USA: CAFC Finds Claim Scope Disclaimer in Poly- America

by Kelly G. Hyndman (Sughrue Mion, PLLC – USA)

In Poly-America v. API Industries, the U.S. Court of Appeals for the Federal Circuit ruled that patentee’s claims were properly narrowed, finding a disavowal of claim scope in the specification and also in the prosecution history. Avoiding claim scope disavowal is a consideration to be addressed at the time of writing the specification and during prosecution.

The claims in question related to a patented trash bag with a built-in drawstring. The claims included a “short seal” requirement. The trial court had interpreted “short seal” to mean a seal that extends inwardly, with the result that the claims were limited to trash bags with an upper opening narrower than the width of the bag proper.

During oral argument, the patentee’s attorneys argued that the plain meaning of the claim term, “short seal,” does not include any requirement regarding the width of the bag opening. Therefore, according to the patentee, the trial court erred by improperly limiting claim 10 to a narrowed-opening bag because the claim included the term, “short seal.”

The CAFC, however, agreed with the trial court. In reaching this decision, the CAFC first laid out a summary of prior case law: (1) claim terms are generally given their ordinary and customary meaning, except when the patentee acts as his own lexicographer or when the patentee disavows the full scope of a claim term. (2) The disavowal can be in the specification or the prosecution history. (3) Disavowal must be clear and unequivocal. (4) Absent an explicit statement disavowing claim scope, disavowal can still be found when the patentee (4a) distinguishes or disparages prior art based on the absence of the feature or (4b) by statements that the particular feature is included in “the present invention” or “all embodiments of the present invention.”

In Poly-America, the CAFC first noted col. 6, lines 11-13 of the specification where the patentee stated, “In looking at both Fig. 1 and Fig. 2, it is important to note that one of the characteristics of the present invention is a reduction in the upper width 152 … of the bag….” Notice that the patentee stated “of the present invention” instead of something more ambiguous such as “of an embodiment of the present invention.”

The CAFC next identified that in three separate locations in the patent, the patentee had stated that one of the problems in the prior art was that such trash bags lacked the narrowed upper opening and therefore had certain disadvantages.

Thirdly, the CAFC pointed to the prosecution history, in which the patentee had argued that “The ‘relaxed upper opening width’ of [the prior art] is the exact same as the ‘bag proper width,’ not less than the ‘bag proper width’ as required by Applicant’s independent claims.” The claim that issued as independent claim 10 did not include such requirements, but the claim was pending at the time that the above statement was made.

Perhaps the statement could have been made with respect to certain independent claims and not with respect to claim 10. Unfortunately for the patentee, this broad statement regarding the “independent claims” in the prosecution history was binding upon all of the independent claims including the claim 10 that did not possess limitations as to the narrowed opening.

The CAFC also focused on the fact that every embodiment described in the specification had the narrowed opening feature, and that each section of the specification also indicated the importance of this feature.

This case is instructive of an aspect of U.S. patent prosecution which must be considered when writing the specification, and during prosecution. The decision may be found at or at