Primos v. Hunter's Specialties

CAFC (June 14, 2006) (interference count enabled by general description where mention made of poxvirus at issue even though difficult and time-consuming experimentation required and other differences were known).

Primos v. Hunter’s Specialties involves a diaphragm mouth call used by hunters to simulate animal sounds.  The call in question involves a membrane that vibrates in response to air being forced between the membrane and the tongue.  The element in question is a “shelf or plate extending above the membrane” which contacts the roof of the mouth.  The plate keeps the membrane separated from the roof of the mouth.

One of the claims in question included “a second roof-of-mouth engaging portion” and the controversy was around the meaning of the word “engaging”.  Appellant Hunter’s Specialties argued that “engaging” meant “sealing” or “interlocking” while Appellee Primos argued for “come into contact with”.  The Court agreed with Primos, stating:  “[W]e ordinarily construe claim terms to have their ordinary meaning as understood by a person of ordinary skill in the art.”  In addition, the Court looked at the intrinsic evidence where “’engaging’ and “sealing” were “both expressly recited in the claim and therefore ‘engaging’ cannot mean the same thing as ‘sealing’; if it did, one of the terms would be superfluous”.  Finally, the Court noted that two of figures in the patent supported the construction of “to ‘come into contact with’”.

Primos asserted that, even though the Hunter’s Specialties device did not literally infringe, it did so under the Doctrine of Equivalents, especially with respect to the plate.  The Hunter’s Specialties device contains a dome extending above the membrane, instead of a shelf or plate.  During prosecution, Primos had amended the term “plate” as having a “length” and that it be “differentially spaced” above the membrane.  Hunter’s Specialties argued that these amendments invoked the Doctrine of Prosecution History Estoppel and thus Primos was thus barred from arguing the Doctrine of Equivalents  The Court held that since all physical objects have length, the amendment was not narrowing.  In addition, the Court held that the “differentially spaced” amendment “[did] not pertain to the disputed element in the [Hunter’s Specialties] device” and that the amendment “[bore] no more than a tangential relation to the equivalent in question”.

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