DCT

0:17-cv-02085

Wirtgen America Inc v. Caterpillar Prodotti Stradali SRL

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 0:17-cv-02085, D. Minn., 06/15/2017
  • Venue Allegations: Plaintiff alleges venue is proper in the District of Minnesota because Caterpillar Paving Products and Caterpillar Inc. have committed acts of infringement and maintain regular and established places of business in the district. Venue over the foreign-domiciled Caterpillar entities is alleged under 28 U.S.C. § 1391(c).
  • Core Dispute: Plaintiff alleges that Defendant’s PM600 and PM800 series of cold milling machines infringe twelve U.S. patents related to various features of road construction equipment, including chassis stabilization, safety mechanisms, height adjustment, sensor controls, auxiliary drives, and scraper blades.
  • Technical Context: The dispute centers on the technology of cold milling machines, large-scale construction vehicles used to remove and recycle the surface layer of paved areas like roads and airports.
  • Key Procedural History: Post-filing, an inter partes review (IPR) was instituted against U.S. Patent No. 7,828,309. The proceeding (IPR2017-02185) resulted in the cancellation of numerous claims, including Claim 26, which the complaint identifies as exemplary for its infringement allegations under this patent. This development may significantly impact the scope of Wirtgen's assertions for this patent family.

Case Timeline

Date Event
2000-06-27 Priority Date for ’628 Patent
2005-03-10 Priority Date for ’309 and ’316 Patents
2005-09-12 Priority Date for ’592, ’871, and ’530 Patents
2006-04-27 Priority Date for ’788, ’395, ’932, and ’474 Patents
2006-05-22 Priority Date for ’641 Patent
2007-08-15 Priority Date for ’340 Patent
2009-05-12 Issue Date for U.S. Patent No. 7,530,641
2010-11-09 Issue Date for U.S. Patent No. 7,828,309
2011-05-24 Issue Date for U.S. Patent No. 7,946,788
2012-02-14 Issue Date for U.S. Patent No. 8,113,592
2012-02-21 Issue Date for U.S. Patent No. 8,118,316
2012-11-13 Issue Date for U.S. Patent No. 8,308,395
2013-08-20 Issue Date for U.S. Patent No. 8,511,932
2014-04-08 Issue Date for U.S. Patent No. 8,690,474
2015-04-21 Issue Date for U.S. Patent No. 9,010,871
2016-04-29 Alleged first importation of accused PM 620 machine
2016-05-08 Alleged first importation of accused PM 622 machine
2017-04-18 Issue Date for U.S. Patent No. 9,624,628
2017-05-09 Issue Date for U.S. Patent No. 9,644,340
2017-05-23 Issue Date for U.S. Patent No. 9,656,530
2017-06-15 Complaint Filing Date
2017-10-19 Filing Date for IPR proceeding against ’309 Patent
2021-09-03 Issue Date for IPR Certificate cancelling claims of ’309 Patent

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,828,309 - "Road-building machine"

The Invention Explained

  • Problem Addressed: Conventional road-building machines with a "floating axle" on only the front or rear wheels suffer from instability when traversing uneven ground or obstacles, which can compromise the quality of the milled surface and the machine's stability (U.S. 7,828,309 B2, col. 1:11-50).
  • The Patented Solution: The invention describes a hydraulic system that creates, in effect, a floating mount for both the front and rear axles. It uses four working cylinders, one for each wheel or track, that are "positively coupled" by hydraulic lines. This coupling causes diagonal pairs of wheels (e.g., left-front and right-rear) to adjust their height in the same direction, while opposing pairs adjust in opposite directions, thereby improving stability and doubling the permissible height of an obstacle that can be driven over by a single wheel (U.S. 7,828,309 B2, Abstract; col. 3:5-14). Figure 7 of the patent illustrates this by comparing the larger "stability diamond" of the invention to the smaller "stability triangle" of prior art machines (U.S. 7,828,309 B2, Fig. 7).
  • Technical Importance: This approach provided enhanced stability for large, narrow-track milling machines, allowing for safer operation and a more consistent milling result on inclined or uneven surfaces (U.S. 7,828,309 B2, col. 3:1-14).

Key Claims at a Glance

  • The complaint asserts independent claim 26, among others (Compl. ¶ 57-58). However, an IPR certificate issued after the complaint filing date indicates that Claim 26 has been cancelled.
  • Exemplary Claim 26 (Cancelled) required:
    • A road-building machine with a chassis and four wheels/caterpillars.
    • Four working cylinders, one for each wheel, for height adjustment.
    • A rotating working roller (milling drum) between the front and rear wheels.
    • "coupling lines connecting the working cylinders to one another and providing a positive hydraulic coupling between the working cylinders" in a specific manner that the left front and right rear wheels adjust in the same direction, and in the opposite direction to the right front and left rear wheels.
  • The complaint reserves the right to assert other claims, including dependent claims (Compl. ¶ 57).

