Minor differences in claim language between parent and child patents are not sufficient to secure a different interpretation. Here, for example, the “neutralizer” claimed in a child patent was interpreted as requiring all the components recited in the claims of a parent patent even though those components were omitted in the claims of the child patent because the claims were otherwise very similar. “If [the patentee] had not [desired a similar interpretation], he could have said so explicitly, or revised the [] patent to include other, broader embodiments.” It may therefore be helpful when filing a child application with claims similar to a parent application to include a disclaimer highlighting the differences or at least stating that the claims should be interpreted independently.
Background / Facts: The patent being asserted here is directed to fitting custom footwear inserts for sports that involve symmetrical, side-to-side movement, such as skiing, skating, and cycling. To determine the insert that is best for a particular athlete, the specification describes the use of a special device called a “neutralizer.” Although the claims of the asserted patent are silent as to what components constitute the neutralizer, the claims of a parent patent to which the asserted patent claims priority recites “said neutralizer having a housing, protractor, an angularly adjustable plate capable of supporting a foot.”
Issue(s): Whether the claiming strategy evident in the prosecution history suggests that the “neutralizer” of the asserted patent was intended to be different from the “neutralizer” in the parent patent because the components of the neutralizer recited in the claims of the parent patent are absent from the claims of the asserted patent.
Holding(s): No. “This argument turns the correct analysis on its head. Here, the prosecution history merely stands as supporting evidence that, starting with the parent [] patent, the inventor understood ‘neutralizer’ to include the housing, protractor, and angularly adjustable plate components. The omission of these limitations in the [] patent is not inconsistent with this; instead, the overwhelming similarities between the parent [] patent and the [] patent suggest that the inventor intended ‘neutralizer’ to have the same meaning between the two patents. If he had not, he could have said so explicitly, or revised the [] patent to include other, broader embodiments of the neutralizer. Accordingly, when read in combination with the rest of the intrinsic evidence, the prosecution history supports, rather than refutes, the district court’s construction.”