United States Mitis Co. v. Carnegie Steel Co.

89 F. 343, 1898 U.S. App. LEXIS 3066
U.S. Circuit Court for the District of Western Pennsylvania·Decided July 30, 1898·Published·Cited by 4 cases

Opinion

ACHESON, Circuit Judge.

The bill charges the defendant with the infringement of letters patent No. 333,373, for an improvement in “the process of manufacturing castings from wrought iron and steel by adding aluminium,” dated December 29, 1885, and issued to Thorsten Nordenfelt, assignee of Carl Gustav Wittenstrom, the inventor. The specification of the patent begins by pointing out that “one of the great difficulties in making castings from steel is to get a product which is solid, sound, homogeneous, or free from blisters or cavities.” It refers to recent improvements in the art of steel casting effected by adding to the metal ferro-manganese and other compounds containing carbon, silicon, and manganese, but states that, while “these admixtures make the product.somewhat more solid, they deteriorate the quality in other respects, as the product gets harder and more brittle, or red-short.” The specification sets out the inventor’s discovery, upon which is based his described process, thus:

“I have found that castings of wrought iron or mild steel may be obtained solid without changing the intrinsic quality of the metal by the addition of the metal aluminium either alone or In the shape of an alloy, such addition to be made after the iron or steel has been melted, and preferably just before the pouring is commenced.”

Then follows this statement:

“The melting point of aluminium is about 800° Fahrenheit, and the effect of such addition is to lower the melting point of the mixture, and thereby render it more fluid (as it at once becomes superheated), so that the gases in the metal pass away easily, the metal runs freely into the mold, and a more perfect product is obtained. I use no fluxes whatever.”

In respect to proportions, the specification states:

“I have found that the use of a minute quantity, never exceeding one per cent, by weight, preferably from one-fifth to one-tenth of one per cent., by weight, of metallic aluminium, added to the molten iron, has the desired influence, and even a very much smaller percentage has an appreciable influence, and the proportions stated may be-departed from to some extent.”

The specification contains this further statement:

“The iron or steel is melted in crucibles or metal smelting furnaces of any suitable description, and the addition of the aluminium or alloy of iron and aluminium is made to the metal after it is molten, and preferably about when it is to be poured. It is convenient to provide a plug in the corner of the crucible, which is removed when the metal is completely melted. A tube is inserted into the aperture, and the aluminium to be added is passed down the tube. The tube is removed. The molten metal is then preferably stirred, and the plug replaced, and the metal is ready for pouring as soon as it is quiet.”

Then follows this disclaimer:

“I am aware that heretofore it has been demonstrated (see Percy’s Metallurgy of Iron and Steel, p. 182, and the Quarterly Journal of Arts and Sciences for 1820, p. 320) that by the addition to steel of about one-fourth of-[345]*345one per coni, of aluminium there could be obtained a product retaining its malleability, and resembling ‘WooIk steel.’ Such product, however, was obtained by melting the aluminium and steel together, which would not only cause a waste of the aluminium, but would render the Anal proportions of the two metals uncertain. Moreover, the addition of the aluminium before Ote iron or steel is melted would not have the effect of superheating the meta] at the time the casting' is effected, which is an important object of my invention. X do not, therefore, wish to be understood as claiming every way of treating wrought iron or steel having aluminium added to it Neither do X wish to be understood as claiming a process of treating wrought iron or steel having addl'd to it aluminium, in which the aluminium and the iron or steel are fused together.”

The specification then states that a superheated state of the metal is essential for the practical performance of casting into several molds, and that by adding the aluminium to the wrought iron or steel, and fusing them together, a superheating would result in injury, as the metal would become red-short, or take up gases; “whereas, by first melting the iron or stool and then adding the aluminium before pouring, the ‘superheating’ (if it may be so-called) produced by a sudden lowering of the melting point, does not: injure the metal.”

The patent contains a single claim, in the words:

“The hereinbefore described process of manufacturing castings from wrought, iron or steel, consisting in the admixture with the molten iron or steel of aluminium in .about the proportions specified, and then casting, substantially as and for the purpose set forth.”

From the contents of the specification, as well as from the terms of the claim itself, it is plain (.hat this patent is not for any metal-making process. The invention does not at all retíate to the production or refining of metal. The; improvement is wholly in the process of manufacturing castings from the two named metals, wrought iron and steel. The patented process begins after the metal to be operated upon has been produced and brought to a molten condition. The evil in (he prior art which the inventor sought to remedy was the difficulty of obtaining' good castings from wrought iron or steel without deteriorating the intrinsic character of the metal itself. This was the desideratum to which Wittenstrom attained. IXis invention consisted in the process of making castings from wrought iron or steel by the addition of a minute quantity of aluminium to the molten metal “at the time the casting is effected,” and as an incident of the operation, whereby, and without changing the intrinsic quality of the metal, su perior tastings are obtained, — castings which are sound inside and externally symmetrical.

Such being the nature of the Wittenstrom invention, I reach the conclusion that it was not anticipated or suggested by any of the prior patents in evidence. Nor can it fairly be said that anything to be found in those patents, or in any prior publications, detracts aught from the importance of Wittenstrom’s discovery, or the undoubted merits of his process based on that discovery. The evidence is quite convincing that Ms invention was of a primary character. Therefore the patent should be liberally construed so as to secure to the patentee and his assignees the fruits of the actual invention in full measure, if this can be done consistently with the terms of the speciticaiion and claim.

[346]*346The specification unnecessarily contains a scientific theory with respect to the action of the aluminium. . It was the supposition of the inventor that the aluminium acted to lower the melting point of the mixture, and thereby render it more fluid. This is not now the generally accepted explanation of the phenomenon which follows the addition of the aluminium to the molten metal. The prevalent opinion among metallurgists is that the aluminium acts here as a deoxidizing agent. It matters not, however, that the patentee may have been mistaken in stating the rationale of his process. He fully described the invention itself, and its practical results, and gave sufficient directions for putting it into practical use', and the law requires nothing more.

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United States Mitis Co. v. Carnegie Steel Co., 89 F. 343, 1898 U.S. App. LEXIS 3066 (circtwdpa 1898).

89 F. 343 (United States Mitis Co. v. Carnegie Steel Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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