Application of Miller

• Decision Date: 13 May 1971
• Docket Number: Patent Appeal No. 8444.
• Citation: 441 F.2d 689,169 USPQ 597
• Parties: Application of William A. MILLER.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

169 USPQ 597, 441 F.2d 689 (1971)

Application of William A. MILLER.

Patent Appeal No. 8444.

United States Court of Customs and Patent Appeals.

May 13, 1971.

Jay P. Friedenson, Morristown, N. J., attorney of record, for appellant.

S. Wm. Cochran, Washington, D. C., for the Commissioner of Patents. Joseph F. Nakamura, Washington, D. C., of counsel.

Before RICH, ALMOND, BALDWIN and LANE, Judges, and FORD, Judge, United States Customs Court, sitting by designation.

RICH, Judge.

This appeal is from the decision of the Patent Office Board of Appeals affirming the examiner's rejection of claims 1, 2, and 4-18 in appellant's application serial No. 321,353, filed November 4, 1963 for ultrafine particles of polytetrafluoroethylene and a method for making them. We reverse.

THE INVENTION

Polytetrafluoroethylene (hereinafter "PTFE") is the plastic well known under the trademark "Teflon." We are told that it is sold commercially in both powdered and powdered ultrafine form and that the powdered ultrafine PTFE as is and the powdered PTFE after further comminution are used to fabricate shaped articles. PTFE powder does not melt and flow even when heated under pressure, but ultrafine PTFE particles can be shaped under high pressure in a mold to a preform sufficiently strong and coherent to be removed from the mold. The preform can then be heated in a furnace to a temperature at which sintering occurs, resulting in coalescence of the particles into usable articles of the same shape as the preform.

Appellant claims PTFE in finely powdered, non-fibrous form and a method of preparing the powdered product consisting of grinding the PTFE powder commercially available in a particular type of air mill which is concededly old for other purposes. Commercially available PTFE powder has been ground in other types of air mills into ultrafine, fibrous particles before premolding, but appellant maintains that grinding such powder in this particular type of air mill, which mills and classifies sequentially, rather than simultaneously as in the previously used air mills, results in non-fibrous, ultrafine PTFE powder with significantly improved preform strength (unsintered flex strength). This is said to be advantageous because it reduces scrap reworking due to cracking on removal from the mold. Claims 1 and 2 are reproduced as illustrative, with subparagraphing supplied and the recitations principally in controversy emphasized:

1. A method for preparing polytetraflouroethylene adapted for molding precision parts and thin sheeting, comprising.

the sequential steps of

(a) subjecting particles of polytetraflouroethylene, which particles are at least 100 microns in their smallest dimension, to milling effected substantially solely by interparticulate collision, at a temperature of less than about 200°F;

(b) classifying the milled particles to separate therefrom particles having a maximum dimension of up to and including about 50 microns, wet-sieve size; and

(c) subjecting the unseparated particles of larger than about 50 microns, wet-sieve size, repeatedly to the milling effected substantially solely by interparticulate collision, at a temperature of less than about 200°F.

2. Ultrafine polytetrafluoroethylene adapted for molding precision parts and thin sheeting comprising

porous non-fibrous particles with rounded countours having

a particle size, wet sieve, no greater than 50 microns,

said polytetrafluoroethylene material having

a distribution function of no greater than about .40,

a sub-sieve size of no greater than about 5.0 microns,

a ratio of wet-sieve size to sub-sieve size in the range of about 2 to about 10;

having, upon molding to a zero void content at 6,000 psi,

an unsintered flex strength of at least 860 psi; and

having, after sintering,

a tensile strength of no less than about 4000 psi,

a percent elongation of no less than about 300,

an anisotropic expansion factor of no greater than about 1.13,

a dielectric strength of no less than about 1200 volts per mill,

a surface roughness of no greater than about 82 microinches at 500 psi and no greater than 32 microinches at 2000 psi and

a percent void content of no greater than 0.1% at pressures greater than 2000 psi.

