(after stating the facts as above). Although the patent is for a socket for electrical lamps, the claims in suit relate solely to the mechanics of providing for the circuit, its making and brealdng. Let it be assumed that the device is clever, and has attained a reasonable measure of commercial success — the questions remain as always — what did the patentee really add to the sum of human know!*49edge, and how did he define in his claims the addition which he disclosed in' his specification.
Tregoning came into a crowded art; the field of invention for mechanical arrangement of circuit carrying or regulating parts, seems very-limited; but it may also be admitted on this record that he was the first to take the trumpet ended tube which has long, carried the chain of a prior art, off the shell or sleeve and affix it to the skeleton or framework within, and this, though a minor feat, was meritorious.
But this device was but a part of what he patented, and covered by claims not in suit, and to measure what a patentee does, and properly judge how he does it, the whole disclosure must be regarded. Tregoning says he would make a socket havirig “definitely related and uniform contact surfaces, which do not change or diminish in area” by alternately making and breaking the circuit; 'i. e., he announces a better mechanism, which requires a strong framework for its support and permanent corelation. He especially points out that his “contact members” — through which the circuit is made and broken — are “peculiar and original in this, that they are stationary as to their position on the socket, and permanently fixed on the opposed insulating discs,” and these are the discs specifically mentioned in both the claims in suit.
This shows that it was of the essence of patentee’s concept to have upper and lower discs, each capable of bearing a contact piece firmly fixed to it, which pieces required all the rigidity of which the mechanism was capable. Obviously it also became necessary as rigidly to connect the discs with each other/
It seems therefore plain that the use of two discs each capable of mechanical (not merely electrical) functioning, and so connected as to make a firm foundation for other parts, was an integral and necessary part of the patentee’s inventive thought; and the presence in the claims of a pair of discs so related that the “eyelet member” can be “rigidly secured,” in result, to both discs, is an essential part of that idea.
Confessedly, defendant’s eyelet member is not rigidly secured to anything; it is (so to speak) clamped against the socket body by the closely fitting shell. As plainly, defendant has no two discs capable of holding or “rigidly securing” anything. The entire mechanism of defendant’s socket is borne by one porcelain piece, dished out to receive the switch parts. That single piece carries all the mechanical strains, which Tregoning divides between his upper and lower discs. Defendant has a lower disc, which, however, performs no mechanical function; it is electrically indispensable as an insulator, but the parts of defendant’s device operate with mechanical perfection with that disc removed, and electrically they would do jus't as well if the disc were of flexible paper.
It is not always easy to harmonize with each other, in the light of given case facts, several legal formulae, each of which singly considered, is axiomatic. The doctrine of equivalents must be adjusted to the maxim that there can be no infringement by reaching the same result, which qua result is always unpatentable; and the same doctrine must not impugn the rule that infringement is always of a claim, and what is not claimed cannot be protected; even though the specification re*50veals its presence in the inventor’s mind. It is only by doing the same thing in substantially the same way, that infringement results, and equivalence is confined to the limits of “substantially.”
This is the’ real teaching of Curtis, J., in his classic judgment in Winans v. Denmead, 15 How. 338, 14 L. Ed. 717; one must look through form to substance, and, if the patent is of or-on substance, the form, however varied by the alleged infringer, is of no importance, but, if the patent be on form only, then a different form avoids infringement.
But whether a patent is on form or substance, is a question which opens inquiry into the art, and its history — to ascertain whether anything more than form was left in the inventive field. This thought is carried forward in Taft, C. J.’s, opinion, in Eibel, etc., Co. v. Minnesota, 261 U. S. 45, 43 Sup. Ct. 322, 67 L. Ed. 523.
But if the patentee is “unfortunate in the language he has chosen” for his claims, and that unfortunate language is “clear and distinct, the patentee is bound by it.” McClain v. Ortmayer, 141 U. S. 419, 12 Sup. Ct. 76, 35 L. Ed. 800; Evans v. Hall Co., 223 Fed. 539, 541, 139 C. C. A. 129.
Applying these considerations, we are of opinion:
(1) That the patent was one of form only — it consisted in changing the relation of a tube to a shell, to the same relation between the tube and a socket framework; consequently depriving the same tube of all fixation and clamping it (so to speak) between shell and framework is not doing the same thing in the same way. If Tregoning had been the first to think out a tube as a lead for the chain, the result would have differed.
Further (2) the claim language is s,o clear and distinct, and so plainly-drawn to correspond with the patentee’s whole thought, that plaintiff must be bound by it, and it is admitted all round that neither claim will literally “read oii” defendant’s device.
Finally we may (3) summarily note, that the file wrapper and contents show that the claims in suit were evolved from two earlier claims, which in terms demanded protection for a “socket * * * having a switch embodied therewith and provided with a flexible connection,” and also for an eyelet member “mounted on the main body of said socket,” or “rigidly secured to the main socket body parts.” The earlier claims were rejected as showing “no invention,” and were thereupon changed to their present form. It seems to us that plaintiff is here asserting for the existing claims a scope which he could, we think, certainly have urged for the originals. This, under rules too familiar to need citation, he cannot do.
Decree reversed, with costs, and direction given to dismiss the bill for noninfringement, with costs.