29 F. 517 | U.S. Circuit Court for the District of Southern New York | 1886
The only issue between the parties is whether the rod coupling of the defendants is an infringement of letters patent No. 105,-
In the accompanying drawings, Fig. 1 represents an exterior view, partly in section, of the ends of two pipes coupled together according to the invention; Fig. 2 represents the ordinary mode of coupling pipes together; and Fig. 3 illustrates the advantages of the invention.
The specification states that—
“It has been usual to cut a slightly tapering screw on the ends of the adjoining tubes, while an internal screw" or thread, without any taper, was formed in the socket; hence but a portion of this internal thread of the socket was in proper binding contact witli the threads of the pipes, as is clearly shown in figure 2; the greater portion of the threads, both on the tubes and in the socket, being of no avail as a medium of effecting a tight junction of the tubes.”
After pointing out the defects in and objections to such screw couplings, the patentee proceeds in the specification as follows:
“In order to obviate these objections, I cut on the ends of the pipes, A77 and A"7 (Figure 3,) a tapering screw. Instead of cutting the thread of this screw to one uniform depth, however, I so cut it that it shall gradually vanish until it disappears at the exterior of the tube as shown at T, figure 3. It should be understood, however, that the thread of the screw does not vanish so abruptly as is shown in that figure, which is exaggerated, with the view of rendering more apparent the advantages of my invention. The socket, B, figure 3, instead of having a screw-thread cut through it as in figure 2, has two screw-threads, tapering, one in one direction for receiving the end of one tube, and the other in another direction for receiving the end of the other tube, the. tapers of each screw corresponding with that of the tube which it has to receive, and the screw-thread vanishes to correspond with the vanishing thread of the tube, as clearly indicated in the drawing.”
The claim of the patent is as follows:
“The rods or tubes, A, A7, having tapering ends and tapering threads upon the same, in combination with a sleeve having tapering sockets and threads corresponding to those of the rods, as set forth.”
The defendants contend that their coupling does not infringe this claim, because, although their tube is cut with a vanishing thread, and their sleeve has a vanishing thread to correspond to that of the tube, their coupling docs not have a rod with a tapering end or screw, or a tapering socket. In their rods the threads of the screw surround a cone-shaped stem, but the exterior lines of the threads form a cylinder, and not a cone-shaped or tapering end or screw; and the exterior lines of their sleeve form a cylindrical chamber, and not a cone-shaped or tapering chamber.
The patentee was the first to combine in a coupling a sleeve and screw in which a vanishing male and female thread were made to correspond with each other. By doing this, he effected a more perfect metallic contact throughout between the socket and the screw, and made a more perfect and secure joint than had been done before. The expert for the defendants admits that he knew of no instance in the state of the art in which a vanishing screw-thread cut upon a tapering mandrel or cone was combined with a tapering female thread cut upon the surface of a hollow cone prior to the date of the patent in question. The patentee was therefore entitled to claim broadly a sleeve or socket and screw in which a vanishing male and female thread were made to correspond with each other. But the question in this case is whether the terms of his claim, when interpreted, as they must be, by the specification, are not narrower than the real invention, and such as to enable the defendants to deny infringement. The claim by itself, so far as it relates to the rods, is capable of an interpretation which would fully cover the real invention. If a rod with a tapering end is to be regarded as a rod in which the stem of the screw is fevering, the claim is ample, and embraces the rod of the defendant. On the other hand, if the term “tapering end” is intended to describe a rod with a tapering screw,—that is, a rod in which the exterior lines of the screw-threads form, a tapering end,—the coupling of the defendant is not an infringen!ent. A rod with a tapering end may mean a rod in which the stem', mandrel, or solid part of the end tapers, or it may mean one in which the end, screw-thread included, as adapted to be fitted into a sleeve or recess, is tapering. The term, as used in the claim, is therefore capable of two meanings; and, being ambiguous, the true meaning must be ascertained by resort to the descriptive part of the specification in order to discover what the patentee describes as new, and what the public have a right to understand was intended to be claimed.
An examination of the specification denotes quite plainly that the patentee supposed that the gist of his improvement upon the couplings previously in use consisted in substituting a tapering screw having vanishing threads, in conjunction with a sleeve or socket adapted to receive such a screw, for tapering screws without the vanishing thread, and a socket not adapted to receive a tapering screw. The drawings distinctly denote this. In describing the advantages of his invention he dwells upon the objections to the use of a “slightly tapering screw” with a socket which does not taper to- receive it. Each of the drawings shows a tapering screw, but Fig. 2, which shows ihe objectionable coupling, has no vanishing thread upon the screw, and lias no tapering recess in the socket,
It follows that the bill must be dismissed.
