What’s in a Name? Means-Plus-Function vs. Step-Plus-Function and the Implications of the Language Used

The intellectual property firm of Renner Otto has a reputation throughout the world for its ability to assist foreign associates in interpreting U.S. patent law. The firm often fields inquiries from international attorneys regarding the preparation of non-infringement opinions, including the narrowing interpretation of the “step-plus function” provisions as it relates to 35 USC 112(f). 

Renner Otto’s Dr. Jon Platt has obtained hundreds of patents for clients in countries throughout the world. His twenty-five-plus years of patent prosecution have focused mainly on patent matters involving the mechanical arts. He shares his expertise regarding the triggering of the step-plus-function provisions of 35 USC 112(f) below.

I will start by offering a quick review of when the US claims fall under the means-plus-function interpretation of 35 USC 112(f). Then I’ll address the similarities and differences between the treatment of means-plus-function and step-plus-function with regards to when 35 USC 112(f) applies. Finally, I’ll try to provide some experienced guidance on the nuances of language in the application of the rule. 

“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.”

There is no bright-line rule regarding a claim formulation that does or does not trigger the means-plus-function provisions of 35 USC 112(f). The use of the word “means” (e.g., “means for cutting” or “cutting means”) sets up a presumption that the means-plus-function provisions of 112(f) apply, but that presumption is rebuttable if the claim also recites structural language associated with carrying out the recited function.

The absence of the word “means” sets up a presumption that 112(f) does not apply. But that presumption is also rebuttable. If a claim element is recited in functional terms without the use of the word means, particularly if it uses a generic placeholder or nonce term (e.g., “cutting device” or “cutting apparatus”), and there is no structural language associated with the claim element, then the presumption is overcome and the 112(f) means-plus-function interpretation is applied. Although there are some terms that have a reasonably understood meaning that describes their function (e.g., fastener) – these are not to be interpreted under 112(f) even if there is no additional recited structural language.

Triggering of the step-plus-function provisions of 112(f) follows a similar approach of rebuttable presumptions, but with “step” replacing “means,” and with recitation of acts substituting for recitation of structure. So, a claim element in a process claim expressed as a function connected with the word “step” sets up a presumption that the element is to be interpreted under 112(f), but that presumption is rebutted if the claim also recites acts for accomplishing that function. The absence of the word “step” sets up a rebuttable presumption that 112(f) is not invoked, but that presumption can be overcome if the claim element only recites a function without any associated acts for accomplishing that function.

There are a couple of differences between the two approaches that are worth noting. The first is that while the distinction between functions and structural language is generally clear, the line between functions and acts can be nebulous. And there isn’t a lot of case law on the subject.

Second, while there is a long list of generic placeholders that have been associated with means-plus-function interpretations (device, element, component, mechanism, etc.), I am not aware of any generic-placeholder alternatives identified for “step.” Again, this may be because there are fewer cases interpreting the 112(f) step-plus-function provision.

There seems to be a reluctance for courts to apply step-plus-function interpretations to process claims. This is true even when corresponding device claims reciting the same functions are interpreted under the means-plus-function provision of 112(f).

There are a few things to keep in mind concerning language. First, combination is key. A preamble simply mentioning “steps” is not a sufficient method for raising the presumption of 112(f). There is case law that the term “step” must be “individually associated” with a function to raise the presumption of a step-plus-function interpretation under 112(f).

Likewise, a step by any other name is not sufficient. As I described above, “step” sets up a presumption for invoking 112(f) that other terms do not, and I am unaware of any generic placeholder alternatives that have been identified for “step.”

It has been my experience that examiners offer little leeway in their interpretation of a term from an application originally drafted in a language other than English. The intention of the drafting attorney or the language the application was drafted in would likely be of little or no relevance to the analysis. 

For further guidance on the best strategy for your situation, please contact us at Renner Otto. You can also find more information from the USPTO on provisions of 35 USC 112(f) here. 

At Renner Otto, the oldest intellectual property firm in Cleveland, we specialize in assisting our clients as they develop efficient Intellectual Property strategies that are tailored to their business’s needs. Our attorneys are knowledgeable on a wide range of domestic and international IP issues, and we partner with Firms around the world to better serve our clients. Someone from the Renner Otto team would be happy to discuss this topic or any related Intellectual Property matters. Contact us for a complimentary consultation to see how we can help your business move your innovation forward.

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