U.S. Patent No. 8,118,316 - "Operational methods for a road-building machine"

The Invention Explained

  • Problem Addressed: The patent addresses the same technical context as its parent, the ’309 Patent: operating a road-milling machine on uneven terrain (U.S. 8,118,316 B2, col. 1:15-24).
  • The Patented Solution: The ’316 Patent claims a method of operating the machine described in the ’309 Patent. The core of the method involves simultaneously adjusting the height of the left front and right rear ground supports in a first direction, while adjusting the height of the right front and left rear ground supports in a second, opposite direction (U.S. 8,118,316 B2, Abstract). This method actively utilizes the "four-way floating" suspension system.
  • Technical Importance: The patent protects the specific operational method that allows a machine operator to leverage the stability benefits of the underlying hydraulic system.

Key Claims at a Glance

  • The complaint asserts independent claim 1, among others (Compl. ¶¶ 78, 81).
  • Claim 1 requires the steps of:
    • Providing a road-building machine with the four-wheel, four-cylinder, positive hydraulic coupling structure (as described in the ’309 Patent).
    • Adjusting the height of the left front and right rear ground engaging supports in a first direction.
    • Adjusting the height of the right front and left rear ground engaging supports in a second direction opposite the first direction.
  • The complaint reserves the right to assert other claims, including dependent claims 10 and 14 (Compl. ¶¶ 78, 83).

Multi-Patent Capsule: U.S. Patent No. 7,530,641

  • Patent Identification: U.S. Patent No. 7,530,641, "Automotive construction machine, as well as method for working ground surfaces," issued May 12, 2009.
  • Technology Synopsis: The patent describes a safety system for a road milling machine. It addresses the risk of the rotating milling drum accidentally contacting the ground when the machine is traveling in reverse (i.e., when the drum's rotation direction matches the travel direction), which could cause the machine to accelerate uncontrollably. The solution is a monitoring device that detects when the raised drum gets too close to the ground and automatically uncouples the drum and/or traveling devices from the engine or generates an alarm (U.S. 7,530,641 B2, Abstract; col. 2:3-12).
  • Asserted Claims: Independent claims 1 and 11 are asserted (Compl. ¶¶ 94-95).
  • Accused Features: Caterpillar’s "automatic rotor disengagement feature," which allegedly uses a moldboard, proximity switches, and a trigger plate to monitor the distance between the drum and the ground and disengage the rotor clutch if contact is sensed while in reverse (Compl. ¶¶ 107-109).

Multi-Patent Capsule: U.S. Patent Nos. 8,113,592; 9,010,871; and 9,656,530

  • Patent Identification: Patents related to a "Path Measurement" family.
  • Technology Synopsis: These patents concern a system for precisely measuring and controlling the height of a construction machine's lifting columns. The invention uses telescoping hollow cylinders for each lifting column, with an internal piston-cylinder unit for adjustment. A measuring device continuously detects the lifting position of each column, allowing a controller to regulate the height in a precise and regulated manner (Compl. ¶¶ 32-35).
  • Asserted Claims: Claims 1, 2, 5, 13-15, 18 and 20 of the ’592 patent are asserted as exemplary (Compl. ¶ 125).
  • Accused Features: Caterpillar's "smart cylinders," which are described as position-sensing hydraulic cylinders that continuously provide a path signal (a pulse-width modulated signal) to an Electronic Control Module (ECM) to regulate the lifting positions of the machine's legs (Compl. ¶¶ 132-135).

Multi-Patent Capsule: U.S. Patent Nos. 7,946,788; 8,308,395; 8,511,932; and 8,690,474

  • Patent Identification: Patents related to a "Sensor Switching" family.
  • Technology Synopsis: These patents describe a leveling system that allows an operator to switch control between different sets of milling depth and slope sensors during operation ("hot swapping") without interrupting the milling process or causing faults in the work result. The system includes an interface that displays data for both the current sensor and a pre-selected next sensor, allowing for a seamless transition (Compl. ¶¶ 36-40).
  • Asserted Claims: Claims 1 and 20 of the ’395 patent are asserted as exemplary (Compl. ¶¶ 177, 190).
  • Accused Features: Caterpillar's "grade and slope control system," which allegedly allows operators to "change between grade sensors, what we would call hot swapping," using a control panel that displays values for multiple sensors and allows for switching between them during operation (Compl. ¶¶ 182-185). A screenshot of the operator panel shows current and target values for both a slope sensor and a side plate depth sensor simultaneously (Compl. p. 77).

