International Salt Co. v. Commissioner of Patents

• Decision Date: 15 April 1970
• Docket Number: 22902.,No. 22900,22900
• Parties: INTERNATIONAL SALT COMPANY v. COMMISSIONER OF PATENTS, Appellant. INTERNATIONAL SALT COMPANY, Appellant, v. COMMISSIONER OF PATENTS.
• Court: U.S. Court of Appeals — District of Columbia Circuit

140 US App. DC 378, 436 F.2d 126 (1970)

INTERNATIONAL SALT COMPANY v. COMMISSIONER OF PATENTS, Appellant.

INTERNATIONAL SALT COMPANY, Appellant, v. COMMISSIONER OF PATENTS.

Nos. 22900, 22902.

United States Court of Appeals, District of Columbia Circuit.

Argued January 13, 1970.

Decided April 15, 1970.

Mr. Jack E. Armore, Atty., U. S. Patent Office, with whom Mr. S. William Cochran, Acting Solicitor, U. S. Patent Office, was on the brief, for appellant in No. 22,900 and appellee in No. 22,902. Mr. Joseph Schimmel, Atty., U. S. Patent Office, at the time the record was filed, also entered an appearance for appellant in No. 22,900.

Mr. Edward B. Beale, Washington, D. C., for appellee in No. 22,900 and appellant in No. 22,902.

Before TAMM and ROBB, Circuit Judges, and JAMESON,^* Senior District Judge.

TAMM, Circuit Judge:

This case arises on cross-appeals from a decision of the district court determining the patentability of a process for producing pure salt brine. The trial court rejected the Patent Office's conclusion that all of the company's seven pending claims were unpatentable; instead, it held that the company was entitled to patents on two of the claims. A third claim was dismissed "without prejudice," all other claims having been withdrawn from suit. For the reasons hereinafter stated, we hold that the district court's determinations of patentability were erroneous as a matter of law and must be reversed.

I. THE CLAIMED INVENTION

As is often true in patent cases, proper disposition of the pending controversy requires both a detailed description of the disputed patent's subject matter and a survey of the technical developments leading to the claimed invention. The product in question, salt, has been used and produced by mankind since prehistoric times, primarily for seasoning and preserving food;¹ in recent years, however, salt has found many new industrial uses, notably in the synthetic chemistry underlying a surprising variety of commercial products. (I J.A. 50; II J.A. 264-65.) In these latter uses salt must be reduced to its constituent elements through electrolytic processes, and for these purposes very pure salt brine is needed. Since brine is merely a mixture of salt and water or some other solvent, the basic problem for industrial users is finding an efficient means of removing the impurities which are found in salt as it exists in its natural state.

The great bulk of industrial salt is mined from subterranean beds of rock which were deposited when primeval seas retreated from the present land masses.² This rock salt contains various impurities in different proportions, but one of the most common and troublesome contaminants is anhydrous calcium sulfate, commonly referred to in the trade as "anhydrite." In comparison to salt, calcium sulfate is relatively insoluble in water; it is, however, more easily soluble in dilute brine solutions. Kaufmann, the developer of the process currently in issue, sought to capitalize upon these differences in solubility as a basis for separating the anhydrite from the brine. In simple terms, his process employed three chief components: a dissolving chamber, a brine pump, and a centrifugal separator. The dissolving chamber, as depicted in the record, is simply a vertical tank into which the rock salt is fed. (II J.A. 340.) The solvent, water, is piped into the bottom of this tank at high speeds, at least in comparison to rates normally found in salt-dissolving chambers. The water proceeds rapidly upward through the bed of rock salt, dissolving the salt but not the less soluble anhydrite; the calcium sulfate, freed from the dissolving rock salt, is "entrained" or carried along largely undissolved in the flowing water. The rapid movement of the water is maintained by a pump attached to a pipe which exists from the top of the dissolving tank. The water (which by this stage of its journey has become brine) is drawn off at that point and fed into a "hydrocyclone" or centrifugal separator, which is designed to achieve rapid removal of the anhydrite before it has an opportunity to dissolve. The separator is simply a cone-shaped tank, with the point of the cone facing downward. The outflow from the dissolving chamber is pumped into the top or wide end of the cone, at high speed and tangentially to the side of the cone. This imparts sufficient rotational motion to the fluid to create a "whirlpool" effect; the undissolved anhydrites and other solid impurities are thus forced outward against the sides of the cone, and then down the sides and through a waste outlet consisting of a pipe exiting from the point of the cone. The purified brine is contemporaneously piped off from the top center of the separator.

