after making the above statement, delivered the opinion of the court.
The art of making paper boxes requires that the better class, of square or other angular shapes, be stayed or reinforced at the comers, Avhere a union of the sides and ends is to be brought about by the application of adhesive strips of paper or muslin placed upon the .joints, and the corners thereby strengthened, before receiving their final covering of paper. Prior to. the Beach invention, the work of thus strengthening the corners of •paper boxes by these adhesive strips had always been performed in a tedious and irregular way by hand.
The Beach machine and its operation are thus described by the plaintiff’s exрert:
“ The machine consists of an anvil or lower die, having at the uppper portion two Avorking faces, Avhich diverge dowmvard from one another at a right angle. Working in connection with this anvil or die, and above it, is a vertical movable die or plunger, having also two diverging working faces, the working faces of the plunger forming a notch therein, Avhich notch cooperates Avith the upper portion of the loAver anvil or die, the dies being adapted to operate upon the right-angle comer of a box to compress the said corner betAveen the Avorking faces of *387 the opposing dies. A strip of paper suitable for the stay is fed by automatically moving mechanism over a pasting device, and between a pair of shears, and thence between the upper and lower die when separated. The operation of the machine briefly described is as follows: A box whose corner is to be strengthened by the addition of a stay strip is placed upon the lower anvil or die, the inside of the corner of the box resting upon the apex of the lower die. The machine as it is revolved then feeds forward the stay strip which has the paste upon it, and as the upper die descends the shears also operate, severing from the continuous stay strip a portion sufficient for the stay. As the cutting operation is completed the upper die or plunger is descending, and forces the gummed stay strip into position upon the outside of the box corner;'and the stay strip and box corner are pressed between the working faces of the two opposing dies, and thus the stay strip is caused to conform to, and be stuck upon, the corner of the box. "When the upper die or plunger rises, the box with its attached stay strip can be removed and another corner presented, when the operation will be repeated. The upper die or plunger is provided with a spring of rubber or metal, so that it may yield slightly in the direction of its motion, so that it may give an elastic pressure upon the box, and also be made to operate upon different thicknesses of box or stay-strips.”
“ Briefly, this description describes fhe machine, so far as it is necessary to dеscribe the same for the purposes-of this case. I must state, however, that the machine is also arranged to fold in the end of the stay strip within and into the interior of the box, and this it accomplishes by having the lower die longitudinally movable, and by supporting the box upon both the working faces of the lower die and upon the faces of the block within which the lower die can move. The faces of the upper portion of the die and of the block are arranged so that they form two planes at right angles to one another, the planes of the upper working faces of the die corresponding with the planes of the upper faces of the block. I refer to this capacity of the machine merely for thе purpose of showing that I have considered the same, but such capacity, that is, the ability to turn the end of *388 the stay strip in and over the edge of the box, is not a feature of the machine which need always be present. I quote as follows from the specification of the patent:
“ ‘In many boxes, the stay is simply pasted against the exterior surface of the box corner, and is not turned in or over, the edge of the same, in which case the work can be done by using a non-reciprocating angular lower die dr anvil, and a single upper die or plunger.’
“ From the above quotation, it will be clearly evident that the patentee contemplated using his machine in the simple form in which I have described it, and divested of that mechаnism which is involved when the stay strip is turned over the edge of the box and into the samé. As the issue in this case involves a mechanism which does not turn the stay strip over and into the box, I have deemed it best not to put into the record a description of the mechanism necessary to accomplish that result.”
The first claim of the patent is for (1) two opposing clamping dies, having diverging working faces; (2) a feeding mechanism which delivers the stay strip between the clamping dies, when the upper die is raised; and (3) a pasting mechanism. The clamping dies ai’e so constructed as to cooperate with one another in pressing upon interposed box corners the adhesive stay strips, substantially as .described.
The second claim also includes the opposing clamping dies with diverging working- faces; the same feeding mechanism, and a cutter for severing the continuous strip into stay strips of suitable length, substantially as described.
The third claim includes the same dies, the feeding mechanism, the pasting mechanism and the cutter; in short, a combination of all the elements of the two preceding claims.
The sixth claim includes the same clamping dies having the diverging working faces, one of which clamping dies is constructed to act with an elastic or yielding pressure, to enable the dies to operate upon box corners of different thicknesses.
