Court Opinion

ID: 8639898
Source: CourtListenerOpinion
Date Created: 2022-11-24 19:51:28.98006+00
Date Added: 2024-06-11T16:56:03.969510
License: Public Domain

WOODRUFF, Circuit Judge.
These suits are prosecuted for the alleged infringement of patents granted to the complainant, and seek an injunction and an account of the income derived by the defendant from such infringement. The patents in question are for improvements in grass and grain harvesters. The first original patent was granted December 5th, 1854, on an application filed March *88816th, 1854, and is numbered 12,044. This patent was surrendered in November, 1859, and reissues were granted for several separate and distinct parts of the improvements claimed to be embraced in the original patent, and such reissues were dated January 3d, 1860, and numbered 875, 876, 877, 878, and 879. Of these reissues, one, No. 876, was again reissued Hay 14th, 1867, and numbered 2,610. The second original patent was applied for September 20th, 1854, and was granted on the 6th of February, 1855, and numbered 12,367. This patent was also surrendered, and, on the 28th of May, 1867, was reissued, numbered 2,632. These suits are brought upon the said two original patents, as reissued under the numbers 875, 877, 879, 2,610, and 2,632. The bill in the first suit alleges infringement of reissues 875, 2,610 and 2,632; and the bill in the second suit alleges infringement of reissues S77 and S79. The answers in each suit are substantially the same, the proofs taken in each,' so far as pertinent or applicable to each, are the same, and the suits were brought to a hearing and argued together.
The defendant insists upon the invalidity of the complainant’s reissued patents, upon want of novelty in the distinguishing features of the complainant’s alleged invention and upon a denial that the defendant has infringed the patents in any particular in respect to which the complainant’s patents can be sustained, if sustained at all. My examination of the patents and of the proofs has led me to a different conclusion upon all of these grounds of de-fence. I shall not probably find time to write in detail my analysis of the patents, discuss the particular proofs, and give the reasoning which brings me to the result. I should be pleased to do all this, and it would be of some convenience to counsel on the. review which, I assume, eases of so much importance will hereafter receive. But, other cases require my attention, and I shall do little more than indicate my opinion on the points chiefly argued by the counsel.
(1) The first ground upon which the complainant’s reissued patents are assailed is, that the original patent of December 5th. 1S54, was void, for two reasons: 1st. That the invention therein mentioned was never reduced to practical use; and, 2d. That the machine, as described and shown in the original record, was not susceptible of being reduced to prae-: tieal operation.
On the argument, it was insisted, that a patent is void, if the patentee did not reduce the invention to practical use before the patent was obtained. This proposition is wholly unsound. No such condition is required by the act of congress; and, if it were true that a patent would be void on that ground, no patent could properly be granted, unless proof was furnished that the invention claimed had gone into practical use, which is not and cannot, under the statute, be made a condition of granting the patent. It is enough, that the inventor has perfected his invention, and is able to furnish to the patent office such specifications and model as the law requires. Having done this, the patent, in so far as prerequisites to its validity, either by way of experiment or use, are material, is valid. 3
But, the terms of the brief before me are, that the “patent of December 5th, 1S54, was void, because it was never reduced to practical use.” This includes, perhaps, the idea, that the patent became and is now void, and was void when it was surrendered and reissued in several divisions, as above stated, because the invention described therein has never, since the patent was granted, been put into practical use. This is an argument, not that the patent was originally .void, but that, through the neglect of the inventor, it has become invalid. It involves the idea of abandonment of the invention. The statute requires that an alien shall put, and continue, on sale to the public the invention or discovery for which he receives a patent, but it contains no such provision in relation to the patentee, when a citizen of the United States. If an invention is not so far perfected as to be adapted to use, that is to say, where the invention is of a machine, or part of a machine, and is not so far completed, that, when constructed, it will produce the desired effect, then, indeed, no patentable invention has been made. But, if the invention be such, that, when the thing invented shall be constructed according to the model and specifications filed, it will operate successfully as a practical and useful thing, the inventor has satisfied the law, and his patent is valid. He is not bound, by law, to construct it, in order to preserve his patent.