Multi-Patent Capsule: U.S. Patent No. 9,624,628

  • Patent Identification: U.S. Patent No. 9,624,628, "Auxiliary drive," issued April 18, 2017.
  • Technology Synopsis: The patent addresses the need to rotate the heavy work drum during tool exchange. It discloses an auxiliary drive, separate from the main work motor, that can be coupled to the transmission to rotate the drum slowly. This is designed to be safer and more efficient than manual rotation or using the main engine (Compl. ¶¶ 41-42).
  • Asserted Claims: Independent claims 1 and 21 are asserted (Compl. ¶¶ 234-235).
  • Accused Features: Caterpillar's "auxiliary rotor service drive," which includes a service drive motor and V-belt that can be engaged to rotate the work drum for servicing, allegedly via a magnetic coupling operated by a switch (Compl. ¶¶ 243-244).

Multi-Patent Capsule: U.S. Patent No. 9,644,340

  • Patent Identification: U.S. Patent No. 9,644,340, "Scraper device, as well as construction machine," issued May 9, 2017.
  • Technology Synopsis: This patent describes a two-part scraper blade located behind the milling drum. A separate "swiveling actuator" allows the entire blade assembly to pivot upward about an axis parallel to the milling drum, providing better access for servicing the drum while maintaining a compact design (Compl. ¶¶ 43-44).
  • Asserted Claims: Independent claim 1 is asserted (Compl. ¶ 251).
  • Accused Features: Caterpillar’s scraper blade, which consists of an upper "rotor service door" and a lower "moldboard." A piston-cylinder actuator is allegedly connected between the rotor service door and the drum casing to pivot the entire assembly upward for servicing (Compl. ¶¶ 255, 257).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Caterpillar’s PM600 Series (e.g., PM620, PM622) and PM800 Series (e.g., PM820, PM822, PM825) cold planer road milling machines (Compl. ¶ 25).

Functionality and Market Context

  • The complaint alleges these are road-building machines that perform cold milling or planing of road surfaces (Compl. ¶ 98). The complaint positions these products as a recent effort by Caterpillar, historically a "minor player" in the U.S. road milling market, to capture market share from Wirtgen, the alleged market leader (Compl. ¶ 25). The complaint alleges that the accused products incorporate six distinct categories of Wirtgen's patented technology, from chassis stabilization to sensor controls (Compl. ¶ 54). Specific accused functionalities include the "ride control" system for chassis stabilization, an "automatic rotor disengagement" safety feature, "smart cylinders" for height adjustment, and a "hot swapping" capability for grade and slope sensors (Compl. ¶¶ 67, 109, 134, 185).

IV. Analysis of Infringement Allegations

U.S. Patent No. 7,828,309 Infringement Allegations

Claim Element (from Independent Claim 26) Alleged Infringing Functionality Complaint Citation Patent Citation
a chassis having a forward direction; The accused products comprise a chassis with a forward direction, as shown in a parts manual diagram. ¶61 col. 13:59
a left front wheel or caterpillar; a right front wheel or caterpillar; a left rear wheel or caterpillar; a right rear wheel or caterpillar; The accused products have four caterpillars: left front, right front, left rear, and right rear. ¶62 col. 13:60-63
a first working cylinder... a second working cylinder... a third working cylinder... a fourth working cylinder... for adjusting a height... The accused products have four working cylinders, described as "leg posts with position sensors," that provide powered vertical movement to adjust the height of each caterpillar relative to the chassis. ¶63 col. 13:65-col. 14:14
a rotating working roller or rotor supported from the chassis between the front wheels or caterpillars and the rear wheels or caterpillars... The accused products include a rotor (milling drum) located in the center of the machine, between the front and rear tracks. ¶64 col. 14:15-19
each of the working cylinders including at least one working chamber filled with a pressure medium; and The products' hydraulic system uses oil as a pressure medium, which fills at least one working chamber (e.g., rod end and head end chambers) of each working cylinder. ¶68 col. 14:20-22
coupling lines connecting the working cylinders to one another and providing a positive hydraulic coupling...in such a way that the left front wheel or caterpillar and the right rear wheel or caterpillar are adjusted in height in the same direction and in the opposite direction to the right front wheel or caterpillar and the left rear wheel or caterpillar. In "ride control" mode, the leg cylinders are allegedly "connected in a series circuit" via five ride control valves and coupling lines. This hydraulic arrangement is alleged to equalize pressure and tie the legs together, causing them to adjust height in the claimed diagonal and opposing manner when traveling over obstacles. A hydraulic schematic from a Caterpillar publication is provided to illustrate these connections. ¶¶69-70 col. 14:23-31
  • Identified Points of Contention:
    • Claim Validity: A threshold issue is the cancellation of the exemplary asserted Claim 26 (along with many other asserted claims) in an inter partes review proceeding subsequent to the complaint's filing. This raises the question of whether Plaintiff can maintain its infringement count under the ’309 Patent based on any remaining, uncancelled claims.
    • Scope Questions: A central question for any remaining claims will be whether the term "positive hydraulic coupling" as used in the patent, which illustrates direct fluid connections, can be construed to read on Caterpillar's "ride control" system, which is described as using five electronically controlled valves to connect the cylinders in a "series circuit" (Compl. ¶ 70).

