States of America but at present of 115 St. Vincent Street,
Glasgow, in the County of Lanark, North Britain, Machinist and Engineer do
hereby declare the nature of my said invention for IMPROVEMENTS IN SPRINGS and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My Invention relates to that class of elliptic springs the plates of which are
made in concavo-convex form in cross section and it consists in making the ends of
the springs for forming the edges for the connecting bolts of the same concavo-
convex form of the plates as that of the rest of the spring instead of the flat
extensions as heretofore whereby the advantage of the superior strength imparted
to the springs by reason of the said concavo-convex form is available in the eye
part as well as in all other parts of the spring.
Springs made of plates of the form described and the said plates arranged in the
spring so that the tension is sustained on the middle web of the plates and the
compression on the edges of said plates are found in practice to possess about twice
the power to sustain the load, that springs made of the ordinary flat plates have,
but as such springs have up to this time been made with the main plate flattened
just where the coil for the eye begins, so that in that part they are not stronger
than the flat plate springs are; the great advantage of the concavo-convex form of
the rest of the spring has not hitherto been so far available as is desirable, although
the defect might be remedied by thickening the plates where the shape changes
from the curved to the flat form that is not practicable because in the manufacture
of the plates it is desirable to roll them out in long strips, and cut them into the
short pieces of different lengths required for springs, hence it is desirable to
continue the said curved form of the plates throughout the coil for the eye for the
bolt that connects the two halves of the spring and thus invest the said parts with

page_text: the same strength as the rest of the plate. The ends of the springs are connected
together by bolts which pass through properly coned clamp washers whose edges
are notched to receive the sides of the plates so that when the bolts are tightened
all the parts are held firmly together.
This mode of coupling together the ends of the springs may also be applied to
spring plates in whose ends the concavo-convex form herein before mentioned is not
adopted.
In order that my said Invention may be properly understood and readily carried
into effect, I will now proceed to describe the drawings hereunto annexed.
Figure 1 of the accompanying sheet of drawings is a perspective view of my
improved concavo-convex elliptic spring and made of concavo-convex plates
arranged for the convex sides to sustain the tension while the edges take the
compression, and shows also the continuation of the concavo-convex form through-
out the entire length of the main plate, and also round the coil for the part which
forms the eye for the connecting bolt; thereby rendering the ends of the main
plate, and also that part of it of which the eye is formed of the same strength as
the other parts of said plate and said plate and plates being of greater thickness in
their middle portion, which sustains the tension, than their edges which are subject
to compression.
Figure 2, is a longitudinal detailed sectional view showing the arrangement of
all the parts of my improved spring. On the left hand side of Figure 2 is shewn
one way in which I form the eye for the connecting bolt by a half coil in each
plate, the extreme ends of the plates meeting and butting together where they are
secured by the washer A and upon the right hand side of Figure 2 is shewn
another way in which I form the eye by coiling the ends of the plates completely
around the bolt B or nearly so, one of the said plates being outside the other where
they are secured by the washer A¹. The plates C of the spring, as before stated
are made in concavo-convex form in cross-section and arranged in the spring with
tbeir convex sides facing towards the longitudinal axis of the ellipse, the letters c,
show the part of the plate where hitherto the concavo-convex form changed to the
flat form but which I now continue throughout the entire length of the plate and
round the coil which forms the eye for the connecting bolt, the letters c¹, represent
the studs, thrust out on one side by indentations made on the other side, to secure
the plates in position within the band D, which has a flat outer part d, and
indentation d, at its inner part and binding screw d². As a molification and as
shewn in Figure 1, the top of the band D may be clamped to the plates by simply
indenting the top of the band to fit the corresponding indentation in the plate
next to it.