(2) This leads to the second of the defendant’s reasons for insisting that the patent of December 5th, 1854, is void, namely, that the machine, as described and shown in the original record of the patent, was not susceptible of being reduced to practical operation. If, by this, is simply meant, that a machine, or a device, that cannot be reduced to practical operation and use without the aid of further invention, is not patentable, there is no occasion here for calling it in question. On the other hand, if it be meant, that no device is patentable which has not in itself, apart from any connection with, or application to, other known devices or instrumentalities, capacity to produce practically useful results, then the proposition is not true.
*889Patents for simple devices, and patents ior parts of machines, are almost numberless, of which it may be truly said, that it is only by connection with other devices or instrumentalities, to which they are intended to be applied, that they can be made to produce any result whatever. True, the patentee is bound to disclose a mode in which they may be rendered practically useful, and it may be one of many modes, and it may necessarily involve the use of many other known devices which are required in order to the useful result. Patents may be granted for combinations, in which some of the parts are old and some are new, and whatever in the several parts is new may be separately secured to the inventor; and yet it may be true, that only in the combination described, or in some similar combination, is the new part thus secured to the inventor of any practical use whatever.
(3) This brings into view the defendant’s claim, that the several reissues of the original patent of 1854 are void, because they are not for the same invention as that described in the original patent record. The original patent embraced, as an aggregate combination, several parts of the entire machine described in the specification, and claimed such aggregate as the invention of the complainant. These parts were all shown in the specification, drawings and models. 1 know of no rule which forbids the inventor, who has omitted to claim separate new devices, or severable and distinct combinations, In the original patent, making a surrender, and taking reissues for the distinct combinations or separate devices. Prom the fact of surrender and reissue, it is to be inferred, that the original patent did not secure to the patentee all that he claims in the reissue; but, that alone does not render the reissue void. If the devices covered by the reissues were, in fact, new and useful, and if they .are shown in the original specification, drawings, or model, then the patentee is entitled to secure the exclusive use of each separately, by a reissue embracing each.
Again. The claim that the original patent of 1854 was void because the irivention therein described was not susceptible of being reduced to practical operation, gains its importance to this controversy from the inference sought to be drawn therefrom, namely, that the several reissues are. therefore, void. These suits are not founded on the original patent, but on the reissues; and the claim is, that, if the orisinal patent was void, because the machine therein described was not capable of reduction to practical use. therefore, the reissues are themselves void. If the premise were here conceded, I do not think that the inference necessarily follows. For example — suppose an inventor of several distinct new devices, or of several new combinations, each capable of being usefully employed in and towards a machine or various machines, and that their separate construction and mode of operation is fully apprehended, and the distinct office or function of each is appreciated — such inventor may, undoubtedly, have a patent for each. Suppose, now, he erroneously conceives that he has arranged a combination of all of them, or a combination of all of them with other known devices, so as to produce a new and useful machine, and for such a machine he applied for and obtains a patent, describing and illustrating all the several new devices, or separate combinations of devices, their construction, and operation, but claiming only the aggregate machine. Such aggregate machine may be utterly useless; the patentee is wholly mistaken in regard to the practical operation of the whole; it will not produce the result for which it was intended, nor, in its aggregate form, any other useful result. Does the inventor, in such case, lose the benefit of his skill and ingenuity in producing devices, or combinations of devibes, which are of practical value, because he first sought his patent in the form of a useless or impracticable combination? I apprehend not. He may surrender his original patent, and have it reissued in parts, which shall claim the respective new and useful devices or combinations of devices, pointing out, of course, in his specification, some mode or manner in which they may be reduced to practical use and value. He might have done this in his original patent, and claimed each separate new device as his invention. Not having done so, he may do so in his application for reissues and his specifications therein; and the fact, if it be true, that his original patent was defective, because he claimed therein the aggregate combination, and that a useless or impracticable one, no more impairs the validity of the reissues, than any other defect or invalidity which makes a surrender and reissue necessary to protect the device or devices which are useful, and which were in fact invented.
