groove having circumferential beads. The defendants then cut away some of the face of the roll between the ribs, making the ribs higher, whereby it became apparent that they were, as they always had been, the edges of disks embedded in the roll; but the structure did not, because its surface contour was thus changed, cease to be a roll-carrying bead. It also continued to have the circumferential groove. Obviously there must be grooves, or else the pipe could not pass through. A groove is an opening with a bottom and with sides, and these parts are sufficiently marked by the three disks. If these were close together, or if two more graduated disks were inserted between the central one and each side one, it would be perfectly apparent that there was a circumferential groove; and we think it no less true because the surface is not completely marked. We are not sure that defendants intend to deny that their device responds to a definition of the terms of the claim, so broadly considered.

Are the side-supporting flanges of plaintiff's rolls to be considered as performing a function essential to the device and as a feature which defendant must use, in form or by equivalent, before there is infringement? We think they are. It is true that the first claim does not call for these flanges in so many words, and that some of the other claims impliedly do so by calling for a "semielliptical groove or pass," since the groove will not be completely semielliptical unless it is carried down to the central plane; but this term, "a pair of rolls," used in this connection, necessarily means rolls that will roll pipe; and such a construction of them or their associated parts that the pipe will retain its general form is necessarily implied. However, the very fact that this limitation as to the form of the roll is not expressed in the claim, but that any implication on that subject arises from the necessity that the device shall operate, indicates that no narrow rule of equivalency can be applied, and that when something else is substituted which was already a well-known means of performing the same function, and when its construction did not involve any invention, the thing so substituted is a mechanical equivalent, and infringement is not thereby escaped. We have already pointed out that these side flanges or extreme ends of the semi-elliptical groove have no function, except to resist the outward bulge of the pipe at this point. In a fair sense they are rolling guides; and the stationary guides used by defendants (shown in cross-section in the above sketch) have precisely the same function and perform it in the same way, except that the friction is sliding instead of rolling. Further, the Root patent, No. 180,643, of August 1, 1876, had skewed rolls, in each of which the groove or pass was not semi-elliptical, but more shallow, and was provided with central stationary guides or "keepers," all arranged (as said in defendants' brief) "just exactly as in defendants' machine." The defendants, therefore, have substi

tuted for the roll-flanges not only an equivalent, but a known equivalent; and this confirms the conclusion that infringement is not thereby avoided.

We find nothing upon the face of the patent requiring the claim to be limited to rolls which had these flanges attached to and integral with the rolls. It is true that neither by drawing nor specification does Fell suggest the performance of this function by stationary parts of the frame, but this is not necessary. In the absence of something clearly showing that the patentee did intend to have his grant confined to a specific form, a broad and generic claim may rightfully stand on a mere specific disclosure; and the invalidity of such a claim (if it is invalid) will result, not from the applicant's failure to use more sweeping language in his specification, but from the state of the art limiting the actual invention. The claims are part of the description required by statute, and in them, and not in that part of the description which is now commonly called “specification," is the proper place in which to define the breadth of the invention, as was most accurately apprehended by Fell's solicitor when he (though quite unnecessarily) said that various changes might be made— without departing from my invention as defined by the appended claims.

(2) Nor can we find the supposed claim limitation to these specific roll-flanges in the fact that Fell's specification and drawings showed rolls having flanges, and that he claimed the rolls "substantially as described." The stress which defendants' counsel in argument have put upon this quoted phrase, and the constant recurrence of the question in cases coming before us, make it advisable to consider and determine what place this phrase should have in the rules of claim construction. We think a review of the controlling principles, of the authoritative cases, and of the established Patent Office practice, in the light of which its grants must be considered, demonstrate that, at least in all recent patents, and save in exceptional instances, the presence or absence of this phrase is of no interpretative importance.

