DCT
1:17-cv-00770
Wirtgen America Inc v. Caterpillar Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Wirtgen America, Inc. (Tennessee)
- Defendant: Caterpillar Inc. (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: 1:17-cv-00770, D. Del., 06/16/2017
- Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant Caterpillar Inc. is a Delaware corporation and therefore resides in the district for purposes of patent venue, citing the Supreme Court’s decision in TC Heartland LLC v. Kraft Foods Group Brands LLC.
- Core Dispute: Plaintiff alleges that Defendant’s PM600 and PM800 series of cold milling machines infringe twelve U.S. patents related to a wide range of technologies, including chassis stabilization, safety interlocks, automated height adjustment, sensor systems, auxiliary drives, and scraper blade mechanisms.
- Technical Context: The technology at issue pertains to cold planers, heavy construction machines used in road resurfacing projects to mill or remove the surface layer of paved areas like roads and bridges.
- Key Procedural History: The complaint states that a related complaint was filed against Caterpillar and four of its subsidiaries in the U.S. District Court for the District of Minnesota one day prior to this action, on June 15, 2017.
Case Timeline
| Date | Event |
|---|---|
| 2000-06-27 | Priority Date for U.S. Patent No. 9,624,628 |
| 2005-03-10 | Priority Date for U.S. Patent Nos. 7,828,309 and 8,118,316 |
| 2005-09-12 | Priority Date for U.S. Patent Nos. 8,113,592; 9,010,871; and 9,656,530 |
| 2006-04-27 | Priority Date for U.S. Patent Nos. 7,946,788; 8,308,395; 8,511,932; and 8,690,474 |
| 2006-05-22 | Priority Date for U.S. Patent No. 7,530,641 |
| 2007-08-15 | Priority Date for U.S. Patent No. 9,644,340 |
| 2009-05-12 | U.S. Patent No. 7,530,641 Issued |
| 2010-11-09 | U.S. Patent No. 7,828,309 Issued |
| 2011-05-24 | U.S. Patent No. 7,946,788 Issued |
| 2012-02-14 | U.S. Patent No. 8,113,592 Issued |
| 2012-02-21 | U.S. Patent No. 8,118,316 Issued |
| 2013-02-26 | U.S. Patent No. 8,308,395 Issued |
| 2013-08-20 | U.S. Patent No. 8,511,932 Issued |
| 2014-04-08 | U.S. Patent No. 8,690,474 Issued |
| 2015-04-21 | U.S. Patent No. 9,010,871 Issued |
| 2016-04-29 | Earliest Alleged Import Date of Accused Products |
| 2017-04-18 | U.S. Patent No. 9,624,628 Issued |
| 2017-05-09 | U.S. Patent No. 9,644,340 Issued |
| 2017-05-23 | U.S. Patent No. 9,656,530 Issued |
| 2017-06-16 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,828,309 - “Road-building machine,” issued November 9, 2010.
The Invention Explained
- Problem Addressed: The patent addresses the problem of instability in road-building machines when traversing uneven surfaces or obstacles (U.S. Patent No. 7,828,309, col. 1:16-24). Conventional machines with, for example, a floating front axle and a rigid rear axle can tilt significantly, which impairs the quality of the milled surface and compromises machine stability (col. 1:16-24).
- The Patented Solution: The invention is a suspension system, described as a "four-way full floating" mount, that hydraulically couples the height-adjustment cylinders of all four wheels or caterpillar tracks (col. 3:5-8). The hydraulic lines are arranged such that diagonally opposed wheels (e.g., left-front and right-rear) adjust in the same direction, while the other diagonal pair adjusts in the opposite direction (col. 2:40-47). This system is designed to create a "stability diamond" (Fig. 7), which expands the machine's stable footprint compared to the "stability triangle" of conventional designs, thereby improving its ability to compensate for transverse and longitudinal inclinations (col. 2:15-24).
- Technical Importance: This approach claims to double the permissible height of an obstacle that can be traversed by a single wheel, improving both operational safety and the quality of the milled surface on uneven terrain (col. 3:10-15).
Key Claims at a Glance
- The complaint asserts independent claim 26 (Compl. ¶45).
- Essential elements of claim 26 include:
- A road-building machine with a chassis and four ground-engaging wheels or caterpillars.
- Four working cylinders, one connected to each wheel/caterpillar, for height adjustment.
- A rotating working rotor supported between the front and rear wheels.
- Coupling lines providing a positive hydraulic coupling between the working cylinders.
- The coupling is configured such that the left front wheel and right rear wheel are adjusted in height in the same direction, and in the opposite direction to the right front wheel and left rear wheel.