These observations upon some of the legal grounds upon which the complainant’s patents are assailed, are made in order to exclude the idea that they are assented to, and not because I find, as a fact proved in the cause, that the machine described in the patent of December 5th, 8S54, was not a practical and. within the meaning of the law of patents, a useful machine. I find the contrary. Doubtless, when viewed in the light of subsequent improvements, it was imperfect, but it was a very large advance upon machines for mowing theretofore attempted. It is one of the embarrassments to which early inventors are constantly subjected, that other persons, availing themselves of the substance of the invention, make improvements thereon, which measurably hide the merit of the original; and, if the right of a patentee to protection were to be tested by the question, whether, in the present state of the arts, his invention (without improvement) would be deemed of any value, or be saleable *890for use, very many authors of most Important inventions would be turned out of court.
(4) The principal ground upon which it is claimed, and attempted to be. proved, that the machine, as described and claimed in the original patent of December, 1854, was not susceptible of reduction to practical use, is, that the socketted piece receiving and holding the finger-bar, (or cutter-bar,) at the inner end, though called a shoe, m, in the re-issued patents, was not a shoe in fact — it had no toe; and it is, therefore, said, that, if it encountered an obstruction in its path, it would not slide over it, but must stop the machine, or the cutter-bar be wrenched from its connection with the frame; and, further, as the rear of the supporting-frame was described as resting on a caster-wheel, midway the sides of the frame, in the line of the cutter-bar, it is certain, that, whenever the caster-wheel passed into a depression in the ground, existing only in its own line of travel, this socket-piece, misnamed a shoe, would come to the ground, and, for want of the curved toe, would plough into the ground, and stop the machine, or wrench the bar, as in the other case.
Now, in the first place, the socket-piece holding and supporting the inner end of the cutter-bar, is, in fact, shown to have its under surface curved or rounded up at its front. It is so shown in the model furnished, before the patent was granted, on the requirement of the patent office, and made on an enlarged scale for the express purpose of exhibiting this particular part of the machine. It may be true, that if, in its path, it met an obstruction higher than the curve of the under surface, its progress would be hindered, but the same is true of the finger-guards (which may properly be likened to small shoes), all along the length of the cutter-bar. If they meet an obstruction higher than their points, some means must be employed to raise them, or they will stop the machine, or plough into the ground. In reference to the path of travel, either of the shoe or socket-piece, or of the finger-bar, at any point therein, such an obstruction might happen; but, such a liability does not render the machine impracticable. No machine has been hitherto constructed which may not encounter such an obstacle, at some point in the path of the cutter-bar. The subsequent addition of the curved toe (which ordinary mechanical judgment would suggest, without the aid of invention), as it appears in the patent of 1S55, and as the complainant’s machines appear to have been, in fact, constructed, was, doubtless, an improvement, (though not a further invention;) but the machine would mow upon level prairies, or other smooth ground, and upon ground containing only slight elevations and depressions, without the toe. A machine cannot be pronounced useless or impracticable, because it is susceptible of improvement which will obviate or prevent embarrassments to its most perfect operation. If it could, then it would be the duty of the courts to pronounce the patent for any machine void, so soon as ordinary mechanical judgment, or even ingenuity, had suggested an improvement which made it perform its desired office more rapidly or more-perfectly.
