(charging fury orally.) It must be borne in mind in all of these cases that the party is not patenting a principle, or, in other words, a result to be produced, but he is patenting machinery by which that result can be produced. This is a combination patent, divided into two claims, and in the present stage of the inquiry the question is whether the defendant uses either of these combinations. The explanatory part or specifications indicate the function or office to be effected bv the plaintiff’s special mechanism. The first is the “vertical shaft, B, with slot, B1, and set-screws, b, l, the shaft having a forward and backward motion, substantially as and for the purposes described.” That forward and backward motion is no part of the invention, but is a mode of producing a result. The party does not claim, and evidently could not do it, the pulleys, shafts, and beveled wheels to make the forward and back motion, as they are common mechanical contrivances.
Now, what is his invention? It is a vertical shaft, with a slot and set-screws, under such conditions, as explained therein, that it may be moved backward and forward. The ordinary doctrine in law concerning patents is that if a party insists on a patent for a combination of devices, (whether new or old is immaterial,) each element of the combination is an essential element; so that one who uses a combination in some respects, but omits one of the elements that the patentee chooses to describe as essential, the supposed infringer does *852not infringe. The patentee is supposed to describe clearly and fully all the elements which he thinks essential to produce the result desired. If he chooses to crowd his supposed inventions or combina'tions with elements that have no functions whatsoever, and a party chooses to use a like contrivance, omitting some of those elements, he does not infringe. The reason of the rule, as explained by the supreme court very frequently, is this: that — First, a party claiming a patent should not incumber the combination or device with matters that are wholly unessential, and thereby block the path of improvement or invention. If he chooses to put such in his contrivance, he must abide by the result.
Now, what is the essential element of this first claim, in the light ■of the specifications stated ? A vertical shaft, with a slot and setscrews, with such contrivances attached thereto that this central shaft may move backward and forward for the purposes stated in the specification. Is there a slot, or an equivalent thereto, in the defendant’s machine ? If there is anything of that description, falling within the doctrine of mechanical equivalents, he violates the first claim. It seems he has omitted the slot altogether. Without the slot, as this patent is described by the plaintiff, there is nothing new and nothing of the slightest importance connected with it. It would be the commonest thought of any one, if he wished to make a coil, that he must fasten the end somehow before he begins to coil. There is a variety of devices for that purpose, and very simple. One would be set-screws; but set-screws, according to the theory of the patent, were not adequate. Therefore he wanted a slot as connected therewith, and, so far as I can discover, the defendant uses no slot at all.
The second claim—
Mr. Wheaton. If your honor will pass that until the model comes, we will show your honor there is a slot in the defendant’s machine as plain as can be.
The Court. That is what you have been trying to do for two or three days. The second claim is this: “The pins or rollers, G, C, C, set in rings, D and D1, together with a grooved weight, substantially as described.”
Now, the fact that the defendant uses a machine horizontally instead of vertically would not excuse him from the allegation of infringe-mént; but, first, we must know what is the defendant’s claim in that particular. For the purpose of compression on the edges of the coil he has a vertical contrivance, - the lower disk being firm, and the weight above moving in proper grooves, and an opening for the shaft, so that it may move up and down, according to the necessities of the pressure. We heard testimony to show that the plaintiff’s contrivance requires more than the weight of the upper disk, or, as he calls it, the grooved weight, I. Practically it was of very little moment. The' weight was to be varied, and the patentee himself, on the stand as a witness, says, without any'particular amount of weight; because *853.somebody had suggested, whieh is not indicated in his patent at all, that the pressure might be produced by an external contrivance, irrespective of such weight. Now, if somebody has invented what would be improvements merely, the defendant supposed to infringe may be an improver, but he is none the less an infringer. Herein the court is reduced to the necessity of determining, first, has this defendant used the patentee’s contrivance as indicated in claim 2, or a mechanical equivalent therefor. It appears that the defendant, placing his contrivance horizontally, instead of trusting to gravity merely, with the weight itself on one end, used springs. Under ordinary modes operating a spring may effect precisely the same result as a small vertical weight. But what does the defendant do ? He has a contrivance which in many particulars differs very essentially from the plaintiff’s mode of operation. No slot, — no vertical pressure; a coiling process (in that respect like the patentee’s) by which a like result may be produced with an essential element of the combination omitted. When I say “omitted,” I moan that the function of the spring may be the same as the weight. But there are other elements of the combination: the pins or rollers, rings, the upper end and the lower fixed, operating in the manner which he has described.
' Without proceeding further with regard to the matter, I have indicated, in a general way, the views the court entertains in respect to the question under investigation. The only difficulty that has been presented to my mind in regard to the matter is with reference to the doctrine supposed to be laid down in 13 Wall, in the case cited, whether the court, instead of presenting these matters to the jury, should undertake, at this stage of the inquiry, to determine the question for itself. That case in 13 Wall, is familiar to the profession. X suppose it is also familiar that since then there have been at least four or five decisions by the supreme court modifying that doctrine essentially. In other words, in the course of a trial before a jury, the plaintiff having closed, the court is at liberty at that stage of the case to instruct a verdict for the defendant; and that is exactly like this case, and the instruction will be accordingly.