The ruling of the circuit court in this case was that the second claim of letters patent of the United States No. 496,449, issued May 2, 1893, on the application of Charles E. Scribner and Earnest P. Warner, to the Western Electric Company, as assignee, is so far limited by the prior art as not to be infringed by devices made by the Standard Electric Company in conformity with letters patent No. 500,403, issued June 27, 1893, to F. H. Lover-idge. The opinion delivered (81 Fed. 192), it is conceded, displays “an appreciation of the points at issue,” intricate a.s in some respects they have been made to appear, but is criticized because its review of the prior art is confined to the patent of Hochhausen, No. 404,848, which it is said, is without significance, because it is for an electric machine which has no pole-pieces. But that objection was considered, and, as we think, sufficiently answered, in the opinion, and, without going again into the details of the subject, we deem it enough to declare our concurrence in the views of the circuit court concerning that patent. A further examination into the prior art, perhaps,
The two claims of (he patent in suit are closely related, the one being for a process, and the other for a product or result of the employment of the process upon the pole-pieces of an electric machine; and it is evident, upon the face of the patent, that neither claim embodies a pioneer discovery, and, if invention is shown, it is of a very narrow scope. The specification describes, in general terms, a. process for discovering variations or lack of uniformity in the lines of force cut by the coils of the armature of an electric dynamo when the resistance in the circuit is gradually cut out or shunted, and the brushes rotated, meanwhile, from the maximum to the minimum point of commutation. In the claim it is called: .
“The method of creaüng a uniform field for the short-circuited portion of the armature coils of a dynamo, which consists in shunting the brushes from the maximum to the minimum, varying the resistance in the circuit as the said brushes are shifted, and maintaining during said shifting freedom from sparking at the commutator by shifting the brushes slightly from the position ihat they would occupy if the field were uniform, in order to determine the amount and character of the variation in the distribution of the magnetic lines of force, and then perforating the pole-pieces to the degree thus found to be necessary, substantially as described.”
It will be observed that neither in the claim nor specification is there disclosed any means or method of determining different degrees of irregularity of force, discovered1 by the experimental movements of the brushes between the maximum and minimum points of commutation; and in this respect the process of this patent differs, apparently to its disadvantage, from the process shown in the earlier patents, Nos. 402,200 and 410,656, granted to J. G-. Stutter, in which a volt meter is used to obtain from the different positions of the brushes "‘relative indications of the electro-magnetic force of the current (which are also relative indications of the resultant magnetic intensity produced by the mutual action upon each other of the field magnets and the armature) flowing through the coils.” If the process of Scribner and Warner «lifers otherwise essentially from the process of Blatter, it is not perceived, and whether there are other differences it is not important for the present purpose to inquire. Reference is made in the specification of the patent in suit to the first patent of Blatter, in which, though the process is explained, the claims are for a dynamo-electric machine or motor having one or more pole-pieces cut away or incised, to neutralize irregularities of force to prevent sparking as the brushes are shifted; hut it is pointed out that the pole-pieces there shown are salient, and, consequently, the armature can be rotated only in one direction, “since when the poles are incised for rotation in one direction the lines of force will not be properly distributed for rotation of the armature in the opposite direction.’'- The special and characteristic advantage claimed for the dynamo of the patent is ihat its armature rotates in either direction, with no necessity for other change except the obviously expedient if not necessary one of making the brushes reversible. Tins is dem-onstraied by the statement in the specification that “our invention consists in producing, in the field, lines of force uniformly distributed as to generating or current producing effect throughout the arc or
“This operation requires the exercise of caution and good judgment, because, to produce the desired result, the exact amount of metal necessary to the uniform distribution of the lines of force must he cut away, and one-half of such amount must he taken from each side of a line that is coincident with a plane passing through the axis of the armature shaft, in order that the dynamo shall run sparkless and maintain a steady current, which under all conditions of load, or when operated in either direction, shall always be the same in amount.”
On cross-examination, after a similar statement, be said:
“in other words, there is just a correct amount of metal to be removed, and a correct disposition of that metal remaining, which will produce a uniform field, and any variation therefrom produces nonuniformity.”
Wben asked whether the separation of the upper or north poles of the machine shown in figure 10 of the Houston patent, No. 258,648, tends to make the field more uniform than it would be if the poles
The proposition announced in Thomson-Houston Electric Co. v. Western Electric Co., 34 U. S. App. 186, 256, 16 C. C. A. 642, and 70 Fed. 69, that, "when such tests are necessary to distinguish one device from another, it is manifestly an impracticable, not to say dangerous, proposition that the making or using of either under a given patent may be declared to be an infringement of a different patent upon the other,” would seem to apply with equal or greater force here. Hut, that aside, it is clear that the earlier electric machines, of which patents No. 184,966, to Holcombe; No. 233,047, to Thomson; No. 258,648, No. 272,256, and No. 286,612, to Houston; No. 330,836, to Johnson; No. 332,682, to F. G. Waterhouse; No. 335,998, to Fisher; and No. 389,029, to A. G. Waterhouse,—are examples, in which the pole-pieces were cut away or perforated or entirely severed at or near the line of the plane of the axis of the armature shaft, were or were not anticipations of the patent in suit according to the result of experimental tesis, and, such tests not having been made, it remains a question of reasoning or conjecture, in the light of the evidence, whether the particular construction shown in any of the prior devices was such as to produce, or to tend in a substantial degree to produce, the desired uniformity in the held of force. It is not enough to exclude those patents from consideration to say that the incisions or perforations or separations of the parts of the pole pieces were intended, or were described as intended, for some other purpose than to produce a uniform Add, as, for instance, for the purpose of ventilating the machine. Ventilation was necessary only to prevent or to restrict the consequences óf sparking, which results from irregularities in the field of force; and in the light of (he learning contributed by the experts it seems probable, if, indeed, not certain, that the beneficial effect accomplished was more the result of decreased irregularities in (he field of force than it was of the ventilation, whether the patentees so understood or not. It was common knowledge that the distribution of the lines of force depended largely upon the form of construction or distribution of metal in the pole-pieces, whether salient or consequent; and that the reason why this was so was also well understood, if not otherwise proved, is demonstrated by the patents-to Stutter and Hochhausen. It is therefore not to be believed that when other and earlier patentees constructed electric generators or motors with pole-pieces incised, severed, or perforated at or near the center, or elsewhere, they did not know that the incision or other particular change of form given to the pole-piece would have a certain and definite effect upon the working of the dynamo, and whether they knew just what the effect would be, or why it would result, is immaterial. It was an inevitable result, and not merely an accidental phenomenon, like the formation of fat acid in Perkins’ steam cylinder, which in Tilghman v. Proctor, 102 U. S. 107, 111, was declared to be of no- consequence. Whatever others had done in the way of shaping pole-pieces, and whatever the effect upon the field of force of what was so done, before the patent to Scribner and Warner, the appellee had the right to do
That the decree below should be affirmed we have no doubt, and it is so ordered.