Welsbach Light Co. v. Rex Incandescent Light Co.

• Decision Date: 26 May 1899
• Citation: 94 F. 1006
• Parties: WELSBACH LIGHT CO. v. REX INCANDESCENT LIGHT CO.
• Court: U.S. District Court — Southern District of New York

94 F. 1006

WELSBACH LIGHT CO. v. REX INCANDESCENT LIGHT CO.

United States Circuit Court, S.D. New York.

May 26, 1899

John R Bennett, for the motion.

Louis Hicks, opposed.

LACOMBE Circuit Judge.

The Welsbach incandescent mantle is a light hood or frame, which is suspended over the flame of a Bunsen burner so as to become heated by it to incandescence, causing it to emit a large body of brilliant light. The hood itself is made of light network fabric,-- such as muslin,-- which, after being impregnated with solutions of salts of the earthy oxides of rarer metals (such as zirconium, lanthanum, etc.) is exposed to the heat of a flame. 'The material of the fabric,-- generally cotton,-- is soon consumed, leaving a skeleton hood or frame, consisting of the incombustible or infusible products of the salts that were employed for impregnating the fabric, and this skeleton hood or frame will remain effective as an illuminant for hundreds of hours. ' Although strong enough to resist the movements of the ignited gas and the distortions produced by ignition and extinguishment, the hood mantle is in fact but an ash extremely fragile, and liable to go to pieces if handled, or allowed to come into contact with any hard body. This peculiarity precludes transportation of the mantles from manufacturer to consumer after the cotton has been burned out, and the article put in condition for use in which the consumer wishes to have it. To meet this condition, it used to be the practice (and according to defendant's affidavits, it is still in the practice in Austria) to send the mantles impregnated with the solution of Welsbach, but not burned out at the factory, to the agents of the company, to be by them burned out at their shops, and then placed upon the gas burner in the house of the consumer. It was the object of the Rawsons' invention to dispense with this method of distribution, and to put the mantles into such a condition that they could, after being burned out, be transported in convenient packages, like other merchandise. The specification sets forth:

That 'the object of our improvement is to render these mantles, after ignition, sufficiently hard and resistant to allow of packing and handling without fear of breakage in the transport. * * * Difficulty has been found heretofore in the transport of these mantles without breakage, and various methods have been proposed. This difficulty our invention is designed to overcome by dipping the mantles, after they have been given their proper shape, into a liquid which will thoroughly penetrate the pores of the material, and will afterwards set to such a degree of hardness as to protect the material, from danger of breakage in packing or handling, and which can afterward be removed without mechanical injury to the mantles, or without leaving any objectionable residue. * * * We have found that a very satisfactory method of carrying out our invention consists in dipping the cone into a hot solution of volatile hydrocarbon-- such as benzine-- mixed with paraffine wax or paraffine alone. By these means the mantle is covered with a thin coating of wax which becomes sufficiently hard on cooling to allow of packing and handling without fear of breakage. The paraffine is capable of burning away without any residue except carbon, which will always be burned completely away by the flame of the Bunsen burner. * * * Other materials may be employed as long as they set hard at ordinary temperatures, and burn away without mechanical destruction to the mantle, and without leaving any residue, which would injure the light-giving properties of the mantle. The materials referred to as being capable of use in lieu of paraffine may be any solid hydrocarbon of a high boiling point, and many resins and gums soluble in spirit, such as alcohol, etc. Shellac will serve the same purpose, but not quite as advantageously .'

The claim is:

'(1) The herein-described improvement in strengthening incandescent mantles, consisting in coating the completed mantle with paraffine or other suitable material, substantially as set forth.'

The patent now in suit came before this court in the case of Welsbach Light Co. v. Sunlight Incandescent Gas Lamp Co., and at final hearing upon pleadings and proofs, and after a three days' argument, was carefully considered by Judge Townsend. His opinion will be found in 87 F. 221. The matters discussed upon that hearing and disposed of in the opinion were anticipation, state of the art, construction of the patent, range of equivalents, and infringement. Reference may be had to the report, but it may be said briefly that the court found that there was no anticipation in the patents of Bright, Gwynn, Toppan, or Clamond; that the state of the art was such that the Rawson invention was a highly meritorious one; that the evidence indicated 'not only the presence of inventive genius, but claimed for the invention the rank of a pioneer'; that because the invention was of such rank the patent should not be narrowly interpreted, but should be so construed as to cover a broad range of equivalents; that the process of the Sunlight Company, which consisted in dipping or immersing the burned out mantles in a solution composed chiefly or collodion, with the addition of a small percentage of castor oil, was an infringement, because, although such a collodion solution was not specifically mentioned in the patent, its mode of operation was well known, and it was fairly within the words of the specification, 'Other materials may be employed as long as they set hard at ordinary temperatures, and burn away without mechanical destruction to the mantle.' In this state of affairs the granting of a preliminary injunction against a defendant using substantially the same collodion mixture, and producing no new evidence of anticipation or as to the state of the art, would seem to be a foregone conclusion; and the writer so held when this application was first made in April, 1898. Welsbach Light Co. v. Rex Incandescent Co., 94 F. 1004. Whatever may be the practice in other circuits, there has been here no departure from that laid down in American Paper Pail & Box Co. v. National Folding Box & Paper Co., 2 C.C.A. 165, 51 F. 229, which indicates that, when a patent has been established by a decision of a circuit court, after careful consideration upon a full record, another judge sitting subsequently in the same cour...