The Claims Interpreted Report

PTAB: BRI of Method Claim Requires Conditional Limitation

Thirty-five PTAB decisions cite Ex parte Schulhauser since that case was designated precedential in October 2016.  Of those thirty-five decisions, all except for one held that the broadest reasonable interpretation of a method claim does not require conditional limitations.  The one exception is Ex parte Hehenberger, Appeal No. 2015-007421 (Jan. 31, 2016).

By way of background, Ex parte Schulhauser held that the BRI a method claim does not require conditional limitations of that claim, but that the BRI of a system claim does require conditional limitations.  The claim at issue in Ex parte Hehenberger is as follows:

A method for operating an energy-generating installation, with a differential transmission with an electrical differential drive, the differential drive being connected via a frequency converter to a DC intermediate circuit to a network, the method comprising:

supplying the differential drive with electrical energy with the aid of an electrical energy store in the DC intermediate circuit of the frequency converter in the case of a voltage dip or a power failure or an overvoltage of the network when the differential drive operates in an operating mode as a motor.

(Emphasis added.)  The Ex parte Hehenberger decision included both a majority opinion and a concurring opinion.  The majority opinion did not cite Ex parte Schulhauser, and did interpret the BRI of the method claim to require the conditional limitation.  The majority concluded that the combination of prior art references did not include the “supplying” step when the conditions were present, i.e., in the case of a voltage dip or a power failure or an overvoltage when the differential drive operated as a motor, so the panel overturned the Examiner’s rejection.

The only point made in the concurring opinion is an explanation of why Schulhauser is not controlling.  The concurring opinion states that because the “supplying” step is the only step, it cannot be interpreted as being conditional, or else the claim would be claiming nothing.  In that light, a person having ordinary skill in the art would have interpreted the claim to require that single conditional step.


This decision may be an outlier, considering it is the only case out of the thirty-five decisions that cite Ex Parte Schulhauser to hold that the BRI of a method claim requires a conditional limitation.  Nonetheless, this case could be cited for the proposition that there are exceptions to the rule from Ex parte Schulhauser, and that the BRI of a method claim requires a conditional limitation when the language of the claim conveys to a person having ordinary skill that the conditional limitation is a requirement.