"Immediately above the stretcher bar B is arranged a stationary card, E, which is attached to the ends of the stretcher bar B by means of thumb screws. (Not shown in [404] drawings.) *The points of the teeth of the card E are close to but do not touch the surface of the skin, so that the hair and fur are both straightened as the skin is fed forward. The teeth of the card E hold down the fine fur, but permit the stiff hairs to stand up between the teeth, owing to the slow forward movement of the skin, which gives the hairs sufficient time to adjust themselves. "Below the stretcher bar B is arranged a rotary separating brush, F, which is supported in oscillating arms F', that are guided by pins f, in arc-shape slots f' of fixed guide plates f, as shown clearly in Figs. 1, 2, and 3, the oscillating arms F' being pivoted to horizontally-reciprocating connecting rods F2, which are provided with yokes f3, having anti-friction rollers at their rear ends, and acted upon by cams F on the cam shaft S′, the cams being so shaped and timed that the forward and upward motion of the brush F takes place at the proper time. To the arms of the rotary knife D, and at| toward the tail, except at the lower part some distance back of the latter, is applied of the neck and shoulders. These *parts are[405] a carding brush, D', which acts on that part at the sides of the head end of the skin, as of the skin that is fed forward over the edge the skin is split open at the under side. At of the stretcher bar immediately after the these parts of the skin the hairs point outhairs of the next preceding section of the wardly and backwardly and are the most skin have been cut off. The shaft D' of the troublesome to cut or pluck, as they lie cutting knife D is rotated from the cam down close to the skin when it is drawn over shaft S', by means of an intermediate longi- the stretcher bar. A sharp and quick rub tudinal shaft, S', and two sets of miter over these parts of the skin from the edge wheels, D, D*. toward the center of the skin is therefore necessary, so as to straighten up the hairs and present them to the action of the cutting knives. When the skin is in place, the stationary card E is drawn backward a few times over that part of the skin that is upon the stretcher bar B, so as to card back the fur and hair and produce thereby a parting of the fur at that part of the skin then covering the edge of the stretcher bar. One half of the fur upon that section of skin will, by the parting, be kept above and the other half below the edge of the stretcher bar. This permits the hair upon that seetion of the skin in front of the edge of the stretcher bar to rise through the fur and keep its place with less trouble than when more fur is acted upon. When the fur and hair have been carded back by the card E, the same is fastened to the stretcher bar by thumb screws. The card is set back from the edge of the stretcher bar to a distance a little more than one half of the length of the fur for the purpose of holding the fur and preventing it from moving forward until the forward motion of the skin takes place. The card at the back of the rotary knife passes then over the skin in front of the edge of the stretcher bar and draws out all the fur and hair on that section, so that the fur and hairs so drawn out assume their natural positions, that is, the positions which they would have if the skin were drawn over the edge of the stretcher bar without anything for holding back the fur and hair. As soon as the card at the back of the rotary knife has passed over the section of the skin in front of the stretcher bar the rubbers are quickly moved over the same toward the center, whereby the hairs that lie down sidewise are raised and pointed outwardly, causing them to stand upright. The rotary separating brush is then quickly *moved upward and forward and re-[406] volved in front of the skin at the edge of the stretcher bar, so as to separate the fur from the hairs, brushing down the former "The skin is placed in the machine by and leaving the stiff hair standing out. The being attached to the feed rollers and drawn rotary separating brush is then quickly tightly over the edge of the stretcher bar, moved backward and downward, so as to so as to lie close to the upper and lower carry with it the separated fur, which is surface of the same. The skin is put in in then held in position by the oscillating guard such a manner that the head end is fore- that follows the brush and carries the fur most. The stiff hairs in seal skins point' still farther back and holds it in position, "The brush F receives rotary motion from two belts, f, which pass over pulleys f on the shaft S' and the brush shaft, and which are kept taut by weighted idlers f, as shown clearly in Fig. 1. "The brush F is made of soft bristles and is rotated at a speed of one hundred and fifty revolutions per minute. The soft bristles allow the stiff hairs to stand, while the quick motion of the brush bends the soft hair in downward direction and brushes it below the stretcher bar, so that it can be taken up and held in position by the softrubber wipers g of an oscillating guard bar, G, which moves in arc-shaped slots g' of the guide plates C." The operation of the machine is thus described. while the vertical knife is raised and shears | successful operation, and was, to a limited off, in conjunction with the rotary knife, the extent, anticipated by the Boyden patent of forward-projecting hairs, as shown in Fig. 1883, it is perhaps an unwarrantable exten1. The separating brush, after it has ac- sion of the term to speak of it as a 'piocomplished its