U.S. Patent No. 8,118,316 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
(a) providing a road-building machine including: ... coupling lines connecting the working cylinders to one another and providing a positive hydraulic coupling between the working cylinders; The complaint alleges that providing one of the accused Caterpillar machines, which includes the "ride control" system as described above for the ’309 patent, meets this element. ¶82 col. 11:51-col. 12:4
(b) adjusting the height of the left front and right rear ground engaging supports in a first direction; and When operated in "ride control" mode over an obstacle, the accused machine allegedly automatically performs this step. The complaint alleges that "actuation of any actuating member causes the left front and right rear caterpillars to be adjusted in height in the same direction." ¶¶70, 81 col. 12:5-7
(c) adjusting the height of the right front and left rear ground engaging supports in a second direction opposite the first direction. When operated in "ride control" mode over an obstacle, the accused machine allegedly automatically performs this step. The complaint alleges the adjustment occurs "in the opposite direction to the right front and left rear caterpillars." ¶¶70, 81 col. 12:8-10
  • Identified Points of Contention:
    • Technical Questions: The infringement analysis for the method claims of the ’316 Patent is directly dependent on the infringement analysis for the apparatus claims of the ’309 Patent. The same questions regarding the scope of "positive hydraulic coupling" apply.
    • Indirect Infringement: The complaint alleges inducement by asserting that Caterpillar's literature instructs operators to use the "ride control system" at speeds above 0.12 mph, which automatically engages the allegedly infringing hydraulic coupling (Compl. ¶ 80). The central question will be whether providing these instructions with knowledge of the patent constitutes inducement to perform the claimed method steps.

V. Key Claim Terms for Construction

  • The Term: "positive hydraulic coupling"
  • Context and Importance: This term is the technological core of the ’309 and ’316 patents. The definition of what constitutes a "positive" coupling will be critical to determining whether Caterpillar’s electronically-mediated "ride control" system, which connects cylinders in a "series circuit" (Compl. ¶ 70), infringes. Practitioners may focus on this term because the patent's figures depict direct hydraulic lines, whereas the accused system involves multiple control valves, suggesting a potential mismatch between a passive system and an actively controlled one.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the functional result of the coupling: it "ensures that the road-building machine...has high stability" and implements a "floating mount of both the front axle and the rear axle" (U.S. 7,828,309 B2, col. 3:1-9). A party could argue that any hydraulic arrangement that achieves this specific, coordinated diagonal and opposing height adjustment constitutes a "positive hydraulic coupling," regardless of the number of valves or specific circuit layout.
    • Evidence for a Narrower Interpretation: The detailed description and figures in the ’309 Patent (e.g., Figs. 1-5) illustrate specific, direct connections between the working chambers of the cylinders (e.g., "The first coupling line 36 connects the first working chamber 20 of the first working cylinder 12 to the first working chamber 22 of the second working cylinder 14") (U.S. 7,828,309 B2, col. 6:19-23). A party could argue that the term is limited to such direct, passive cross-connections, as distinct from a system that requires multiple valves to create a "series circuit."

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement for multiple patent families. For the ’316 patent, it alleges Caterpillar induces customers by providing literature instructing them to "[u]se the ride control system," which allegedly causes the machine to practice the patented method (Compl. ¶ 80). For the sensor switching patents, it alleges inducement by promoting the "hot swapping" function (Compl. ¶¶ 179, 200).
  • Willful Infringement: The complaint alleges that Caterpillar was "fully aware of and have or had actual knowledge of" the asserted patents, and that its infringement was "deliberate and willful" (e.g., Compl. ¶¶ 72, 74, 88, 90). These allegations are made for each of the twelve asserted patents.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of claim viability: following the cancellation of the exemplary asserted claim of the ’309 patent (Claim 26) and numerous other asserted claims in an inter partes review, can the Plaintiff sustain its infringement theory for the "four-way full floating" technology under any remaining, uncancelled claims of that patent?
  • A key question of definitional scope will be central to multiple patent families: can claim terms rooted in one technical embodiment be construed to cover a different technical implementation? Specifically, does the "positive hydraulic coupling" of the ’309 and ’316 patents read on Caterpillar’s valve-controlled "series circuit," and does the "switchover device" of the sensor patents read on Caterpillar's integrated "hot swapping" software feature?
  • The case presents a question of litigation complexity: by asserting twelve patents spanning six distinct technologies—from mechanical suspension to electronic sensor controls and auxiliary drives—the litigation raises the strategic question of whether the dispute will be adjudicated as a broad-based attack on the entire accused product line or be narrowed to a few dispositive technological features.