Bad Boy Inc v. Spartan Mowers LLC
1:16-cv-00114
| E.D. Ark. | Feb 1, 2018Background
- Bad Boy, Inc. owns U.S. Patent No. 7,708,292 claiming a vibration-damping system for high-end riding mowers that uses elastomeric "pillows" between wheels and frame.
- Robert Foster, an inventor with ties to both parties, allegedly assigned the '292 patent to Bad Boy; Spartan (and related manufacturers Intimidator and RF Products) make the accused SRT mower line.
- Bad Boy alleges Spartan's SRT mowers infringe the '292 patent; Spartan disputes infringement and challenges claim scope and definiteness.
- The court held a Markman hearing and considered only intrinsic evidence (claims, specification, prosecution history); no extrinsic expert testimony was relied on.
- The court construed several claim terms, rejected broad disavowal of non-preferred embodiments but found an express disavowal of springs, shock absorbers, and airbags, and left many disputes for the jury on infringement.
Issues
| Issue | Plaintiff's Argument (Bad Boy) | Defendant's Argument (Spartan) | Held |
|---|---|---|---|
| Whether the patent is limited to the preferred embodiment | Claims cover the novel use of elastomeric pillows broadly, not just the depicted form | Patent text and specification limit the invention to the preferred embodiment | Court: No broad disavowal to preferred embodiment; claims read to protect the novel pillow concept, not only the drawing |
| Whether patent disclaims other damping systems (springs/shocks/airbags) | Patent claims elastomeric pillows and distinguishes from prior art; seeks protection for pillows' material-based damping | Patent should not be limited to exclude other damping methods absent clear disclaimer | Court: Bad Boy disclaimed springs, shock absorbers, and airbags during prosecution/specification; these are excluded |
| Definiteness of disputed claim terms | Terms give skilled artisans reasonable certainty about scope (pillow-based damping fastened between wheel and frame) | Terms are indefinite and fail to inform with reasonable certainty | Court: Patent is not indefinite under Nautilus; terms provide sufficient notice |
| Construction of specific claim terms (e.g., "elastomeric pillow," "either," "suspension cage") | Proposes constructions focused on pillows' material/function and suspension structure | Seeks narrower or alternative constructions based on specification/context | Court: Adopted limited constructions — defined "elastomeric pillow" (resilient material, excludes airbags/springs/shocks), adopted "each said wheel" = "every wheel," adopted "suspension cage" = "hinged structure that supports the wheel assembly," but left many terms without special construction; infringement left for jury |
Key Cases Cited
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (claim construction framework; primacy of intrinsic evidence)
- Markman v. Westview Instruments, Inc., 517 U.S. 370 (U.S. 1996) (claim construction is a matter for the court)
- Renishaw PLC v. Marposs Societa' per Azioni, 158 F.3d 1243 (Fed. Cir. 1998) (presumption against disavowal)
- Trustees of Columbia Univ. in City of New York v. Symantec Corp., 811 F.3d 1359 (Fed. Cir. 2016) (limiting claims to preferred embodiment requires clear disavowal)
- Poly-America, L.P. v. API Indus., Inc., 839 F.3d 1131 (Fed. Cir. 2016) (exacting standard for disavowal)
- Williamson v. Citrix Online LLC, 792 F.3d 1339 (Fed. Cir. 2015) (means-plus-function analysis guidance)
- Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (U.S. 2014) (definiteness standard)