Comparing Claims in Reissue Oath Haunts Patent HolderOn Wednesday, the Federal Circuit reversed a decision of the ITC that excluded the imports of Lucky Litter, LLC. The case (here) related to cat litter boxes having an automated cleaning feature. In reversing the ITC, the CAFC found that the “predetermined event” recited in claim 33 of the patent at issue (RE 36,847), was not limited to a cat exiting the litter box.Prior to seeking patent reissue, claim 1 of the patent recited a “cat exit sensor for sensing a cat exit” and a “delay means.” The Patentee filed a broadening patent reissue to remove these features. The reissue application oath explained that “[i]n particular, claim 1 of U.S. Patent 5,477,812 contains recitations regarding a cat exit sensor and delay means which are too limiting of the invention and unnecessary in view of the prior art. Claims 23 through 48 of the reissue application have limitations similar to those of claim 1, but define the invention with greater breadth.”The CAFC performed a traditional Phillips analysis of the ITC claim construction and held that “predetermined event,” by plain meaning, could not be limited to “cat exit.”  Still, the statement in the oath was cited by the court as a guidepost of the broader meaning of the claims added in reissue. Hindsight always being 20/20, what could the Patentee have done to potentially avoid this result?Claim construction issues aside, recent BPAI cases illustrate the importance of oaths in patent reissue. All too often, the preparation of the oath is deemed ministerial, and ignored in favor of prior art/claim drafting concerns. Oath preparation and wording should be a focal point of any patent reissue effort.When identifying an error in an original patent via added/amended claims in patent reissue, comparison to the originally issued claims is very attractive. This practice is not necessarily wrong, but can have unintended consequences as demonstrated by Lucky. By making such direct comparisons, the scope of the newly added claims becomes unnecessarily intertwined with the issued claims. For example, the oath in Lucky Litter would have been better off stating “new claims 23 through 48 are directed to the automated comb operation of a self cleaning cat litter box, albeit independent of any specific sensor or means-plus-function structure of the issued claims.” (I know, easy for me to say 10 years after the fact)It may be that the Patentee in Lucky still would have lost, oath or not. Nevertheless, the case demonstrates that oath filings are far from form practice, and can come back to haunt Patentees.  Finally, the patent is subject to an ongoing ex parte reexamination (90/010,389) and, as you may have guessed, new claims were added expressly reciting “cat exit.”  (see new claim 5

On Wednesday, the Federal Circuit reversed a decision of the ITC that excluded the imports of Lucky Litter, LLC. The case (here) related to cat litter boxes having an automated cleaning feature. In reversing the ITC, the CAFC found that the “predetermined event” recited in claim 33 of the patent at issue (RE 36,847), was not limited to a cat exiting the litter box.

Prior to seeking patent reissue, claim 1 of the patent recited a “cat exit sensor for sensing a cat exit” and a “delay means.” The Patentee filed a broadening patent reissue to remove these features. The reissue application oath explained that “[i]n particular, claim 1 of U.S. Patent 5,477,812 contains recitations regarding a cat exit sensor and delay means which are too limiting of the invention and unnecessary in view of the prior art. Claims 23 through 48 of the reissue application have limitations similar to those of claim 1, but define the invention with greater breadth.”

The CAFC performed a traditional Phillips analysis of the ITC claim construction and held that “predetermined event,” by plain meaning, could not be limited to “cat exit.”  Still, the statement in the oath was cited by the court as a guidepost of the broader meaning of the claims added in reissue. Hindsight always being 20/20, what could the Patentee have done to potentially avoid this result?

Claim construction issues aside, recent BPAI cases illustrate the importance of oaths in patent reissue. All too often, the preparation of the oath is deemed ministerial, and ignored in favor of prior art/claim drafting concerns. Oath preparation and wording should be a focal point of any patent reissue effort.

When identifying an error in an original patent via added/amended claims in patent reissue, comparison to the originally issued claims is very attractive. This practice is not necessarily wrong, but can have unintended consequences as demonstrated by Lucky. By making such direct comparisons, the scope of the newly added claims becomes unnecessarily intertwined with the issued claims. For example, the oath in Lucky Litter would have been better off stating “new claims 23 through 48 are directed to the automated comb operation of a self cleaning cat litter box, albeit independent of any specific sensor or means-plus-function structure of the issued claims.” (I know, easy for me to say 10 years after the fact)

It may be that the Patentee in Lucky still would have lost, oath or not. Nevertheless, the case demonstrates that oath filings are far from form practice, and can come back to haunt Patentees.  Finally, the patent is subject to an ongoing ex parte reexamination (90/010,389) and, as you may have guessed, new claims were added expressly reciting “cat exit.”  (see new claim 54).