Caterpillar Inc v. Wirtgen America Inc

1. Case Identification

• Case #: IPR2017-02188
• Patent #: 9,656,530
• Filed: October 19, 2017
• Petitioner(s): Caterpillar, Inc.
• Patent Owner(s): Wirtgen America, Inc.
• Challenged Claims: 1–7, 13–24, and 26

2. Patent Overview

• Title: Automotive Construction Machine, as Well as Lifting Column for a Construction Machine
• Brief Description: The ’530 patent discloses an automotive construction machine, such as a road recycler or milling machine, equipped with height-adjustable lifting columns. The invention purports to improve upon conventional machines by integrating a measuring device (sensor) within each lifting column to determine and regulate its current lifting position.

3. Grounds for Unpatentability

Ground 1: Claims 1, 2, 15, 21, 24, and 26 are obvious over Swisher in view of Glasson.

• Prior Art Relied Upon: Swisher (Patent 4,325,580) and Glasson (Patent 6,234,061).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Swisher disclosed a planer-type road construction machine with all the basic elements of claim 1, including a machine frame, working drum, ground supports, and telescoping lifting columns with internal hydraulic actuators. However, Swisher’s height-monitoring sensors were located externally on the machine frame. Petitioner asserted that Glasson remedied this deficiency by teaching a position sensor designed to be mounted inside a hydraulic cylinder, with elements that move relative to one another to produce a position signal. For dependent claims, Petitioner argued that Swisher’s existing elevation control assembly functioned as the claimed "controller" that receives signals and regulates lifting positions (claim 2). This controller, in conjunction with the lifting columns, regulated the working depth of the drum (claim 15), adjusted working depth by moving the lifting columns while the drum was fixed to the frame (claim 21), and allowed for independent raising and lowering of the columns (claim 24). Finally, the transducer in Glasson was described as an LVDT that included "inductive or capacitive sensors," directly teaching the "inductive path measuring devices" of claim 26.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Swisher and Glasson to solve a known problem. Glasson explicitly identified the disadvantages of mounting sensors externally on heavy equipment, where they are exposed to harsh environmental conditions, and proposed its in-cylinder sensor as a low-cost, long-life solution. Therefore, a POSITA would have been motivated to replace Swisher's external sensors with Glasson's more robust internal sensor to improve the machine's reliability and durability.
  • Expectation of Success: Petitioner contended that a POSITA would have had a reasonable expectation of success because combining the references involved implementing a known type of sensor (Glasson) into a known type of machine (Swisher) to achieve the predictable result of a more durable sensing system.

Ground 2: Claims 3, 4, 14, 16–20, and 22–23 are obvious over Swisher and Glasson in further view of Davis.

• Prior Art Relied Upon: Swisher (Patent 4,325,580), Glasson (Patent 6,234,061), and Davis (Application # 2002/0047301).
• Core Argument for this Ground:
  • Prior Art Mapping: Building on the Swisher/Glasson combination, Petitioner argued that Davis taught the additional advanced control features recited in the remaining claims. Davis described an integrated management system for a road scarifier that addressed the shortcomings of uncoordinated controls. Specifically, Davis taught using displays as an "indicator device" to show lifting positions (claims 3, 22, 23), a PLC controller that stores preset parameters and compares them to sensor signals to define a reference position (claim 4), calibrating lifting positions by zeroing the sensors when the machine is on the ground (claim 14), and operating all four cylinders synchronously during its "parameter setting cycle" to raise or lower the frame (claims 16, 17).
  • Motivation to Combine: Davis expressly disclosed the drawbacks of prior art systems where operators managed depth controls in a "non-coordinated way." A POSITA would be motivated to incorporate Davis's integrated control system into the Swisher/Glasson machine to provide improved functionality, such as automatic height correction based on a preset profile and a unified display for the operator. This would overcome the known problem of inefficient, uncoordinated manual adjustments.
  • Expectation of Success: Petitioner asserted a high expectation of success, as it involved the integration of a known control and display system (Davis) with a conventional road construction machine (Swisher/Glasson). The result—a more automated and user-friendly machine—was predictable.

Ground 3: Claims 5–7 and 13 are obvious over Swisher and Glasson in further view of Hosseini.

• Prior Art Relied Upon: Swisher (Patent 4,325,580), Glasson (Patent 6,234,061), and Hosseini (Patent 5,189,940).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Hosseini provided the teachings for claims related to preventing mechanical damage and improving control precision. Hosseini disclosed a control system for hydraulic implements on work vehicles that set programmable upper and lower "kickout heights" as "limiting values" for the hydraulic cylinders' range of motion (claim 5). This system avoided mechanical damage by initiating a "kickout-begin-modulation" phase that gradually slowed the implement before it reached the kickout height, thus preventing the piston from engaging a mechanical stop (claims 6 and 7). This same speed-reduction feature inherently reduced or eliminated overshooting when the controller regulated the lifting positions with reference to these desired kickout heights (claim 13).
  • Motivation to Combine: Hosseini explicitly addressed the problem of mechanical stress, increased maintenance, and accelerated failure caused by hydraulic cylinders abruptly impacting their mechanical stops. A POSITA would have been motivated to incorporate Hosseini’s control methods into the Swisher/Glasson machine to improve its longevity, reduce maintenance costs, and increase operator comfort by preventing harsh, jolting stops.
  • Expectation of Success: Petitioner argued that success would be expected because applying Hosseini's well-understood hydraulic control strategies to the Swisher/Glasson machine was a straightforward application of known engineering principles to achieve the predictable benefits of smoother operation and reduced mechanical wear.

4. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1–7, 13–24, and 26 of Patent 9,656,530 as unpatentable under 35 U.S.C. §103.