DCT
5:18-cv-06001
Gray Mfg Co Inc v. Vehicle Service Group LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Gray Manufacturing Company, Inc. (Missouri)
- Defendant: Vehicle Service Group, LLC (Delaware)
- Plaintiff’s Counsel: Murphy, Taylor, Siemens & Elliot P.C.; Hovey Williams LLP
- Case Identification: 5:18-cv-06001, W.D. Mo., 01/08/2018
- Venue Allegations: Plaintiff alleges venue is proper because Defendant VSG sent a letter alleging infringement into the district, is registered to do business in Missouri, and sells products in the district through a local distributor.
- Core Dispute: Plaintiff seeks a declaratory judgment that its mobile vehicle lifts do not infringe two patents owned by Defendant related to systems for synchronizing the vertical movement of multiple lift posts.
- Technical Context: The technology concerns control systems for multi-post vehicle lifts, which are used in automotive repair shops to ensure that separate lifting columns raise and lower a vehicle in unison to maintain stability.
- Key Procedural History: The complaint alleges that prior to the lawsuit, the parties met to discuss potential patent infringement and licensing. Defendant VSG allegedly demanded that Plaintiff Gray take a license to the patents-in-suit. On December 1, 2017, VSG sent Gray a letter with infringement claim charts, which forms the basis for the justiciable controversy required for this declaratory judgment action.
Case Timeline
| Date | Event |
|---|---|
| 2002-04-12 | Priority Date for '916 and '322 Patents |
| 2004-07-20 | Issue Date for U.S. Patent No. 6,763,916 |
| 2005-11-15 | Issue Date for U.S. Patent No. 6,964,322 |
| 2017-07-13 | Principals from VSG and Gray meet to discuss patent issues |
| 2017-09-25 | VSG President allegedly states Gray needs a license to the patents-in-suit |
| 2017-12-01 | VSG sends letter with infringement claim charts to Gray |
| 2018-01-08 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,763,916 - "Method and Apparatus for Synchronizing a Vehicle Lift," Issued July 20, 2004
The Invention Explained
- Problem Addressed: The patent addresses the problem that in vehicle lifts with multiple independent, vertically movable superstructures (e.g., the columns of a two-post or four-post lift), factors like unequal loading or inherent differences in hydraulic components can cause the superstructures to move at different rates, creating an unsafe, unlevel condition (’916 Patent, col. 1:39-49).
- The Patented Solution: The invention proposes a control system that uses position sensors on each superstructure to generate position signals. A "position synchronization circuit" receives these signals and determines a "proportional-integral error signal" based on the difference in the superstructures' vertical positions. This error signal is then used to adjust the control signals for each superstructure's actuator (e.g., hydraulic valve), thereby synchronizing their movement and keeping the lift level (’916 Patent, col. 4:35-56). The control logic is illustrated in a control diagram in Figure 2 (’916 Patent, Fig. 2).
- Technical Importance: The use of a proportional-integral (PI) control loop allows for a more responsive and precise method of synchronization compared to simpler on/off or purely mechanical systems, accommodating dynamic changes in load and system performance.
Key Claims at a Glance
- The complaint identifies independent claim 1 as illustrative and notes that VSG has asserted claims 1, 18, and 56 (Compl. ¶9, ¶20).
- Independent Claim 1 requires:
- A controller for a vehicle lift, where the lift has a first and a second vertically moveable superstructure.
- An interface to receive a first position signal from the first superstructure and a second position signal from the second superstructure.
- A position synchronization circuit that responds to the position signals and is configured to synchronize vertical movement by determining a "proportional-integral error signal" relative to the respective vertical positions of the superstructures.
- The complaint does not explicitly reserve the right to assert dependent claims, but disputes infringement of "any claims of the '916 patent" (Compl. ¶21).
U.S. Patent No. 6,964,322 - "Method and Apparatus for Synchronizing a Vehicle Lift," Issued November 15, 2005
The Invention Explained
- Problem Addressed: Similar to the '916 Patent, this patent, which is a divisional of the '916 patent's application, addresses the need to maintain multiple points of a vehicle lift system within the same horizontal plane during vertical movement (’322 Patent, col. 1:16-22).
