Court Opinion

ID: 6840382
Source: CourtListenerOpinion
Date Created: 2022-07-23 20:16:00.585148+00
Date Added: 2024-06-11T16:04:50.047030
License: Public Domain

L. HAND, Circuit Judge
(dissenting). On July 14, 1919, Hazeltine prepared a draft specification which contained in Figure 2 a schematic diagram of plate circuit neutralization, described as an “alternative arrangement” to that “preferred,” i. e., grid circuit, and claim 4 of which was for plate circuit neutralization per se. This application he never filed, and in his application of August 7th of that year, which became patent 1,450,080, he disclosed only grid circuit neutralization, apparently not then regarding the “alternative” as important. The parent application of the patent in suit was filed on December 28, 1920, and it disclosed the same two figures as had been used in the draft application, one for grid, and the other for plate, circuit neutralization, together with multistage amplifiers which the draft application had not contained. The specifications described means for the complete neutralization of natural grid-plate capacity, so as to eliminate all backfeed whatever, to wit, close coupling between the primary in grid or plate circuit with the secondary in the auxiliary circuit, together with a ratio of turns in the transformer equal to the ratio of the introduced capacity in the auxiliary circuit to the natural grid-plate capacity, by both of which equal and opposing currents would flow through the inherent and the introduced capacities.
Of his original first 11 claims, some, e. g., Nos. 1, 2 and 5, were general; that is to say, the transformer might be in either circuit, though claims 3, 4, and 11 were specific for grid circuit neutralization. All the claims were at once rejected oh Rice, who, the Examiner said, “uses the almost identical method as applicant.” Thereupon, on September 13, 1922, Hazeltine canceled all 11 claims and substituted 6 others, all for grid neutralization, except the first 2, which were for either grid or plate, and all containing as elements close coupling and the ratio of turns equal to that of capacities. He urged their allowance, because the “scope” of the claims “had been so restricted as to make them allowable over Rice.” Before any aetion had been taken, and on November 8,1922, he added 9 new claims, of which Nos. 15,16, 17, and 18 were specifically for plate circuit neutralization, and are the progenitors of claims 1, 3, 4, and 5 in suit. Nos. 16 and 17 contained the elements of dose coupling and the same ratio of turns to capacities, but Nos. 15 and 18 prescribed more generally that the apparatus should be made so as to cause equal currents to flow through the natural and the introduced capacities.
On November 12, 1923, the Examiner again rejected all the claims on Rice, and on December 28, 1923, Hazeltine transferred claims 15, 16, 17, and 18 to the division in suit, and submitted further argument, supported by Pupin’s affidavit, to show that dose *642coupling equal to “100 per cent.” made a “radical difference” from Rice, since it set up “equal currents” through the capacity in the auxiliary circuit and the inherent grid-plate capacity. While Pupin’s affidavit did say in conclusion that Riee did not show plate circuit neutralization, the bulk of it was directed to proving that Hazeltine completely eliminated feed-back by his “close” coupling, while Rice did so only partially at best. Claim 2 in suit was introduced during the progress of the division and adds nothing of substance.
Thus it appears that Hazeltine got Nos. 1, 2, and 5 of the claims in suit upon a limitation introduced to avoid Rice. He now argues that “equal currents” cannot mean the same as close coupling and an equal ratio of turns to capacities, and I agree that it might cover other means of reaching the same result, if they were electrical equivalents. Perhaps there are such, though none are suggested; but, whatever these may be, they must be at least designed to eliminate all feed-back by creating equal and opposed currents through the capacities, for that is certainly what the words were intended to mean. It is no answer to say that this is theoretically impossible. The point is that the patent was obtained only upon a concession that it covered a device which aimed to do so, so far as it was humanly possible. The defendant does not do it, does not try to do it, does not want to do it. In so far as its grid resistance may be said to accomplish the same result, it is a means which Hazeltine did not even intimate. As an excuse for ignoring the language, the plaintiff argues that one does not avoid infringement by practicing the invention imperfectly. I agree, if he practices it at all, but we must first find out what the invention is, and if it appears that it was voluntarily circumscribed in the office, it carries its limitations always.
The remaining claims in suit first appeared in the division on December 28, 1923, or later. They are only for the application of the invention to multistage amplifiers, as the specifications prove (page 2, lines 129-131; page 3, lines 5-11; lines 27-35; lines 56 — 63; lines 71-86), and the elements necessary to the general claims 1, 2, and 5 are implied in them. Indeed, I do not understand that the plaintiff distinguishes between the two groups in this respect. At any rate, the patent issued on a concession as to the genus, which may not be retracted as to the species. I do not think that the defendant has infringed any of the claims in suit.