work, is lowered sufficiently neer,' although the principle involved subseso as not to touch the skin at all, except quently and through improvements upon when it is in front of the working-edge of this invention became one of great value to the stretcher bar. The next section of the the public." skin is now moved by the feed rollers over the edge of the stretcher bar, and the same operation of the parts produced by the next rotation of the driving shaft, and so on un-invention, nevertheless it cannot be said to til the skin is finished." The great merit of this invention is said to consist in the use of the brush, applied by means of the mechanism shown, so as to brush down the fur, and permit the long hairs, which should be removed, and which rise at the edge of the stretcher bar, when the pelt is drawn over it, to be acted upon by the knives when the fur is brushed away, so as not to be injured. In determining the construction to be given to the claim in suit, which is alleged to be infringed, it is necessary to have in mind the nature of this patent, its character as a pioneer invention or otherwise, and the state of the art at the time when the invention was made. It is well settled that a greater degree of liberality and a wider range of equivalents are permitted where the patent is of a pioneer character than when the invention is simply an improvement, may be the last and successful step, in the art theretofore partially developed by other inventors in the same field. Upon this subject it was said by this court (Westinghouse v. Boyden Power Brake Co. 170 U. S. 537, 42 L. ed. 1136, 18 Sup. Ct. Rep. 707, quoted with approval in Singer Mfg. Co. v. Cramer, 192 U. S. 265, 48 L. ed. 437, 24 Sup. Ct. Rep. 291): [407] *"To what liberality of construction these claims are entitled depends to a certain extent upon the character of the invention, and whether it is what is termed in ordinary parlance a 'pioneer.' This word, although used somewhat loosely, is commonly understood to denote a patent covering a function never before performed, a wholly novel device, or one of such novelty and importance as to mark a distinct step in the progress of the art, as distinguished from a mere improvement or perfection of what had gone before. Most conspicuous examples of such patents are: The one to Howe of the sewing machine; to Morse of the electric telegraph; and to Bell of the telephone. The record in this case would indicate that the same honorable appellation might safely be bestowed upon the original air-brake of Westinghouse, and perhaps also upon his automatic brake. In view of the fact that the invention in this case was never put into While it may be admitted that the Sutton patent was a distinct step in the art, and is entitled to protection as a valuable be a pioneer patent in any just sense. In the English Lake patent of 1881, of which more will be said hereafter, there is doubtless a suggestion of the use of brushes for the purpose of separating the fur from the long hair to be removed. And so in the Covert patent of 1884, which was the subject of consideration by Judge Wheeler in the case of Cimiotti Unhairing Co. v. Mischke, 98 Fed. 297. In that case it was said that Covert's patent had been mechanically, but not commercially, successful, and that in lieu of a rotating separating brush, shown in Sutton's patent, Covert used a revolving cloth-covered cylinder, and it was held that this was not equivalent to the separating brush, and Sutton's invention was an advance upon anything *theretofore shown. Of[408] the Covert patent Judge Coxe, in the course of an able opinion sustaining the Sutton patent (Cimiotti Unhairing Co. v. American Unhairing Mach. Co. 53 C. C. A. 230, 234, 115 Fed. 498, 502), said: "Covert came nearer than anyone else to a successful machine. He had but one more step to take, and here he became bewildered and went astray. He missed the apparently simple arrangement of the rotary brush, which alone was necessary. It will not do to say that the prior art showed such a brush. Every element of the combination in controversy was unquestionably old, but there was nothing in the prior art to suggest a rotary brush working in the environment shown in the Sutton patent. There was nowhere a rotary brush making a 'part' on a keen-edged stretcher bar and brushing the fur down and out of the reach of the cutting knives during the moment necessary to the removal of the stiff hairs. It is the presence of this element in the combination which produces a new result and entitles its originator to protection." In the same case, Judge Wallace (p. 237, Fed. p. 508), in his concurring opinion, says: "I do not think the machine of the Sutton patent a prodigious advance upon that of the prior Covert patent, and I think a higher degree of merit has been attributed to it than it deserves; but it was enough of an advance to be patentable, and to de- | serve protection against an infringing maehine which appropriates it." Furthermore, it appears that while the Cimiottis acquired an exclusive license under the Sutton patent in 1888, the same was not put into commercial use until the introduction of coney skins as a substitute for sealskins, about the year 1890. During this time the Cimiottis were unhairing a large number of skins, and preferred to continue to use the air-blast machine of their own invention while paying tribute to Sutton. It was the introduction of the coney industry, in 1890, that gave stimulus to the use of such mechanisms as those used by the Cimiottis and the respondent in this [409] case. We think it fair to say that this record discloses an invention