Hewitt v. American Telephone & Telegraph Co.

272 F. 392, 1921 U.S. App. LEXIS 1625
CourtCourt of Appeals for the Second Circuit
DecidedMarch 10, 1921
DocketNo. 47
StatusPublished
Cited by8 cases

This text of 272 F. 392 (Hewitt v. American Telephone & Telegraph Co.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Second Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Hewitt v. American Telephone & Telegraph Co., 272 F. 392, 1921 U.S. App. LEXIS 1625 (2d Cir. 1921).

Opinion

HOUGH, Circuit Judge.

[1] The nature of the evidence produced, and method of presentation, has produced a somewhat misleading resemblance between this suit and the ordinary proceeding for infringement. It must, however, he recognized that the usual infringement suit is to restrain a continuing tort, while this is upon a contract, under which defendant is a licensee. Therefore it is admittedly estopped to deny validity, and bound to accord to plaintiff a benevolent interpretation of the patents under which license exists. This last statement is really but a corollary to the rule that invention is part of validity, and the obligation to admit invention practically limits the evidential [396]*396value of such prior art as may exist. With the foregoing admitted — • and it has not been denied in argument — we perceive no question of law in this record. The thing said by plaintiff to “operate in accordance with” the claims above enumerated, is used as a relay in what is just at present the longest of long-distance telephony.

Defendant yields tribute to De Forest 841,387 (claims 4 and 6), and. we are convinced that this relay is in fact a descendant of the “three-member device” there revealed by that patentee.1 The relay shows an in-put circuit connected with the filament and grid, and an out-put with the filament and plate. The filament is independently heated, and both filament and plate as used by defendant and others, are older than the inventions of either De Forest or Hewitt.

“Grid” is a word perhaps coined by that well-known phrasemaker, De Forest; at all events it is called throughout this record the De Forest grid. Filament, plate, and grid are in practice inclosed in an evacuated tube exhausted to a pressure of the order of one hundred-thou-' sandth of a millimeter. . That pressure can be still further reduced, but such reduction is expensive and does not change or improve the working of the apparatus. The normal operation of this audion amplifier, with the grid located between filame'nt and plate, is, according to the electronic theory, that a current consisting of negative carriers tends to pass from filament to plate because they, being negative, are attracted to the plate, which is positive. The rate of passage, and therefore the amount of current flowing, will depend upon how forcibly the positive plate attracts, and that depends upon the intensity of the electrical field acting in the space between plate and filament.

The grid acts (as testified by plaintiff’s expert, and imitating Hewitt’s specification language) as a capacity charged to a potential rather than as a current flowing; but, be that as it may, it is asserted by defendants that the transmitter on the in-put varies the potential impressed upon the grid, and the grid in turn similarly varies the electrical -field between filament and plate wherein said grid is commonly located. Therefore the tendency of the negative carriers to pass from filament to plate increases or decreases according to th,e fluctuating of grid potential, and similarly varies the current flowing across said electrical field and into the out-put. The result as claimed by defendant is that “the action is due solely to the De Forest grid,” and when the elements of the audion amplifier are properly (and from the evidence apparently empirically) .proportioned and co-related, repetition and amplification take place without distortion, but always the work is said by defendant to be done by the properly placed and proportioned grid.

Plaintiff’s contention may be summarily stated thus: (a) It is not the grid per se that does the work or accomplishes.the result; for the nature of an atmospheric residuum in even so highly evacuated a tube as that of defendant either has something to do with it or produces a condition answering to the “vapor” of Hewitt’s patents; but anyhow (b) the De Forest grid, if not in its original conception, at all events in re[397]*397spect of its use by defendant, is the Hewitt shield of the later patents above mentioned.

Much of this record is occupied .with evidence pro and con as to whether the theory of operation advanced in the disclosures of 781,001 and 781,002 is not wholly erroneous; whether the devices there suggested are of any practical use; whether they constituted any real advance upon the prior art; and whether defendant did or did not utilize them, or either of them, in the construction of a mercury vapor amplifier which was made — allegedly under other patents of Hewitt not here involved, and on which plaintiff received royalties. We do not find it necessary to discuss this evidence, but prefer tO'ground decision as to the earlier patents on one proposition only.

[2] Plaintiff (or his counsel for him) contends that a vapor tube, a vacuum bulb, and an evacuated container all mean practically the same tiling for the purposes of this case. He admits that when these patents were applied for, he was thinking in terms of those mercury tubes which have made him famous. But it was then true, and always will be true, that, as long as there is any residual air left in an evacuated container, that container incloses a vapor. Therefore it is as much a vapor tube for the purposes of the present discussion as if it were filled at a fairly high pressure with any of the numerous gases suggested in plaintiff’s earlier specifications (not here involved). But the moment the vacuum becomes absolute, the vacuum space is a perfect dielectric, as we have all been taught— consequently, since defendant does not pretend to have an absolute vacuum, it must have a vapor tube.

As matter of definition, commercial usage, or of mere words, the contention may be right; we are not concerned to go further into it. Let it be admitted that per se defendant has a vapor tube; the question still remains whether its vapor has any such causal connection with what the audion amplifier does as Hewitt’s vapor possesses in respect of the means or method of the claims at bar. This plaintiff never obtained a patent covering every amplifier that employed a vapor tube; at the most, his patents can only cover every vapor tube used to amplify by substantially the same means, or in substantially the same method, as Hewitt’s amplifier. It is we think admitted, and, if not, it is proven, that when a vapor of anything like the order of pressure necessary for the operation of Hewitt’s device be introduced into defendant’s amplifier it will not and cannot work. Why this is so is the crux of so much of this litigation as rests on the earlier patents.

On such a point this court can pretend to do no more than to carefully weight all the evidence, and attempt to base decision on facts, and on facts as simple as the evidence permits. In this instance, however, we can find no satisfactory basis for judgment, except the electronic theory as expounded by defendant’s expert, and not, we think, successfully combatted even in detail by plaintiff. Indeed, except for its application to the present case, plaintiff’s expert is firm in the same faith ; both regard the theory as the majority of men look upon the theory of the rotation of the earth.

As applied to this litigation, we find the fact to be that it is an essential part of the operation of the devices suggested by the earlier pat[398]*398ents of plaintiff that the evacuated chamber must contain a gas or vapor capable of ionization; unless there be ionization, the devices will not work.

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272 F. 392, 1921 U.S. App. LEXIS 1625, Counsel Stack Legal Research, https://law.counselstack.com/opinion/hewitt-v-american-telephone-telegraph-co-ca2-1921.