DCT

4:13-cv-01895

Nidec Motor Corp v. Broad Ocean Motor LLC

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 4:13-cv-01895, E.D. Mo., 07/09/2021
  • Venue Allegations: Venue is asserted based on Defendants’ alleged residence and/or regular and established places of business within the Eastern District of Missouri, coupled with allegations that acts of infringement occurred within the district.
  • Core Dispute: Plaintiff alleges that Defendants’ Azure Digi-Tech line of HVAC motors infringes four patents related to variable speed motor control, electronic torque adjustment, and surge protection technology.
  • Technical Context: The dispute centers on high-efficiency, electronically commutated motors (ECMs) designed as "drop-in" replacements for older, less-efficient permanent split capacitor (PSC) motors in residential and commercial HVAC systems.
  • Key Procedural History: The complaint details a long and complex procedural history, originating with a lawsuit filed in 2013. Defendants subsequently filed multiple inter partes review (IPR) petitions against the asserted patents. The Patent Trial and Appeal Board (PTAB) and the U.S. Court of Appeals for the Federal Circuit have reviewed the patents, with outcomes including the invalidation of some claims, the confirmation of others, and the reversal of a PTAB invalidity finding on appeal. Notably, claims of the ’970 patent were also confirmed patentable in a separate ex parte reexamination. U.S. Patent No. 5,818,194 expired during the course of the litigation.

Case Timeline

Date Event
1996-04-01 ’194 Patent Priority Date
1998-10-06 ’194 Patent Issue Date
2004-01-09 ’970 Patent Priority Date
2005-06-24 ’895 Patent Priority Date
2007-04-24 ’895 Patent Issue Date
2007-12-25 ’970 Patent Issue Date
2008-09-08 ’092 Patent Priority Date
2011-08-02 ’092 Patent Issue Date
2013-09-25 Original Complaint Filed
2015-03-27 Alleged Notice Date for ’194 and ’092 Patents
2019-12-04 ’194 Patent Expiration Date
2021-07-09 Second Amended Complaint Filing Date

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

U.S. Patent No. 5,818,194 - "Direct replacement variable speed blower motor"

The Invention Explained

  • Problem Addressed: The patent describes the difficulty and expense of upgrading existing HVAC systems from traditional fixed-speed permanent split capacitor (PSC) motors to more energy-efficient variable-speed motors. Such upgrades typically required complex changes to the system's wiring and control configuration (’194 Patent, col. 2:42-56).
  • The Patented Solution: The invention provides a "drop-in" variable-speed motor unit that connects to the same simple power terminals as a PSC motor (e.g., separate "hot" lines for heating and cooling). The unit includes a control system with a multiplexing unit that senses which power line is energized and automatically selects a corresponding, pre-set reference signal to command the motor to the correct speed for that function, thereby eliminating the need for rewiring (’194 Patent, Abstract; col. 3:1-17; Fig. 3).
  • Technical Importance: This technology simplified the process of upgrading HVAC systems, allowing for the installation of modern, efficient motors without requiring a costly and invasive overhaul of the existing system's electrical controls (’194 Patent, col. 2:48-59).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶124).
  • The essential elements of claim 1 are:
    • A variable speed motor with at least two speeds and a reference input.
    • A power input with a first and second current input to supply operating power.
    • A multiplexing unit that selects a reference signal based on which of the current inputs is energized.
    • A reference source that supplies the pair of reference signals to the multiplexing unit.

U.S. Patent No. 7,990,092 - "Blower motor for HVAC systems"

