Sufficient appears to show that a patent in due form was granted to John Myers and Robert G. Eunson, on the 23d of May, 1854, for an alleged invention described in the specification as relating to certain new and useful improvements in machines for sawing lumber into thin stuff for the backs of mirrors and picture-frames, and other purposes for which thin stuff is used. Due application was subsequently made for an extension, and the record shows that the patent was regularly extended for the further term of seven years from the expiration of the first term.

Subsequent to the extension of the patent, one of the patentees, to wit, Robert G. Eunson, sold and assigned all his right, title, and interest in the same and the extension thereof to Eugene S. Eunson, one of the complainants who instituted the present suit in the court below. Pending the suit the other complainant departed this life, and Margaret Myers, his sole executrix, was duly admitted in his stead to prosecute the suit as co-complainant with the assignee of the other half-interest in the extended patent. Infringement is charged, and that the respondents have made large gains and profits by the unlawful use of the patented invention, and the complainants pray for an account and for an injunction.

Process having been issued and service made, the respondents appeared and filed an answer, in which they set up in substance and effect the following defenses: 1. That the invention is of no utility or value. 2. That the patentees are not the original and first inventors of the alleged improvement, 3. That the alleged improvement was well known and had been in public use long prior to the supposed invention by the patentees. 4. That knowledge of such prior public use was possessed by the several persons whose names and places of residences are set forth in the answer. 5. That the patented improvement, years before the application for the patent was executed, was fully described in the respective printed publications mentioned in the answer filed by the respondents.

Minute and accurate description of the patented machine is given in the drawings, and the specification divides the invention into four separate features, as follows: 1. That it consists in the employment or use of deflecting plates (one or two), placed at the sides of a circular saw for the purpose of enlarging or expanding the saw-kerf to prevent the sawed stuff from coming in contact with the sides of the saw and binding the edge of the same near the teeth. Deflecting-plates of the kind also allow the saw to be stiffened by a proper plate, so that a thin veneer-saw may be employed, which will cause but a small waste of stuff in sawing. 2. That the invention consists in the employment or use of elastic clamps attached to the ordinary adjustable and elastic beds between which the stuff is fed to the saw. Clamps of the kind have an elasticity independent of the beds, and compensate for the varying thickness of the different pieces of stuff to be sawed, by holding

firmly the extreme end of the stuff and keeping it in proper position to the saw, however much the elastic bed may be expanded by a succeeding piece of stuff of greater thickness. 3. That the invention also consists in the employment or use of knives or cutters secured to the adjustable beds, and so arranged as to cut or smooth off the rough and projecting sides of the stuff at the ends, making it of uniform thickness. 4. That it also consists in the combination of an adjustable bed and circular saw, arranged as shown in the specification.

Such a machine necessarily requires a frame, and the patentees state that the frame of the machine described in the specification may be constructed in any proper manner, and that the circular saw is placed on a shaft which runs transversely across the front of the frame.

They employ a circular saw, made of thin steel plate, such as is used for sawing veneers, on one side of which is a circular plate secured by rivets and screws, the plate being less in diameter than the saw, which has the effect to stiffen the plate of the saw and to enable the operator to use a thinner saw than he would otherwise be able to do.

Two deflecting-plates are also employed by the patentees, one on each side of the saw-the one on the same side of the saw with the stiffening-plate covers the upper part of that plate, the outer end of which projects farther from the saw than the inner end, the deflecting-plate on the other side of the saw being of the same description, except that it is rather smaller in diameter and that it projects from the saw at about an equal distance at both ends. They are arranged one on each side of the saw, and are attached to the frame by means of bolts, rivets, or

screws.

Two feed-roller beds are placed vertically in the back part of the frame parallel with each other, both of which are made adjustable by screw-rods which bear against the sides of the beds, the screw-rods of each bed being operated simultaneously by means of chains passing round small toothed wheels at the ends of the screw-rods.

Two cranks are also employed, one of which is attached to one of the toothed wheels of each bed. Lateral elasticity is given to the beds by means of India-rubber or other springs attached to them in a proper

manner.

