CAFC reiterates criteria for disavowal of broad claim scope based on patent’s disclosure and prosecution history.
Linda Shapiro | November 2, 2016
Poly-America, L.P. v. API Industries, Inc.
October 14, 2016
Before Prost, Reyna, and Hughes. Opinion by Reyna
Infringement of Poly-America’s patent hinged on construction of “short seal” in claim 10. Based on the specification and prosecution history, the district court adopted the accused infringer’s proposed construction, which incorporated structure described in the specification but not explicitly recited in the claim. The CAFC affirmed, finding clear and unequivocal statements in the specification and prosecution history “that the inventor intended to limit the claimed invention to a trash bag with ‘short seals’ at its upper corners that extend inwardly to narrow the bag’s upper opening,” and thus disavowed a broader interpretation.
Poly-America sued API for infringement of claim 10 of its Patent No. 8,702,308 (“the ‘308 patent”) for a “Reduced opening elastic drawstring bag.” Resolution of the infringement determination turned on interpretation of the term “short seals.”
The specification of the ‘308 patent describes prior art drawstring trash bags as having “a pair of drawstrings enclosed within hems running along the top edges, or upper opening, of the trash bag. The drawstrings are attached to the bag by a pair of short seals located near the upper corners of the bag.”
In contrast, in the patented trash bag:
[T]wo elastic drawstrings are secured within their respective hems by a pair of short seals which are located proximately to the side seals of the bag along the upper edges. The innermost edges of the first and second short seals define the inner boundaries of the short seals. The upper opening width is defined by the distance between these inner boundaries…. Embodiments of the elastic drawstring bag contemplated by the present invention have an upper opening with a width that is less than 97% of the width of the rest of the bag (by virtue of the extended short seals).
The short tabs are designated by reference number 120 in Figure 1, reproduced below:
The ‘308 patent has three independent claims, claims 1, 10, and 16, of which claims 1 and 16 include limitation to the effect that the width of the upper opening in a relaxed state is less than the width of the bag proper. * Claim 10 does not include such a limitation, but does recite “the first panel, the first elastic drawstring, the second panel, and the second elastic drawstring inseparably joined together at a first short seal and at a second short seal.”
Construction of “short seal” was central to the infringement determination. Based on the specification and prosecution history, the district court adopted API’s proposed construction that a short seal is “A seal for securing the elastic drawstring, which seal is located adjacent to a side seal, and that is not substantially aligned with the side seal, but extends inwardly from the interior edge of the side seal.”
Based on this construction, API’s accused bags do not infringe claim 10 because “the short seals do not extend inwardly, so the width of the relaxed upper opening is equal to the bag proper width.” Poly-America stipulated non-infringement under this construction, and appealed, arguing that the district court’s construction was in error.
The CAFC affirmed on appeal, based on what it termed “disavowal,” clear and unequivocal statements in the specification and prosecution history “that the inventor intended to limit the claimed invention to a trash bag with ‘short seals’ at its upper corners that extend inwardly to narrow the bag’s upper opening.” There are only two circumstances when it is permissible to depart from the ordinary and customary meaning of a claim term: when the patentee acts as his or her own lexicographer, or “when the patentee disavows the full scope of the claim term in the specification or during prosecution.”
Disavowal requires “clear and unequivocal evidence that the claimed invention includes or does not include a particular feature,” but “need not be explicit.” The CAFC helpfully provides two examples of when an inventor may disavow claims lacking a particular feature: “when the specification describes ‘the present invention’ as having that feature” and “when the specification distinguishes or disparages prior art based on the absence of that feature.”
The CAFC’s opinion points to at least six instances where the specification ties the configuration of the short seals to the reduced upper opening, as well as an argument in the prosecution history distinguishing the independent claims from the prior art based on the short seals of the prior art not being extended to reduce the bag’s relaxed upper opening width relative to the bag proper width. The CAFC particularly noted that in allowing the claims, “[t]he examiner explained that ‘the prior art fails to teach elastic drawstrings welded into the bag hem at short seals that form an upper opening that is smaller than the width of the bag.’”
Be aware that statements in the specification describing the invention as having a particular feature, or distinguishing or disparaging prior art based on the absence of the particular feature may result in disavowal of a broad claim scope. Failure to dispute the Examiner’s reasons for allowance can also support disavowal.
*Claim 1 recites “a bag proper width defined by a distance between an interior edge of the first side seal and an interior edge of the second side seal, and a relaxed upper opening width defined by a distance between the interior edge of the first short seal and the interior edge of the second short seal when the bag is in a relaxed state, the relaxed upper opening width being less than the bag proper width.”
Claim 16 recites “the distance between an interior edge of the first short seal and an interior edge of the second short seal being less than a bag proper width of the polymeric bag.”