Mr. Justice Brown,
after stating the case, delivered the opinion of the court.
There are thirty-nine assignments of error in this case, but in the view we have taken, it will only be necessary to consider the twenty-first, which is : " That the court erred, [in refusing] upon the close of all the testimony in the case, and upon the request of the defendant's counsel, to instruct the jury to render a verdict in favor of the defendant."
The patent in question is for a portable coal screening device which may be moved to any place on the wharf where a vessel happens to be discharging her cargo. The portability of the device, however, is not mentioned in any of the claims except the first, which also includes the screen as an element of the combination. The coal is hoisted from the hold of the vessel in buckets or tubs, which are swung over the machine, and the coal dumped into the hopper, through which it falls upon the first screen and lodges in the reservoir until required for use, when the coarser coal slides down upon a chute, having an outlet or gate, through which it is withdrawn into carts. The finer coal falls through the first screen upon a second, where it is again sifted, the coarser sliding down to the side of the machine, the finer falling through the meshes upon the wharf, directly beneath the hopper.
. The defendant also uses a portable machine. consisting simply of a square hopper, of the form ordinarily used in grist mills and elevators, through which the coal of all sizes falls directly upon a chute having an outlet or gate toward, but some distance from, the bottom, which can be raised or lowered at pleasure, and through which the coal is withdrawn as required. There is no provision whatever for screening the coal shown in the drawings of defendant's chutes put in by one of plaintiff's witnesses, nor in his model introduced as an exhibit.
As the combinations described in the first, second, and fifth claims of the Roberts patent include a screen or screens as an element,- it is entirely clear that the defendant's machine, as above described, does not infringe those claims.
The third claim includes the metal blank or false bottom (K), in combination with the receiving hopper (BJ3'), reservoir (0), chute (F), and gate (A), the fourth claim, the combination of the hopper, the reservoir, the chute, and the gate, differing only from the third in the omission of the metal blank or false bottom.
Now, in determining the question of patentability raised by the twenty-first assignment of error, we are to take into consideration only the device alleged to be infringed. Granting for the purposes of this case that the combinations set forth in the first, second, and fifth claims, of all of which the screens are an element, constitute a patentable invention, it does not follow that, if these screens be omitted, as they are by the .substitution of the false bottom or metal blank (K) in lieu of the upper screen, this machine, which is the-only one alleged to be infringed by the defendant, contained a patentable combination. Eliminate the screens by the substitution of the false bottom, and there is nothing left but an elongated hopper, a reservoir beneath, a chute, and a gate. Hoppers with chutes beneath them have been used for a dozen different purposes, but principally for grain elevators, by means of which vessels lying alongside a wharf are loaded in a fraction of the time required by hand or animal power. Indeed, these devices are so common that we think judicial cognizance may be taken of them. Brown v. Piper, 91 U. S. 37; Terhune v. Phillips, 99 U. S. 592; King v. Gallun, 109 U. S. 99; Phillips v. Detroit, 111 U. S. 604.
If there be any invention at all, then, in the combinations specified in the third and fourth claims, it is in the introduction of the reservoir (0) beneath the hopper, which is really an enlargement of the chute, 'for the purpose of affording a lodgment for the coal until it is drawn off for use. Great stress was laid by plaintiff's counsel upon this feature of the invention, but even conceding it to be patentable, there is nothing corresponding to it in the defendant's machine. Op the contrary, the coal falls • through a square opening in the bottom of the hopper, directly upon the chute, where it is detained by a gate, which is kept closed'until the coal is withdrawn. It is evident that the hopper itself .is substantially the only reservoir, although a small amount of coal is necessarily detained in the upper part of the chute until the gate is raised. The chute is nowhere enlarged to form a reservoir.
The fact that the machine is portable undoubtedly adds to its usefulness, but its portability is only made an element of the first claim, of which the screens are also an element. So that if portability were itself a patentable feature, which it is not, (Hendy v. Miners' Iron Works, 127 U. S. 370,) there is no infringement of- the first claim, as the defendant does not use the screens.
There was some evidence tending to show that one. of the machines used by the defendant was provided with a chute, the bottom of which consisted of a screen, and that it was used until about the time this suit was brought, when the screen was covered over with planking and the bottom of the chute made' solid. This' machine doubtless approximated more closely to that described in the plaintiff's patent. No attempt, however, was made to separate the damages arising from the use of this device from those arising from the use of the chute Avith the solid bottom. The trial appears to have proceeded largely upon the theory that there was no distinction between the two devices. The court instructed the jury that the plaintiff's patent Avas not limited to a device in Avhich 9, screen is one of the element's, and that if they found that defendant had used a device substantially identical with the device shown in the patent, but having a solid bottom to the reservoir, and a chute which extends from the receiving hopper instead of having a screen bottom, that such device Avas also covered by the patent and Avas an infringement.
An exception was taken to this portion of the charge, and the twenty-fourth assignment of error was intended to cover it. For the reasons given above, we think the court erred in its interpretation of the patent. If there was any invention at all disclosed, it was in the use of the reservoir and the screening device, and without expressing fin opinion upon this point of patentability, it is clear .that no infringement was involved in the use of defendant's hopper and chute, with or without a solid bottom, if for no other reason, because it lacked the reservoir of the plaintiff's patent.
There was no question to go to the jury in the case, and the court should have directed a verdict for the defendant.
The judgment of the court below is, therefore,
Reversed, and the case remanded, with directions to set aside the verdict and grant a new trial.