## Facts

- Gilbert P. Hyatt filed a patent application for a Fourier transform processor.
- The only claim ultimately at issue, claim 35, used “means-for” functional language but effectively recited a single element (“incremental means”) for producing Fourier transformed incremental output signals from incremental input signals.
- The examiner initially rejected claim 35 under 35 U.S.C. § 102.
- On Hyatt’s first appeal, the Board of Appeals reversed the § 102 rejection but entered a new rejection under 35 U.S.C. § 112, ¶ 2, treating claim 35 as a “single means claim” and concluding the claim’s scope could not be determined without speculation about an implied combination.
- Hyatt continued prosecution and amended claim 35, but the amendment did not change the claim’s basic single-means character.
- The examiner maintained the § 112 rejection; on a second appeal, the Board reiterated its § 112, ¶ 2 rejection.
- Hyatt appealed to the United States Court of Appeals for the Federal Circuit, which reviewed the Board’s affirmance of the rejection.

## Issues

1. Whether a “single means” claim drafted in means-plus-function form satisfies the requirements of 35 U.S.C. § 112.
2. Whether the proper statutory basis for rejecting such a claim is 35 U.S.C. § 112, ¶ 2 (definiteness) or 35 U.S.C. § 112, ¶ 1 (enablement/undue breadth).

## Decision

- The Federal Circuit affirmed the rejection of claim 35.
- The court agreed claim 35 was an unpatentable “single means claim.”
- The court held the defect was more properly analyzed under § 112, ¶ 1 (enablement/undue breadth), rather than § 112, ¶ 2 as the Board had stated.

## Legal Principles

- A claim that uses broad functional language to cover “every conceivable means” of achieving a result may be unpatentable if the specification enables only the means known to the inventor.
- Overbroad functional claiming is properly addressed under 35 U.S.C. § 112, ¶ 1 when the claim scope exceeds the enabling disclosure.
- Section 112, ¶ 2 addresses whether the claim particularly points out and distinctly claims the invention, but uncertainty about scope may reflect an underlying enablement/commensurability problem governed by § 112, ¶ 1.
- Means-plus-function claiming under § 112’s last paragraph (now § 112(f)) does not permit functional claiming that, in effect, preempts undisclosed and later-developed implementations beyond what the specification teaches.

## Conclusion

The Federal Circuit affirmed the USPTO’s rejection of Hyatt’s single-means, means-plus-function claim because its functional breadth exceeded what the application enabled; the court clarified that the correct statutory basis was § 112, ¶ 1 rather than a pure definiteness rejection under § 112, ¶ 2.


In re Hyatt, 708 F.2d 712 (Fed. Cir. 1983)