ED Wisc discusses "a sandbox for gratuitous sniping" in case about lithium-ion batteries used in power tools

Of the case, MILWAUKEE ELECTRIC TOOL v. Snap-on, 2017 U.S. Dist. LEXIS 155132 :


Plaintiffs [ MILWAUKEE ELECTRIC TOOL et al] assert infringement of the following claims against Snap-on:

claims 1 and 8-10 of U.S. Patent No. 7,554,290 (the "'290 Patent"), claims 1, 4, 5, 7-13, and 16-19 of U.S. Patent No. 7,999,510 (the "'510 Patent"), and claims 1, 8-10, 12, and 13 of U.S. Patent No. 7,944,173 (the "'173 Patent"). Independent claim 1 of the '290 Patent, which is representative of its counterparts, recites
a battery [*2] pack for power a hand held power tool, the battery pack comprising:
a housing connectable to and supportable by the hand held power tool; and
a plurality of battery cells supported by the housing, the battery cells being capable of producing an average discharge current greater than or equal to approximately 20 amps, the battery cells having a lithium-based chemistry.

(Docket #187-1 at 77). Further, later claims provide, in relevant part, that the pack's battery cells each have "a nominal voltage of 4.2 volts" and that they have "a capacity of approximately 3.0 ampere-hours [("Ah")]." Id.

Because of the vast factual record presented, the Court will provide here a broad overview of the relevant background and timeline. Facts pertinent only to one narrow argument or another will be discussed at the appropriate juncture. This may lead to some repetition, but the Court has found no better way to fully and fairly treat each matter for decision.1

1 The Court pauses here to note that the parties often treated their factual briefing as a sandbox for gratuitous sniping at each other. Even when the core, material fact at issue could not be disputed, they rarely overlooked a chance to disagree over minutiae. Additionally, in stating the facts, they often included their own interpretive gloss on the document or testimony in question, which invited




Of claim constructiuon:


Tethering construction to a person of ordinary skill in the art is critical, teaches the Federal Circuit, because such a person reads the words of the claims against the context of their meaning in the relevant field of study, including any special meanings or usages, and in light of closely related documents such as the specification and the prosecution history. Id. at 1313. Because of the sometimes specialized meanings attributed to terms based on the field in question, general-purpose dictionaries are not always useful. See id. Before resorting to such a resource, courts should begin with the materials that a person of skill in the art would use: "the words of the claims themselves, the remainder of the specification, the prosecution history, and extrinsic evidence concerning relevant scientific principles, the [*19] meaning of technical terms, and the state of the art." Id.
After evaluating the claim language itself, the Federal Circuit instructs that the specification "is the single best guide to the meaning of a disputed term." Vitronics, 90 F.3d at 1582. Although the patent specification may not be used to rewrite the claim language, SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir. 2004), the specification may be used to interpret what the patent holder meant by a word or phrase in the claim,
E.I. du Pont de Nemours & Co. v. Phillips Petroleum Co., 849 F.2d 1430, 1433 (Fed. Cir. 1988).
After considering the claim language and the specification, a court may consult the final piece of intrinsic evidence: the patent's prosecution history. Vitronics, 90 F.3d at 1582. "[S]tatements made during the prosecution of a patent may affect the scope of the invention." Rexnord Corp. v. Laitram Corp., 274 F.3d 1336, 1343 (Fed. Cir. 2001). This is especially true if a particular interpretation of the claim was considered and specifically disclaimed during the prosecution of the patent. Warner-Jenkinson Co., Inc.
v. Hilton Davis Chem. Co., 520 U.S. 17, 30 (1997); Vitronics, 90 F.3d at 1582- 83.
Generally, the body of intrinsic evidence will eliminate any ambiguity in the claim terms, rendering unnecessary any reference to extrinsic evidence. Vitronics, 90 F.3d at 1583. Yet, if needed, a court may consider extrinsic evidence, which "consists of all evidence external to the patent and prosecution history, including expert and inventor testimony, dictionaries, and learned treatises." [*20] Phillips, 415 F.3d at 1317-19. Extrinsic evidence may assist the court in understanding the underlying technology, the meaning of terms to one skilled in the art, and how the invention works, but it may not be used in derogation of the intrinsic evidence. Id.



Of the argument by Snap-on:



Snap-On asks the Court to engraft an additional limitation onto the 20 Amp Limitation out of practicality-that is, because tools in the field are not routinely turned on and their batteries run down completely without pause. See (Docket #201 ¶¶ 5, 12-13). Snap-On reasons that "the word 'average' in the 20 Amp Limitation implies that the discharge current may drop well below 20 amps so long as the average current remains above 20 amps." (Docket #207 ¶ 127). According to Snap-On, it is unlikely that any power too would have to deliver a constant current discharge reasonably close to 20 amps for its entire rated capacity in any real-life application. (Docket #201 ¶ 12).