The proofs show that Mr. Beach made application for his patent in June, 1885 ; that while pending in the Patent Office it was placed in interference with five other claims, and that the patentee was awarded priority of invention by the examiner of interferences, by the board of examiners-in-chief on appeal, and finally by .the Commissioner of Patents.. It also appears that, in a suit in the Northern District of New York, defended by two of the contestants in the interference proceeding, these three'claims were sustained by the Circuit Court, Beach v. American Box Machine Co., 63 Fed. Rep. 597, and on appeal, by the Circuit Court of Appeals for the Second Circuit. Inman Mamifacturing Co. v. Beach, 71 Fed. Rep. 420; S. C., 35 U. S. App. 667. Nor do we understand that in the case under consideration the Circuit Court for the District of Massachusetts differed from the New York courts as to the validity of the first three claims. Indeed, the learned Circuit Judge says expressly: “ On the questions of anticipation and the state of the art, we therefore follow the conclusions of the Circuit Court of Appeals for the Second Circuit.” The difference between him and the Circuit Court of Appeals, to. which this case was carried, related to the proper construction of these claims; and to the question of their infringement. Of course, we are bound to give to this question of anticipation an independent consideration. At the same time, we feel ourselves bound to defer somewhat to this unanimity of opinion upon the part of so many learned and distinguished judges, whose lives have been largely devoted to the examination of patent causes.
Taking up these prior patents, our attention is at once challenged to the fact that none of them covers a machine for attaching paper or muslin stays to the corners of boxes; and the question arises whether the uses to which these machines, are adapted are so nearly analogous to the use made of them by
*390
Beach that the applicability of the old device to the new use would occur to a person of ordinary mechanical skill, within the case of
Potts
v.
Creager,
It is sufficient to observe of the patents to Cohn of 1874, to Lieb of 1880, and of the English patent to Hadden of 1884, that they cover machines for stitching wire or attaching metallic stays, and that, while all three оf them have the clamping dies with diverging faces, they lack most of the other elements of the first three claims of the Beach patent. The possibility of adapting these devices to the attaching of gummed strips to the corners of paper boxes might occur to an ordinary mechanic, but could scarcely be carried into effect without the employment of something more than mechanical skill.
Most of the other prior patents relate to machines for making paper tags, wherein a piece or patch is gummed or cemented to the side of the tag to strengthen it; to preparing paper for covering paper boxes; to covering such boxes with pasted paper; to machines for making match or other paper boxes; forming heel stiffeners; shaping or working sheet metals, or addressing machines.
The. only patents requiring special notice are the Maxfield and Terry patents for making paper boxes, which relate to mechanism for pressing a strip of glued paper upon the edge of circular collar boxes at the junction of the bottom and sides, or rim, so as to form a union of the circular end with the cylindrical side of the box. The operation of the machines seems to be only partly mechanical, and differs so widely from the Beach patent that they can hardly be seriously insisted upon as anticipating it. It would seem from the specifications that a great part of the wоrk is done by hand ; indeed, in the Terry patent, it is said “ that the invention connects the circular parts with the strips, said parts forming the tops and bottoms and *391 sides of boxes; tbe remaining work, such as the pasting of the strip in one part, being done by hand, as also the covering of the boxes, if desired, with colored paper.” The machine is in no sense automatic, and if it were, its functions are so different from those of the Beach device it is clearly no anticipation.
None of these patents approximates so nearly to the Beach patent as that of Dennis and York’s addressing machine, which was the only one deemed worthy of special notice in the courts below. This relates to “ addressing machines in which a strip of pаper, with the addresses printed thereon, is run through the machine, the addresses cutoff in slips, and automatically affixed to the newspapers, envelopes, or other articles by a descending knife and platen.” The object of the invention is stated to be “ to change or adjust the feed automatically by the running of the machine itself so that addresses of greater or less width can b.e eat accurately'without attention of the operator, the machine adjusting itself accurately to the work to be done; and, second, to enable the addresses to be affixed to single sheets beneath the platen.” The machine has a feeding, pasting and cutting mechanism, combined with a vertical reciprocating plunger, armed at its lower end with a knife to cut off the addresses, and descending with a flat head upon a flat platen, a newspaper being interposed between. The bed on which the papers rest is called a “ follower,” and instead of being rigid, is supported upon light coiled springs and by lever action, so that it will move up and down freely and produce just enough pressure under all circumstances to receive the pasted slip upon the upper sheet. Being designed for light work it is not built with the solidity required for pasting strips upon boxes, and in other particulars differs from the Beach device.
In its operation, it approaches much more nearly to the Beach device than any other which has been put in evidencе, and we agree with ■ the Circuit Court of Northern New York that if this be not an anticipation, none of the others áre. By changing the flat head and the flat platen to clamping dies with diverging faces, and strengthening and changing the machine in some minor particulars, it could be used to fasten stay strips *392 to box corners. Indeed, a model of the Dennis and York machine, so altered, was put in evidence, and shown to be capable of doing the work of the Beach patent, though somewhat crudely and imperfectly. It is insisted that, as the only material change in the Dennis and York machine is the substitution of dies with diverging faces for the flat head and platen of that structure, this involves no invention, and that it would at once occur to a mechanic of оrdinary skill.
