Milwaukee Electric Tool Corp v. Irwin Industrial Tool Co

1. Case Identification

• Case #: IPR2015-01462
• Patent #: 8,579,555
• Filed: June 22, 2015
• Petitioner(s): Milwaukee Electric Tool Corporation
• Patent Owner(s): Irwin Industrial Tool Company
• Challenged Claims: 1-34

2. Patent Overview

• Title: Hole Cutter with Fulcrums for Slug Removal
• Brief Description: The ’555 patent describes a hole saw with a cylindrical blade body having at least one axially-elongated aperture in its sidewall. The aperture defines multiple fulcrums, allowing a user to insert a tool (e.g., a screwdriver) to pry and remove a workpiece slug lodged inside the hole saw after cutting.

3. Grounds for Unpatentability

Ground 1: Anticipation by Redford - Claims 1, 3-5, 14-18, 20-26, 29-30, and 33-34 are anticipated by Redford.

• Prior Art Relied Upon: Redford (Patent 7,237,291).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Redford, which discloses a combined nut driver and debris cleaner, teaches every element of the challenged claims. Redford's "debris removing portion" was asserted to be a hole saw with a "cleaning flange" that is substantially cylindrical and has a cutting edge. This flange includes a continuous, S-shaped channel that serves as the claimed "axially-elongated aperture." The upper and lower depressions within this channel function as the "plurality of fulcrums" for levering out debris, directly corresponding to the limitations of independent claims 1 and 22. Petitioner contended that the functional language in the claims, such as "configured to receive... a lever," is met because Redford's structure is inherently capable of this function.

Ground 2: Obviousness over Redford and Starbuck - Claims 2, 6-13, and 31-32 are obvious over Redford in view of Starbuck.

• Prior Art Relied Upon: Redford (Patent 7,237,291), Starbuck (Patent 2,473,077).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Redford discloses the core invention of a hole saw with a multi-fulcrum slot. Starbuck discloses a conventional hole cutter with angled slots, a well-known feature used to guide cuttings away from the teeth during operation. The combination addresses claims requiring features like angled slots and specific spacing from the cutting edge.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the teachings to improve the Redford device with a known technique for a predictable result. Specifically, a POSITA would add Starbuck’s angled chip-removal slots to Redford's hole saw. It would have been obvious to merge Redford's S-shaped fulcrum channel with Starbuck's chip-removal slot into a single aperture to reduce manufacturing costs and improve the sidewall strength of the hole saw.
  • Expectation of Success: Because both references relate to slots in hole cutters, a POSITA would have had a high expectation of success in combining their features to gain the benefits of both.

Ground 3: Obviousness over Singh and Redford - Claims 1-34 are obvious over Singh in view of Redford.

• Prior Art Relied Upon: Singh (Application # 2009/0035082), Redford (Patent 7,237,291).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Singh discloses a hole saw with multiple, separate slots positioned at different axial and circumferential locations to serve as fulcrums for slug removal. However, Singh requires the user to remove and reinsert the lever to move between fulcrums. Redford teaches the benefit of a single, continuous, S-shaped slot that connects multiple fulcrum points, allowing an object to move between them without being removed.
  • Motivation to Combine: A POSITA would be motivated to modify Singh by connecting its separate fulcrum slots with a continuous channel as taught by Redford. The motivation was to increase functionality and convenience by eliminating the need to remove the lever from the hole saw when moving between different leverage points, a specific problem addressed by Redford's design.
  • Expectation of Success: The combination involved applying a known technique (Redford's continuous slot) to a similar device (Singh's hole saw) to achieve a predictable improvement in usability. The resulting structure would inherently meet the limitations of the claims.

• Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 2) based on Redford alone, arguing that if Redford did not anticipate, it would have been obvious for a POSITA to use Redford's cleaning flange as a conventional hole saw and to make minor design-choice modifications to arrive at the claimed invention.

4. Key Claim Construction Positions

• "fulcrum": Petitioner argued for the broadest reasonable interpretation, defining a fulcrum as simply "a support... on which a lever can turn." This construction avoids any requirement that a lever is actively or constantly engaged, which was critical for mapping the term onto the static structures disclosed in the prior art.
• "configured to...": Petitioner contended that claim phrases like "configured to receive therethrough a lever" constitute functional, intended-use language that should not be given patentable weight beyond the underlying structure. The proposed construction was that the aperture need only be "capable of" receiving a lever, arguing that the prior art devices possessed the necessary structure even if not explicitly described for that specific purpose.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-34 of the ’555 patent as unpatentable.