So, in regard to the suggestion that the caster-wheel at the rear end of the supporting-frame (which ordinarily bore this socket-piece or shoe very slightly above the surface)might pass into a depression in its own path, and bring the socket-piece to the ground, and so the finger-bar would be influenced by irregularities in the ground, not in the path of the cutters. If this be so, it only points to-another particular in which subsequent experience has taught that improvement is possible. The objection is itself greatly exaggerated. In any machine which has been produced on the trial, wherein the finger-bar conforms most perfectly to the undulations of the ground, if either end passes into a depression, there is a liability to bring the bar and cutters, at some intermediate point, to-the ground. The most that can be truly claimed, adverse to the complainant’s original machine, in that respect, is, that the path within which such a depression is liable to affect the undulations of the cutter-bar is a little wider than if, instead of the caster-wheel between the ends of the frame, a wheel was placed at the inner end of the cutter-bar, or the shoe or socket-piece was furnished with the curved toe-before mentioned.
What I before said on the subject of making an improvement, is apt to this point; and I am clearly of opinion, that it would be a-great perversion of the law, as it would be a most unwarranted assumption of fact, to hold,, that these criticisms of' the complainant’s-patent were a defence, or that the complainant’s patent was void, because it described an impracticable or useless machine for mowing.
In thus overruling the objections above stated. made by the defendant to the patent of 1854, I recognize and concur with the defendant in the claim, that that patent derives no-aid or support from the patent of February, 1855. Each patent must stand or fall by itself. It is, however, pertinent to say, that,, in no just view of the duty of the patentee to reduce the patent of 1854 to practical use, could the incorporation of the improvements of 1855, in the machine, when constructed, impair the validity and effect of such patent, if it was, as, in fact, I find it to have been, without such an improvement, a patentable machine.
And. once more, that the function of a shoe was indicated in the model of the socket-piece, m, by its curved under and forward surface, has already been stated; and, that such a function was in the mind of the patentee, even if, in its original structure, it was imperfect, is shown in the almost contemporaneous prolongation of the curve, by the addition of the toe. In considering that fact, it must be borne in mind, that a shoe, to assist in slid-*891mg' an object over the ground, was no new invention. It was a common, and may, I think, be declared an obvious, aid to that operation From the large drogue, or stone-boat, having a similar function, through the shoe applied to coach or wagon wheels, to slide the vehicle (there retarding motion), down to its smaller and other varieties, including application to attempted mowing-machines, it was a common device. Ordinary mechanical judgment would suggest its use; and, had the complainant, in his patent, claimed anything as invention, in the function of a shoe, assigned to the socket-piece, m, as a distinct subject, such claim would have been invalid. He did assign to the socket-piece that function, and it exhibited that capacity, in some degree, in the model. It was, therefore, no departure nor enlargement of the patent of 1854, to exhibit the same well-known function by reference to the like well-known curved under surface, more perfectly developed in the subsequent reissues.
(5) In regard to the novelty of the complainant’s invention, it is quite impossible for me to write at length an analysis of the various attempts at the construction of a useful mowing-machine, prior to his invention, in any similar form, or by similar devices. Counsel have, with great ability, done this, in their elaborate, and valuable arguments, which have been preserved and printed; and I should be compelled, to a large extent, to re-write what they have skillfully done, as an aid to the court. My conclusion is, that none of the previous machines or inventions impair the validity of the complainant's patents, in any of the claims of which I deem the defendant to be an infringer.
(6) On the subject of infringement, it is claimed, that the absence of the caster-wheel at the end of the vibrating frame to which the finger-bar is hinged, not only distinguishes the Clipper machine constructed by the defendant, but assigns it to a distinct class of machines, substantially and radically different, in their organization and operation; and this, upon the suggestion, that, in the complainant’s machine, as patented in 1854, the caster-wheel carried the end of the vibrating frame, and that carried the inner end of the cutter-bar, the latter being raised or lowered by the frame, and the frame being raised or lowered by the caster-wheel, according to the undulations in its path, while, in the Clipper machine, the inner end of the cutter-bar rests on a shoe, following the undulations of the ground, raising and lowering the vibrating frame, according to those undulations in the path of the shoe. Within certain limits, this is true. When the path of the caster-wheel was such that the shoe or socket-piece, holding the finger-bar. did not touch the ground, the end of the vibratingframewas sustained by the caster-wheel, and rose and fell with it; but. -when inclination of tne ground was such that the socket-piece bore upon the ground, and performed (whether more or less perfectly) the function of a shoe, then the shoe sustained the end of the frame, and the latter rose and fell with the undulations over which the shoe passed, as it confessedly does, in the Clipper machine. Thus, the complainant’s machine had both features. The one caused by the presence of the caster-wheel nray have been a disadvantage, but its omission, while the other substantial features of the complainant’s invention were appropriated, cannot be said to constitute the Clipper machine a new machine in organization, and in its principle and mode of operation, though it were conceded that the omission of the caster-wheel, at the centre between the ends of the vibrating frame, is an improvement.