- The complaint also asserts claims 1-3, 5-24, and 27-36 (Compl. ¶44).
U.S. Patent No. 8,118,316 - “Operational methods for a road-building machine,” issued February 21, 2012.
The Invention Explained
- Problem Addressed: This patent, a continuation of the application that led to the ’309 Patent, addresses the same machine instability issues on uneven ground (U.S. Patent No. 8,118,316, col. 1:16-24).
- The Patented Solution: Rather than claiming the machine itself, the ’316 patent claims the method of operating a machine equipped with the "four-way full floating" hydraulic system (col. 2:25-30). The core of the patented method involves the simultaneous, coordinated height adjustments of the ground supports: adjusting the left-front and right-rear supports in a first direction (e.g., up) while adjusting the right-front and left-rear supports in a second, opposite direction (e.g., down) (col. 6:18-26).
- Technical Importance: This patent protects the functional use of the stabilization technology, extending coverage beyond the physical apparatus to the dynamic process of compensating for terrain irregularities (col. 2:15-24).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶68).
- Essential elements of claim 1 include:
- (a) Providing a road-building machine with the structural elements of the ’309 Patent’s invention (chassis, four supports, four cylinders, rotor, and positive hydraulic coupling).
- (b) Adjusting the height of the left front and right rear ground engaging supports in a first direction.
- (c) Adjusting the height of the right front and left rear ground engaging supports in a second direction opposite the first direction.
- The complaint also asserts claims 2-16, 19, and 20 (Compl. ¶65).
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 to prevent sudden, uncontrolled acceleration when traveling in reverse with the milling drum raised (’641 Patent, col. 2:51-56). When the drum is raised and rotating in the same direction as the machine's travel, a monitoring device detects if the drum comes too close to the ground and automatically triggers a safety measure, such as uncoupling the drum from the drive engine or generating an alarm (’641 Patent, Abstract).
- Asserted Claims: Independent claims 1 and 11 are asserted (Compl. ¶81, 83).
- Accused Features: The complaint alleges that Caterpillar’s "automatic rotor disengagement feature" infringes by monitoring the machine's state (traveling in reverse, rotor on) and automatically disengaging the clutch to uncouple the rotor if ground engagement is sensed (Compl. ¶96).
Multi-Patent Capsule: U.S. Patent Nos. 8,113,592; 9,010,871; and 9,656,530
- Patent Identification: This family of patents relates to path measurement and is titled “Automotive construction engine and lifting column for a construction engine” or similar.
- Technology Synopsis: These patents describe a system for precise, regulated height adjustment of a construction machine’s lifting columns (’592 Patent, Abstract). Each lifting column is equipped with a measuring device that continuously detects its lifting position and sends a path signal to a controller, which then regulates the height of the columns in response to those signals (Compl. ¶18).
- Asserted Claims: The complaint asserts independent claims 1 and 23 of the ’871 patent and independent claim 1 of the ’592 and ’530 patents (Compl. ¶112, 138, 143, 155).
- Accused Features: The accused features are Caterpillar’s "four leg posts with position sensors" that allegedly send pulse-width modulated (PWM) signals to an Electronic Control Module (ECM), which in turn regulates the lifting positions of the columns (Compl. ¶115, 119, 122).
Multi-Patent Capsule: U.S. Patent Nos. 7,946,788; 8,308,395; 8,511,932; and 8,690,474
- Patent Identification: This family of patents relates to sensor switching systems for leveling devices.
- Technology Synopsis: These patents describe a leveling system with a plurality of selectable sensors for milling depth and slope, along with a controller and switchover device (’788 Patent, Abstract). The key feature is the ability to switch control from a first set of active sensors to a second, different set of sensors during the milling operation without interrupting the work and without causing erratic changes to the milling depth or slope, a feature described as "hot swapping" (Compl. ¶22, 172).
- Asserted Claims: The complaint asserts various independent apparatus and method claims across the family, including claim 1 of the ’788 patent and claim 9 of the ’932 patent (Compl. ¶185, 164, 197, 209).
- Accused Features: The accused feature is Caterpillar’s "grade and slope control system," which allegedly allows operators to "hot swap" between different grade sensors (e.g., from a side plate sensor to a sonic averaging system) during operation without interruption (Compl. ¶172).
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 describes an auxiliary drive system for a construction machine’s work drum (’628 Patent, Abstract). This secondary drive, with its own motor, can be coupled to the main transmission to rotate the work drum at a slow speed, which is useful for tasks like changing tools when the main work motor is disengaged (Compl. ¶26-27).
