In constructing a term in the independent claim in the inter parte review of Kranos Corporation v. Riddell, Inc., (Case IPR2016-01649, Final Written Decision on Feb. 7, 2018), the Patent Trial & Appeals Board rejected the application of the doctrine of claim differentiation based on a clear definition of the term that was provided in the specification.
The claim term at issue is “releasable coupler mechanism” in claim 1. In the decision to institute, the PTAB interpreted that term to mean “a coupler mechanism that does not employ a threaded connector, such as a screw, that is rotated to attach or detach a component, such as a face guard.” Dependent claim 2 recites the negative limitation that “the actuation force lacks a rotational component.” In the Final Written Decision, the PTAB initially indicated that this dependent claim suggested that, under the doctrine of claim differentiation, the construction of the phrase “releasable coupler mechanism” in independent claim 1 must be broader than dependent claim 2 and thus, claim 1 is not limited a releasing motion that lacks rotation.
However, strong evidence in the specification led the Board to decide otherwise. For example, the Abstract describes that the quick release connector allows for rapid disconnection with an inwardly directed actuation force that lacks rotational component. The Technical Field has a similar definition. Finally, the Detailed Description described that the releasable coupler mechanism provides for rapid attachment and detachment without the deliberate and time consuming use of a screwdriver. Statements made by the applicant during prosecution also supported this definition. On that basis the PTAB concluded that the doctrine of claim differentiation was not applicable to this case.
This is another example of how clear definitions and consistent use of those definitions can be beneficial for claim construction. This case can be compared to another recent post in which a district court did apply the doctrine of claim differentiation to determine the broadest reasonable interpretation of a claim term.