Application of Crockett, Patent Appeal No. 6478.

• Decision Date: 08 June 1960
• Docket Number: Patent Appeal No. 6478.
• Citation: 126 USPQ 186,279 F.2d 274
• Parties: Application of John M. CROCKETT and Philip M. Hulme.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

126 USPQ 186, 279 F.2d 274 (1960)

Application of John M. CROCKETT and Philip M. Hulme.

Patent Appeal No. 6478.

United States Court of Customs and Patent Appeals.

June 8, 1960.

Clarence M. Fisher, Washington, D. C. (H. Hume Mathews, Murray Hill, N. J., of counsel), for appellants.

Clarence W. Moore, Arthur H. Behrens, Washington, D. C. (Raymond E. Martin, Washington, D. C., of counsel), for the Commissioner of Patents.

Before WORLEY, Chief Judge, and RICH, MARTIN, and SMITH, Judges, and Judge WILLIAM H. KIRKPATRICK.¹

RICH, Judge.

This appeal is from the decision of the Patent Office Board of Appeals affirming the rejection of claims 94, 95 and 96 of appellants' patent application No. 305,315 entitled "Cast Irons and the Manufacture thereof." The appealed claims are as follows:

"94. A method for treating gray iron prior to casting thereof, comprising, establishing a bath of a gray cast iron composition containing iron more than 90%, carbon from 1.7% to 4.5%, silicon from 1.0% to 3.5%, and manganese from 0.1% to 1.0%, injecting into said bath a mixture comprising essentially a major proportion of finely-divided calcium carbide and a minor proportion of finely-divided magnesium oxide, said mixture being injected with a carrier gas stream in an amount such that the total amount of carbide injected is in the range from 5 to 75 pounds of carbide per ton of molten metal, and casting the resulting treated molten metal promptly following said carbide-oxide treatment to provide an as-cast product having a retained magnesium content of less than .02% and which is substantially free of retained elemental calcium and which is characterized by the presence of uncombined carbon in nodular form.

"95. A method for treating gray cast iron prior to casting thereof, comprising establishing a bath of a gray cast iron composition containing iron more than 90%, carbon from 1.7% to 4.5%, silicon from 1.0% to 3.5%, and manganese from 0.1% to 1.0%, injecting into said bath a mixture comprising essentially a major proportion of finely-divided calcium carbide and a minor proportion of finely-divided rare earth oxide, said mixture being injected with a carrier gas stream in an amount such that the total amount of carbide injected is in the range from 5 to 75 pounds of carbide per ton of molten metal, and casting the resulting treated molten metal promptly following said carbide-oxide treatment to provide an as-cast product which is substantially free of retained elemental rare earth and elemental calcium and which is characterized by the presence of uncombined carbon in nodular form.

"96. A treating material for injection into molten gray cast iron to produce upgrade or nodular gray cast iron products and which comprises essentially a major proportion of finely-divided calcium carbide in admixture with a minor proportion of a finely-divided nodulizing agent selected from the group consisting of magnesium oxide and rare earth oxides."

The references relied on are:

                  Morrogh I    2,488,512  November 15, 1949
                  Morrogh II   2,552,204  May       8, 1951
                  Morrogh III  2,747,990  May      29, 1956
                

Appellants' invention relates to the production of cast iron having its graphitic carbon wholly or partly in the form of nodules. The step in the claim process with which we are here concerned consists of supplying to a bath of molten cast iron a stream of inert gas carrying a major proportion of finely-divided calcium carbide and a minor proportion either of magnesium oxide (claim 94) or an oxide of a rare earth metal (claim 95) in a finely-divided condition and promptly thereafter casting the treated molten metal.

The three reference patents are referred to by the board and in the briefs as Morrogh I, II, and III and will be so referred to here.

Morrogh I discloses a process for the production of a high silicon corrosion-resistant cast iron containing more than ten percent of silicon by weight, in which cerium is added to the molten iron "immediately before pouring." The result is said to be a cast iron free from coarse graphite flakes with improved mechanical properties and a freedom from porosity cavities, the graphite being present "in very finely-divided form or as a mixture of very finely-divided graphite and nodular graphite." The cerium may be added in pure metallic form, as an alloy with other metals or as "a reducible cerium compound."

Morrogh II relates to the production of cast iron in which the free carbon is present as graphite predominantly in the form of nodules. This result is said to be obtained by adding to the molten iron, before casting, magnesium oxide (magnesia) which may be introduced in the form of briquettes which also contain lime and silicon.

Morrogh III relates to the production of cast iron in which the graphite is present wholly or predominantly in nodular form, and discloses a process in which finely-divided calcium carbide entrained in a stream of inert gas is injected into the molten iron before casting.

The claims were rejected on Morrogh III as a primary reference in view of the other Morrogh patents as secondary references. Claim 94 was considered unpatentable over Morrogh III in view of Morrogh II on the ground that it would be within the skill of the art, in view of the latter patent, to add a minor proportion of magnesium oxide to the calcium carbide of the former.

We agree with the Patent Office tribunals that the combination of steps of claim 94 would have been obvious to a person of ordinary skill in the art. The patents clearly teach that both magnesium oxide and calcium carbide, individually, promote the formation of a nodular structure in cast iron, and it would be natural to suppose that, in combination, they would produce the same effect and would supplement each other. Even assuming, as appellant alleges to be the case, that the two together produce an effect somewhat greater than the sum of their separate effects, we feel that the idea of combining them would flow logically from the teaching of the prior art and therefore that a claim to their joint use is not patentable. In re Heinrich, 268 F.2d 753, 46 CCPA 933, and cases there cited. Accordingly the affidavits of record indicating that the process of claim 94 yields good results and has been commercially successful are not persuasive of the patentability of claim 94.

Appellants contend that magnesium oxide, as used in the Morrogh II process, will not produce a nodular structure in cast iron, and they have submitted affidavits purporting to establish this. We have considered the affidavits, but agree with the examiner and the board that they are inconclusive and fail to overcome the presumption of operativeness which attaches to the patent. Certain specific examples are given in the affidavits in which a nodular structure was not obtained although magnesium oxide was used, but it does not appear that any thorough investigation was made as to the effect of various amounts of that substance, nor does it appear that it was used...