- The Patented Solution: The invention describes a hydraulic fluid control system for a vehicle lift. The system comprises at least two hydraulic actuators (one for each superstructure), each in fluid communication with a hydraulic fluid source. A "proportional flow control valve" is placed between the source and each actuator. A central controller is connected to these valves to independently control the flow of hydraulic fluid to each actuator, thereby synchronizing the movement of the superstructures (’322 Patent, col. 1:23-28; Fig. 1).
- Technical Importance: This approach provides direct, independent electronic control over the hydraulic flow to each lifting column, enabling precise, software-driven synchronization.
Key Claims at a Glance
- The complaint identifies independent claim 1 as illustrative and notes that VSG has asserted claims 1, 2, and 4 (Compl. ¶11, ¶28).
- Independent Claim 1 requires:
- A hydraulic fluid control system for a vehicle lift.
- At least one source of hydraulic fluid.
- A first hydraulic actuator to move a first superstructure and a second hydraulic actuator to move a second superstructure.
- A first proportional flow control valve between the source and the first actuator.
- A second proportional flow control valve between the source and the second actuator.
- The first and second valves being independently controllable.
- A controller connected to the first and second valves for controlling fluid flow.
- The complaint notes that claims 2 and 4 are dependent claims and argues they are not infringed because the base claim is not infringed (Compl. ¶31).
III. The Accused Instrumentality
Product Identification
- The accused instrumentality is Plaintiff Gray's "Model WPLS-185" lift system (Compl. ¶12).
Functionality and Market Context
- The complaint describes the Model WPLS-185 as a system of "mobile column lifts that compete with VSG's mobile column lifts" (Compl. ¶12). A provided image shows two independent, mobile lifting columns, each positioned at a wheel of a vehicle. This image of the accused "Model WPLS-185" lift system depicts two separate columns lifting a truck. (Compl. at 5). Plaintiff Gray specifically alleges that its system does not include a "lift (singular) having multiple movable substructures" but is instead a system of individual lifts (Compl. ¶22, ¶30). The complaint contrasts Gray's product with VSG's "Mach Flex" lifts, which are also depicted. The image of the defendant's "Mach Flex" lifts shows them lifting a school bus. (Compl. at 2).
IV. Analysis of Infringement Allegations
'916 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A controller for a vehicle lift, said vehicle lift having a first pair formed of a first vertically moveable superstructure and a second vertically moveable superstructure... | The Model WPLS-185 system, when used as a pair of columns to lift a single vehicle, is alleged to constitute a single "vehicle lift." | ¶19, ¶22 | col. 9:1-8 |
| ...an interface configured to receive a first position signal indicative of the vertical position of said first vertically moveable superstructure and a second position signal... | The control system of the Model WPLS-185 lift is alleged to receive position information from each column in the system. | ¶16 | col. 9:9-14 |
| ...a position synchronization circuit...operably configured to synchronize vertical actuation...by determining a proportional-integral error signal... | The control system of the Model WPLS-185 lift is alleged to use a "proportional-integral technique" to synchronize the columns. | ¶15, ¶22 | col. 9:15-22 |
- Identified Points of Contention:
- Scope Question: A primary dispute appears to be whether Gray's system of individual, mobile columns constitutes a single "vehicle lift having a first pair formed of a first... and a second... superstructure" as claimed in the patent. Gray argues its product is not a singular "lift," which raises a question of claim scope (Compl. ¶22).
- Technical Question: Gray explicitly denies that its system uses a "proportional-integral error signal" (Compl. ¶22). This creates a direct factual dispute over the technical operation of the accused product's control algorithm.
'322 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A hydraulic fluid control system for a vehicle lift comprising: ...a first hydraulic actuator configured to move a first vertically moveable superstructure...[and] a second hydraulic actuator configured to move a second vertically moveable superstructure... | The Model WPLS-185 system, comprised of multiple individual columns, is alleged to be a single "hydraulic fluid control system for a vehicle lift" with multiple actuators. | ¶27, ¶30 | col. 9:6-14 |
| ...a first proportional flow control valve...a second proportional flow control valve...each being independently controllable... | The control system in each Gray column is alleged to contain an independently controllable proportional flow control valve. | ¶11, ¶30 | col. 9:15-25 |
| ...a controller connected to said first and second proportional flow control valves for controlling flow of said hydraulic fluid to said first and second hydraulic actuators. | The control system of the Model WPLS-185 is alleged to use a single "controller" that is connected to and controls the valves in multiple columns. | ¶30 | col. 9:26-29 |
- Identified Points of Contention:
- Scope Question: As with the '916 patent, a central issue is whether Gray's set of individual columns can be considered a single "hydraulic fluid control system for a vehicle lift comprising" a first and second actuator, as required by the preamble and body of the claim (Compl. ¶30).
