Wright v. Yuengling/Opinion of the Court
The object of the invention in question was to add both lightness and strength to the construction of frames for horizontal, singlecrank engines. To attain this the patentee, instead of employing the ordinary flat, parallel slides for the piston and cross head, makes use of a hollow cylinder, arranged concentrically with the steam cylinder, and serving as a guide for the cross head, together with a trough connecting this cylinder with the base, H, and deep enough to permit the free movement of the connecting rod. This construction is further strengthened by a rib extending along the upper edge of one side, p, of the trough, D, continued along the upper edge of the base, H, and also along the upper edge of the other side, m, of the trough, and terminating at an extension of the cylinder head, a; and also, to add vertical strength to the frame, a rib or web, t, was extended from the base, H, to the cylinder head, a, merging in a foot, w, which serves as one of the supports of the frame. The cylinder head, a, the guiding cylinder, b, with its connecting piece, the trough, D, the base, H, and the web, t, are cast in a single piece, and firmly bolted to the head of the steam cylinder, A.

1. The first claim is for a combination of the cylinder, b, the cylinder head, a, and the semicircular connecting piece, d, while the third claim includes the same elements, and, in addition thereto the trough, D, the base, H, and the web, t.

In view of the fact, to which we shall hereafter call attention, that a cylinder had been used long before for guiding the cross head of a piston, it is at least open to doubt whether there was any novelty in the first claim. Such novelty, if there be any at all, consists in leaving certain lateral openings, e, e, in the guiding cylinder, and in taking half the top off of such cylinder as it approaches the steam cylinder, in order to give convenient access to the cross head. But, in the view we take of the alleged infringing device, it is unnecessary to express a decided opinion upon this point.

The connecting piece, d, which is described in the specification as a semicircular connecting piece, merging at one end in the guiding cylinder, and at the other end in the cylinder head, thus uniting the two, is not only made an element of both these claims, but is said to constitute, in connection with the guiding cylinder and cylinder head, a special feature of the invention. This so-called 'connecting piece' is distinguished from the guiding cylinder in that it is only semicircular, and thus admitting of access to the stuffing box with perfect freedom throughout a complete half circle. This access is had, not through a mere hole or opening, such as are e, e, but through such an opening as can be obtained by cutting away the upper half of the frame at this point.

The device used by the defendant contains a similar cylinder for guiding the cross head, and a trough connecting it with the base; but this cylinder, instead of having its entire interior surface bored out, so that it may guide the cross head in the same way that the piston is guided in the steam cylinder (as in the Wright patent) merely contains an upper and a lower guide, formed of two slides or fitting strips, the surfaces of which are bored out, but no other portion of the cylinder. We do not regard this, however, as a material departure from the Wright patent, as it constitutes a mere difference in detail of construction, not affecting in any way the operation of the cross head of the cylinder, or changing materially the efficiency of such cylinder. Nor do we think it material that in defendant's structure there is no cylinder head forming part of, cast with, and constituting a portion of, the engine frame, since the frame of the defendant's device terminates in a flange adapted to be bolted to a cylinder head, and thus, in fact, constituting a part of it.

But the absence of the semicircular connecting piece, d, is a circumstance worthy of more serious consideration. In the defendant's engine there is no such semicircular connecting piece as is described in the Wright patent, but the guiding cylinder extends backward to a connection with the head of the steam cylinder, the side of such guiding cylinder, through which the cross head operates, containing an opening oval in shape and narrower at each end than in the center. The equivalent for the connecting piece, if found at all, must be in this continuation of the guiding cylinder backward to the steam cylinder. But this portion of the cylinder is neither scooped out in a semicircular form, nor does it admit of ready access to the cross head shown at this point in the Wright patent. Instead of access to the cross head being easier at this point than any other, it is in reality more difficult, as the oval opening is narrower there than in the center. Now, while this semicircular connecting piece may be an immaterial feature of the Wright invention, and the purpose for which it is employed accomplished, though less perfectly, by the extension of the guiding cylinder in the manner indicated in defendant's device, yet the patentee, having described it in the specification, and declared it to be an essential feature of his invention, and having made it an element of these two claims, is not now at liberty to say that it is immaterial, or that a device which dispenses with it is an infringement, though it accomplish the same purpose in, perhaps, an equally effective manner. Vance v. Campbell, 1 Black, 427; Meter Co. v. Desper, 101 U.S. 332; Gage v. Herring, 107 U.S. 640, 648, 2 Sup. Ct. 819; Gould v. Rees, 15 Wall. 187; Brown v. Davis, 116 U.S. 237, 249, 6 Sup. Ct. 379.

