Application of Adolph P. Alexander

311 F.2d 585, 50 C.C.P.A. 1112

• Court: Court of Customs and Patent Appeals
• Decided: January 16, 1963
• Docket: Patent Appeal 6839
• Status: Published

Opinions

WORLEY, Chief Judge.

Appellant seeks a patent on a method of nodularizing cast iron and the resulting product. The Board of Appeals affirmed the examiner’s rejection¹ of claims 3 through 14, and 16 through 18 in appellant’s application ² entitled “Ductile Iron Casting” as being obvious in view of the prior art. Appellant asks us to reverse that decision.

Claims 4 and 16 of the appealed claims read:

“4. A method of producing an improved iron casting of the type having in the as-cast condition- free carbon agglomerated subtantially in nodular form dispersed in the matrix thereof comprising the establishing of a molten iron mix of hyper-eutectic composition and containing sulfur' in an amount not exceeding 0.03 percent which molten iron if then cast would result in cast iron containing free carbon in flake form dispersed in the matrix thereof, introducing into said molten iron mix an effective amount to retain from 0.02 percent to 1 percent by weight in said improved iron casting of at least one nodular carbon impelling agent selected from the group of elemental metals consisting of lanthanum, samarium, praseodymium and neodymium and thereafter pouring said improved iron casting from the resulting molten iron composition.

“16. As an article of manufacture an improved iron casting containing uncombined carbon substantially in spherulitic nodular form dispersed in the matrix thereof, said improved iron casting having no sulfur in excess of 0.03 percent by weight and containing at least 0.02 percent and not more than 1 percent by weight of at least one element selected from the group of elemental metals consisting of lanthanum, samarium, praseodymium and neodymium as a nodular carbon impelling agent, said improved iron casting being re-meltable and re-cast while retaining said carbon in spherulitic nodular form without further addition of said nodular carbon impelling agent.”

The application relates to a method of producing cast iron having its free carbon in nodular form, and the resulting products described as “nodular iron.” The method involves adding to molten iron a small amount of one or more of the metals lanthanum, samarium, praseodymium and neodymium. That treatment of cast iron causes the carbon present therein in flake form to coalesce into microscopic speroidal particles called nodules. It appears that the carbon, when present in the iron in flaked form, causes interruptions in the continuity of the metal matrix with resultant physical weakness; whereas, when the carbon is present in nodular form, such interruptions are lessened, resulting in a corresponding increase in the strength of the metal.

The single reference relied on is:

British patent 721,717 January 12, 1955.

That patent describes a method for improving the properties of cast grey iron by adding certain nodularizing agents. The general technique and purpose of nodularizing cast iron with many metals and alloys is acknowledged by the reference as having been common knowledge in the prior art. The main purpose of the patentee is to replace the expensive metals previously used, such as magnesium, with cheaper and less hazardous materials.

The following portions of the British patent were relied upon by both the examiner and the board, and seem to be the most pertinent:

“ * * * It is believed that the calcium carbide reacts with the magnesium oxide to reduce it and free elemental magnesium, which then participates in the calcium carbide injection treatment to cause the subsequent formation of nodular iron.

“Other nodulization-impelling agents may be used instead of, or in addition to, the magnesium addition of Table IV. For example, rare earth metals, alloys, or compounds or mixtures thereof, such as alloys of lanthanum and the lanthanum series rare earth metals or mixtures of their oxides, may be used. * * * ******

“It is believed that when the combination calcium carbide-rare earth oxide treatment is used, the carbide reduces the oxide and frees the rare earth metal element, which then participates in the combination treatment to form the upgraded or nodular iron. Thus, the rare earth metal itself could be used, if desired, in combination with the calcium carbide to effect the combination treatment. * * *

******

“The rare earth oxides as used with the present invention are believed to be reduced by the injected calcium carbide at the normal founding temperatures * * * to liberate cerium, lanthanum, and other rare earth elements. * * * ” (Italics supplied.)

The issue is whether, when viewed in light of the entire disclosure of the British patent, it would be obvious to one skilled in the art to use lanthanum in metallic form as a nodulization-impelling agent.

In affirming the examiner’s rejection the board stated:

“We have carefully considered appellant’s arguments but we find no error in the Examiner’s rejection. The reference makes a clear and unequivocal statement that lanthanum and lanthanum series rare earth metals may be used as nodulizationimpelling agents. We see no invention in actually employing these metals for this purpose and finding that they actually do function in the manner taught by the reference. Claim 6 of the British patent specifies the use of lanthanum as a nodulization agent. (Italics supplied.)

******

“ * * * We are of the opinion that it would be obvious to one skilled in this art to employ alloys of lanthanum and other rare earth metals such as neodymium as nodulization-impelling agents in view of the fact that in the British patent alloys of lanthanum may 'be used.Jfc # ff

Appellant argues that the board has misconstrued the teachings of the reference, i. e., that the patent discloses the use of lanthanum, only in conjunction with calcium carbide, without any teaching that the metal alone is usable as a nodulizing agent. He contends'also that whatever teaching might exist is further obscured by the fact that the patentee “includes at least some materials, which when used alone (apart from calcium carbide and other agents) are relatively ineffective to produce nodular iron,” citing the following from the reference :

'“The invention not only enables extremely small amounts of the rare earth nodulization-impelling agents to be used but also enables the rare earths to be used in their inexpensive, readily available, oxide form. Tests show that rare earth oxides when injected alone (the calcium carbide and other agents being omitted) are relatively ineffective.”

It seems to us the interpretation of the reference by the board is correct. The British patent discloses that when rare earth metal oxides are used the calcium carbide functions to reduce the oxides to their elemental metallic form; the reference also teaches that in their elemental form the metals act as nodulization-impelling agents. Since the rare earth metals themselves, such as lanthanum and neodymium, are taught to be active ingredients in the nodulization process, the reference contains an adequate suggestion to one skilled in the art that the metals are useful by themselves as nodulization-impelling agents.

Appellant’s argument that the teaching of the reference is obscured by the fact that it states that the metal oxides alone are ineffective, was adequately answered by the board:

“We attach no patentable significance to the fact that the reference uses the rare earth metal oxides in •combination with calcium carbide, or that the reference indicates that these oxides are relatively ineffective when used alone. Appellant’s rejected claims do not exclude the presence of other components such as calcium carbide. It appears clear to us that it is the free metal, whether magnesium, cerium, lanthanum or other rare earth metal, which is the effective nodulization impelling agent. * * * ” (Italics supplied.)

Full consideration has been given to all of appellant’s arguments, including those regarding proportions and allegedly unobvious results, but we are unable to agree that the board erred in denying appellant’s application.

The decision is affirmed.

Affirmed.

1 . One claim was allowed.

2 . Serial No. 625,298, filed November 30, 1956.