249 F. 61 (6th Cir. 1918), 3036, General Electric Co. v. Cooper Hewitt Electric Co.

Docket Nº:3036.
Citation:249 F. 61
Case Date:January 08, 1918
Court:United States Courts of Appeals, Court of Appeals for the Sixth Circuit

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249 F. 61 (6th Cir. 1918)




No. 3036.

United States Court of Appeals, Sixth Circuit.

January 8, 1918

Squire, Sanders & Dempsey, of Cleveland, Ohio, and Pennie, Davis & Marvin, of New York City (W. B. Morton and Wm. H. Davis, both of New York City, of counsel), for appellant.

Parker W. Page and Thomas B. Kerr, both of New York City, for appellee.

Before KNAPPEN, MACK, and DENISON, Circuit Judges.

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DENISON, Circuit Judge.

This is the ordinary suit for infringement, based upon patent No. 1,090,992, issued March 24, 1914, to Kuch for an improved mercury vapor lamp. Appellant acquired title to the patent and was the plaintiff below. The bill was dismissed because the patent was thought to be invalid, and the plaintiff appeals.

The conclusion of invalidity is rested upon two grounds: First, that new matter was introduced into the application and was not supported by new oath; and, second, that Kuch was anticipated by Bastian, and that this priority had been adjudicated in an interference between them. A due understanding of the questions thus presented requires a brief explanation of the invention. Lamps of this type consist essentially of a sealed glass tube, more or less exhausted, having a mercury electrode at each end. When the tube is filled with the mercury vapor and the electric current passed through, the vapor becomes luminous or incandescent. One of the recognized difficulties is that, since greater heat develops at the anode than at the cathode, there is at the anode a greater vaporization, and the mercury is distilled over and accumulates at the cathode, so as to destroy the proper balance. This difficulty had been met by devices or constructions which caused or permitted the excess mercury at the cathode to run back occasionally along the tube to the anode; but this remedy brought new operating difficulties in the high pressure lamps. Kuch's object was to find a better way to preserve an automatic balance between the two electrodes. He took that style of lamp which had a horizontal tube carrying the mercury at each end in a depending enlargement or bulb, and he accomplished a first or general automatic balance by directly attacking the vaporization at the anode. His remedy for the excess was to make the anode bulb larger than the cathode bulb. It followed that the outer surface of the former bulb, which would radiate heat, would be larger, and would therefore by radiation subtract heat from that generated inside the bulb, and so diminish what may be called the net heat of the mercury, and the comparative resulting anode vaporization. He knew that the effect of a given current upon these electrodes and under given conditions could be computed, and his inventive thought was that, if the radiating surfaces of the two bulbs were proportioned to the amount of the heat to be generated in each, there would be corresponding radiation and the proper vaporization balance would be maintained. 1 He thus brought about a rough and general equalization by attacking the cause of inequality; but changes of external temperature or other conditions would prevent this preliminary regulation from entirely and always stopping the accumulation of excessive mercury at the cathode, and so Kuch provided a further and final automatic regulation. He knew that there occurred at the cathode a phenomenon called the 'cathodic aigret.' This was an agitation suggestive of boiling, and it extended a certain depth from the surface of the mercury in the cathode. Obviously, the bulb surface adjacent to the mercury thus agitated would radiate heat much

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more actively than the remaining and lower part of the bulb surface. Kuch utilized this effect of this phenomenon by interposing, between his horizontal illuminating tube and his depending cathode bulb, an intermediate upwardly-inclined tube of much less diameter than the illuminating tube. A small excess accumulation of mercury in this intermediate tube would very considerably raise the lowest point of this aigret agitation and so diminish radiation, increase the net heat, and promote vaporization. A slight drop in the mercury in this tube would have the converse magnified effects; and the mercury level would, automatically, maintain itself substantially constant. We here reproduce Fig. 1 of the Kuch patent as originally filed and as amended. Claims 2 and 3 are given in the margin. 2 Claims 1 and 4, also sued upon, do not require separate consideration

The original drawing did not show any anode bulb or passage thereto from the illuminating tube, nor did the specification contain any particular description of either. During the progress of the application,

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an amended drawing was filed as above, and the specification was made to say, in so many words, that the anode bulb was larger than the cathode, and that the passage leading from the...

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