Letters patent No. 66, 130, granted to James B. Clark, June 25.
1867, for an "improvement in the manufacture of blanks for carriage
thin shackles," are not infringed by the manufacture of blanks for
shackles in accordance with letters patent No. 106,225, granted to
William B. Smith, August 9, 1870.
The features of the Clark patent are that, by dies, the arms of
the blank are bent into an oblique direction, and the body into a
curved form, so that the parts where the arms join the body are
rounded on the outside as well as the inside, and that when
subsequently the curved body is straightened, there will be in it
sufficient metal to form sharp outside corners by being pushed out
into them.
The arms of the Smith blank are not bent in an oblique
direction, its body is not curved, the parts where the arms join
the body are not rounded, either on the inside or on the outside,
and in afterwards straightening the back, surplus metal is not
pushed toward or into the corners to form them, but the existing
corners, already formed, are forced further apart by driving
surplus metal into the back between the corners.
In view of the state of the art and the terms of the Clark
patent, it must be confined at least to a shape which, for
practical use in subsequent manipulation, has a disposition of
metal which causes a sharp corner to be formed in substantially the
same way as by the use of his blank.
This was a bill in equity to restrain an infringement of a
patent. The facts are stated in the opinion of the Court.
MR. JUSTICE BLATCHFORD delivered the opinion of the Court.
This is a suit in equity brought in the Circuit Court of the
United States for the District of Connecticut by James B. Clark
against The Beecher Manufacturing Company, a Connecticut
corporation, and D. F. Southwick, for the infringement of letters
patent No. 66,130, granted to the plaintiff,
Page 115 U. S. 80
June 25, 1867, for an "improvement in the manufacture of blanks
for carriage thill shackles." The main defense to the suit is
noninfringement. The circuit court, after a hearing and two
rehearings, dismissed the bill, holding that infringement had not
been proved. 7 F. 816. The plaintiff has appealed.
A history of the state of the art and of the progress of
invention in making shackle blanks will conduce to a determination
of the questions involved. A carriage thill shackle is a device by
which the thills of a carriage are hinged to the axle. The finished
shackle is a horizontal plate with a pair of vertical ears rising
therefrom, one at each end of the back. The cockeye on the end of
the thill is received between the ears, and a bolt passing through
the ears and the cockeye secures the parts. The flat back or body
part of the article is forged with a projection at each side,
forming what is commonly called the "clip," by which the article is
secured to the axle. In forming the shackle, it is necessary that
the outside corners, where the ears join the back, should be sharp,
full, and square, to obtain a good bearing on the axle, or the
article will not be salable. The old style of shackle was of this
shape:
image:a
It was formed by bending up the two ears from a piece or metal
of equal thickness, and the outer corners became round, and the
bearing on the axle was not firm and true. It was desirable to
obtain in some way a reservoir or surplus of metal, which could be
utilized, in the bending, by being thrown out into or remaining in
the corners to make them full and square on the outside. To
Page 115 U. S. 81
attain this result, one James P. Thorp made an invention for
which he obtained letters patent No. 28,114, granted May 1, 1860,
which were reissued to his assignees, H. D. Smith and others, as
No. 2,362, September 18, 1866. Thorp's blank was of the following
shape:
image:b
The two projections on the bottom of the blank were intended to
furnish sufficient metal to make the outer corners of the shackle
square and sharp, when the ears were bent in the direction
indicated by the arrows. The projections were at the places where
the arms joined the body. Thorp's patent showed a die for making
the blank, constructed with recesses or cavities to form the
projections, and stated that, after the arms were bent up, the
blank, instead of being the old form, Fig. 6, with rounded corners
a a, thus:
image:c
Page 115 U. S. 82
would be the form of Fig. 7, with square or right-angled corners
a a, thus:
image:d
the blank being stronger at the junction of the arms and body,
and the expansion of the metal, in bending the arm, being
compensated for by a diagonal contraction of the metal, which
operated to prevent the destruction of the cohesion of the
particles of the metal and the consequent weakening of the blank at
the parts where it was bent.
The next step is shown in letters patent No. 65,641, granted
June 11, 1867, to Leander Burns and Josiah Wilcox, on the invention
of Burns. That patent shows, in Fig. 7, an upper die M and a lower
die N and the blank made between them, with square corners L L,
thus:
image:e
Fig. 7 is a transverse vertical section taken in the plane of
the line
y y in Fig. 6. Fig. 6 is a face view of the lower
die N, and shows also the blank after it is acted on by the dies.
The specification states that if the arms of the blank are bent up
at right angles in a direction toward each other, perfect square
corners will be left at L L, with the metal through those corners
and the other parts of a uniform thickness.