It appears from the testimony that several of these addressing machines, of which that of Dennis and York is a type, and which are now claimed to have inspired the Beach patent, had been upon the market for many years, and yet it never seems to have occurred to any one engaged in the manufacture of paper boxes that they could be made available for the purpose of attaching strips to the corners of such boxes. This very fact is evidence that the man who discovered the possibility of their adaptation to this new use was gifted with the prescience of an inventor. While none of the elements of the Beach patent— taken separately or perhaps even in a somewhat similar combination — was new, their adaptation to this new use and the minor changes required for that purpose resulted in the establishment of practically a new industry, and was a decided step in advance of any that had theretofore been made.
We agree that if the Dennis and York machine were designed for the purpose of attaching together the edges of paper boxes, where each surface was in line with the other, with the aid of flat dies and platen, it would require no invention, in view of other anticipating devices, to change this to dies with diverging faces for gluing boxes at their corners. But that is not all. Beach did not have before him a machine for attaching strips to the corners of pаper boxes, but a machine for attaching addresses to newspapers, and while there is an analogy, there can scarcely be said to be a similarity in these functions. We agree with the courts below that it did involve invention to see that a machine of the Dennis and York type was adaptable to the work of the Beach device, and, second, to make such changes as were necessary to adapt that device to its new function. With all the anticipating devices before us, it is apparent that *393 the mere change in the shape of the dies was a minor part of the work involved in so changing the Dennis and York machine as to make it perform a wholly different function, the invention consisting rather in the idea that such change could be made, than in making the necessary mechanical alterations. As stated by Judge Coxe in his opinion in Beach v. American Box Machine Co., 63 Fed. Rep. 597, “ the question is whether a mechanic before any one had thought of pasting stay strips to the corners of boxes by machinery, would construct the Beach machine after seeing the labeling machine. Would the latter suggest the idea and the embodiment of the idea ? Would the thought enter the mind of the skilled mechanic with the Dennis and York device before him on his work bench; and if it did, would it not be a creative thought whose presence would convert the mechanic into an inventor ? ”
In passing upon the question of novelty we feel at liberty to consider the fact that the Beach machine and its congeners have completely supplanted the former method of applying strips by hand; that no manufacturer can successfully compete for the trade without adopting such machine.; that it not only applies these strips with much greater rapidity than is possible by hand, but the work done is stronger, cheaper, cleaner and more uniform ; that the machine attaches the strip more rigidly about the corner, and that by reason of its greater compression forces out the moisture and dries the box, for immediate use; that there is also, a saving of material by cutting the strips of the proper length instead of tearing them, and that by reason of the greater compression heavier and stronger material may be employed than was рossible when the work was done by hand. We find no difficulty in holding that the first three claims of this patent were not anticipated by any prior devices.
What we have said regarding these claims applies with even greater potency to the sixth claim, which introduces a new feature of a clamping die constructed to act with an elastic or yielding pressure, to enable the dies to operate upon box corners of different thicknesses. While the mere introduction of springs to enable the plunger to act with an elastic pressure may not of itself have been a novelty, its introduction into a machine *394 which was itself .novel certainly did not destroy its novel character. The claim does not cover simply a die construсted in this manner; but the elastic feature introduced into one of opposing clamping dies, having diverging working faces, constructed to cooperate in pressing an adhesive stay strip upon an interposed box corner, was clearly novel; and while the introduction of this feature into an old and non-patentable machine may not itself involve invention, in this case it is merely an additional element introduced into a machine which did itself involve invention. This feature was introduced into Beach’s claim as early as May 4, 1886, by an amen'jnent to his specification, before the patent was issued, and hence could not have been inserted to cover the Horton patent used by defendants, which never was known to the tradе before 1889 or 1890.
All this was prior to the invention of the Horton machine, which was first put into use in September, 1889. Of course, the amendment of May, .1886, could not have been made with *396 reference to this device. It is true that, in November, 1890, after application had been made for the Horton patent, new specifications and claims were filed, in which the invention was stated much more in detail-, and with much fuller and more accurate language than before. But there appears to have been no attempt to expand the original claims for the' purpose of including the Horton patent.
The patent had been the subject of an earnest contest in the Patent Office for four years; had been put in interference with five other devices, and it was scarcely possible that, after this long litigation, the patentee should not have detected defects in his original application, and have taken this opportunity of correcting them. Ilis experience in this litigation had doubtless apprised him of the weak points in his prior specification and claims, and it was perfectly competent for him to restate them, provided his patent was not essentially broadened to cover intervening devices.
In
Railway Co.
v.
