271 F. Supp. 3d 990
E.D. Wis.2017Background
- Milwaukee sued Snap-On for infringement of three patents on Li-ion battery packs for handheld power tools, centering on a claim requiring battery cells "capable of producing an average discharge current greater than or equal to approximately 20 amps" (the "20 Amp Limitation").
- Key development history: Milwaukee worked with Canadian cell maker E‑One Moli from 2001–2003; Moli supplied prototype 15A, then 25A/30A/40A cells and packs that were tested by Milwaukee engineers. Early prototypes failed constant‑current 20A tests but showed mixed results in tool (pulse/profile) testing.
- Disputes focused on claim construction (how to measure the 20 Amp Limitation, meaning of "nominal voltage," and "supported by the housing") and multiple invalidity/defense theories by Snap‑On: derivation (§102(f)), anticipation, indefiniteness, inequitable conduct, pre‑suit damages/marking, and IPR estoppel issues.
- PTAB and a prior magistrate had previously construed similar claim language and held against indefiniteness; Snap‑On participated in multiple IPRs (and agreed to be estopped by certain instituted grounds).
- The district court (Stadtmueller, J.) adopted Plaintiffs’ constructions, denied Snap‑On’s summary judgment motion, granted Plaintiffs’ summary judgment in part (invalidity, derivation, anticipation, inequitable conduct defenses), and resolved scope of IPR estoppel and marking fact issues for trial.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Construction of "20 Amp Limitation" (how to measure "average discharge current") | The limitation requires capability to deliver ~20A continuously over the pack's entire rated capacity as measured by an industry standard constant‑current discharge test. | "Average" allows profile/pulse testing or intermittent use averaging; construction is indefinite. | Adopted Plaintiffs' construction: constant‑current test over entire rated capacity; not indefinite. |
| "Nominal voltage" meaning | Means the designated/approximate (rated) voltage (a named value), not a particular measured voltage. | Ambiguous—depends on point of measurement (open/closed circuit, state of charge). | Adopted Plaintiffs' construction: "designated approximate voltage." |
| "Supported by the housing" scope | "Supported" has its plain, broad meaning (bearing/supporting the cells), not limited to being fastened in a single fixed position. | Should require structure that holds cells in place (narrower). | Adopted Plaintiffs' broader plain‑meaning construction. |
| Derivation / 102(f) (was Moli prior inventor?) | Milwaukee conceived and directed pack design; Moli was a supplier; no complete conception by Moli before Milwaukee. | Moli conceived and provided cells/packs meeting the limitation earlier; invention derived from Moli. | Dismissed Snap‑On's derivation defense: record shows joint development/supplier role; no clear prior conception/communication of the full claimed pack. |
| Inequitable conduct (failure/omission to PTO) | Alleged omissions/misstatements (Meyer 2009 declaration, withheld tests, later Moli cells). | Mischaracterizes testing; constant‑current data were provided; omissions not material or shown to be deliberate. | Dismissed Snap‑On's inequitable conduct defense for lack of clear‑and‑convincing proof of materiality and specific intent. |
| Anticipation / §102 (Moli prototypes) | Moli cells/packs anticipated or disclosed invention prior to plaintiffs' dates. | Plaintiffs' pack claims require assembled packs and capability over full rated capacity; Moli cells alone do not anticipate. | Dismissed anticipation defenses based on Moli cells: cell samples did not disclose full claimed pack limitations. |
| IPR estoppel scope | Plaintiffs: estoppel should bar grounds petitioner reasonably could have raised (including non‑instituted or omitted but reasonably available art). | Snap‑On: Shaw controls; non‑instituted petitioned grounds not estopped; some non‑patent references not subject to IPR estoppel. | Adopted hybrid approach: (1) instituted IPR grounds and reasonable variants are estopped; (2) non‑instituted petitioned grounds are not estopped; (3) petitioner is estopped from grounds it reasonably could have included in its IPR petition (diligent‑search standard); physical specimens/videos not automatically estopped because §311(b) limits IPR to patents/printed publications. |
| Pre‑suit damages / marking (§287) | Plaintiffs contend marking (own products and licensees) provided constructive notice; proffered monitoring efforts and sales data. | Snap‑On argues inadequate monitoring, gaps in licensee marking periods, and lack of proof of continuous marking. | Denied summary judgment on marking — material fact for jury: evidence sufficient to create a triable issue whether marking was "substantially consistent and continuous." |
Key Cases Cited
- Markman v. Westview Instruments, 517 U.S. 370 (1996) (claim construction is a matter of law for the court)
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (claim terms given their ordinary and customary meaning to a person of skill in the art)
- Nautilus, Inc. v. Biosig Instruments, 134 S. Ct. 2120 (2014) (definiteness requires reasonable certainty to skilled artisans)
- Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276 (Fed. Cir. 2011) (inequitable conduct requires materiality and specific intent proven by clear and convincing evidence)
- Teva Pharm. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335 (Fed. Cir. 2015) (indefiniteness and issues about measurement methods)