Page 115 U. S. 83
image:f
Then followed the patent to the plaintiff, the specification and
drawings of which are as follows:
"This invention relates to the construction of carriage shaft
shackles from solid blanks and to the shape of the dies for forming
the same, so that, with the least amount of labor and power, the
said shackle may be gradually formed into the required shape. In
the annexed drawings this invention is illustrated."
image:g
"Fig. 1 is a vertical sectional view of a shackle blank, showing
it between the dies. Fig. 2 is a top or plan view of a shackle
blank, as the same is formed by the dies. Similar letters of
reference indicate like parts. The blank, which is made in the
shape of a cross, in the usual manner, is placed upon the lower die
A and the upper die B is then forced down upon it, whereby the arms
a a of the blank are bent into an oblique direction, and
the body
b is curved as shown in the figure. The portion
of the blank where the arms join
Page 115 U. S. 84
the body is rounded, as shown, on both the inside as well as on
the outside, the straightening of the body of the shackle pushing
out sufficient material for forming the sharp corners, without
having any hindersome and impracticable projections. The dies are
formed so as to give the blank the required shape. This process of
forming shackle blanks has proved by practice to be the most
expeditious and simple yet performed, as it requires the least
amount of machinery and forms each part of the shackle with just
the required amount and thickness of metal for completing the
article."
The claims, two in number, are these:
"1. The carriage shaft shackle blank, so formed between dies
that the body
b of the blank is curved, substantially as
herein shown and described."
"2. The dies A and B for making the said blank, when so
constructed and arranged as to form the rounded corners and the
curved body of said blank, substantially as herein shown and
described."
The plaintiff, according to his description, takes a blank in
the form of a cross and, by dies of proper shape, bends the arms of
the blank into an oblique direction and the body into a curved
form, the result being that the parts where the arms join the body
are rounded on the outside as well as the inside, and when
subsequently the curved body is straightened, there will be in it
sufficient metal for form sharp outside corners by being pushed out
into them. The plaintiff's patent stops with the curved blank shown
in Fig. 1 of his drawings. That blank is, in practice, afterwards
formed by other dies into the following shape:
image:h
Page 115 U. S. 85
Putting the blank into shape is what the specification refers to
when it speaks of "the straightening of the body," and "forming the
sharp corners."
The defendants make shackle blanks by dies, under letters patent
No. 106,225, granted to Willis B. Smith, August 9, 1870.
image:i
Fig. 3 of that patent is a plan view of the blank which the dies
forge, and Fig. 4 is an end view of the blank. In these figures
b b are the ears;
d is the clip;
f is
the shaft;
g is the body of the blank;
h h are
the corners at the junction of the ears and the body;
H is
the whole blank. The corners,
h h are formed at right
angles to each other. The specification says that the blank
H is then placed in a trimming die, and the surplus metal
which projects from its edges is removed, and that the blank is
then heated and the oblique portions of the body
g are
bent so as to throw the ears
b b upward, in the form shown
in Fig. 5,
image:j
in which operation the corners
h h,
Page 115 U. S. 86
previously formed at right angles, remain unmolested and are
square and full. The specification says:
"I am aware that dies for the same purpose have been previously
used, as shown in the patents to L. Burns, June 11, 1867, and J. B.
Clark, June 25, 1867. In Burns' dies, the body of the shackle is
formed straight, while the ears are curved, the curve commencing at
the plane where the ears are to be bent to form the corners, and
therefore said corners are not right angled; neither is it possible
for curved ears to be both on one and the same line. In Clark's
dies, the ears are formed straight but were arranged on different
lines, so that the edge of the blank at the side of each ear was
thrown out of a vertical line, which seriously interferes with
trimming off the surplus metal. I make no claim to either of the
above or similar dies."
Smith's patent claims the blank so constructed and formed, and
also the dies for forging it.
The circuit court was of the opinion that in straightening the
angularly bent back of the defendants' blank to get it into the
shape of Fig. 5 of the Smith patent, surplus metal was not pushed
toward or into the corners to form them, but the existing corners
were forced further apart, to the extent of one-fourth of an inch,
by driving surplus metal into the back, between the corners. We are
of opinion that this view is correct. Besides this, the arms of the
defendants' blank are not bent in an oblique direction, its body is
not curved, and the parts where the arms join the body are not
rounded either on the inside or on the outside. The defendants'
blank, as in Fig. 4 of the Smith patent, has abundance of material
near the corners
h h, which are to be sharp and square and
are already formed, while the plaintiff's blank, by reason of its
rounded corners, has a deficiency of material near the points where
the square corners to be formed are to be.
In the efforts to make by dies a shackle blank which should
ultimately have sharp outside corners, the inventors, in
succession, had the idea of a reservoir or surplus of metal. Thorp
had it in the downward projections. Burns had it in his sharp lower
corners with curved arms. The plaintiff had it in his
Page 115 U. S. 87
curved body and rounded corners. Smith has it in his shape. But
in view of the state of the art and the terms of his patent, the
plaintiff must be confined to a curved body, rounded corners, and
oblique arms, or at least to a shape which, for practical use, in
subsequent manipulation, has a disposition of metal which causes a
sharp corner to be formed in substantially the same way as by use
of his blank. The defendants' blank does not have such a shape.
Decree affirmed.