Caterpillar Inc v. Brookins Ernie

1. Case Identification

• Case #: IPR2017-01020
• Patent #: 7,824,290
• Filed: March 3, 2017
• Petitioner(s): Caterpillar Inc.
• Patent Owner(s): Ernie Brookins
• Challenged Claims: 1-10

2. Patent Overview

• Title: Rotational Power Distribution and Control
• Brief Description: The ’290 patent describes a rotational power distribution and control device, such as a continuously variable transmission, for automotive applications. The device uses a planetary gear set coupled with a hydrostatic pump and hydraulic fluid circuit to continuously vary the ratio between an input shaft (e.g., from an engine) and an output shaft (e.g., to the drive wheels).

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 2, 6, and 7 by Keiser

• Prior Art Relied Upon: Keiser (Application # 2003/0032517).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Keiser discloses an infinitely variable ratio transmission (IVRT) that meets every limitation of independent claims 1 and 6. Keiser's system includes a planetary gear set with three rotational interfaces, a hydrostatic pump coupled to one interface (the sun gear), a hydraulic circuit, and a control valve. Critically, Petitioner asserted that an alternative embodiment in Keiser (Figs. 9-10) discloses a piston pump with a casing (110) that functions as the claimed "cylinder block" and is coupled to the sun gear. This teaching directly contradicted the Patent Owner's argument during prosecution that no prior art showed a cylinder block coupled to a gear set.
  • Key Aspects: Petitioner contended this ground was particularly strong as Keiser's disclosure directly refutes the specific argument for patentability that persuaded the Examiner to allow the claims.

Ground 2: Obviousness of Claims 1-3 and 6-9 over Keiser in view of Rush

• Prior Art Relied Upon: Keiser (Application # 2003/0032517) and Rush (WO 2004/033906).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Keiser taught the overall IVRT system, including the planetary gear set, rotational interfaces, and hydraulic control circuit. However, the primary pump embodiment in Keiser is a gear pump, which does not have a "cylinder block." Rush was cited for its teaching of an axial piston positive displacement pump that includes a rotary cylinder block coupled to a planetary gear set in a power transmission system. Petitioner asserted that combining these references renders the claims obvious.
  • Motivation to Combine: A POSITA would combine these references as a simple substitution of one known element for another to obtain predictable results. Keiser explicitly stated that its variator pump "may be any type of positive displacement pump known...in the art," providing a clear invitation to substitute its gear pump. Rush disclosed a common and well-known type of positive displacement pump (an axial piston pump with a cylinder block) already used in similar transmission applications.
  • Expectation of Success: A POSITA would have a high expectation of success, as the substitution involves replacing one type of pump with another well-known type in a standard transmission architecture, with both pumps performing the same function.

Ground 3: Obviousness of Claim 10 over Keiser, Rush, and Britt

• Prior Art Relied Upon: Keiser (Application # 2003/0032517), Rush (WO 2004/033906), and Britt (Patent 6,634,976).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground built upon the combination of Keiser and Rush to address the additional limitation in claim 10, which recites a "differential gear set" instead of a planetary gear set. While the Keiser/Rush combination provided the core transmission with a planetary gear set, Britt was introduced for its disclosure of a continuously variable transmission that uses a differential gear set coupled to a hydraulic braking circuit.
  • Motivation to Combine: A POSITA would be motivated to replace the planetary gear set of the Keiser/Rush combination with the differential gear set from Britt. Britt explicitly taught that a differential gear set and a planetary gear set are interchangeable and can be used to produce substantially the same results in this type of power delivery system. This teaching provided a direct reason to make the substitution.
  • Expectation of Success: The substitution would yield predictable results because Britt demonstrated the functional equivalence of the two gear set types in this context.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including Claim 4 over Keiser, Rush, and Whitaker (Application # 2004/0187491) for adding a leaked fluid return path, and Claim 5 over Keiser, Rush, and Britt for claims directed to a differential gear set apparatus.

4. Key Claim Construction Positions

• "Cylinder Block of Said Hydrostatic Pump" (claims 1, 2, and 5): Petitioner argued this term should be construed to mean "a rigid casing in which cylinders of a pump are bored." This construction, based on the plain and ordinary meaning and supported by the specification, was central to the argument that the casing (110) of the pump disclosed in Keiser's Figs. 9-10 met this limitation, thereby anticipating the claims.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate. The primary references of Keiser, Rush, and Whitaker were not before the Examiner during prosecution. While Britt was of record, it was presented in this petition in new combinations with prior art the Examiner never considered. Petitioner asserted these new combinations and arguments demonstrated the novelty-destroying feature (coupling a cylinder block to a gear set) was, in fact, well known in the art, overcoming the basis for the original allowance.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-10 of the ’290 patent as unpatentable.