104 F. 337 | 6th Cir. | 1900
after making the foregoing statement, delivered the opinion of the court:
It appears from the opinion of the learned judge who heard this case at the circuit, that some stress was there laid upon a decree sup
It is necessary to look into the condition of the art at the date of Frost’s inventions relating to valves in steam engines controlling the admission of steam from the steam chest into the cylinder. For a long period prior to the use of independently actuated valves, such as a,re here described, the customary way to control the transmission of steam from the chest to the cylinder was by a valve actuated to open and close the ports by a rod connected with an eccentric located upon the main shaft of the engine. Of course, something was to be gained if the eccentric and the rod connecting it with the steam valve could be dispensed with by the provision of means for bringing the steam directly from the chest to the actuation of the valve, instead of employing the power of the steam through the engine, the eccentric, and its rod, for that purpose. It would save the loss of some power in transmission and some cost in machinery. Prior to Frost’s invention several inventors had obtained patents for devices tending to the accomplishment of this object. Among these was a patent to McFaul, No. 178,792, dated June 13, 1876; one to J. A. Tilden, No. 248,834, of October 25, 1881; one to Brazell, No. 271,181, of date February 16, 1883; and a still earlier one to Washburn, No. 98,725. Later than all these came the Marsh patents, already mentioned, of 1888 and 1889. It will not be necessary to analyze all of these in detail. It will he sufficient for the present purpose to state the progress which had been made prior to the applications for the Frost patents, and then to identify his inventions. Generally speaking, there had been patented devices for actuating steam valves of this kind, by which live steam was taken from the steam chest through ports and passages into the cylinder, or into a peripheral depression in a prolonged piston head moving through the cylinder, and from
*342 “Referring to tlie lettered parts of the drawings, R is the cylinder, and F is the piston head, having an annular depression, Z, in the periphery of said piston head, as shown in Fig. 2. At B is shown the steam chest having therein what is usually termed a ‘float valve,’ A, said valve having enlarged heads, C, C, at each end, which play hack and forth in the internal enlargements, m, in the ends of the steam chest. Referring to Fig. 2, the valve, A, is shown, having an annular depression, 4, 4, at each end, and centrally at 1 and at 3, 3, between said center and end depressions. Each end of the valve, A, has a live steam port, e, leading from the annular depressions, 4, 4, internally and longitudinally through said valve into the annular depressions, 3, 3. These several depressions, 4, 4, 3, 3, and 1, may be termed ‘annular steam ports.’ This valve. A, is like the one shown in my prior application herein referred to. The ports, e, through the valve, are as clearly shown at right hand in Fig. 2. At P is the ordinary steam-supply pipe, and from said pipe the live steam ports, 5, 5, lead into the interior of the steam chest and into the steam passage, h, which leads into the cylinder, H, Figs. 1 and 2. D, D, are ports leading from the steam chest into each end of the cylinder, and E is the exhaust port. Ports, d, e, lead from either end of the steam chest into the cylinder, R. The piston rod, L, passes from the cylinder, R, through the stuffing boxes, 6, 6, in the steam receiver, H, and on into the pump, S, said pump, of course, being of the ordinary construction. Each end of this rod has a steam port, i, passing longitudinally through it from the steam receiver, H, and into the piston head, F, and leading thence out into the annular depression, z, in the periphery of said head. This port, i, has two openings, y, x, into the steam receiver, H, one of which is closed by passing into the stuffing box at each end of the stroke. Fig. 2 shows these ports at one end.”
Tbe substance of the present controversy rests upon claim 3:
“In an engine employing a steam-actuated valve in the steam chest, a steam receiver, and a piston rod extending into and having bearings in said receiver, the piston head of said rod having the peripheral depression, and a live steam passage leading through said rod and out through the head into said depression, which depression registers with the live steam ports leading to the ends of the valve, substantially as set forth.”
