Robert Bosch LLC v. Westport Fuel Systems Canada Inc

1. Case Identification

• Case #: IPR2023-00292
• Patent #: 6,298,829
• Filed: December 14, 2022
• Petitioner(s): Robert Bosch LLC, and Mercedes-Benz USA, LLC
• Patent Owner(s): Westport Fuel Systems Canada Inc.
• Challenged Claims: 1-3, 6, 11-12, 14-15, and 18-20

2. Patent Overview

• Title: Directly Actuated Injection Valve
• Brief Description: The ’829 patent discloses a high-pressure fuel injector for an internal combustion engine. The invention is characterized by a directly controllable actuator (e.g., piezoelectric) that operates a valve needle via a "passive hydraulic link" which transmits force and is configured to auto-adjust to compensate for thermal expansion and wear during periods of inactivity.

3. Grounds for Unpatentability

Ground 1: Obviousness over Wirbeleit and Klügl - Claims 1-3, 6, 11-12, 14-15, and 18-19

• Prior Art Relied Upon: Wirbeleit (Patent 5,479,902) and Klügl (DE 197 08 304 A1).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Wirbeleit taught a directly actuated fuel injector with all major components of claim 1, including a piezoelectric or magnetostrictive actuator, a valve needle, and a passive "hydraulic transmission element" that transmits force from the actuator to the needle. However, Wirbeleit did not explicitly disclose that its hydraulic link was adjustable to compensate for thermal expansion and wear. Petitioner asserted that Klügl supplied this missing teaching, as it described a transmission module containing a passive hydraulic link (pressure chamber 5) specifically designed to allow fluid redistribution during idle periods to "account for thermal expansion differences and gradual wear." The combination of Wirbeleit's directly actuated injector with Klügl's auto-adjusting hydraulic link allegedly rendered the claims obvious.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would have been motivated to combine the references because Wirbeleit stated its "hydraulic transmission element" was "not shown in detail," compelling a designer to look to known solutions like Klügl. Petitioner contended that the structural and functional similarity of the injectors in both references would provide a strong motivation to incorporate Klügl's module to solve the well-known industry problem of compensating for temperature and wear effects in fuel injectors.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining the references because both relate to fuel injectors with analogous hydraulic force transmission elements, making the integration of Klügl's more detailed design into Wirbeleit's system straightforward and predictable.

Ground 2: Obviousness over Klügl and Hayes - Claims 1-3, 6, 11-12, 14-15, and 18-19

• Prior Art Relied Upon: Klügl (DE 197 08 304 A1) and Hayes (Patent 5,779,149).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground was premised on the Patent Owner's alleged claim construction from co-pending litigation, under which the claims encompass indirectly actuated injectors. Petitioner argued Klügl taught such an indirectly actuated injector, where its actuator moves a piston and ball valve (the claimed "valve needle") that opens an intermediate servo valve, which in turn causes a separate injection needle to open. Klügl provided the core inventive concept of the passive, auto-adjusting hydraulic link. Petitioner used Hayes, another indirectly actuated fuel injector, to provide exemplary details of structures (e.g., fuel inlet port, nozzle orifice) that a POSITA would have understood to be part of Klügl's injector, even though they were not explicitly shown in Klügl's figures.
  • Motivation to Combine: Petitioner asserted that Hayes simply provided elaboration for what a POSITA would already understand Klügl to teach. The motivation was not to modify Klügl, but to use Hayes as a technical dictionary to demonstrate how the un-illustrated components of Klügl's standard indirectly actuated injector would be structured, thereby fully mapping Klügl onto the claim limitations.
  • Expectation of Success: Success was expected because Hayes showed conventional structures for an injector of the same type disclosed in Klügl, making it a reliable guide for a POSITA to understand Klügl's complete structure.

• Additional Grounds: Petitioner asserted two additional obviousness grounds adding Newcomb (Patent 4,284,263) to the primary combinations. Ground 2 challenged claim 20 as obvious over Wirbeleit, Klügl, and Newcomb. Ground 4 challenged claim 20 as obvious over Klügl, Hayes, and Newcomb. In both grounds, Newcomb was cited for its teaching to select materials with similar thermal expansion coefficients for the valve housing, needle, and actuator to reduce dimensional changes caused by temperature, as required by claim 20.

4. Key Claim Construction Positions

• Petitioner argued for a central claim construction dispute concerning the scope of the term "valve needle" and the nature of the injector's actuation.
• Petitioner's Proposed Construction ("Direct Actuation"): The plain language of the claims, supported by the specification and the patent's title ("Directly Actuated Injection Valve"), requires a directly actuated injector. This means the claimed "valve needle" must be the component that directly seals and unseals the nozzle orifice leading into the combustion chamber.
• Patent Owner's Alleged Construction ("Indirect Actuation"): Petitioner asserted that in district court litigation, the Patent Owner had advanced a broader construction where the claims also cover indirectly actuated injectors. Under this interpretation, the "valve needle" could be an intermediate component that opens a separate control valve, which in turn causes the main injection valve to open.
• This dispute formed the basis for Petitioner's alternative invalidity arguments, with Grounds 1 and 2 relying on the "direct actuation" construction and Grounds 3 and 4 demonstrating invalidity even under the Patent Owner's alleged "indirect actuation" construction.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial would be inappropriate under both 35 U.S.C. §314(a) and §325(d).
• Against Fintiv Denial (§314(a)): Petitioner contended that the petition presented "compelling evidence of unpatentability" and that the parallel district court cases were in very early stages, with no trial dates, claim construction orders, or dispositive motions filed. These factors weighed heavily in favor of institution.
• Against §325(d) Denial: Petitioner argued that its grounds were substantially different from the art considered during prosecution. The key prior art references, Wirbeleit and Klügl, were never before the Examiner. The Examiner had previously allowed the claims after the applicant distinguished prior art (O'Neill) for lacking a "passive hydraulic link"—the very feature that Petitioner argued Wirbeleit and Klügl teach.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 6, 11-12, 14-15, and 18-20 of the ’829 patent as unpatentable.