(7)Without attempting, by further writing, to discuss the many other considerations and particulars urged in behalf of the defendant, none of which have, I think, been overlooked by me, although not here noticed, I pass to a very brief consideration of the claims infringed by the defendant’s Clipper machine.
The first claim of the reissued patent No. 875 is, “In combination with the hinged bar, H, and the finger-bar, the intermediate shoe, m, hinged to said bar, H. substantially in the manner and for the purpose set forth.” The only ground upon which it seems to me possible to question the infringement of this claim by the Clipper mowing machine, is by maintaining that the Clipper does not contain the hinged bar, H, and, therefore, does not use the shoe, m, in the combination described.
It is, certainly, true, that the circular or curved plate used by the defendant in the Clipper, to cause the finger-bar to oscillate, is, in appearance and form, very unlike the hinged arched bar, H, which is used for the same purpose in the complainant’s machine; and it is, also, true, that the hinged arched bar performs, in the latter machine, an office of which the Clipper’s curved plate is incapable, namely, the office of bracing or strengthening the vibrating frame to which, on each side, it is attached. It is the single instrument for oscillating the cutter-bar, and, at the same time, giving strength to the frame. In the Clipper mower, the same two results are effected in a different form. The curved plate is the means of oscillating the cutter-bar, but it lies lengthwise, instead of crosswise, the frame; and an additional cross bar. from one side to the other of the frame, gives it firmness and strength. The two perform precisely the same functions, and all the functions of the complainant’s hinged bar.
A patent for a device cannot be avoided by dividing it into two parts, which, when combined, produce the same result, in substantially the same way. That the defendant's cross-bar does strengthen the vibrating frame, by a firm connection between its two sides, and in substantially the same way as the curved bar, H, strengthens the frame in the complainant’s mower, seems to me quite clear. If. then, the curved plate in the Clipper performs the same office in the oscillation of the cutter-bar, and in substantially the same way, then the defendant uses the *892mere equivalent of the complainant’s hinged bar. That hinged bar turns on a bolt, acting as a pivot, or centre of motion. The defendant’s curved, oscillating plate turns on a centre of motion, about which it is made to turn, not by a bolt through that centre, but by being hung to bolts arranged in a -curve around such centre, and moving in curved slots in the oscillating plate. The testimony shows, and it seems to me obvious, that this device for oscillating or rotating the curved plate, is the plainest mechanical ■equivalent for a rotation on a bolt at the eentre; and that they are commonly and readily substituted the one for the other, whenever any incidental or collateral purpose makes one preferable to the other. For all the purposes for which the complainant’s curved-bar was used, in either the support or the oscillation of the finger-bar, this device ■of the defendant is an equivalent.
True, a collateral purpose made the defendant prefer a motion on bolts and slots curved so that the plate would rotate thereon, instead of on the bolt in the centre. That purpose was this. It was desired, and the use •of the curved plate, set lengthwise of the frame, made it necessary, to pass the rod or pitman, which moves the knives, through this curved plate, and that cut away the centre. But, this only made the choice of an equivalent mode of effecting the rotation a necessity. The defendant could not (if the precise arrangement of the Clipper in other respects was adhered to) rotate the oscillating plate on a bolt in the centre, and, therefore, used curved slots, made around the centre, and bolts, on which the curved slots should move. I concur fully with the witness Mr. Renwiek, in his testimony on this point.