The Invention Explained

  • Problem Addressed: The patent notes that motor manufacturers must often produce many slightly different motor versions to meet the unique torque specifications of various HVAC equipment OEMs. Customizing motors by physically changing winding taps is inefficient and costly (’092 Patent, col. 6:1-11).
  • The Patented Solution: The patent discloses a method to electronically adjust a motor's performance. An installer or OEM selects an "adjustment factor" within a specified percentage range (e.g., 60% to 99%). This single factor is then used to proportionally scale all of the motor's pre-programmed torque settings, creating a custom performance profile without physical modification (’092 Patent, Abstract; col. 18:1-19).
  • Technical Importance: This method allows a standard motor model to be easily customized for a wide range of applications post-manufacturing, reducing inventory complexity and cost for both motor manufacturers and HVAC OEMs (’092 Patent, col. 6:5-18).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶134).
  • The essential elements of claim 1 are:
    • A method of adjusting torque values of a motor.
    • Selecting an adjustment factor (between 60% and 99%) to obtain an adjusted maximum torque value less than the rated maximum.
    • Adjusting all the motor's torque settings with that factor to get proportionally reduced torque settings.
    • Operating the motor at the new settings.

U.S. Patent No. 7,208,895 - "Control Systems and Methods for Permanent Magnet Rotating Machines"

  • Technology Synopsis: The patent addresses the need for improved electronic control systems for permanent magnet motors to enhance performance (’895 Patent, col. 1:26-31). The invention describes a method for controlling motor torque by first calculating a "scaled torque demand" (which accounts for motor speed and other factors to achieve constant torque) and then calculating an optimal "dr-axis injection current" to compensate for any torque contributions from that injection current, thereby improving efficiency and control (’895 Patent, Abstract; col. 3:35-46).
  • Asserted Claims: Claim 21 (dependent on method claim 12) (Compl. ¶145).
  • Accused Features: The complaint alleges that the HP Broad Ocean Motor is configured with a controller to perform the claimed method steps, including calculating and combining torque and injection current demands (Compl. ¶149).

U.S. Patent No. 7,312,970 - "Low Cost Surge Protection"

  • Technology Synopsis: The patent seeks to solve a problem where traditional surge protectors, like metal oxide varistors (MOVs), interfere with the high-voltage "hi-pot" insulation testing required for appliances, often forcing manufacturers to use a costly process of connecting and disconnecting the protection circuit for testing (’970 Patent, col. 1:21-38). The patented solution is a surge protection circuit that combines a varistor in series with a gas discharge tube (GDT). The GDT is designed with a trigger voltage that is above the hi-pot test voltage but below a true surge voltage, allowing the test to be performed without triggering the protector, while still providing protection against high-energy surges (’970 Patent, Abstract).
  • Asserted Claims: Claim 1 (Compl. ¶157).
  • Accused Features: The complaint alleges the accused products are motor drives that include the claimed combination of a rectifier, capacitors, and a surge protector comprising a varistor and a GDT connected in series (Compl. ¶160).

III. The Accused Instrumentality

Product Identification

  • The "Infringing Devices" are identified as the "Azure Digi-Tech" product line, including the Azure Direct Drive Moto, Azure Condenser Fan Motor, and specific MARS and Broad Ocean product numbers (e.g., MARS No. 10860, 10861) (Compl. ¶98).

Functionality and Market Context

  • The complaint describes the Azure Digi-Tech motor as a "higher-efficiency variable speed direct drive blower motor" that is "designed for easy installation by wiring exactly like a PSC motor 'but without the capacitor'" (Compl. ¶¶ 100-101). A training guide for the accused product, referenced as Image 1, explicitly states that it replaces Plaintiff's "Ecotech Rescue motors" (Compl. ¶50, Image 1).
  • The products are alleged to feature multiple operating speeds selected via low-voltage speed taps, an "auto-sizing" or hand-held programming feature to adjust torque values, a speed sensor, and an outboard surge protector (Compl. ¶¶ 102, 110, 113, Image 10). Image 6 from an installation guide depicts five different motor speeds available through low-voltage taps (Compl. ¶102, Image 6). Image 12 from product literature describes an "auto sizing learn mode" where the motor measures system pressure and "assigns torque values to each of its speed taps" (Compl. ¶110, Image 12). A photograph included as Image 16 purports to show a Hall-effect speed sensor on an accused motor (Compl. ¶113, Image 16).