- Asserted Claims: Independent claims 1 and 21 are asserted (Compl. ¶221-222).
- Accused Features: The complaint alleges the infringing products include an "auxiliary rotor service drive" that includes a service drive motor and pulleys to rotate the work drum when the main clutch is disengaged (Compl. ¶230-231).
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: The invention is a two-part scraper blade located behind the milling drum, with an upper part and a sliding lower part (’340 Patent, Abstract). A lifting actuator adjusts the height of the lower part, while a separate swiveling actuator is connected between the upper part of the blade and the machine frame to pivot the entire blade upward for service access (Compl. ¶29).
- Asserted Claims: Independent claim 1 is asserted (Compl. ¶239).
- Accused Features: The accused products allegedly have a two-part scraper blade comprising an upper "rotor service door" and a lower "moldboard," with separate actuators for lifting the moldboard and swiveling the entire assembly upward (Compl. ¶242-244).
III. The Accused Instrumentality
- Product Identification: The accused products are Caterpillar’s PM600 Series (e.g., PM620 and PM622 models) and PM800 Series (e.g., PM820, PM822, and PM825 models) of cold milling machines (Compl. ¶10). A product badge for a PM622 model is shown in the complaint (Compl. p. 12).
- Functionality and Market Context:
- The accused products are large construction machines equipped with a rotating milling drum for removing layers of pavement (Compl. ¶47, 51). They operate on four caterpillar tracks, each connected to the chassis via a height-adjustable working cylinder (Compl. ¶49-50).
- A central feature accused of infringement is the "ride control" system, which the complaint alleges is a "four-way full floating" mode that automatically activates at speeds over 0.12 mph (Compl. ¶54). In this mode, the hydraulic leg cylinders are allegedly connected "in a series circuit" to allow "flow sharing and automatic adjustment of the legs when traveling over obstacles" (Compl. ¶57, 58). The complaint includes a detailed hydraulic schematic of this system (Compl. p. 28, Illustration 48).
- The complaint alleges that Caterpillar, historically a minor player in the U.S. road milling market dominated by Wirtgen, recently refocused its efforts to capture market share, a decision that allegedly coincided with its purchase and "dissection of the Wirtgen-brand road milling machine" (Compl. ¶10).
IV. Analysis of Infringement Allegations
7,828,309 Infringement Allegations
| Claim Element (from Independent Claim 26) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A road-building machine... | The accused PM600 and PM800 series are identified as road-building cold planer machines. | ¶47 | col. 2:32-33 |
| a chassis having a forward direction... | The accused products comprise a chassis, referred to as a "frame" in product manuals. | ¶48 | col. 4:51-52 |
| 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 are equipped with four ground-engaging caterpillar tracks. | ¶49 | col. 2:34-36 |
| a first working cylinder rigidly connected to the chassis and connected to the left front wheel or caterpillar for adjusting a height... [and similarly for 2nd, 3rd, 4th cylinders] | The accused products have four working cylinders ("leg posts") rigidly bolted to the chassis, with each cylinder connected to one of the four caterpillars to provide powered vertical movement. | ¶50 | col. 4:55-64 |
| 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) supported by the chassis and located between the front and rear tracks. | ¶51 | col. 5:21-25 |
| each of the working cylinders including at least one working chamber filled with a pressure medium... | The accused products have a hydraulic system where oil is supplied to chambers within each leg cylinder. | ¶55 | col. 3:20-23 |
| coupling lines connecting the working cylinders to one another and providing a positive hydraulic coupling between the working cylinders 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. | The accused "ride control" system allegedly connects the four leg cylinders in a "series circuit," which equalizes pressure and ties the legs together hydraulically. This connection is alleged to cause the claimed diagonal height adjustments when traveling over obstacles. | ¶57, ¶58 | col. 2:40-47 |
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: [recites structure from '309 patent]... | Caterpillar provides the accused products, which allegedly contain the structure recited in this limitation, as detailed in the infringement analysis for the '309 patent. | ¶69 | col. 5:2-17 |
| (b) adjusting the height of the left front and right rear ground engaging supports in a first direction... | The complaint alleges that when the "ride control" system is active, actuation of any member causes the left front and right rear caterpillars to be adjusted in height in the same direction. | ¶58, ¶67 | col. 6:3-6 |
| (c) adjusting the height of the right front and left rear ground engaging supports in a second direction opposite the first direction. | The complaint alleges that the "ride control" system concurrently adjusts the right front and left rear caterpillars in the opposite direction to the adjustment in step (b). | ¶58, ¶67 | col. 6:6-9 |
- Identified Points of Contention:
- Scope Questions: A central dispute for both the ’309 and ’316 patents may concern the scope of the term "positive hydraulic coupling." The question for the court will be whether the accused products' "ride control" system, which allegedly connects cylinders in a "series circuit" to "equalize" pressure (Compl. ¶57-58), meets the specific coupling requirements of the claims. Caterpillar may argue its system operates on a different principle (e.g., passive pressure balancing) than the direct, forced coupling described in the patent's embodiments.
