Tucker v. Spalding - 80 U.S. 453 (1871)
U.S. Supreme Court
Tucker v. Spalding, 80 U.S. 13 Wall. 453 453 (1871)
Tucker v. Spalding
80 U.S. (13 Wall.) 453
1. In an action at law where a patent of prior date is offered in evidence as covering the invention described in the plaintiff's patent on a charge of infringement, the question of the identity of the two instruments or machines must be left to the jury if there is so much resemblance as raises the question at all.
2. It is no ground for rejecting the prior patent that it does not profess to do the same things that the second patent does.
3. If what it performs is essentially the same, and its structure and action suggest to the mind of an ordinarily skillful mechanic its adaptation to the same use as the second patent, by the same means, this adaptation is not a new invention, and is not patentable.
Spalding brought an action at law against Tucker, to recover damages for the infringement of a patent for the use of movable teeth in saws and saw-plates.
The plaintiff's patent claimed the forming of recesses or sockets in saws or saw-plates for detachable or removable
teeth on circular lines, and in combination with these recesses, teeth having their base or bottom parts formed on circular lines as described.
The defendant offered in evidence as covering the subject matter of the plaintiff's patent a patent to Jonah Newton, confessedly prior in date and invention to that of plaintiff. This patent of Newton's had cutters of the same general shape and form, including circular base, as the saw-teeth of the other patent, attachable to a circular disk, and removable as in the other, but attached by screws or nuts, and the claim or purpose of the Newton patent was for cutting tongues and grooves, mortices &c. In connection with the offer of the patent to Newton, the defendant offered to prove by experts that the process of Newton's patent, and of the machine made thereunder, and of the result produced thereby, were the same process, machine, and result as were involved in the patent of the plaintiff; that saws were made under Newton's patent, and were in practical operation (the exhibition of the saws so made and operated being also offered); that the machine made under Newton's patent rotated in precisely the same manner and with the same effect as a circular saw, and that what in Newton's patent were designated "cutters" performed the same functions as the detachable teeth described in the plaintiff's patent, and accomplished the same result; and that the said "cutters" were nothing in reality but detachable saw-teeth, inserted on circular lines and rounded at the base and inserted in circular sockets, and secured an equal distribution of the pressure on the said "cutters," over and upon the circular sockets in which they were set, and thus prevented fracture of the disk or plate.
The court refused to admit the patent to Newton in evidence. Verdict and judgment were rendered accordingly for the plaintiff, Spalding, and the other party brought the case here on error, assigning several errors in the rejection of evidence and in the charge of the court. The cardinal point of the case, however, was the refusal of the court to permit the Newton patent to be read to the jury, the bills
of exception including, however, the rejection of the testimony of experts, to prove the identity of the invention described in the Newton patent with that of the plaintiff.