If the guiding cylinder of this patent had been a pioneer invention, it is possible the patentee might have been entitled to a construction of this claim broad enough to include the defendant's device, notwithstanding the absence of the semicircular connecting piece; but, as we have already said, the novelty of the invention is at least open to doubt, and we think the patentee should be held to a rigid construction of these claims. The opening in the guiding cylinder, which is supposed to be the equivalent of the connecting piece, d, instead of increasing so as to form a semicircular opening, as in the patent, decreases, so as to prevent, if anything, ready access to the stuffing box, and, under the circumstances, does not constitute a mechanical equivalent for it. Indeed, the guiding cylinder of the defendant's engine bears a stronger resemblance to those shown in the prior patents hereinafter cited than to that of the Wright patent; and hence, if the prior patents anticipate the Wright cylinder, the defendant's does not infringe it.

2. The second claim of the patent is for 'the combination, in a horizontal engine frame, of the guiding cylinder, b, base, H, and trough-like connection, D.' The guiding cylinder, which is used in lieu of the ordinary parallel slides, was, however, by no means a novelty in the construction of engine frames. It is found in different stages of perfection in several prior patents, viz.: In a patent issued to Samuel Wright, as early as 1837, for locomotive engines, and was there used, as the patentee states, 'to subserve the twofold purpose of a [steam] pump and guide;' in the patent to Gelston San ford, of February 15, 1859, in which the invention related to elongating the cylinder, 'by which means it becomes a part of the frame, used for the support of the crank shaft, and so constructed that, when bored out, it forms a guide and rest for the crose head;' in the patent to William Wright, of August 8, 1865, in which the movement of the piston is transmitted to the main crank by means of a connecting rod, jointed to the cross head, to which the piston is attached and which is guided in ways or guides, fast to the frame, and in which a semicircular connecting piece is also shown; in that to John B. Root, of August 14, 1866, in which the piston also works in two cylindrical guides attached to the cylinder heads; in that to Maxwell & Cope, of February 13, 1872; in that to Edward H. Cutler, of November 26, 1872; and in that to George H. Babcock, of December 10, 1872.

It is true that none of these patents exhibit distinctly the trough-like connection, D, of the Wright patent, but that also is found in the patent to Chilion M. Farrar, of March 19, 1872, in which it is fully shown in the drawings, though not described in the specification, and is used in connection with the ordinary flat guides or parallel slides.

Wright's only invention, then, was in the combination of the cylindrical guide with the trough shown in the Farrar patent. Did this accomplish a new and valuable result, it is quite possible that a patent therefor might have been sustained; but we do not find this to be the case. The cylindrical guide performs the same functions as in the prior patents; the trough, in which the connecting rod works in the Farrar patent, is practically the same as in the Wright patent; and the combination is a mere aggregation of their respective functions. If the combination of the trough and cylindrical guide of the Wright patent gives greater lightness and strength to the frame than the combination of the trough and the flat guides of the Farrar patent, it is a mere difference in degree; a carrying forward of an old idea; a result, perhaps, somewhat more perfect than had theretofore been attained, but not rising to the dignity of invention. We have repeatedly held patents of this description to be invalid. Stimpson v. Woodman, 10 Wall. 117; Smith v. Nichols, 21 Wall. 112; Guidet v. Brooklyn, 105 U.S. 550; Hall v. MacNeale, 107 U.S. 90, 2 Sup. Ct. 73.

The decree of the court below dismissing the bill is therefore affirmed. 

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