Upon principle the matter seems clear. The statute requires that the specification should describe the invention, and that the patentee should specifically claim what is new. He cannot claim that which he has not substantially described; and it seems necessarily to follow that the idea-not "exactly as described " or " precisely as described,” but "substantially as described," that is to say, "not varying in any vital way from the description" or "either in the form shown or in its substantial equivalent "-is necessarily inherent in every claim. So, in Mitchell v. Tilghman, (5 O. G., 299; 86 U. S., 19 Wall., 287; 22 L. Ed., 125,) referring to these words, it was said:

Words of such import, if not expressed in the claim, must be implied;

and again, in Hobbs v. Beach, (C. D., 1901, 311; 94 O. G., 2357; 180 U. S., 383; 21 Sup. Ct., 409; 45 L. Ed., 586,) speaking of the rule that these words refer us back to the specifications, that Court says: This rule, however, is equally applicable whether these words be used or not. To say that these words must be implied, if not expressed, and to say that if expressed they import an otherwise non-existent limitation, is to propound a dialectic paradox. We cannot lightly assume such a self-destructive contradiction in the law, and its seeming existence calls for a careful analysis of the apparently pertinent and authoritative cases.

In Seymour v. Osborne (78 U. S., 11 Wall., 516; 20 L. Ed., 33) the question was whether the claims were void as being for an effect or a function, as for example:

Discharging the cut grain from a quadrant-shaped platform on which it falls as it is cut, by means of an automatic sweep-rake sweeping over the same, substantially as described.

The Court unquestionably placed reliance on this phrase, "substantially as described," in reaching the conclusion that the claims were not functional, but it is not apparent that the Court would have reached any different decision if the words had not been there; and the language of the opinion on this point is written by Mr. Justice Clifford, who, only three years later, in Mitchell v. Tilghman, supra, (5 O. G., 299; 19 Wall., 287; 22 L. Ed., 125,) found it necessary to use the language which we have already quoted:

Words of such import, if not expressed in the claim, must be implied, else the patent in many cases would be invalid, etc.

It seems quite clear that Mr. Justice Clifford could not have regarded his language in Seymour v. Osborne as laying down any rule of law to the effect that the actual presence of words, always constructively present, could have controlling importance. It is further to be noted that Seymour v. Osborne was decided in 1870, construing patents issued before 1865, and both issue and construction were before the Patent Office rule on the subject became finally settled as hereafter pointed out. In the Corn Planter Patent (6 O. G., 392; 90 U. S., 23 Wall., 181; 23 L. Ed., 161) the claim involved called for a combination of several parts "substantially as and for the purpose set forth." From the discussion and disposition of the matter it is apparent that the Court construed the claim by reading into it what was necessary to make it an operative device of the general class and for the general purposes described; and it is difficult to see that any different course could have been taken if the concluding phrase had not been present in the claim. The remark that this phrase "throws us back to the specification for a qualification of the claim" seems rather casual, because clearly we will be thrown back to the specification for that purpose without any propelling aid from this clause.

In Westinghouse v. Boyden (170 U. S., 537; 18 Sup. Ct., 707; 42 L. Ed., 1136) the opinion was by Mr. Justice Brown, and his remark on this subject, on page 558, (170 U. S.,) referred only to Seymour v. Osborne and to the Corn Planter Patent, omitting reference to Mitchell v. Tilghman. The question as to the proper construction of the claim had already been decided, and the presence of this phrase is only referred to as one of the "other facts which have a strong bearing in the same connection." Just as Mr. Justice Clifford, when the matter was the second time before him, did not seem to be controlled by his comment the first time, so Mr. Justice Brown, going into the subject more thoroughly in Hobbs v. Beach, was unwilling to say that these words had any meaning.

In Hobbs v. Beach, supra, (C. D., 1901, 311; 94 O. G., 2357; 180 U. S., at page 399; 21 Sup. Ct., at page 416; 45 L. Ed., 586,) the Court was confronted more squarely than ever before with the question of what force should be given to these words. This question was one of those upon which the two courts below had differed, and if they were held to import full limitation to the form of the specifications and drawings, there was no infringement. It seems a fair conclusion from the opinion that Justice Brown found himself embarrassed by what had been said in the three last above cases, on the one side, and on the other by Mitchell v. Tilghman and the inevitable logic of the situation, which compelled him to say that the rule of going back to the specification for a qualification of the claim and for the elements of the combination "is equally applicable whether these words be used or not." He, therefore, while unwilling to say that they are "absolutely meaningless," did conclude that

