PTAB

IPR2016-00344

Snap-on Incorporated v. Milwaukee Electric Tool Corporation

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1. Case Identification

2. Patent Overview

  • Title: Rechargeable Battery Pack for a Power Tool
  • Brief Description: The ’173 patent describes a rechargeable, lithium-based battery pack for use with hand-held power tools. The invention purports to solve problems associated with prior art NiCd or NiMH batteries by using higher-power lithium-chemistry cells in a similar battery pack structure.

3. Grounds for Unpatentability

Ground 1: Claims 1-13 are obvious over Takano in view of Yanai.

  • Prior Art Relied Upon: Takano (Application # 2003/0096158) and Yanai (Japanese Patent Application No. 2001-118569).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Takano discloses all elements of independent claim 1 except for the high-current discharge capability. Takano taught a rechargeable battery pack for a cordless power tool, comprising a housing connectable to the tool, a plurality of battery cells, terminals for current discharge, and an inherent locking mechanism for securing the removable pack. Takano also disclosed using lithium-ion cells. Petitioner asserted that Yanai supplies the missing element: battery cells capable of producing an average discharge current greater than 20 amps. Yanai described high-current discharge lithium-manganese battery cells and provided data from which a person of ordinary skill in the art (POSA) could estimate that industry-standard cells using Yanai's material would meet or exceed the 20-amp requirement, either singly (for a 26650-size cell) or in a simple parallel configuration (for 18650-size cells). For dependent claims, Petitioner argued the specific limitations were also taught or made obvious by the combination. For example, Yanai taught lithium-manganese chemistry (claim 2) with a spinel structure (claim 3), and a POSA would find it obvious to arrange Yanai's cells to meet the specific cell counts (claim 4), voltages (claims 5, 7, 11), ampere-hour capacity (claim 6), and tool types (claim 10) recited.
    • Motivation to Combine (for §103 grounds): A POSA would combine Takano's power tool battery pack with Yanai's high-discharge cells to satisfy the known industry demand for higher power and performance in cordless power tools. Yanai itself identified its high-discharge material as being versatile and useful for applications including "electric power tools," directly suggesting its use in a product like Takano's.
    • Expectation of Success (for §103 grounds): A POSA would have a reasonable expectation of success because Yanai's cells could be configured in standard series and/or parallel arrangements to fit within a typical power tool battery pack, like Takano's, to achieve the desired high-current output.

4. Key Claim Construction Positions

Petitioner dedicated significant argument to the indefiniteness and proper construction of key claim terms, asserting that these constructions were critical to the obviousness analysis.

  • "a housing connectable to and supportable by the hand held power tool": Petitioner argued these terms are purely functional, reciting a capability rather than a specific structure. As such, they should be afforded no patentable weight and are met by any prior art housing merely capable of connecting to a power tool.
  • "battery cells being capable of producing an average discharge current greater than or equal to approximately 20 amps": Petitioner contended this limitation is indefinite under 35 U.S.C. §112 because the patent provides no objective standard, time period, or methodology for measuring the "average discharge current." The specification's only mention is a conclusory statement. Under the broadest reasonable interpretation (BRI), Petitioner argued a POSA would understand this limitation to be met if the cells could produce ~20 amps for a time period consistent with the intended use of a power tool, which often involves short, intermittent bursts of high-current draw.
  • "nominal voltage" (claims 5, 7, 11): Petitioner asserted this term is also indefinite because it has several competing meanings in the art (e.g., midpoint voltage, fully charged voltage, or typical operating voltage) and the patent's specification uses multiple, different "nominal" voltages (3.6V, 4.0V, 4.2V) without defining the term or basis for calculation. Given the ambiguity, Petitioner argued that under the BRI standard, the term would encompass any of these common meanings.

5. Arguments Regarding Discretionary Denial

  • Petitioner filed this IPR with a motion for joinder with an already-instituted IPR (Case No. IPR2015-01165) that challenged the same claims on the same grounds. The petition was filed within 30 days of the institution decision in the earlier case, in accordance with rules governing joinder.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-13 of the ’173 patent as unpatentable.