of merit, entitled to some range of equivalents in determining the question of infringement, but it is not one of those broad, initiative inventions where original thought has been embodied in a practical mechanism, which the courts have been ever zealous to protect, and to which a wide range of equivalents has been accorded. Due weight is given to the Sutton patent when it is given credit for dispensing with the plate which Covert had in addition to the brush, and which he supposed would carry down the fur away from the cutting mechanism, but which Sutton has accomplished in giving, in a measure, at least, this added function to the brush of not only parting the fur, but carrying it down and away in preparation for the clipping by the knives. Any one who accomplishes the same purpose by substantially the same mechanism, using the elements claimed in Sutton's patent, may be held to be an infringer. Sutton has taken the step which marks the difference between a successfully operating machine and one which stops short of that point, and that advance entitles him to the protection of a patent. The argument here is confined, as to the alleged infringement, to the eighth claim of the Sutton patent, which is as follows: below the same; 5, mechanism whereby the rotary brush is moved upward and forward into a position in front of the stretcher bar, "substantially as set forth." *In making his claim the inventor is at [410] liberty to choose his own form of expression, and while the courts may construe the same in view of the specifications and the state of the art, they may not add to or detract from the claim. And it is equally true that, as the inventor is required to enumerate the elements of his claim, no one is an infringer of a combination claim unless he uses all the elements thereof. Shepard v. Carrigan, 116 U. S. 593–597, 29 L. ed. 723, 724, 6 Sup. Ct. Rep. 493; Sutler v. Robinson, 119 U. S. 530-541, 30 L. ed. 492-495, 7 Sup. Ct. Rep. 376; McClain v. Ortmayer, 141 U. S. 419-425, 35 L. ed. 800-802, 12 Sup. Ct. Rep. 76; Wright v. Yuengling, 155 U. S. 47, 39 L. ed. 64, 15 Sup. Ct. Rep. 1; Black Diamond Coal Min. Co. v. Excelsior Coal Co. 156 U. S. 611-617, 39 L. ed. 553555, 15 Sup. Ct. Rep. 482; Walker, Patents, § 349. This principle is particularly important when we come to consider the “stationary card above the stretcher bar,"-an element of the eighth claim. The anticipating mechanism set up in this case is the so-called English Lake patent of October, 1881. This patent has been the subject of much adverse comment in the cases involving a consideration of it. And it appears to have lapsed for nonpayment of taxes in June, 1885, and not to have been a successful machine. It may be the fact that the patent is not distinctly worded, and that the drawing and specifications are somewhat confused. It does appear, however, without contradiction in the record, that the machine now used by the respond ents was made in a large measure from the drawings of the Lake patent. Mischke, one of the respondents, was put upon the stand by the petitioners, and testified that he made the changes in a short time from the Lake patent, which resulted in the alleged infringing machine. The Lake patent showed two brushes, whereas the respondents' machine has dispensed with one and changed the position of the other. He also admits to have changed the position of the cam and shortened the crank arm as shown in the Lake machine. It seems to be the "8. The combination of a fixed stretcher bar, means for intermittingly feeding the skin over the same, a stationary card above the stretcher bar, a rotary separating brush below the same, and mechanism, substan-position of the petitioners' expert that tially as described, whereby the rotary brush is moved upward and forward into a position in front of the stretcher bar, sub stantially as set forth." The elements of this claim are five in number: 1, a fixed stretcher bar; 2, means for intermittently feeding the skin over the same; 3, a stationary card above the stretcher bar; 4, a rotary separating brush Mischke made the changes in the Lake patent necessary to convert it into an operative machine by adopting the controlling features of the Sutton patent. But whatever are the defects of the *Lake patent, the ques-[411] tion here is, Does the machine of the respondents infringe the eighth claim of the Sutton patent? One of the respondents' machines is in evidence, and we have care [412] fully examined it. Its general outline may | the hair, carried upwardly, to be acted up- In the case under consideration the respondents have dispensed with the fixed stretcher bar and have adopted a movable the same application of power. This mech- And see Kokomo Fence Co. v. Kitselman, anism, capable of accomplishing a much The Sutton device, as we have seen, has "If, however, such changes of size, form, or location effect a change in the principle or mode of operation such as breaks up the relation and co-operation of the parts, this results in such a change in the means as displaces the conception of the inventor. and takes the new structure outside of the patent." "Immediately above the stretcher bar B is arranged a stationary card, E, which is attached to the ends of the stretcher bar B by means of thumb-screws. (Not shown in the drawings.) The points of the teeth of the card E are close to but do not touch the surface of the skin, so that the hair and fur are both straightened as the skin is fed forward. The teeth of the card E hold down the fine fur, but permit the stiff hairs to stand up between the teeth, owing to the slow forward movement of the skin, which |