- Technical Question: Gray denies that its system uses a "controller (singular) connected to multiple proportional flow control valves" (Compl. ¶30). This suggests a dispute over the architecture of the control system—specifically, whether there is a single, central controller as claimed, or a distributed control system where each column has its own controller.
V. Key Claim Terms for Construction
Term 1: "a vehicle lift" (from '916 Patent, Claim 1 and '322 Patent, Claim 1)
- Context and Importance: The definition of this term is critical because Gray's primary non-infringement argument is that its product is a system of separate lifts, not one singular "lift" with multiple superstructures (Compl. ¶22, ¶30). If "a vehicle lift" is construed to require a single, integrated mechanical frame, Gray's system of independent mobile columns may not be covered.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states that examples of lifts include "portable lifts" (’916 Patent, col. 1:26). One might argue this term encompasses systems of coordinated but physically separate columns like the accused product. The term "superstructure" is also broadly defined to include "all vehicle lifting interfaces between the lifting apparatus and the vehicle" (’916 Patent, col. 1:32-34).
- Evidence for a Narrower Interpretation: The embodiments depicted in the patent figures, such as the "two post vehicle lift" in Figure 7 and the "four post vehicle lift" in Figure 8, show superstructures that are part of a single, common apparatus (’916 Patent, Figs. 7-8). This could support a narrower construction limited to integrated, non-mobile systems.
Term 2: "proportional-integral error signal" (from '916 Patent, Claim 1)
- Context and Importance: Gray explicitly denies using this technique (Compl. ¶22), making it a core technical dispute. Practitioners may focus on this term because its definition will determine what type of control algorithm infringes. The case may turn on whether the accused system's synchronization method, whatever it may be, meets the specific mathematical and functional definition of a PI controller.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent does not define the term with mathematical formulae in the claims. A party might argue that any control system that considers both the current position error (proportional) and the accumulated past error (integral) falls within the plain and ordinary meaning of the term.
- Evidence for a Narrower Interpretation: The specification provides a specific diagram for the "proportional-integral controller" (’916 Patent, Fig. 2, items 38a, 38b). The detailed description explains that the output is generated by summing the output of a proportional control and an integral control (’916 Patent, col. 4:46-56). A party could argue the claim is limited to this specific "cross coupled" architecture.
VI. Other Allegations
- Indirect Infringement: The complaint does not contain allegations of indirect infringement by VSG against Gray, as VSG has not yet filed a counterclaim.
- Willful Infringement: The complaint does not contain an allegation of willful infringement by VSG. However, Gray's complaint establishes facts that would be relevant to a future willfulness claim by VSG, noting that VSG provided notice of the patents-in-suit and its infringement allegations in a letter dated December 1, 2017 (Compl. ¶15-¶16).
- Exceptional Case: Gray requests that the court find the case "exceptional" pursuant to 35 U.S.C. § 285, which would entitle it to an award of reasonable attorney's fees (Compl. Prayer for Relief ¶B). The basis for this appears to be the pre-suit conduct alleged, including VSG's alleged threats of a "never-ending litigation battle" during a meeting (Compl. ¶13).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of definitional scope: Can the term "a vehicle lift," which is described in the patent specification with reference to integrated two- and four-post systems, be construed broadly enough to read on a system of physically separate, mobile lifting columns like the accused Model WPLS-185?
- A key evidentiary question will be one of technical operation: Does Gray's control system, as a matter of fact, implement the specific control schemes claimed in the patents? Specifically, does it determine a "proportional-integral error signal" as required by the '916 patent, and does it use a singular "controller" connected to multiple valves as claimed in the '322 patent?
- A third question relates to the system architecture: Does the accused product function as a single, integrated system with one controller and multiple subservient actuators (as the patents appear to claim), or as a distributed system of intelligent, communicating peers, which may create a fundamental mismatch with the claimed invention?