But the standard of review is not what a person of skill in the art would find realistic; it is instead what a person of skill in the art would understand. There is no question that, [*26] putting aside matters of practicality, a person of ordinary skill in the art would comprehend the meaning of the 20 Amp Limitation, including the requirement that 20 amps be continuously delivered during the entire rated capacity of the battery pack. Such a person would understand that the limitation describes the capability, not the potential real-world use, of the invention. See Hitachi, 2012 WL 10161527, at *4 ("[T]he fact remains that the capacity of a battery is normally measured by discharging at a constant current until the battery has reached its terminal voltage, consistent with Metco's construction."). This is true notwithstanding the fact that even Plaintiffs concede that tool simulations are an important part of assessing the real-world functionality of the ultimate product.5

5Snap-On claims that Plaintiffs' construction reads the word "average" out of the claim language, (Docket #205 at 13), but the Court does not agree. Plaintiffs' construction incorporates the concept of "average" as meaning "reasonably close to" the required discharge current. Snap-On rightly notes that there are other senses of the word "average," including averaging a discharge current over a specified interval, but Snap-On's belief that its interpretation of the word is the only reasonable one does not make it so. Moreover, the deposition testimony of the named inventors on this point cannot undermine the clarity of the intrinsic [*28] record, which supports Plaintiffs' interpretation. See Kara Tech. Inc. v. Stamps.com Inc., 582 F.3d 1341, 1348 (Fed. Cir. 2009) (finding that "extrinsic sources like expert testimony cannot overcome more persuasive intrinsic evidence").

Finally, the Court rejects Snap-On's suggestion that the 20 Amp Limitation is indefinite and therefore invalid. A patent must "conclude with one or more claims particularly pointing out and distinctly [*27] claiming the subject matter which the applicant regards as [the] invention" 35 U.S.C. § 112, ¶ 2 (emphasis added).6If, when "read in light of the specification delineating the patent, and the prosecution history, [a patent claim] fail[s] to inform, with reasonable certainty, those skilled in the art about the scope of the invention," the claim is invalid as indefinite under Section 112. Nautilus, Inc. v. Biosig Instrums., Inc., 134 S. Ct. 2120, 2124 (2014). A claim "must be precise enough to afford clear notice of what is claimed, thereby appris[ing] the public of what is still open to them." Id. at 2129; see also Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1370 (Fed. Cir. 2014). Moreover, a reviewing court must remember that "[i]t cannot be sufficient that a court can ascribe some meaning to a patent's claim; the definiteness inquiry trains on the understanding of a skilled artisan at the time of the patent application, not that of a court viewing matters post hoc." Nautilus, 134 S. Ct. at 2130.



Of indefiniteness:


A claim is indefinite where it can be measured in several ways and the claim language, considered against the specification and prosecution history, do not provide adequate guidance on which method to use. See Teva Pharms. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335, 1344-45 (Fed. Cir. 2015); Eli Lilly, 845 F.3d at 1370. Put differently, "the patent and prosecution history must disclose a single known approach or establish that, where multiple known approaches exist, a person having ordinary skill in the art would know which approach to select." Dow Chem. Co. v. Nova Chems. Corp., 803 F.3d 620, 634-35 (Fed. Cir. 2015).
However, "a patentee need not define his invention with mathematical precision." Invitrogen Corp. v. Biocrest Mfg., L.P., 424 F.3d 1374, 1384 (Fed. Cir. 2005). Instead, "[t]he definiteness requirement mandates clarity, while recognizing that absolute precision is unattainable." Apple Inc. v. Samsung Elecs., Co., 786 F.3d 983, 1002-03 (Fed. Cir. 2015) (quotations and alterations omitted), rev'd on other grounds in 137 S. Ct. 429 (2016); Nautilus, 134 S. Ct. at 2128 (recognizing that "[s]ome modicum of [*29] uncertainty" may be tolerated). Indefiniteness is a question of law and must, like any other invalidity defense, be proven by clear and convincing evidence. Sonix Tech. Co., Ltd. v. Publ'ns Int'l, Ltd., 844 F.3d 1370, 1377 (Fed. Cir. 2017); Teva, 789 F.3d at 1345.
Snap-On's indefiniteness objection has two aspects. First, it says that Plaintiffs conveniently used functional language-the requirement for a 20-amp discharge current-just at the point of novelty from prior art, which is not permitted under General Electric Co. v. Wabash Co., 304 U.S. 364, 371 (1938). However, the Federal Circuit has explained that functional language, standing alone, is not sufficient to render a claim indefinite.
Application of Swinehart, 439 F.2d 210, 213 (C.C.P.A. 1971); Cox Commc'ns,
Inc. v. Sprint Commc'n Co. LP, 838 F.3d 1224, 1232 (Fed. Cir. 2016). Although neither expressly considered the matter, is it worth noting that neither Magistrate Callahan nor the PTAB had difficulty in construing the 20 Amp Limitation, much less such insurmountable difficulty as to render the limitation indefinite. Rather, the relevant materials provide a skilled artisan with sufficient information to describe the claimed subject matter and distinguish it from prior art, which is all that is required. See Microprocessor Enhancement Corp. v. Tex. Instruments Inc., 520 F.3d 1367, 1375 (Fed. Cir. 2008). Snap-On devotes little space to this argument and does no more than point out the functional language, expecting that effort to carry the day, and so the Court need not address the point further. See Hardrick v. City of Bolingbrook, 522 F.3d 758, 762 (7th Cir. 2008); United States v. Berkowitz, 927 F.2d 1376, 1384 (7th Cir. 1991) [*30] .
The second aspect of the indefiniteness challenge is more involved. According to Snap-On, the 20 Amp Limitation is fraught with uncertainty as to how to test the "average discharge current" of the battery pack which a person of ordinary skill in the art could not unravel, including in relation to "how long the battery is used, the application or task for which the tool is used, the acceptable voltage performance, and even the ambient temperature." (Docket #182 at 7). Put simply, Snap-On claims that a pack might not be able to produce a constant 20-amp discharge current over its entire rated capacity but could do so on average if used intermittently. (Docket #187-5 ¶ 32). In light of this, one of its experts, Yet-Ming Chiang ("Chiang"), opines that a pack must be tested in various ways that simulate real-world applications. Id. ¶ 34. This makes Meyer's 2001 cutting test and pulse test at least as relevant-indeed more so-that the constant-current test he performed. Id. ¶ 39; see also (Docket #187-13 163:6-23) (Reimers
testifying that average discharge current denotes averaging the discharge produced during pulse or profile tests). On this point, Snap-On asserts that Magistrate Callahan failed to [*31] consider the issue of indefiniteness as reinvented by the Supreme Court in Nautilus, rendering his opinion less persuasive. See Dow, 803 F.3d at 630 ("[T]here can be no serious question that Nautilus changed the law of indefiniteness.").



The district court referenced the Teva/copaxone case


Plaintiffs admit that tool simulation profiles are among the tests used to assess the performance of Li-ion battery packs. (Docket #201 ¶¶ 14-15). Moreover, other witnesses, include two of the named inventors, testified that a battery pack could be run both intermittently and constantly to ascertain an average discharge current. See id. ¶¶ 24-26. Because of the diversity of potential testing conditions and applications, Chiang concludes that skilled artisans could reasonably differ in how they assess whether the 20 Amp Limitation is met and that the patents-in-suit, even when considered alongside the specification and prosecution history, do not provide adequate instruction on which test should be used. (Docket #187-5 ¶¶ 45-47); see also (Docket #187-10 47:19-48:18) (testimony of Plaintiffs' expert during IPR, opining that continuously running a power tool until its battery runs out is not a "typical" way such tools are operated).

The Court does not agree. The Federal Circuit [*32] has found indefinite patent claims that do not teach how they are to be measured. For instance, in Teva, a patent claim prescribed a particular "molecular weight" of a product but did not specify which of three methods should be used to measure it. Teva, 789 F.3d at 1345. Neither the claims nor the specification provided guidance, and the prosecution history contained inconsistent statements by the patentee about which measure was correct. Id. at 1344- 45.



After lengthy discussion, the outcome:


For the reasons stated above, the Court adopts Plaintiffs' proposed
construction of the disputed claim terms. The Court further finds that Snap-On's motion for summary judgment should be denied in its entirety, and
that Plaintiffs' motion should be denied as to assignor estoppel, granted in part as to IPR estoppel, and granted in full as to Snap-On's anticipation, derivation, invalidity, and inequitable conduct defenses.
Accordingly,
IT IS ORDERED that Plaintiffs' motion for summary judgment (Docket #185) be and the same is hereby GRANTED IN PART and DENIED IN PART as stated herein;
IT IS FURTHER ORDERED that Defendant's motion for summary judgment (Docket #183) be and the same is hereby DENIED;
IT IS FURTHER ORDERED that Plaintiffs' motion for leave to file its opening claim construction [*115] brief (Docket #177) be and the same is hereby
GRANTED;