The second Frost patent is, for the purposes of this spit, merely inert matter. Counsel for complainant contends that it is competent to be referred to as explanatory of the invention disclosed in the first patent. The suggestion is that the former may be broadened in its interpretation by reading backward from the particulars of the second patent. The meaning of this would be simply to expand, or diminish, or change the form of the parts of the combination with reference to each other according to the hints of the second patent. But there is nothing in all this. Without any auxiliary support, the claims of a patent, unless in terms or by necessary implication they are restricted, will include all changes of form, whether of size or shape, if the mode of operation is not changed. It is the character of the means employed, and not their dimensions or details of form, which denote the substance of an invention. Morey v. Lockwood, 8 Wall. 230, 19 L. Ed. 339; Ives v. Hamilton, 92 U. S. 431, 23 L. Ed. 426; Elizabeth v. Pavement Co., 97 U. S. 137, 24 L. Ed. 1000. So, too, the mere change of the location of the parts of a combination, if the parts still perform the same duty, and by. the same mode of operation, will not take the structure out of the bounds of the patent. Northwestern Horse-Nail Co. v. New Haven Horse-Nail
We come now to the consideration of the Metcalf patent, which is the gist of the infringement of which complaint is made. This patent dispenses with a steam receiver external to the cylinder, but there is that in the construction of the other members which is to some extent a substitute for it, though not an equivalent, which we will refer to-presently. The following is a copy of the drawing and the substance of the specifications referring thereto:
“A represents the engine cylinder, B the piston rod, P the piston head, •O the live steam supply tube, and II is the head of the cylinder, of which the supply tube, C, is a fixture. The piston rod, B, is provided with a longitudinal channel or chamber, J, reaching a suitable portion of its length from its fixed end in the piston head, where the contiguous hushing or stuffing-box, o, serves the purpose of a closure of the said longitudinal chamber, and in which the tube, O, has sliding engagement, as seen. Adjacent to the inner end of the hushing, o, a steam conduit, B, rises parallel with the face of the piston head, and connects the longitudinal chamber of the rod with the live steam annular chamber, M, situated between the packing rings, i, i, of the piston head, P. Firmly fixed centrally of the head, H, of the engine cylin*344 der, is situated' the supply steam tube, O, whose free opposite end reaches sufficiently near the end of the cylinder to secure telescopic engagement with the channel, J, of the piston rod throughout the reciprocations of the engine piston, as clearly seen in the drawing. From the fixed end of the tube, C, opens the steam passageway, W, leading from the live steam chest or other source of supply; and near each end of the engine cylinder valve-tripping steam passages, v, v, alternately connect the piston chamber or steam reservoir, M, with the end chambers of the valve at each reciprocation of the piston, whose pulsations are thereby actuated and controlled in manner following, to wit: Steam is conveyed from the chest through the passageway, W (dotted lines), to the tube, C, of the cylinder head, H, and delivered by means of the telescopically sliding chambered piston rod, B, and connected conduit, B, into the annular chamber or steam reservoir, XT, of the piston head, whence it alternately passes through the valve-tripping passage v, v, to the respective end chambers thereof, whereby the valve is moved to reverse the action of the engine piston.”
It will be seen that the steam is taken by a passage coming through the cylinder head into and through a tube extending from the head into a channel in the rod. From the open end of the tube it passes back in a space between the tube and the rod to a passage in the cylinder head, and through that to a depression in the periphery of the head. This depression registers with a port in the cylinder at each end as the piston moves in opposite directions through the cylinder. A passage leading from each of these ports takes the steam to the ends of the valve, thus giving the isochronous movement of piston and valve which is essential to all the constructions to which we have referred. The learned judge who heard the case at the circuit considered that Metcalf had dispensed altogether with a steam reservoir, but it is proper to observe that in his specification he speaks of the channel in the rod as a “chamber,” and of the depression in the periphery of the piston head as “the annular chamber or steam reservoir, M, of the piston head”; and it would seem a just inference that he intended the space between the tube and the rod and that in the annular periphery of the head as furnishing the necessary storage room for steam. But, if so, the fact remains that in this patent there is no steam reservoir outside of the cylinder, which was the prime idea of the Frost patents, but, such as they are, the means for taking steam after it is brought through the passage from the chest to the respective passages leading to the ends of the valve are located, receiver and all, entirely within the cylinder; in this respect according with the earlier Marsh and other patents. It is claimed by counsel for complainant that the reservoir of Frost finds an equivalent in the storage spaces for steam in the Metcalf patent, but we think this contention cannot be sustained. Where, as in this case, the invention is for -an. improvement upon former constructions designed and operated to produce similar results, the invention must be measured by the improvement. Things cannot be held to be equivalents simply because they produce the same or similar results. Barth used the channeled rod for the purpose of conveying steam from the outer end of the piston head through the cylinder to registering ports for passage to. the ends of the valve. But his means did not provide for the use of live steam. Marsh