it is difficult to say exactly what effect should be given to these words, and that

the authorities really throw but little light upon their proper interpretation, and finally concluded that

without determining what particular meaning, if any, should be given to these words,

they did not limit the patentee to the exact mechanism described, but that he was still entitled to the benefit of the doctrine of equivalents. In spite of the uncertainty shown by the language of the opinion, and on studying the specification and claim of the Beach patent and the scope that must be given in order to sustain the charge of infringement by defendant's device, and also the opinions of the courts below, it is difficult to see why Hobbs v. Beach is not a decision that a claim containing these words is entitled to the same breadth of benefit of the rule of equivalents as if the words were not there.1

1 In addition to the cases cited in Hobbs v. Beach, the Supreme Court had referred to the subject in Brown v. Davis (C. D., 1886, 69; 34 O. G., 435; 116 U. S., 237; 6 Sup. Ct.

Since Hobbs v. Beach, the Supreme Court has mentioned the question only once, so far as we find. In Singer v. Cramer (C. D., 1904, 688; 108 O. G., 1869; 192 U. S., 265; 24 Sup. Ct., 291; 48 L. Ed., 437) Mr. Justice White clearly indicates his supposition that the presence of this phrase in a claim did have a limiting effect; but what is said on this subject is without reference to Hobbs v. Beach, and is said after a discussion of the Patent Office proceedings and the limitations accepted therein had led him to the conclusion that the limited construction of the claim must be given. We do not think this case should be taken as a decision that the presence of the words necessarily imports a limitation. It may be usefully noted that in most, if not all, of those Supreme Court cases which give claims a broad construction and do not limit them to the form shown in the specification these words were present. (See (e. g.) Winans v. Denmead, 56 U. S., 15 How., 330; 14 L. Ed., 717; Clough v. Barker, C. D., 1882, 523; 22 O. G., 2137; 106 U. S., 166; 1 Sup. Ct., 188; 27 L. Ed., 134; Morley Co. v. Lancaster, C. D., 1889, 380; 47 O. G., 267; 129 U. S., 263; 9 Sup. Ct., 299; 32 L. Ed., 715; Hoyt v. Horne, C. D., 1892, 435; 59 O. G., 1764; 145 U. S., 302; 12 Sup. Ct., 922; 36 L. Ed., 713.)

In the decisions of this court, statements are to be found looking in both directions. In Stilwell Co. v. Eufala Co. (117 Fed. Rep., 410; 54 C. C. A., 584) Judge Day was illustrating the rule that a claim should be construed by the specifications, and cited some of the above-named Supreme Court cases referring to "substantially as described." So far as the case indicates, he did not, in reaching the result, place any dependence upon that phrase; on the contrary, the defendant's claim of non-infringement was overruled and the claims were given a construction sufficiently broad to cover defendant's apparatus. In Sanders v. Hancock (128 Fed. Rep., 434; 63 C. C. A., 166) it was said of this phrase that it "carried into the claims the description of the specification." Judge Severens again was only illustrating the propriety of a decision that when an element was named in a claim without description, except the name, resort should be had to the specification to see what the element was.

decision was intended as to the definite effect of "substantially as described" is evident from the fact that of the four cases cited by Judge Severens one (Stilwell Co. v. Eufala Co.) treated the point only incidentally as above noticed, two (Soehner v. Favorite Co., 84 Fed. Rep., 182; 28 C. C. A., 317, and Canda v. Michigan Co., 124 Fed. Rep., 486; 61 C. C. A., 194) contain no reference to the point,

379; 29 L. Ed., 659) and in Pope v. Gormully, (C. D., 1832, 360; 59 O. G., 471; 144 U. S., 248; 12 Sup. Ct., 641; 36 L. Ed., 423,) but in neither of these cases is the matter of any particular importance to the decision, nor is it considered upon principle or authority, nor in connection with the fixed Patent Office practice. See, also, Avery v. Case, (C. C., 139 Fed. Rep., 878; reversed, but not on this point, in 148 Fed. Rep., 214; 78 C. C. A., 110.)