While it is true that means-plus-function elements are interpreted narrowly as covering the specific embodiments disclosed in the specification, extrinsic evidence may be brought in to show that one skilled in the art would recognize that structure within the specification. The key inquiry is simply whether “one skilled in the art will know and understand what structure corresponds” to the claim limitations. This might be useful in traversing the now fashionable indefiniteness rejections for lack of corresponding structure in means-plus-function claims.
Background / Facts: The patent being asserted here is directed to machines for pitting soft fruit, such as prunes and dates. The claims at issue recite a fruit-pitting apparatus in which the fruit pits are punched out by pitting knives while the fruit is held in place by an “active assembly” whose function is to engage the fruit and apply a variable force. The district court construed the active-assembly limitations as means-plus-function limitations. In turning to the specification, however, the district court identified only two classes of actively driven actuator assemblies corresponding to the active-assembly limitation, i.e., pneumatic and solenoid-driven actuators. Although a “mechanical linear actuator” is mentioned elsewhere in the specification, the district court held this to be referring only to a sub-class of pneumatic or solenoid-driven actuators, such that purely mechanical actuators did not fall under the purview of the means-plus-function limitations.
Issue(s): Whether the disclosure of a “mechanical linear actuator” in the patent specification is a sufficient description of structure that “one skilled in the art will know and understand what structure corresponds” to the claim limitations.
Holding(s): Yes. “Based on record evidence submitted by both [the patentee] and the defendants, we conclude that mechanical linear actuators are a distinct and identifiable class of actuators separate from pneumatic and solenoid-based actuators. The district court therefore erroneously granted summary judgment of noninfringement based on its conclusion that a mechanical linear actuator not driven pneumatically or by solenoid could not infringe the … patent. The evidence makes clear that a person of ordinary skill in the art would understand mechanical linear actuators to be a distinct and identifiable class of actuators.”