II. PROCEDURAL HISTORY OF THE CASE

Appellant International Salt Company (hereinafter "plaintiff" or "the company") is assignee of Patent Application No. 261,929, filed by Kaufmann on February 11, 1963. This application consisted of a number of separate claims describing the foregoing process, which was denominated the "Fractional Dissolution Method." After extended proceedings before the Patent Office, which we need not discuss in any detail, the Board of Appeals ruled that the process described above was not patentable because it would be obvious to one skilled in the art, and would produce a result which "constitutes only a difference of degree and not a difference in kind such as would give rise to patentable invention." (II J.A. 366-67.) The company then brought an action against the Commissioner of Patents in the district court pursuant to 35 U.S.C. § 145 (1964), seeking a judgment authorizing the issuance of patents on claims 2 through 8 of the application. When the case came on for trial, plaintiff withdrew four claims from suit, leaving in issue only claims 4, 5, and 8. (I J.A. 14-15.) At the conclusion of the trial, the court ruled that plaintiff was not entitled to a patent on any of these three claims. (I J.A. 94.)

Plaintiff thereupon retained new counsel, filed notice of appeal (I J.A. 96), and then filed a motion in the district court seeking to have the judgment vacated and a new or reopened trial granted. On June 6, 1968, the district court ordered the trial reopened pursuant to Rule 60(b) (6) of the Federal Rules of Civil Procedure "to permit plaintiff to present additional evidence" and "to permit plaintiff to modify the withdrawal of claims 2, 3, 6 and 7." (I J.A. 97.) Thereafter this court remanded the pending appeal, and a second trial was held in November of 1968 on claims 4, 5, and 6. On January 8, 1969, the district court entered a second judgment authorizing the issuance of a patent on claims 5 and 6 but dismissing the complaint as to claim 4 "without prejudice."³ The Commissioner of Patents took the present appeal, contending that the district court erred as a matter of law in holding the two claims patentable, and dismissing the other claim without prejudice; the plaintiff cross-appealed, asserting that the district court erred in dismissing its complaint as to claim 4.

III. PATENTABILITY OF THE CLAIMED INVENTION

Most of the substantial questions presented by this appeal center around the standard of "obviousness" codified in 35 U.S.C. § 103 (1964), which provides that a patent may not be obtained "if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains." The broad outlines of our approach in determining questions of obviousness were sketched in Higley v. Brenner, 128 U.S.App.D.C. 290, 292, 387 F.2d 855, 857 (1967): "What the prior art is and what the claimed invention is are questions of fact. However, whether the standard of obviousness applied to those facts is correct, is a question of law."

In the instant case there is no doubt that the individual components of the claimed invention were well known in the prior art; as the district court found, "we have here a situation that occurs on occasion when an inventor takes known elements, the significance of which had not been fully appreciated, puts them together and harnesses them to do something that had not been done the same way before." (I J.A. 217.) The Supreme Court has counseled judicial caution in evaluating such patent claims:

Courts should scrutinize combination patent claims with a care proportional to the difficulty and improbability of finding invention in an assembly of old elements. The function of a patent is to add to the sum of useful knowledge. Patents cannot be sustained when, on the contrary, their effect is to subtract from former resources freely available to skilled artisans. A patent for a combination which only unites old elements with no change in their respective functions * * * obviously withdraws what already is known into the field of its monopoly and diminishes the resources available to skillful men.

Great Atlantic & Pacific Tea Co. v. Supermarket Equip. Corp., 340 U.S. 147, 152-153, 71 S.Ct. 127, 130, 95 L.Ed. 162 (1950).

With this general philosophy in mind, we turn to the claims presently in issue. In general, the distinctions among the three claims may be summarized as follows: claim 4 describes an upward flow of solvent in the dissolving chamber, but does not specify any flow rate; on the other hand, claims 5 and 6 do not require any particular direction of solvent flow, but do require a flow rate of at least ten gallons per minute per square foot of cross-sectional area of flow path. Finally, claim 4 does not specify how the final separation of anhydrite from brine is to be effected, but claims 5 and 6 require centrifugal separation. According to the trial court's findings and the company's brief in this court, the common nexus among all of these claims, and the nugget of patentable invention if any is to be found here,...