Four feed-rollers are employed, two of which are placed in each bed, and the specification states that the feed-rollers project some distance beyond the inner edges of the beds. Clamps, two in number, are attached to the inner ends of the beds, and at the back part of each clamp there are two journals, one at the top and one at the bottom, fitted in boxes which work or slide in recesses in the top and bottom pieces of the beds. Set-screws are also provided, which pass transversely through the top and bottom pieces of each bed, the inner ends of which bear against India-rubber springs placed directly back of the boxes.

There are two of these rubber springs at the top of the clamps, one to each clamp, and it appears that they are placed between the clamps and the set-screws passing transversely through the top pieces of the

beds. Hence it follows that the clamps may be made to vibrate laterally; but it also appears that two stops are provided, which pass through the top pieces of the beds, one through each top piece, for the purpose of limiting and regulating the extent of such lateral vibration.

Knives or cutters are also provided, which are placed vertically, one in each bed, but it is unnecessary to enter in those details, as it is not pretended that the respondents have infringed the third claim of the patent.

Motion is given to the feed-rollers by gearing, which is shown in the drawings at the lower part of the rollers.

Means are also provided for adjusting the beds relatively to the saw, so that the boards or other lumber may be sawed into the desired thickEither side of the saw may be made the line side in the operation of sawing by the adjustment of the proper roller-bed so as to prevent expansion or contraction.

ness.

Stuff to be sawed, whatever it may be, is placed between the feedrollers in the beds, and motion being communicated to the saw and rollers, the stuff is fed forward toward the saw and is cut by it, the two pieces being prevented from bearing against the sides of the saw by means of deflecting-plates. When the outer end of the material to be sawed has passed the inner feed-roller, the clamps bear against the board and hold it in a proper relative position to the saw, so that if another board to be sawed is placed between the feed-rollers it will advance and press forward the board first placed between the rollers, and if the last board is thicker than the preceding one the only effect is that it acts upon the beds and forces the elastic one farther from the permanent one without affecting the clamps, which, owing to the springs, have an independent elasticity.

Tested by the example given in the specification, as illustrating the mode of operation, it is plain that either side of the saw may be made the line side in the practical working of the machine. In the example put by the patentees, they assume that the roller-bed in line with the deflecting-plate, which is on the same side of the saw as the stiffeningplate, is permanently fixed at one-quarter of an inch from the side of the saw, and that, the opposite bed being elastic, the side of the saw on which the thin strip passes is the line side during the operation of sawing, but the patentees state that the opposite side of the saw may be made the line side by permanently fixing the opposite roller-bed, and by allowing the other one to remain elastic, and that by these improvements they are enabled to use a thin veneer-saw, and to keep the stuff to be sawed in a proper relation to the saw, even when varying in thickness. Three of the claims of the patent, it is charged, are infringed by the respondents, to wit, the first, second, and fourth. They are as follows:

1. The employment or use of the deflecting-plates, one or both placed at the sides of the saw, as shown, for the purpose of preventing the sawed stuff from bearing against the sides of the saw and expanding the saw-kerf, and also for the purpose of allowing a thin veneer-saw to be stiffened by plates, one or two, as desired.

They claim

2. The employment or use of the clamps arranged as shown, or in any equivalent way, so that they may have a lateral elastic movement independent of the roller-beds, to which the clamps are attached, for the purpose of compensating for the varying thickness of different pieces of stuff, and to keep the same in a proper relative position to the saw.

They also claim—

4. The employment of an adjustable bed with clamps, as described, in combination with the saw when the saw has a stiffening-plate in line with the adjustable bed, by which the stiffened or rounded side of the saw is made the line side of the same for practical operation.

Prior to the hearing the complainants filed a petition in the Patent Office, in which they state that the patentees, through inadvertence, accident, and mistake, and without any fraudulent or deceptive intention, claimed more in their specification than that of which they were the original inventors. Pursuant to that petition they were permitted to enter a disclaimer in two respects: (1.) To amend the first claim by striking out the words "one or" before the word "both," so that the claim includes only the employment and use of the saw with both of the deflecting-plates when both of the plates are used at one and the same time, in the manner and for the purposes described. (2.) They also made a corresponding amendment in the specification, limiting the description of the invention to the employment of the two deflectingplates placed at the sides of the circular saw, disclaiming the use of one plate only for the purposes set forth in the specification.