It is urged, that the oscillation in the two machines causes the two finger-bars to turn on different lines, as centres of oscillation. No doubt, there is a slight difference in that respect. But, it would be trifling with the subject, and making the rights of- a patentee in general valueless, to hold that this deviation protected an infringer. ' The substantial purpose, and the substantial result is, to raise and lower the points of the cutters, according to the desire of the operator, when passing over ascending or descending ground. This is done in both, and by substantially the same means. That the centre of motion in that raising and lowering of those points is not identical, is not of the least importance. In one, that centre is an inch or two higher than in the other, and that is all. I cannot regard this, on the question of infringement, as of the slightest significance. I greatly doubt whether this feature in the Clipper is even an improvement. If it be, it is, nevertheless, in the just sense of the law of patents. an appropriation of the complainant’s invention, in the combination described in the claim under discussion.
The third claim is, ‘The shoe, m, as a hinge and a support both, to the cutter-bar, substantially as described.” This is the part above called the socket-piece or shoe. In its socket it receives and firmly holds the inner end of the cutter-bar, and, by its hinge, it attaches it to the oscillating bar at the end of the vibrating frame. That such a device was never used prior to the complainant’s invention, I find, from the evidence. That the Clipper mower uses this device, is entirely clear. In both machines, it receives the finger-bar in a socket, and holds and supports it. In both, it is hinged to the oscillating piece; and, by its hinge, the outer end of the finger-bar is permitted to rise and fall, to adapt itself to the undulations of the ground. The only difference, worthy of notice is, that its forward edge or side is, in the Clipper, elongated and curved upward, in the more perfect form of a shoe. On that difference I have already observed, at some length, and will not here repeat my observations. I may add, however, that it- partakes rather of the character of difference in degree than difference in function, although, in the complainant’s machine, this function of the device is imperfectly performed, and, in some situations, might not be effective. Besides, this court, on a former occasion,—Sarven v. Hall [Case No. 12,369],—held, that a device is not less an equivalent of another, merely because, superadded to all the functions of such other, it may perform a further office. Still less does it fail to be the equivalent of another, because, besides all the functions of such other, it performs some one of the offices more effectively or better, so long as it performs them in substantially the same way, and uses substantially the same means.
The fourth claim of this reissue is for “the socket or recess, n, in the shoe, m, for the reception of the finger-bar, substantially as described.” If this be interpreted as claiming, simply and broadly, a socket, in whatever is designed to receive and hold the finger-bar at its inner end — a mere socket or recess of the form and capacity of that described-then it was not new; it was old, not only in itself, but in its application to this purpose. Whoever provides a proper device to which to attach the inner end of the finger-bar, without, in other respects, infringing the complainant’s patent, may make therein such a socket as the complainant has made, and may insert the finger-bar therein. If the claim be interpreted to mean the socket in the shoe, m, as a combination in substance as the complainant made it, so that it embraces, at the same time, the features of that shoe, then what has been said on the subject of the third claim also embraces this.
The claim in reissue No. 2,610 is as follows: “I claim, in combination with a harvester frame, that is free to vibrate about a gear centre, a laterally projecting finger-bar. so hinged to one end and comer of said frame, as to permit the finger-bar, at each end, to follow the undulations of the ground over *893which it is drawn”; and the claim number two of reissue No. 2,632, of the patent of February 6th, 1855, is for “The combination of a vibrating frame with a cutting apparatus hinged thereto, a driver’s seat, an arrangement of one or more levers, whereby the driver in his seat can raise and sustain the cutting apparatus, when desired.” One of the defendant’s objections applies alike to both of these claims — First, that they are invalid because too broad. If they must be read as claiming any and each possible mode, and every possible instrumentality, by which the result can be attained, there is force in the objection. But, they are both definite combinations, wherein none of the parts are claimed separately, or treated as new. Thus, the first is a combination of a harvester frame, free to vibrate about a gear centre (of which it may be assumed, for the purpose of testing this claim, that many were well known), with a laterally projecting finger-bar, hinged to one end and corner of said frame, so as to .permit the finger-bar, at each end, to follow the undulations of the ground over which it is drawn (which, also, for the purposes of the test, may be deemed already well known). This combination was new, and it is this combination which the patentee claims. If he had claimed any and every finger-bar which might be so hinged as to permit it to follow the undulations of the ground, the objection of too great generality might be pertinent. Bead in connection with the specification itself, I do not think the claim is objectionable; and this same combination is not found in any prior invention.
