Power Packer North America v. GW Lisk Co Inc

1. Case Identification

• Case #: IPR2017-02034
• Patent #: 6,601,821
• Filed: August 31, 2017
• Petitioner(s): POWER-PACKER NORTH AMERICA, INC. d/b/a GITS MANUFACTURING CO.
• Patent Owner(s): G.W. LISK CO., INC.
• Challenged Claims: 1-11

2. Patent Overview

• Title: Two-Stage Proportional Control Valve Assembly
• Brief Description: The ’821 patent relates to a valve assembly configured to regulate the flow of a "first" fluid by controlling the flow of a separate "second" fluid using an electrical control signal. The assembly generally includes a flow-regulating valve, a double-acting actuator, a directional valve, and an electrical actuator.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-10 - Claims 1-10 are anticipated under 35 U.S.C. §102 by Martin.

• Prior Art Relied Upon: Martin (Patent 4,201,116).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Martin, which discloses a two-stage "electro-hydraulic proportional control servo valve," teaches every limitation of claims 1-10. For independent claim 1, Martin’s main control valve 16 is the claimed "flow-regulating valve" for a first fluid. Its double-acting cylinder 46, powered by a second fluid from pump 28, is the claimed "double-acting actuator." Martin’s pilot spool 27 is the "directional valve," and its solenoid unit 12 is the "electrical actuator." Petitioner asserted that Martin’s components function identically to those claimed, with the electrical actuator (solenoid 12) controlling the directional valve (spool 27), which in turn directs the second fluid to operate the actuator (cylinder 46) and move the flow-regulating valve (valve 16). For dependent claims, Petitioner contended Martin discloses the four-way nature of the directional valve (claim 2), the piston-based actuator (claim 3), the spool-based directional valve (claim 4), a neutral position (claim 5), and the feedback spring mechanism (claims 6-10).

Ground 2: Anticipation of Claims 1-5 - Claims 1-5 are anticipated under 35 U.S.C. §102 by Eggers.

• Prior Art Relied Upon: Eggers (German Published Examined Application No. 1268494).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Eggers discloses a control valve device with all features of claims 1-5. Eggers’ valve 1 with slide 2 is the "flow-regulating valve" for a first fluid. The pneumatic piston drive 6 is the "double-acting actuator" powered by a second fluid (compressed air). The control device including control slide 16 and control pistons 9 is the "directional valve." The electric stepper motor 15 is the "electrical actuator" that responds to electrical pulses to position the directional valve. Petitioner argued these components perform the functions recited in claim 1. For dependent claims, Petitioner contended that Eggers’ directional valve is a four-way valve (claim 2), the actuator is a double-acting piston (claim 3), the directional valve is a spool type (claim 4), and it has a neutral position (claim 5).

Ground 3: Obviousness of Claim 11 - Claim 11 is obvious over Martin in view of Oleksiewicz.

• Prior Art Relied Upon: Martin (Patent 4,201,116) and Oleksiewicz (Patent 6,006,732).

• Core Argument for this Ground:

  • Prior Art Mapping: Claim 11 adds the limitation that the flow-regulating valve includes a "poppet head pressure balanced with respect to the first fluid." Petitioner argued that Martin teaches all limitations of base claim 1 but discloses a spool-type flow-regulating valve. Oleksiewicz, however, explicitly teaches a pressure-balanced, dual poppet-head valve for an exhaust gas recirculation (EGR) system.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to substitute the pressure-balanced poppet valve from Oleksiewicz for the spool valve in Martin. Poppet-head valves were well-known to be more efficient and less prone to leakage than spool valves. A POSITA would therefore combine the references to improve the efficiency and reduce leakage of Martin's design.
  • Expectation of Success: The combination represented a predictable substitution of one known type of valve for another to achieve a known benefit. Both Martin's spool valve and Oleksiewicz's poppet valve are configured for linear actuation, making the substitution straightforward and predictable for a POSITA.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 1-10 are obvious over Eggers and Martin, and claim 11 is obvious over Eggers, Martin, and Oleksiewicz. These grounds relied on arguments for combining Martin's solenoid-based proportional control and linear component alignment with Eggers's system to achieve finer control and a more compact design, and further adding Oleksiewicz's pressure-balanced poppet for improved efficiency.

4. Key Claim Construction Positions

• "First fluid" and "second fluid": Petitioner argued this phrase should be construed to mean two separate fluids, but not necessarily two different types of fluids (e.g., gas and liquid). This construction is important because the prior art systems may use the same type of fluid (e.g., oil) from different circuits, and a narrower construction might allow the patent to improperly escape the prior art.
• "Two-stage" and "proportional": Petitioner contended these terms in the preamble of claim 1 are not limiting because the body of the claim recites a functionally complete invention. However, if they are found to be limiting, Petitioner proposed constructions based on their plain meaning and the specification. "Two-stage" should mean a valve assembly with two valves configured such that one regulates the other. "Proportional" should mean a valve that moves in proportion with an input signal. These constructions ensure that the prior art systems, described as two-stage and proportional, fall within the scope of the claims.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the grounds should not be denied under §325(d) because the prior art and arguments were not previously considered by the USPTO during prosecution.
• Martin: Although Martin was cited during prosecution, Petitioner contended the Examiner's analysis was cursory and failed to explain any distinction between Martin and the claims. This petition presented a new, in-depth analysis supported by an expert declaration.
• Eggers: Eggers was submitted in an Information Disclosure Statement (IDS) on the same day the ’821 patent issued, after the issue fee had been paid. Petitioner argued that the Examiner had lost jurisdiction over the application at that point, making any subsequent consideration of Eggers a legal nullity. Therefore, Eggers was effectively never before the Office for substantive consideration.

6. Relief Requested

• Petitioner requests the institution of an inter partes review and the cancellation of claims 1-11 of the ’821 patent as unpatentable.