AN IMPROVED ELLIPTIC SPRING FOR CARS AND OTHER PURPOSES
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "AN IMPROVED
ELLIPTIC SPRING FOR CARS AND OTHER PURPOSES." A communication from
abroad by B. S. Clark and E. K. Righter, both of New York City, and
Edward Cliff, of Newark, in the County of Essex, State of New Jersey, both
in the United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 9th May 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "AN IMPROVED ELLIPTIC SPRING FOR CARS AND
OTHER PURPOSES." [A communication from abroad by B. S. Clark and E. K.
Righter, both of New York City, and Edward Cliff, of Newark, in the County of
Essex, State of New Jersey, both in the United States of America.]
This Invention consists in an improved elliptical spring, which when bent into
the required form or shape has at all times the greatest amount of steel in the
centre, both lengthwise and sidewise, and the sides or edges of which are of the
same thickness from end to end of the entire bar.
The Invention also consists in "pounding" out from the end of the bar of steel
the "eye," so that the eye and bar are of one and the same piece.
The bar of which the spring is made is elliptical, that is, of such a form that the
greatest amount of metal lies in the centre of the bar from end to end graduated
from the middle to either end, always having the most metal above and below the
straight line through the centre of said bar, and the sides or edges are of an equal
width and plain surface after the said bar is formed in its elliptical or bent shape,
and thus the point of fracture so commonly found in elliptical bar springs is
removed, for as the sides of the bar have the same thickness form end to end there
is no decrease in the massing of metal, and no crack, or fracture, or point of
weakness is formed.

page_text: These elliptical bars thus formed are joined together or attached to eyes.
Heretofore these eyes were attached to such elliptical springs only by welding or
moulding the eyes into the bar.
According to the method of this Invention the eye is forged out of the same
piece as follows:-A bar of steel is chosen a little shorter than the required length
of a finished spring. The hammering commences at, say, 1 inch or 1½ inches from
the end, and the bar is hammered down to the required shape or size towards the
middle of the spring. This leaves a knob at the end, which is placed between dies
and spread outward side to side. The knob is placed in a suitable die, and a drop
hammer drives out the ears, leaving a recess in both female and male eyes. The
entire bar is now placed in dies and the drop hammer operated on them and the
bar is lengthened. After the fur or roughened edge has been removed the spring
is completed. These long bars may be reinforced by stouter leaves added in as
usual.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander. Melville Clark in the Great Seal Patent Office. on the
9th November 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "AN IMPROVED ELLIPTIC SPRING FOR CARS AND
OTHER PURPOSES." A communication from abroad by B. S. Clark and E. K.
Righter, both of New York City, and Edward Cliff, of Newark, in the County of
Essex, State of New Jersey, both in the United States of America.
This Invention consists in an improved elliptical spring constructed of an
elliptical bar of steel, which when bent into the required form or shape has at all
times the greatest amount of steel in the centre, both lengthwise and crosswise,
and the sides or edges of which are of the same thickness from end to end of the
entire bar. The Invention also consists in "pounding" out from the end of the
bar of steel the "eye," so that the eye and bar are of one and the same piece.
In the Drawings Figure 1 is a side view of the bar of steel ready for bending;
Figure 2, an end view of said bar; Figure 3, a side view of the bar when bent
into the form of a spring; Figure 4 shows on a larger scale the ends of the two
elliptical bars forming a spring joined together by means of the eye; Figure 5 is
the male eye; and Figure 6, the female eye.
The elliptical spring is constructed of a bar of such a form that the greatest
amount of metal lies in the centre of the bar from end to end, said bar tapering
from the middle of its length to either end and from the middle of its width to
either side, there being always the most metal above and below the straight line
through the centre of said bar, and the sides or edges being of an equal width and
plane surface after the said bar is formed in its elliptical or bent shape. Thus the
point of fracture so commonly found in elliptical bar springs is removed, for it will
be seen that as the sides of the bar have the same thickness from end to end there
is no decrease in the massing of metal aud no crack or fracture or point of
weakness is formed. This is plainly seen in Figure 1,.which is a side view of the
bar of steel drawn out, showing the greatest amount of metal above and below the
centre, and its sides d, d, of an even width from end to end. These elliptical bars
thus formed are joined together or attached to eyes. Heretofore these eyes were
attached to such elliptical springs by welding or moulding the eyes into the bar.
The new method, as set forth in Figures 4, 5, and 6, consists in forging the eye out
of the same piece. This is done as follows:-A bar of steel is chosen a little
shorter than the required length of a finished spring. The hammering commences
at, say, an inch or an inch and a half from the end, and the bar is hammered down
to the required shape or size toward the middle of the spring. This leaves a knob
at the end. This is placed between dies, and is spread outward from side to side.
Then the knob is placed in a suitable die and a drop hammer drives out the ears
a, a, leaving the semicircular recess b in both female and male eyes. The entire bar
is now placed in dies and the drop hammer operated on them, and the bar is
lengthened, as will readily be understood. After the fin or roughened edge has
been removed the spring is completed. These long bars may be reinforced by
stouter leaves added in as usual.
The bars are joined together to form the spring by the ears of the male eye fitting
between those of the female eye and in the recess b of the latter, the two parts
being connected by a pin passing through the ears, as shown in dotted lines in
Figure 6.

page_text: Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is,―
1st. An elliptic spring constructed of a bar of steel, whose thickness is greatest
through its middle from end to end, crosswise and lengthwise, and whose sides d, d,
are of the same thickness from end to end, thus obviating the point of fracture, for
the purpose specified and substantially as described.
2nd. The forming out of the same bar of metal of which the elliptical spring is
made, the eyes both male and female, one on each bar, whereby the two may be
joined together, thus forming an elliptical hinged spring, substantially as described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Ninth day of November, A.D. 1881.
AT DI
A. M. CLARK.
(D)