Brooks Sports Inc v. Townsend Herbert

1. Case Identification

• Patent #: 7,490,416
• Filed: February 3, 2018
• Petitioner(s): Brooks Sports, Inc.
• Patent Owner(s): Herbert E. Townsend
• Challenged Claims: 1 and 6

2. Patent Overview

• Title: Shoe with Cushioning and Speed Enhancement Midsole Components and Method for Construction Thereof
• Brief Description: The ’416 patent relates to an athletic shoe with a midsole containing at least one cavity below the wearer's foot. This cavity is filled with an encapsulated dilatant compound (e.g., Silly Putty) to provide cushioning and energy-return properties that vary with the runner's speed, being soft during slow movement and elastic during rapid movement.

3. Grounds for Unpatentability

Ground 1: Anticipation and Obviousness over Izumi - Claim 1 is anticipated by or, in the alternative, obvious under 35 U.S.C. §103 over Izumi.

• Prior Art Relied Upon: Izumi (Japanese Patent Publication No. H7-9105).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Izumi, which was not considered during prosecution, discloses every element of independent claim 1. Izumi teaches a "sport shoe" with a foam midsole (e.g., EVA or foam urethane) having a fixed elastic modulus. The midsole includes "hollow portions" (cavities) on its top surface, located below the inner sole and thus below the foot. These cavities are filled with "silicone bouncing putty," which Petitioner asserted is a dilatant compound compositionally equivalent to materials described in the ’416 patent. Izumi also discloses retaining this putty within the cavities using a cover member or a pre-filled bag, satisfying the final limitation of claim 1.
  • Motivation to Combine (for §103): As an alternative argument, Petitioner contended that if the Board found Izumi's "silicone bouncing putty" contained additives (like silica filler) that placed it outside the scope of "material consisting essentially of a dilatant compound," it would have been obvious to a POSA to modify the formulation. A POSA would have known to adjust or remove such fillers to achieve the desired dilatant properties, a common practice in the art.

Ground 2: Obviousness over Izumi and Chang - Claim 6 is obvious over Izumi in view of Chang.

• Prior Art Relied Upon: Izumi (Japanese Patent Publication No. H7-9105), Chang (Patent 4,918,838).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that while Izumi teaches the elements of claim 1, Chang supplies the limitations of dependent claim 6. Claim 6 requires the cavity to be cylindrically shaped with specific diameter and height ranges. Chang, also not considered during prosecution, discloses a shoe with "replaceable air cylinders" inserted into "purposely dimensioned recesses," including a "cylindrical body" placed into a "circular recess" in the heel. Petitioner argued the specific dimensions recited in claim 6 were merely obvious design choices, falling within known, practical ranges for shoe inserts constrained by the shoe's overall dimensions.
  • Motivation to Combine: A POSA would combine Izumi and Chang because both patents are directed to midsoles that provide cushioning and energy return. As Izumi is not explicit about the shape of its cavities, a POSA would have been motivated to use the simple, economical, and functionally effective cylindrical shape taught by Chang to improve stability and shock absorption in Izumi's design.
  • Expectation of Success: A POSA would have had a reasonable expectation of success in combining the references, as incorporating a known insert shape (Chang's cylinder) into a shoe (Izumi's) to hold a cushioning material is a simple mechanical combination that would yield predictable cushioning results.

Ground 3: Obviousness over Rudy and Plant - Claim 1 is obvious over Rudy in view of Plant.

• Prior Art Relied Upon: Rudy (Patent 6,158,149), Plant (U.K. Application # GB 2 349 798).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Rudy discloses key elements of claim 1, including footwear with cushioning devices in a midsole. These devices can be filled with various fluids, including "rheopexic fluids," which Petitioner asserted a POSA would recognize as dilatant compounds. Plant explicitly teaches an "energy absorbing pad" for apparel that uses a well-known dilatant compound (Dow Corning No. 3179), the same type disclosed in the ’416 patent.
  • Motivation to Combine: A POSA would combine the teachings because both Rudy and Plant are in the same technical field of energy-absorbing devices incorporated into articles worn by a person. It would have been an obvious and predictable substitution to use the specific, well-known dilatant compound taught by Plant as the cushioning material within the shoe insert system of Rudy.
  • Expectation of Success: A POSA would expect that substituting Plant's dilatant material for Rudy's rheopexic fluid would function successfully, as both materials share the same physical properties and are used for the same purpose of impact absorption.

• Additional Grounds: Petitioner asserted additional obviousness challenges for claims 1 and 6 based on combinations of Christensen (Application # 2003/0120353), Ito (Patent 4,768,295), and Chang, as well as combinations including Applicant Admitted Prior Art (AAPA) with Izumi and Chang, relying on similar theories of combining known elements for predictable results.

4. Key Claim Construction Positions

• "dilatant compound": Petitioner asserted this term should be interpreted broadly, consistent with the patent’s multiple definitions, to encompass any material that exhibits shear-thickening or shear-stiffening properties, including those that change from soft to elastic under increasing strain rates.
• "material consisting essentially of a dilatant compound": Petitioner argued that under the broadest reasonable interpretation, this phrase permits the inclusion of non-dilatant additives (such as fillers or lubricants) so long as they do not materially affect the fundamental dilatant properties of the compound. This construction was central to arguing that prior art materials like Silly Putty, which contain such additives, meet the claim limitation.
• "material having a fixed elastic modulus": Petitioner contended this term describes the conventional midsole foam material (e.g., EVA, PU) and is defined in contrast to the variable-modulus "dilatant compound."

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1 and 6 of Patent 7,490,416 as unpatentable.