- Technical Questions: A key factual question will be whether the operation of the accused "ride control" system functionally results in the claimed diagonal adjustments. While the complaint asserts this outcome (Compl. ¶58), the actual hydraulic behavior of the accused system as depicted in its schematic (Compl. p. 28, Illustration 48) will require expert analysis to determine if it performs the specific functions required by the claims.
V. Key Claim Terms for Construction
The Term: "positive hydraulic coupling"
Context and Importance: This term is the central inventive concept of the ’309 and ’316 patents. Its construction will likely determine infringement, as it defines the required relationship between the four hydraulic cylinders. Practitioners may focus on this term because the complaint's allegations rely on characterizing Caterpillar's "series circuit" and "pressure equalization" system as meeting this limitation.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification describes the object of the invention as improving stability and compensating for transverse and longitudinal inclinations (’309 Patent, col. 2:14-24). A party could argue that "positive hydraulic coupling" should be construed functionally to cover any hydraulic arrangement that achieves the disclosed "four-way full floating" effect and resulting stability diamond (col. 3:5-8).
- Evidence for a Narrower Interpretation: The patent’s detailed description and figures illustrate specific embodiments where coupling lines directly connect specific working chambers of the cylinders (e.g., first chamber to first chamber) (’309 Patent, col. 5:16-25; Fig. 1). A party could argue the term should be limited to such direct, forced-displacement connections, rather than a more general system of pressure equalization or balancing.
The Term: "adjusting"
Context and Importance: This active verb in method claim 1 of the ’316 patent is critical for determining whether the operation of the accused products constitutes infringement. The dispute will center on whether Caterpillar’s "ride control" system actively "adjusts" the diagonal pairs in opposite directions or merely allows for a passive, reactive balancing of forces.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent uses the term in the context of the machine automatically compensating for obstacles (’316 Patent, col. 2:15-24). A party could argue that any automated height change performed by the system in response to terrain, which results in the claimed diagonal movement, constitutes "adjusting."
- Evidence for a Narrower Interpretation: The patent describes various "operating modes" that can be selected, including modes for raising or lowering individual wheels via a valve control (’316 Patent, col. 4:7-52). A party could argue that "adjusting" implies a direct, commanded action from a controller, rather than the passive "flow sharing" alleged to occur in the accused products' "ride control" system (Compl. ¶58).
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement of infringement for the asserted method patents, including the ’316 patent. The basis is that Caterpillar provides literature, such as the Operation and Maintenance Manual, that allegedly instructs users to operate the accused products in a manner that infringes (e.g., by using the "ride control system" at speeds above 0.12 mph), thereby actively encouraging the infringing acts (Compl. ¶67, 73).
- Willful Infringement: Willfulness is alleged for all twelve asserted patents. The complaint alleges that Caterpillar had actual knowledge of the patents and that its infringement was deliberate (Compl. ¶59, 61). As factual support, the complaint alleges that Caterpillar’s decision to re-enter the U.S. market coincided with its "purchase, and subsequent analysis, of a Wirtgen-brand road milling machine" (Compl. ¶10).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of functional equivalence: does Caterpillar’s "ride control" system, described in its own literature as a "series circuit" that "equalizes" pressure for "flow sharing," perform substantially the same function, in substantially the same way, to achieve substantially the same result as the "positive hydraulic coupling" recited in the ’309 and ’316 patents? The outcome will depend heavily on the court's claim construction and its interpretation of competing expert testimony on hydraulic systems.
- A second central question will be one of infringement across a product line: the complaint asserts twelve distinct patents covering numerous features against entire product series. The case will likely fragment into a series of sub-disputes over whether the specific implementation of each accused feature—from the "hot swapping" of sensors to the "auxiliary rotor service drive"—meets all the limitations of the corresponding asserted claim.
- A key factual question for damages will be one of intent: what can be proven about Caterpillar's knowledge and intent, particularly in light of the allegation that it reverse-engineered a Wirtgen machine? Evidence related to this allegation could be critical to Plaintiff’s attempt to prove willful infringement and seek enhanced damages.