Power Packer North America Inc v. GW Lisk Co Inc

1. Case Identification

• Case #: IPR2017-02035
• 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: 12-22

2. Patent Overview

• Title: Proportional Control Valve
• Brief Description: The ’821 patent discloses a two-stage proportional control valve assembly. The assembly regulates the flow of a first fluid by using an electrical control signal to manipulate a directional valve, which in turn controls the flow of a separate, second fluid to a double-acting actuator linked to a main flow-regulating valve.

3. Grounds for Unpatentability

Ground 1: Anticipation over Martin - Claims 12-22 are unpatentable under 35 U.S.C. §102 over 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 independent claims 12 (method) and 20 (apparatus). Martin's device controls a first fluid flow using a second fluid, where an electrical signal to a solenoid (electrical actuator) moves a directional valve (spool 27). This directional valve controls the second fluid's flow to a double-acting actuator (cylinder 46), which is linked to the main flow-regulating valve (spool 20). Petitioner contended that Martin's feedback spring (75), which connects the actuator and the directional valve, performs the same feedback and restoration function recited in the claims. The argument extends to dependent claims 13-19 and 21-22 by mapping their respective limitations to corresponding structures and functions in Martin.

Ground 2: Anticipation over Eggers - Claims 12-13 and 16-18 are unpatentable under §102 over 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 that meets the limitations of the challenged claims, albeit with different specific mechanisms than Martin. Eggers teaches regulating a first fluid (through valve 1) using a second fluid (compressed air). The system is controlled by an electric stepper motor (15) that converts electrical pulses to move a directional valve (control pistons 9). This valve directs the second fluid to a double-acting actuator (piston drive 6) linked to the flow-regulating valve. Petitioner argued Eggers' mechanical feedback system, comprising a working rod (3), feedback arm (4), and cable pull (14), links the actuator and directional valve to restore a neutral position, thereby anticipating the broader structural requirements of claims 12-13 and 16-18.

Ground 3: Obviousness over Eggers and Martin - Claims 12-22 are obvious over Eggers in view of Martin.

• Prior Art Relied Upon: Eggers (German Published Examined Application No. 1268494) and Martin (Patent 4,201,116).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that to the extent Eggers does not anticipate all limitations, it would have been obvious to a Person of Ordinary Skill in the Art (POSITA) to modify Eggers using the teachings of Martin. The primary modification would be replacing Eggers' stepped, discrete position control (via a stepper motor) with Martin's solenoid-based proportional control, which allows for continuous and more precise valve positioning. This would also involve adopting Martin's compact, linear component alignment.
  • Motivation to Combine: A POSITA would combine the references to improve the precision, accuracy, and range of the valve control. Martin's solenoid offered a known method for achieving continuous proportional control, a clear improvement over Eggers' stepped-pulse system. Furthermore, a POSITA would be motivated by the "universal" desire to make devices smaller, lighter, and more commercially versatile by adopting Martin's compact linear alignment over Eggers' less-integrated parallel component layout. Replacing Eggers’ rigid rod feedback with Martin’s feedback spring would be a predictable and necessary adaptation for this combination.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining the references, as it involved the straightforward substitution of known mechanical and electrical components (e.g., a solenoid for a stepper motor, a spring for a rigid link) to perform their established and predictable functions.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 19 is obvious over Martin alone or in combination with Oleksiewicz (Patent 6,006,732), which was cited to teach a pressure-balanced flow control component.

4. Key Claim Construction Positions

• "first fluid" and "second fluid": Petitioner argued these terms should be construed to mean two separate fluid flows, not necessarily two different types of fluids (e.g., liquid vs. gas). This construction is based on the ’821 patent’s description of flow paths that are independent and do not commingle, and it ensures that prior art using the same type of fluid in two separate circuits is not improperly excluded.
• "proportional": Petitioner contended that the term "proportional" in the preamble of claim 20 should not be treated as a substantive claim limitation. Alternatively, if considered limiting, it should be construed broadly to mean "a valve that moves in proportion with an input." This construction is supported by the specification and the ordinary meaning in the art, and under this interpretation, both Martin and Eggers would meet the limitation.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the grounds were new and not substantially the same as those considered during prosecution, making discretionary denial under 35 U.S.C. §325(d) inappropriate.
• Regarding Martin: Although Martin was before the examiner, the prosecution record contains only a cursory acknowledgment of the reference without any substantive analysis or explanation of how the claims were patentable over it. Petitioner asserted that the in-depth analysis and expert testimony presented in the inter partes review (IPR) were never before the Office.
• Regarding Eggers: Petitioner contended that Eggers was never substantively considered by the examiner. The reference was submitted in an Information Disclosure Statement on the same day the issue fee was paid and the patent issued, at which point the examiner had lost jurisdiction. Petitioner argued the examiner's subsequent post-hoc statement purporting to have considered Eggers was a "legal nullity."

6. Relief Requested

• Petitioner requests institution of an IPR and cancellation of claims 12-22 of the ’821 patent as unpatentable.