by Dennis Crouch
Littelfuse, Inc. v. Mersen USA EP Corp., 2022 WL 995611, — 4th — (Fed. Cir. Apr. 4, 2022)
The district court narrowly construed Littelfuse’s U.S. Patent No. 9,564,281–leading to an admission of non-infringement. On appeal, the Federal Circuit has vacated and remanded–finding that the proper construction provides a broader scope.
The patent claims an end-cap for a fuse and particularly requires “a fastening stem [465] that extends from the mounting cuff [460] and into [a] cavity [410] of the terminal [432].” Claim 1 does not expressly indicate whether these parts (cuff / stem / terminal) are made from a single piece of metal (unitary) or instead are multi-piece. Claims 8 & 9, do provide for unitary bodies that are machined/stamped “from a single, contiguous piece of conductive material.”
The district court construed claim 1 as covering only a multi-piece apparatus. Since Mersen’s fuses were clearly unitary, Littelfuse conceded the absence of literal infringement. In addition, Littelfuse had narrowed this portion of the claim during prosecution — that amendment also likely foreclosed a claim of equivalents.
On appeal, the Federal Circuit rejected this narrow claim construction on the following canons:
- Textualism: Look first to the language of the claim at issue. Here, claim 1 does not require a multi-piece arrangement.
- Claim Differentiation: Interpret an independent and dependent claims so that their coverage fits like nested dolls. Here, the district court interpreted claim 1 as excluding a unitary-body while dependent claims 8&9 require a unitary body.
- Consider the Prosecution History: Here, the examiner wrote in their reasons for allowance that claims 8 & 9 “require all the limitations of [claim 1].” This gives weight to the Claim Differentiation canon.
- Don’t Limit Claims to the Preferred Embodiment: Here, the only embodiment that included the stem/cuff/terminal arrangement was a multi-piece apparatus. But, “Nothing in the specification states that a fastening stem cannot be present in a single-piece apparatus. . . . One can envision a stem that projects from the side of the mounting cuff even in an embodiment in which the fuse end cap is formed from a single piece of material.”
These canons together led the Federal Circuit to reject the district court’s claim construction.
Not such an easy case: So far, I’ve suggested that this was an easy case. But, the district court also had good reason for its determination that the end-cap was a multi-part. In particular, embodiments of the specification appear to provide for two types of end-units. Unitary and multi-part. The unitary embodiments do not have the fastening stem — it is not needed because the cuff and terminal are made of the same piece of metal. On the other hand, the multi-part embodiments do show the fastening stem — it is needed in order to connect the cuff and terminal because they are separate pieces of metal. You can see this difference from the multi-part drawing (above) with the unitary drawing (below). The original claims did not include the fastening stem, but that limitation was added during prosecution in order to avoid prior art. That addition, according to the district court, shifted the claim meaning to only cover multi-part caps. The district court noted the dependent claims but suggested that it was a mistake by the examiner to allow those after the amendment.
On remand: The patent discloses a multi-part cap with a stem; and a unitary cap without a stem. The accused product is apparently a merger of these two – a unitary cap with a stem. The Federal Circuit has ruled here that the claims extend that far. On remand, the district court may consider whether the full extent of this expanded claim scope is supported under the written description and enablement requirements of 112(a).
Meanwhile, some Examiners will continue to come up with their own individual approaches to claim interpretation divorced from the Applicant’s specification, and in direct contradiction to established case law.
You mean, as displayed on this pages with the various views of Examiners for such things as eligibility and use of 103 art as merely separate pieces of 102 art (and merely cobbled together with nothing more)?
Sir, please keep up with the result of the 112(a) issue.
OT:
Vidal confirmed!
Predictions for the filing date of the American Axel brief?
I’ll take May 6th since it’s gotta be on her 1st month TODO list.
“Predictions for the filing date of the American Axel brief?”
At this rate, likely Spring of ’23. 🙂
Given the presumed $1M+ each side has already / will by final resolution cough up for what appears to be a very low value, easily-designed-around innovation, how was this effort justified?
Sounds like someone’s got a burr stuck where the sun don’t shine.
Don’t Limit Claims to the Preferred Embodiment: Here, the only embodiment that included the stem/cuff/terminal arrangement was a multi-piece apparatus. But, “Nothing in the specification states that a fastening stem cannot be present in a single-piece apparatus. . . . One can envision a stem that projects from the side of the mounting cuff even in an embodiment in which the fuse end cap is formed from a single piece of material.”
link to c.tenor.com
That’s not a statement of a preferred embodiment, that’s a statement that nothing is in there and therefore you can’t limit. But “One can envision” is not the standard for written description.
Re: “The district court construed claim 1 as covering only a multi-piece apparatus. Since Mersen’s fuses were clearly [not] [sentence fixed] multi-piece, Littelfuse conceded the absence of literal infringement.”
As many of you know, but some might not, it is now a fairly common practice in patent litigation for the patent owner to admit non-infringement under the D.C. Markman interpretation of the claims in order to get a summary judgement and thus to get a Fed. Cir. pre-trial de novo decision on just claim interpretation. If that claim interpretation is reversed on appeal so as to be infringed that often leads to a case settlement, since infringement is the only issue the patent owner has to prove, and there is no pre-trial decision on any validity issues if there was no IPR.
Thanks Paul – very interesting.
[And by this point in time it is usually now too late for the defendant to file an IPR, per the 35 USC 315(b) bar to an IPR petition “..filed more than 1 year after the date on which the petitioner, real party in interest, or privy of the petitioner is served with a complaint alleging infringement of the patent.”] [Even if the defendant has really great prior art, pre-trial summary judgment on anything other than a clear 102 bar is quite rare.]
> Even if the defendant has really great prior art
I’m a little surprised. I would think that, once you have The FedCir Approved Claim Interpretation, just about every 102 should be “clear.”
101, 103, damages, and injunctive relief OTOH…
Last I heard, some time ago, the percentage of patent suits ended by summary judgements [that were not reversed on appeal] based on 102 or 103 prior art was only about 5%. [If someone has new and different statistics, please speak up.] Not only do you need “clear and convincing evidence,” you need the absence of material “disputed facts.”
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