The other claim is still more clearly for a specific combination, to which like observations are applicable.
Second, it is insisted, that the claim in the reissue 2,610, above named, is proved to be invalid, by evidence that the combination there professedly described, as -exhibited in the specification, drawings and model of the original patent, will not produce the result stated, that is to say, the finger-bar, as the machine is shown in the record of the patent and the model, will not, at each end, follow the undulations of the ground over which it is drawn. The claim is, therefore, said to be liable to two objections: 1st. That the reissue seeks to extend the patent beyond the invention shown by the record of the original; and, 2d. That the claim is only for a conceived result, which cannot be accomplished by the instrumentalities referred to in the specification, drawings and model.
Whatever may be true of the legal propositions involved in these objections. I apprehend. that, when the claim is justly and reasonably interpreted, it is not liable to the criticism which they assume to be well founded. The fact is, that, as a general rule, each end of the finger-bar is permitted, as the claim states, to follow the undulations of the ground over which it is drawn. On exceptional occasions, the caster-wheel may pass over an elevation which is of so-limited an extent that n does not reach the inner end of the finger-bar, in which case it will not be exact to say that such inner end follows precisely the undulation of the-ground over which it passes. But, the same-strictness applied to any finger-bar would lead to the same necessary concession, that, in some part thereof, in special and exceptional instances, it does not follow the undulation of the ground over which it passes. When one end -passes over an elevation, it is raised, in the centre, from the ground. When the centre passes over an elevation, one end or the other is raised from the ground over which it passes. The claim here should be taken to express nothing more-than the general rule of the operation of the machine in this respect. Undulations in a field are not like possible casual obstructions (as by a stone, or a stump, or the like); the caster-wheel is not remote from the innei end of the finger-bar, and, in passing whatever can be properly called undulations, the arrangement does permit that end to follow them. The argument of the defendant, and, to some extent, the testimony, confound such obstructions as are above mentioned, and possible holes in the path of the caster-wheel, with an undulating surface, in respect to which the claim in question states the truth, and gives the general operation of the combination included in .the claim.. That there may be special, possible or occasional exceptions, ought not to, and does not, destroy the truth of the claim as stated, nor impair its validity. It must, I think, be conceded, that the defendant’s criticism of this claim has something of foundation in an exact literal interpretation of its language. At first, it seemed to me sufficient to raise a doubt whether the claim should be sustained; but, consideration of the subject matter, and of the general practical operation of the machine over undulating surfaces, leads me to the conclusion above stated, and that, to construe the claim so strictly and narrowly as the defendant requires, would be giving force to letter instead of substance, would be unreasonable, would be adopting a needlessly rigid construction, warranted only by a disposition hostile to patentees, and not inclined to reasonable fairness. As to the arrangement of levers, mentioned in the claim in reissue No. 2,632, above stated, it must suffice to say, that the proofs, as well as my examination of the machine put in evidence, tend strongly to the conclusion, that, although the defendant’s machine contains a decided improvement, by which, with a single hand, what is, in substance, two levers, may be operated, yet their mode of operation and their mechanical construction, widely as they differ in form, are substantially the same, and that their combination, in the Clipper machine, so as to be operated at a single end or handle, is to be regarded as an improvement only. Viewed separately from this combination, one, by means of an upright attached to the *894shoe, m, connected to the lever by a linked connection (in substance, in relation to the operation contemplated, a chain;, raises the outer end of the cutter-bar; the other, connected with the ground as a fulcrum, by the intermediate parts of the structure, raises the end of the frame, and, with it, the inner end of the finger-bar, when desired. Though there is room for some doubt, my conclusion is in conformity with some of the evidence, that the one system of levers is the mechanical equivalent of the other.
