Rescinding estoppel: the most overlooked means to a broader claim construction

  • Jul 2 2015
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  • Category: News

By Jason Scher

The starting point for achieving a broad claim construction is a well written application, the use of non-limiting traversal of adverse patent office assertions, and avoiding unnecessary amendments during prosecution.  Despite these efforts, if disclaimers were nonetheless made during the prosecution of a patent application, scope-limiting estoppel is created.  See e.g., Omega Eng’g Inc. v. Raytek Corp., 334 F.3d 1314, 1323 (Fed. Cir. 2003).  When one or more continuation or divisional applications are subsequently filed, as is often the case, the scope-limiting estoppel may similarly effect those related children applications.  See e.g.Microsoft Corp. v. Multi-Tech Systems, Inc., 357 F.3d 1340, 1349 (Fed. Cir. 2004).  This may be true even if the claims of children applications are broader than those of parent applications.  To avoid the cascade of disclaimer and estoppel from parent to child applications, affirmative rescission of the disclaimer can be utilized to recapture the disclaimed subject matter.

Guidance for affirmative rescission was provided by the Federal Circuit in Hakim v. Cannon Avent Group, PLC, when it noted that, “a disclaimer made during prosecution can be rescinded, permitting recapture of the disclaimed scope.” 479 F.3d 1313, 1318 (Fed. Cir. 2007).  But in finding that Hakim had failed in its attempt to rescind, the Federal Circuit cautioned that “the prosecution history must be sufficiently clear to inform the examiner that the previous disclaimer, and the prior art that it was to avoid, may need to be revisited.” Id.

What constitutes “sufficiently clear” has not been specifically delineated.  InHakim the Federal Circuit found that Hakim’s failure to “specifically point out that he no longer intended to be limited to the specific mechanism that he had previously argued was the distinguishing feature of his invention,” was insufficient to effectuate a rescission.  Id. at 1317.

Nonetheless, applicants should consider systematically submitting statements rescinding prior disclaimers and stating that the patent office should revisit the art previously considered.     An example recapture statement might read as follows:

To the extent any amendments, characterizations, or other assertions previously made (in this or in any related patent applications or patents, including any parent, sibling, or child) with respect to any art, prior or otherwise, could be construed as a disclaimer of any subject matter supported by the present disclosure of this application, Applicant hereby rescinds and retracts such disclaimer.  Applicant also respectfully submits that any prior art previously considered in any related patent applications or patents, including any parent, sibling, or child, may need to be re-visited.

Based on Hakim, such a recapture statement appears to satisfy the shortcomings highlighted by the Federal Circuit in finding no effective rescission. See Hakim, 479 F.3d at 1317-1318 (holding that “re-filing the application with broader claims … [and] inform[ing] the examiner that the new claims were broader than those previously allowed” was inadequate for proper disavowal).

This recapture statement could be made in any communication to the patent office, but should be made as early as possible, preferably at the outset of prosecution.  Importantly, in filing such a statement one should also be mindful of timing because of potential patent term adjustment pitfalls related to 37 C.F.R. §1.704.  Specifically, patent term may be cut short if these recapture statements are filed with a preliminary paper less than one month before the mailing of an Office Action (see 37 C.F.R. §1.704 (c)(6)) or if filed as a supplemental reply (see 37 C.F.R. §1.704 (c)(8).

Such rescission might also be effective against statements made during litigation that are cited to the patent office.    For example, in Golden Bridge Technology, Inc. v. Apple Inc., 758 F.3d 1362 (Fed. Cir. 2014), the patentee cited a stipulated claim construction (previously framed during related litigation) as part of an information disclosure statement.  CitingHakim, the Federal Circuit held that that without making a disavowal sufficiently clear to the Office, submitting a stipulated construction in an information disclosure statement constitutes clear and unmistakable disclaimer of broader claim scope. See id. at 1366 (where patentees’ failure to affirmatively rescind the disclaimer in the stipulated construction effectively precluded them from obtaining broader claim scope).  Accordingly, the filing of a clear and unmistakable recapture statement, as set forth above, might have altered the court’s ruling.

In short, while carefully choosing what to say and what not say is paramount to a broad claim construction, failing to implement a strategy that considers the effects of submitting (or not submitting) an affirmative rescission of disclaimer can have a profound impact on claim construction, and thus effective enforcement of an issued patent.