U.S. MPEP on Step-Plus-Function Claiming

Under 35 U.S.C. 112, sixth paragraph:

"an element in a claim for a combination may be expressed as a means or step for
performing a specified function without the recital of structure, material, or
acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof."

I am not aware of any appellate court decision that has specifically interpreted "step for" claim language with regard to equivalent "acts" disclosed in the specification. However, according to MPEP 2181:

. . . The Court of Appeals for the Federal Circuit, in its en banc decision In re Donaldson Co., 16 F.3d 1189, 29 USPQ2d 1845 (Fed. Cir. 1994), decided that a "means-or-step-plus-function" limitation should be interpreted in a manner
different than patent examining practice had previously dictated.

. . . Seal-Flex, Inc. v. Athletic Track and Court Construction, 172 F.3d 836, 850,
50 USPQ2d 1225, 1234 (Fed. Cir. 1999) (Radar, J., concurring) ("claim elements without express step-plus-function language may nevertheless fall within 112 6 if they merely claim the underlying function without recitation of acts for performing that function…In general terms, the underlying function' of a method claim element corresponds to what that element ultimately accomplishes in relationship to what the other elements of the claim and the claim as a whole accomplish. Acts,' on the other hand, correspond to how the function is accomplished…If the claim element uses the phrase step for,' then § 112, 6 is presumed to apply…On the other hand, the term step' alone and the phrase steps of' tend to show that § 112, 6 does not govern that limitation.").

. . . Caterpillar Inc. v. Detroit Diesel Corp., 41 USPQ2d 1876, 1882 (N.D. Ind. 1996) (35 U.S.C. 112,sixth paragraph, "applies to functional method claims where the element at issue sets forth a step for reaching a particular result, but not the specific technique or procedure used to achieve the result.")