[For other 'cases involving this patent, see Wheeler v. McCormick, Cases Nos. 17,498 and' 17,499.]
The claims in the patents alleged in the second suit to be infringed by the defendant, are the first claim in reissue No. 877, and the single claim in reissue No. 879. The first is as follows: “So hinging a finger-bar, by one of its ends only, to the main frame, as that it may oscillate or turn around its longitudinal axis, for the purpose of raising or lowering the points of the fingers, to adapt the machine to the condition of the ground, or of the crop to be cut, substantially as described.” Nothing in the evidence warrants the suggestion that this was not a new invention; and it is not possible to deny that the Clipper machine has the capacity to oscillate the finger-bar, so as to raise or depress the points of the fingers, for the purpose mentioned. If, then, in the Clipper machine, this capacity to oscillate is effected in substantially the same way, and by substantially the same means, as are described and shown in the complainant’s patent, the defendant infringes this claim. What has already been said in relation to the first claim in reissue No. 875. is, perhaps, sufficient to dispose of this question. The hinged bar, H,. there mentioned, is the means or instrument by which the finger-bar is connected with the main frame, so that the oscillation becomes practicable; and this present claim is infringed by the use of a substantially like instrument, operating in substantially the same manner, or, to use the language of this claim, “substantially as described.”
But, the defendant insists that the finger-bar, in the Clipper machine, does not turn on or around precisely the same axis as in the complainant’s machine. This, according to the testimony, is true. In the latter, the centre of oscillation is a little higher than it is in the Clipper mower, the oscillation is more nearly a swinging motion than a turning on its own cen-tre; while, in the Clipper mower, the oscillation partakes more nearly of the latter character. But. can it be said, that, in relation to such a subject as this, that difference js substantial? With reference to the object in view — the raising and lowering of the fingers, which is the sole useful purpose contemplated — the effect is identical. The means, according to my opinion, expressed in discussing tne other reissue (No. 875), are substantially the same, and they operate probably not in the same geometrical curve, but, in substance, in the same manner. To hold otherwise, would be to give to immaterial variations capacity practically to destroy the value of any patent whatever.
Reissue 879 exhibits the single claim, “In combination with a cutter-bar. the shoe, m. and its hinge, and a supporting piece, and its hinged connection to the main frame, the arranging of the pivots of said hinges at right angles to each other, and in or near the line of the finger-bar. as described.” It is quite unnecessary to enlarge upon this claim. That the pivots referred to are arranged, in both machines, as therein described, is unquestionable. If, therefore, the defendant’s Clipper machine employs, in substance, the shoe, m, and its hinge and the supporting piece, H, and its hinged connection to the main frame, the conclusion that this claim is infringed is inevitable. I have already expressed the opinion, that the Clipper machine does, in substance, employ both, or what is a mere mechanical equivalent; and it follows, that, the described arrangement of the pivots of the hinges being the same, the defendant infringes the reissued patent in question. Without going into the discussion of further details. I am of opinion, that the complainant is entitled to a decree in conformity with the foregoing opinion.

 Counsel, in arguing that an invention must be reduced to practical use before a patent is granted, or the patent is void, must, I think, have meant to claim no more than that it must be reduced to some private or experimental use, practical in kind, but distinct from a public use. If not. then the unsoundness of the proposition is quite obvious, since, under the former law, the public use of the invention defeated the subsequent patent, and could be set up as a defence, by an alleged infringer: and the same is true under the present law. if the machine patented have been in public use for more than two years. Note by Woodruff, Circuit Judge.