How are “wherein” and “whereby” clauses interpreted in patent claims?

The interpretation of “wherein” and “whereby” clauses in patent claims depends on their specific context and effect on the claim. According to MPEP 2111.04:

“The determination of whether each of these clauses is a limitation in a claim depends on the specific facts of the case.”

For “wherein” clauses, they can be limiting if they give “meaning and purpose to the manipulative steps” as noted in Griffin v. Bertina.

For “whereby” clauses, the Hoffer v. Microsoft Corp. case provides guidance:

• If a “whereby” clause states a condition that is material to patentability, it cannot be ignored.
• However, in a method claim, a “whereby” clause that simply expresses the intended result of a process step positively recited is not given weight.

Patent attorneys and examiners should carefully analyze these clauses to determine if they add limitations to the claim or merely state the intended result of other claim elements.

To learn more:

• wherein clause
• whereby clause
• claim interpretation
• claim limitation
• patent claims