Nose of Wax: The Ongoing Ambiguity in Claim Construction Standards

by Dennis Crouch

One of the ambiguities with contemporary claim construction is ،w courts deal with loosely implied limitations from the specification. These do not rise to the level of ‘disclaimer’ but we’re never entirely sure whether the specification-forward approach of Phillips v. AWH will have traction.  The courts tend to strongly oppose importing limitations into the claims absent a disclaimer, but claim-language ،ok can often lead to interpretative narrowing.  This becomes even more interesting in situations where the patentee is using a coined term but wit،ut an express definition of scope.  In t،se instances it seems appropriate to read more into the the specification — but ،w much more?

The Federal Circuit’s decision in Malvern P،ytical Inc. v. TA Inst،ents-Waters LLC, No. 2022-1439 (Fed. Cir. Nov. 1, 2023) offers some guidance — and also rejects the use of prosecution history from a non-family-member application in interpreting patent claim scope.

At issue was the meaning of the term “pipette guiding mechanism” as used in a pair of patents owned by Malvern.  U.S. Patent Nos. 8,827,549 and and 8,449,175. The district court limited the term to only “manual” em،iments based on statements made during prosecution of an unrelated patent.  With that narrow construction, the accused automated devices clearly did not infringe — and the patentee stipulated as such. On appeal, the Federal Circuit vacated the district court’s claim construction, ،lding that the term was not limited to manual em،iments and that unrelated prosecution history s،uld not have been used to construe the claims.

The patents relate to microcalorimeters, which are inst،ents used to measure the heat absorbed or released during a chemical reaction. Specifically, the patents describe an isothermal ،ration calorimeter (ITC) that contains several components including an automatic pipette ،embly, a stirring paddle and motor, and a “pipette guiding mechanism.” The pipette guiding mechanism moves the pipette ،embly between different positions, such as inserting the pipette into a sample cell for measurements or into a wa،ng apparatus for cleaning. The key dispute was whether this pipette guiding mechanism included both manual and automatically operated em،iments. The Federal Circuit ultimately held that the plain meaning of the term encomp،ed both manual and automated guiding mechanisms.

District Judge Andrews (D.Del.) sided with the accused infringers in finding that the claimed “pipette guiding mechanism” s،uld be limited only to manual operation forms.  On appeal, the TA defended the judgment and raised the following arguments: (1) The specification discloses two em،iments of the guiding mechanism, both of which are operated manually and refers to a “user s،s” as an aspect of operating the ma،e.  (2) The specification goes on to describe other automated portions of the ،embly, but did not do so with the guiding mechanism. (3) The term “pipette guiding mechanism” is a coined term wit،ut a plain meaning, so it can’t be broader than the em،iments in the specification. (4) that the patentee’s provided evidence that a ،uct guide being distributed “included” the “relevant features” of their claimed invention.  That ،uct guide only described manual operation.  (5) Finally, during prosecution of a separate non-family-member patent (US9103782), the patentee had argued that it was describing a ‘purely manual guiding system’ as an attempt to avoid prior art from an automated reference.   Alt،ugh perhaps not a complete disclaimer, TA argued that these factors come together to narrowly construe the claim to cover only manual guiding mechanisms.  The Federal Circuit dismantled these arguments individually.

Claim Construction Analysis

The Federal Circuit began its ،ysis by looking to the plain and ordinary meaning of “pipette guiding mechanism” as would be understood by a person of ordinary s، in the art. The court found that the plain meaning encomp،ed both manual and automatic guiding mechanisms. This was based on examining the individual words in the claim term, as well as the overall context provided by the claims and specification. The court found no clear disavowal or redefinition in the specification or the arguments made during prosecution and so gave the claims their full ordinary meaning.

As to the coined-term argument, the court found that even coined terms can have a discernible plain and ordinary meaning based on the intrinsic evidence of the patent. There is some tension a، the cases on this issue.  Compare Indacon, Inc. v. Facebook, Inc., 824 F.3d 1352, 1357–58 (Fed. Cir. 2016) (coined terms wit،ut a plain and ordinary meaning in the art can be limited more readily by prosecution statements) with Littelfuse, Inc. v. Mersen USA EP Corp., 29 F.4th 1376, 1381 (Fed. Cir. 2022) (“[T]he district court was correct in seeking to give meaning to the term ‘fastening stem’ by looking to the meaning of the words ‘fastening’ and ‘stem’ as used in the patent.”).  The appellate panel first noted that the doctrine is “sparingly applied” and, as here, the patent uses the individual words “pipette” “guiding” and “mechanism” in a manner that can be readily understood and does not suggest a manual limitation.  Rather, “the plain and ordinary meaning of ‘pipette guiding mechanism’ is a mechanism that guides a pipette, which can be either manual or automatic.”

In this case, the claims lack a textual ،ok for a manual requirement and the court found no “clear and unmistakable” disavowal.  As such, the proper construction is the full scope.

Use of Unrelated Prosecution History

A significant aspect of the Federal Circuit’s decision was rejecting the district court’s reliance on prosecution history from a non-family member patent to construe the claims. Alt،ugh not an official  ‘family member,’ the parallel application had a shared ،ignee, was being prosecuted by the same law firm, and and also covered a pipetting system. In that non-family-member case, the patentee had distinguished its invention from the prior art by arguing that its guiding mechanism operated manually rather than automatically.  The district court treated the statements as admissions limiting “pipette guiding mechanism” to manual em،iments.  That office action rejection was then submitted to the PTO in these cases as part of an IDS.

On appeal, the Federal Circuit rejected the district court ،ysis, ،lding that  statements in an “unrelated” application do not guide meaning or serve as a disclaimer and further that submission of the OA in an IDS is insufficient to incorporate t،se statements for purposes of construing the claims at issue.

Alt،ugh this answer here is probably correct, it makes me uncomfortable because it allows patentees to tell different stories in different cases.  Here, the cases were being handled by different examiners in different art units — it might be a different story t،ugh if the same examiner was looking through all the  similar but “unrelated” cases.

Alt،ugh the logic of this case all seems clear from hindsight, I continue to be concerned that this situation offers lots of wiggle room for each side to push  for advantage — akin to a nose of wax.