Sayles,
Had there been any expansion-' of the original specification *397 and claims subsequent to tbe introduction of the Horton machine, especially if made with reference thereto, we should not have hesitated to apply the doctrine of that case, but we see no evidence of an intent to cover that machine, unless it were already covered, and agree with Judge Lacombe, that “the original drawings and specifications suggest the claims finally made, which recognize and claim the two different operations of outside and inside applications.”
This reply to defendants’ assignment is so conclusive that we have not thought it worth while to inquire whether the Jaeger British patent and the Beach patent were for substantially the same invention. Nor do we find it necessary to express an opinion whether the lapsing of a foreign patent by the failure of a patentee to pay a renewal fee required by British law would shorten the term of his patent here.
Bate Refrigerating Co.
v. Hammond,
The blade of the cutting mechanism cоnsists of the inner edge of the plunger operating in connection with a portion of the frame of the machine. As the Horton machine is only intended *399 to apply stay strips to the exterior of a box, all the mechanism shown in the patent which specifically relates to the turning in of the stay strip within the box is absent. The principal difference between the two devices consists in the details of the mechanism, and in the fact that under the Beach patent the stay strip is fed at right angles to the line of the opposing dies and the corner joint of the box, while in the Horton machine the stay strip is fed on a line' parallel to the line of the box corner, in other words, a back feed instead of a side feed; but they are both alike in that they grasp the paper and project it forward over the corner of the box when the dies are open. There is also a dissimilarity in the fact that the lower clamping die of the Horton machine is not movable into and out of its usual working position, is not moved when the machine is in operation, and is made movable only for the purpose of adjustment; but as the device is only used for the purpose of applying stay strips to the exterior of the box corner, such movability becomes unnecessary, or, as explained in the Beach patent, “ the said anvil I is herein shown as constructed to move horizontally and as extending through a horizontal bearing aperture a in the frame, by which it is supported, a horizontal movеment being given to the said anvil to aid in turning in or pasting stay strips to the inside of the box corner.”
In the case of a pioneer patent like this, (and while the patent is not a great one, we are not speaking too highly of it in calling it a pioneer in its limited field,) there would be no difficulty in holding that these differences were immaterial, were it not for the fact that each one of the claims is limited by the words “ substantially as described.” In other words, that unless the infringing device contains mechanism substantially such as is described in the patentee’s specification, and shown in his drawings, there can be no infringement. It was upon this point, and upon this alone, that there appears to have been any difference of opinion between the Circuit Court and the Court of Appeals. While the words “ substantially as described or set forth ” are not absolutely meaningless, they do not limit the patentee to the exact mechanism described in his specification, or prevent recovery against infringers who have adapted mechanical equivalents for such mechanism. In determining the range of such
*400
equivalents much depends upon the question whether the machine is a primary one, or whether the patent covers some novel feature introduced "into an old machine. It is difficult to say exactly what effect should be given to these words. In one sense it may be said that no device can be adjudged an infringemeiit that does not substantially correspond with the patent. But another'cоnstruction, which would limit these words to the exact mechanism described in the patent, would be so obviously unjust that no court could be expected to adopt it. The authorities really throw but little light upon their proper interpretation. In
Seymour
v. Osborne,
Without,determining what particular meaning, if any, should jbé given to these^ words, we are of opinion that they are not to be construed as .limiting the patentee to the exact mechanism
*401
described; but that he is still entitled to the benefit of the doctrine of equivalents, and that it is still true, as observed in
Morley Sewing Machine Co.
v. Lancaster,
The Horton machine not only accomplishes the same result as the Beach device, but accomplishes it by the employment of the same combination of the same elements. The mere-fact that the continuous strip is introduced between the dies from a different direction is immaterial. The fact that the Horton device contains no mechanism for turning the strip in.to the inside of the corner, merely indicates that it does not perform all the functions of the Beach patent. But it is no less an infringement' if it performs its primary function in practically the same way. We are not concerned with the subordinate differences in the mechanism;, leаst of all with the different names given by Horton to parts of his machine similar to the corresponding parts in the Beach patent. As -the two machines are alike in their functions, combination and elements, it is unnecessary to go further and inquire whether they are alike or unlike in their details.
There seems to be no denial of defendants’ infringement of the sixth claim. Plaintiff’s, expert testifies that he finds “ in the defendants’ machine two opposing clamping dies having diverging Avorking faces, the upper one of which is constructed to act Avith an elastic or yielding pressure to enable the die to operate upon box corners of different thicknesses. This is the combination referred to in the sixth claim, and it is found in. the defendants’ machine.” We do not find this to be denied. Both the Circuit Court and the Court of Appeals found this claim to have been infringed, and we accept their conclusion.
The decree of the Court of Appeals is therefore
Affirmed.