THE REJECTIONS

The references relied on are:

                Thomas et al.    2,936,301    May  10, 1960
                Wallace          3,178,121    Apr. 13, 1965
                                          Filed Apr. 24, 1962
                

The examiner rejected all claims now appealed "as indefinite under 35 U.S.C. § 112," reasoning that, "If a product is to be claimed, it must be defined in terms of its own properties" and that "Applicants' sic recitation of an unsintered flex strength is not * * * indicative of the properties of the PTFE powder, rather of the unsintered premolded article the powder will be used for." He additionally rejected claims 1, 2, 4-8, and 15-18 as unpatentable over Thomas under 35 U.S.C. § 102 on the ground that "These claims are not considered to define over powder G of Thomas et al in that unsintered flex strength does not define the PTFE claimed" and all claims as unpatentable over Thomas under 35 U.S.C. § 103 on the ground that

It would be obvious to one skilled in the art to employ any mill, including a "Jet-O-Mizer"¹ to prepare the powdered PTFE products of Thomas et al. Applicants\' sic affidavit does not present any significant results that would refute this contention. Routine experimentation by one skilled in the art would lead to the use of any air mill to grind PTFE in view of the fact that Thomas et al disclose air mill grinding of PTFE and more particularly to a "Jet-O-Mizer" admitted by applicant to be an old milling device.

The board affirmed all three rejections. However, it advanced what we consider to be three separate rationales for the section 112 rejection. The first, which it denominated "The more important point," was that the unsintered flex strength recitation is "directed at a result in the preform that is obtainable from the claimed powder upon forming it" and is therefore "Obviously * * * not helpful in defining the particulate composition or the method for producing it." Second, even if such recitation might be permissible as a last resort when the product could not otherwise be identified,

* * * the characteristics of the composition which contribute to the resulting flex strength and the steps of the process used in producing it are all physical or mechanical, presenting no apparent difficulties in direct identification * * * and thus require no resort to indirect modes of identification.

Finally, the flex strength limitation is indefinite because it "fails to recite the temperature of molding and the compositional characteristics of the material molded, which obviously will profoundly affect the preform strength."

As to the prior art rejections, the board affirmed both the section 102 and section 103 rejections without clearly distinguishing between them. However, it would seem that the board, like the examiner, first determined the flex-strength recitation to be impermissible, thereafter ignored it, and found everything else to have been anticipated by Thomas. As far as it considered the possibility that appellant's product and process were "not identically disclosed or described" in Thomas, it focused on the degree of interparticulate collision in appellant's mill and the mill disclosed in Thomas, which is a characteristic on which appellant expressly did not predicate patentability, and ignored sequential versus simultaneous classification, the characteristic on which appellant did rely for patentability. Additionally, the board questioned the sufficiency of appellant's comparisons, which indicated that a flex strength of 828 psi was the maximum obtainable by the method disclosed in Thomas in contrast to the minimum of 860 psi recited in appellant's claims, but held that

* * * even assuming a valid comparison in all respects, a difference between 828 and 860 in the "unsintered flex strength" would hardly have been an unobvious one in the use of an apparatus more effective in the degree of interparticulate reduction achieved.

OPINION

The Section 112 Rejection

The principal rationale for the section 112 rejection was simply that unsintered flex strength is a property of compacted preforms made from PTFE powder rather than a property of the powder itself, and that only properties of the powder, as a powder, could be used in defining the powder claimed. Appellant argues that the powder's capability of being compacted into a preform having at least the specified "unsintered flex strength" of the preforms is a property of the powder which may be used to define the powder.

The first sentence of the second paragraph of 35 U.S.C. § 112 requires only that claims "set out and circumscribe a particular area with a reasonable degree of precision and particularity." In re Moore, 439 F.2d 1232, 1235, 58 CCPA (1971). In the absence of evidence to the contrary, we will assume, as we said in Moore, that what the claims define is what the applicant regards as his invention. If those skilled in the art can tell whether any particular PTFE powder is or is not within the scope of a claim, the claim fulfills its purpose as a definition. As we remarked recently in reversing a section 112 rejection made on the ground that particular language was "functional" and thus "indefinite," "we are unable to see merit in any proposition which would require the denial of a claim solely because of the type of language used to define the subject matter for which patent protection is sought." In re Swinehart, 439 F.2d 210, 212, N. 4, 58 CCPA (1971). See also In re Wakefield, 422 F.2d 897, 904, 57 CCPA 959, 967 (1970) (holding the scope of a claim to be definite "because each recited limitation is definite").

In this case, it seems to us that those skilled in the art will be in no uncertainty concerning what subject matter falls within the scope of the claims. The claims in question...