Figure 3, represents transverse sections of one of my improved springs showing
both sides of the plates C, constructed on the same curvature and made thicker in
the middle and thinner at the edges in accordance with the present invention, both
sides should be on the same radius or curvature as indicated by the dotted lines
which are prolonged beyond the edges of the plates C, to show more clearly the
taper of the plates from the middle to the edges, it also shows my arrangement
of the studs c', and corresponding indentations for confining the plates C and
keeping them securely in position and also shews the band D, for confining the
plates with its flat outside d, and convex inside d³, indentation d, and binding
screw d
As a modification in the construction of the band I may use a separate plate flat
on the outer surface and convex on its inner surface, to fit into the concavity of
the plate next to it.
Figure 4, represents a side elevation of the end of my spring showing the single
cone hubbed washer A and also a double cone hubbed washer A2 as used in
connecting groups of springs. The single cone hubbed washer A is shewn with
its conical hub a, and flange a¹. The double cone hubbed washer A having
double cone hubs a, and double flanges a³, the whole being bound together by
the connecting bolt B and nut E.

page_text: Figure 5, represents the same as above, but showing the cone hubbed washers
with overlapping flanges at which may be sometimes used as explained hereafter.
Figures 6 and 7 are enlarged views of A Figure 2, and the modification A¹
shewn in the same Figure and shewing the notched part a³, of the edges of the
washers A to receive the edges of the plates.
Figures 8 to 11 shew slight modifications of single and double coned washers.
By reference to Figures 1 and 2 it will be readily observed that the effect of a
load upon springs constructed of concavo-convex plates as there represented and
arranged with their convex sides towards the chord of the arc formed by the
longitudinal direction of the spring, is to produce tension on the middle web of
the plates and compression on their edges Now it is evident that the effect of
compression is much less destructive to the integrity of the metal, than that of the
tension, hence if the metal is so disposed in the construction of the plates as to
make them thinner at their edges, and thickest at their middle it is best arranged
to suit the requirements of plates of this form and arrangement and tlu; be best
adapted to secure the best results with the least amount of metal, also of labor in
the construction of the springs for the smaller the quantity of metal the less
amount of labor and power required to construct them and for vehicle springs
lightness is of great importance.
Again it will be observed that by this same construction of these concavo-convex
plates, thicker in their middle and thinner at their edges they are made to bear
upon the other with uniformity throughout their whole surface so that the friction
and wear are no greater on one part than another, and each plate is sustained by
the other, and the effect of the load is evenly distributed over the whole spring, so
as to have the best effect, whereas if the plates have parallel sides or are thicker at
their edges than at their middle web, they can only bear along their edges where
they will as a matter of course wear faster and unequally and they will be less
powerful either as a single plate, or in a combination of plates for this part that is to
cause the plates to bear fairly upon each other both sides should be formed on the
same radius or curvature as indicated by the dotted lines in figure 3, which are
prolonged beyond the edges of the plates C, to show more clearly the taper of the
plates from their middle to their edges and for the advantage of the thicker and
middle and thinner edges merely in point of the best distribution of the metal for
instance in a spring having only one plate I do not confine myself to the same
radius, for both sides of the plate, for the concave side may be of greater radius,
making the edges still thinner in proportion to the middle, if desired; the curvature
which I prefer for the cross-section of the plates, is that of which the chord of the
concave side of the plate equals the radius of the circle, but it may be varied at will,
and the plates may have parallel edges from their middle sections to their end, or
be tapered, and the curvature may vary from middle to end, if desired, the said
concavo-convex form is produced on the plates by means of the dies of a drop
hammer or other press in which the plates are struck while in a heated state the
dies heretofore used for this purpose have been so formed that the concavo-convex
form terminated at c, Figures 1 or 2 leaving the extreme end of the main plate,
and also that part of it which forms the eye for the connecting bolt flat and it is
this part which sometimes fails, when the spring is loaded to the full capacity of
its other parts, therefore I continue the curved form throughout the entire length
of the main plate, and continuing it around the part which forms the eye for the
connecting bolt, B, thus extending the form of the main plate to where it finds
rest and support that greatly relieves it in supporting the load.
