How is Interference Practice Doing? Alive & Well, Thank You.

Scott Daniels | February 27, 2012

Where should we look for guidance in following the recently proposed rules for the various post-issuance proceedings created by the AIA?  A prime source for such guidance will be rich lore of past interference practice, as suggested by the many parallels between the proposed AIA rules and existing interference rules.  The PTO suggested as much when it identified interferences as “contested cases” in its comments on the proposed rules.

Interference cases themselves – not just the case law they have generated over the years – will also continue, at least in some instances, to be an effective means for challenging patents for years to come, despite our recent adoption of a first to file system.  In particular, interference is often a recommended approach for a party to assert that it has been improperly omitted as an inventor from an issued patent.

 A recent example is Nextreme v. EnerDel (Patent Interference No. 105,770).  There, the strategy of challenging inventorship through interference was logical, even though the challenger’s evidence corroborating his claim fell short.  The dispute was initiated when Nextreme filed a patent application for a fire retardant system, copying a pending application filed by EnerDel.  Nextreme then proposed an interference between the two applications.  The EnerDel application issued as a patent and the PTO declared an interference.

Nextreme moved for judgment, attacking the inventorship of EnerDel’s patent: Nextreme claimed that its application correctly named one of its employees and a Delphi employee (EnerDel being a successor in interest to Delphi) as joint inventors, whereas the EnerDel patent incorrectly named only the Delphi/EnerDel employee as the inventor.  In support of its motion, Nextreme offered the testimony of its employee, describing a long exchange of ideas and data between the respective companies that ultimately resulted in the claimed fire retardant system.

In particular, Nextreme justified its employee as an inventor because he had contributed the key idea of replacing chlorinated polyethylene found in the prior art fire retardant systems with high density polyethylene as recited in the parties’ claims.  The only evidence, however, of this contribution was the testimony of Nextreme’s employee.  Although various details of the collaboration between the companies were corroborated by evidence in addition to the employee’s testimony, there was no collaboration for the Nextreme employee’s testimony that he had made a significant contribution to the claimed invention.  The PTO therefore denied Nextreme’s motion and awarded judgment against Nextreme.

Clearly, resort to interference will not be the solution in all cases, but in some it will.

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