“Whereby” or statement of ultimate result clauses are broadly classified as functional clauses, and are permitted in a patent claim. Such statements should be used to state only the necessary outcome or result of the previously described structure.
A “whereby” clause that merely states the result of the limitations in the claim adds nothing to the patentability of the invention in the claim. But it may help the reader understand the claimed structure, sum it up, and make the claim more readable to a layman not familiar with the legalities of a patent claim.
Some use case scenarios and points to consider for “whereby” clause are listed below:
- The “whereby” clause should only be used, when the claim recites structure to support that “whereby” clause.
- The “whereby” clause should not be relied upon to add a structural limitation, whether or not that structure is critical to accomplish the invention.
- Some precedents suggest that “whereby” clauses can be used to add structural limitations in a patent claim. However, it is dangerous to rely on the “whereby” functional clause to add structure.
- If needed, the claim should be amended to add structural elements that are antecedents to the “whereby” clause.
- Since the “whereby” clause likely will state some objective of the invention, the fact that no element is present which would serve as an antecedent to the “whereby” clause should raise a question as to the sufficiency of the structural limitations of the claim.
It may be understood that the ‘whereby’ clause provides a different result compared ‘wherein’ clause, in a patent claims:
- Use a ‘whereby’ clause or ‘thereby’ clause to specify to specify the necessary consequences of the arrangement, construction, and/or operation of already recited elements.
- Use a ‘wherein’ clause to specify an effect or result produced by the arrangement, construction, and/or operation of already recited elements.