In my improved band D. Figures 1, 2 and 3, that side of it which crosses the
outer concave side of the spring is required to be flat on its outside at d. for
properly connecting it with the carriage, at the same time the concavity of the
plate must be filled inside of the band to afford substantial rest and holding for
the plate, therefore in order to accomplish this without the use of an additional
piece to be shaped and fitted in, for that purpose I make the band with one of its
sides flat outside at d, and convex at d³, in conformity with the concavity of the

page_text: plates C, it is designed to fit on the band D, while hot and enlarged enough to
admit the stud c, of the bottom plate into its indentation d¹, in the band, and
after the band has shrunk tight, fit in the binding screw d³, Figure 3 also shows
my arrangement of the studs c¹, and corresponding indentations for confining the
plates, in conformity with the said concavo-convex arrangement, the stud of one
plate fitting into the indentation of another plate, as is common in springs but in
this case, these studs being formed on concavo-convex plates are according to my
invention arranged to project from their convex sides for maintaining the continuity
of the convex surface, as before described, thereby preserving the advantage gained
by presenting the convexity of the spring to the tension of service.
My single cone hubbed washer A and my double cone hubbed washer A is seen
in Figures 4 and 5, as in use, their conical hubs a, and a³, as will be clearly seen,
being used to fill the flaring portion of the eyes, for the bolt to afford the required
support to the plate and these conical hubs I may sometimes use separate from the
washer, and when the plates of the spring extend only half round the bolts I make
the washer with a flange a', to overlap the edges of the plates, and more securely
hold them and these flanged washers are also applicable to springs having their
eyes made of flat coiled plates, the washer being made without the hubs.
It is evident that many slight changes in the construction and arrangement of
the several parts and devices of my improvements, may and can be resorted to,
without departing from the spirit of my invention, and I would have it understood
that I do not limit myself to the exact construction and arrangements as shewn
and described but hold myself at liberty to make such changes and alterations as
fairly fall within the spirit and scope of my Invention.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
First. In elliptic or semi-elliptic springs made of one or more plates of concavo-
convex form in cross-section, and so arranged that the load causes compression on
the edges, and tension on the middle webs of said plate or plates, the said plate
or plates being made thickest in the middle, and thinner at and towards the edges
substantially as described.
Second. In elliptic or semi-elliptic springs made of one or more plates of concavo-
convex form in cross-section and so arranged that the load causes compression on
the edges and tension on the middle webs of said plates, the said plates having both
their concave and convex sides, constructed on one and the same curvature, or radius,
and thereby made thicker in the middle than at the edges, and also made to bear
uniformly and alike upon each other from edge to edge substantially as described.
Third. In elliptic or semi-elliptic springs the plate or plates of which are of
concavo-convex form in cross-section and arranged with the convex sides of the
plates facing the longitudinal axes of the ellipse; the extreme end of the main
plate and that part of it of which the coil for forming the eyes for the connecting
bolt, is formed being of the same curved form as the other parts of the plate, the
said curved form being extended uniformly throughout the entire main plate, and
that part of it, of which the eye for the connecting bolt is formed substantially as
described.
Fourth. In elliptic or semi-elliptic springs made of a concavo-convex plate or
plates in cross-section and arranged so that the load causes the compression on the
edges and tension on the middle web of said plate or plates the stud or studs for
securing the plates in position being struck up on the convex side thereof by
indentation of the concave side substantially as described.
Fifth. The combination with a spring the plate or plates of which are of concavo-
convex form in cross-section of a band that is convex on that portion of the inner
side that crosses the concave side of the spring and fitting the concavity thereof,
and is shaped on the outside of said portion in flat or other equivalent form adapted
for the bearing connection with the carriage substantially as described.

page_text: Sixth. The combination of washers having cone shaped hubs, with elliptic springs
the eyes of which are formed of a plate or plates of concavo-convex form in cross-
section substantially as described.
Seventh. The combination of washers, having flanges, with the eye bolts and
the bolt eyes of elliptic and semi-elliptic springs. The said flanges overlapping the
edges of the coils of the plates forming the eyes for the connecting bolt substantially
as described.