Proofs were taken, and, both parties having been heard, the court entered a decretal order in favor of the complainants and referred the cause to a master. Due report was made by the master, to which both parties excepted, but the court overruled the exceptions, and, having confirmed the report, entered a final decree in favor of the complainants for the sum of nine thousand one hundred and twenty dollars and ninety-four cents, being the gains and profits made by the respondents, as ascertained by the master. Both parties appealed to this court.

Eight errors are assigned by the respondents, two of which only will be examined: (1.) That the court erred in holding that there was invention in using two deflecting-plates when the use of one was well known. (2.) That the court erred in holding that the respondents infringed the letters patent granted to the complainants.

Viewed in the light of the disclaimer it is clear that the first claim of the patent is for the employment or use of two deflecting-plates, one being placed on each side of the saw, for the purpose of preventing the sawed stuff from bearing against the sides of the saw, and to allow a thin veneer-saw to be stiffened by the plate employed or used for that purpose; and it is equally clear that the employment or use of one deflecting-plate for the purpose was well known and in public use long before the original patentees in this case applied for a patent.

Conclusive evidence to support that proposition is found in the dis

claimer filed by the complainants, pending the suit, in addition to the other evidence in the case, which is abundantly sufficient to establish the proposition, even without the disclaimer. Authority to make such a disclaimer is beyond question, if it be made in writing, and is duly attested and recorded in the Patent Office. When so made, attested, and recorded, it becomes a part of the original specification, to the extent of the interest of those who make it; but the provision is that it shall not affect any action pending at the time of its being filed, except so far as may relate to the question of unreasonable neglect or delay in filing it. (16 Stat. at Large, 206; Rev. Stat., sec. 4917.)

Pending suits may proceed, but the disclaimer, when recorded, becomes a part of the original specification, and must be taken into account in construing the patent, and in ascertaining the rights of the parties to the suit, unless it appears that the effect of the disclaimer is to enlarge the nature of the invention and prejudice the rights of the respondents. (Perry vs. Skinner, 1 Webster, P. C., 253; Ralston vs. Smith, 9 C. B., N. S., 145; same case, 11 C. B., N. S., 474; Smith vs. Nichols, 21 Wall., 117.)

Where the effect of the disclaimer is to diminish the claims of the patent without prejudicing the rights of the respondent, the suit may proceed, notwithstanding the disclaimer, it being held that the disclaimer under such circumstances does not affect the pending suit, except to limit and qualify the claims of the patent, and in respect to the question of unreasonable neglect or delay in filing the same. Unreasonable delay not having been suggested, the only effect of the disclaimer in such a case is to limit the nature of the invention secured by the patent, and to diminish the claims of the patent as set forth in the specification. (Guyon vs. Serrell, 1 Blatch., 245; Hall vs. Wiles, 2 Blatch., 198.)

Matters properly disclaimed cease to be a part of the invention, and it follows that the construction of the patent must be the same as it would be if such matters had never been included in the description of the invention or the claims of the specification. (16 Stat. at Large, 206; Seed vs. Higgins, 8 Ell. & Bl., 767; Higgins vs. Seed, 8 Id., 763; O'Reilly vs. Morse, 15 How., 121; Taylor vs. Archer, 8 Blatch., 317.)

Tested by these considerations it is clear that the first claim of the patent is for the employment or use of two deflecting-plates, one placed on each side of the saw, for the purposes therein set forth and described. Circular plates attached to circular saws, secured by rivets or screws, for the purpose of strengthening the central portion of the saw-plate, and sometimes called stiffening-plates, are old devices, which have been known to the operators of the circular saw ever since the circular saw came into general use for sawing shingles, laths, and clapboards. Nor is any argument necessary to show that the employment of one deflecting-plate covering the upper part of the stiffening-plate on the same side