IV. Analysis of Infringement Allegations

U.S. Patent No. 5,818,194 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a variable speed motor having at least two operating speeds and a reference input for selecting an operating speed; The Azure Digi-Tech motor is a variable speed motor with at least five operating speeds (e.g., Low, Med Low) selected via a reference input. ¶127a-c, ¶102 col. 12:10-13
a power input comprising a first and a second current input, each of the current inputs coupled to the motor so that an operating current applied to either of the current inputs supplies operating power to the motor; The Azure Digi-Tech motor has a power input with at least a first and second current input coupled to the motor controller to supply operating power. ¶127d, ¶103 col. 12:13-18
a multiplexing unit coupled to the power input and the motor reference input, the multiplexing unit selecting one of at least a pair of reference signals and applying the selected reference signal to the reference input, the selection depending upon which of the first and the second current inputs has an operating current applied thereto; and The Azure Digi-Tech motor allegedly includes a multiplexing unit that selects a reference signal based on which current input receives operating current. ¶127e, ¶104 col. 12:19-27
a reference source coupled to the multiplexing unit and supplying the at least a pair of reference signals thereto. The Azure Digi-Tech motor allegedly includes a reference source that supplies reference signals to the multiplexing unit. ¶127f, ¶105 col. 12:28-30
  • Identified Points of Contention:
    • Scope Questions: A central dispute may arise over the term "multiplexing unit." The patent appears to teach a unit that selects a speed based on which high-voltage power line (e.g., heating vs. cooling) is active. The complaint's evidence, such as the wiring diagram in Image 9, suggests the accused product may select speeds based on separate low-voltage thermostat signals applied to different taps (Compl. ¶106, Image 9). The court will have to determine if this alleged mode of operation falls within the scope of a claim limitation that ties selection to which "current input" receives "operating current."
    • Technical Questions: The complaint's allegations regarding the "multiplexing unit" and "reference source" are conclusory (Compl. ¶¶ 104-105). A key evidentiary question will be what proof exists that the accused product's circuitry performs the specific input-dependent signal selection required by the claim, rather than simply responding to independent control signals.

U.S. Patent No. 7,990,092 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
selecting an adjustment factor to obtain an adjusted maximum torque value that is less than the maximum rated torque value wherein the adjustment factor is a percentage between 60% and 99%; The Azure Digi-Tech motor uses an "auto-sizing" feature or a hand-held tool to select an adjustment factor, alleged to be between 60% and 99%, to adjust torque values. ¶137b, ¶110 col. 18:8-14
adjusting all the torque settings of the motor with the adjustment factor to obtain proportionally reduced torque settings; and The accused motor allegedly adjusts its torque settings using the selected factor to achieve proportionally reduced settings. ¶137c, ¶110 col. 18:15-17
operating the motor at the proportionally reduced torque settings. The accused motor then operates at the new, proportionally reduced torque settings. ¶137d, ¶111 col. 18:18-19
  • Identified Points of Contention:
    • Scope Questions: The claim requires "adjusting all the torque settings of the motor with the adjustment factor." This language suggests a global, proportional scaling of every pre-set value. The accused "auto-sizing" feature is described as "measuring the external static pressure" and then "assigns torque values to each of its speed taps" (Compl. Image 12). This raises the question of whether individually programming taps based on a real-time measurement is the same as applying a single, pre-selected "adjustment factor" to all existing settings.
    • Technical Questions: The complaint alleges the selected adjustment factor is between 60% and 99% (Compl. ¶110), but the supporting visual evidence states the hand-held programmer displays a "% of torque" value "between about 20 and 90" (Compl. Image 14). This factual discrepancy raises an evidentiary question about whether the accused product actually operates within the specific numerical range required by the claim.

V. Key Claim Terms for Construction

For the ’194 Patent:

  • The Term: "multiplexing unit...the selection depending upon which of the first and the second current inputs has an operating current applied thereto"
  • Context and Importance: This term is the functional heart of claim 1. The infringement case for this patent will depend on whether the accused product's method for speed selection—which appears to be based on low-voltage thermostat signals—can be defined as a "multiplexing unit" that operates based on which high-voltage "current input" is supplying power.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the invention in general terms as a "multiplexing unit for selecting one of at least a pair of reference signals" (’194 Patent, col. 3:6-9), which a party could argue covers any circuit that selects an output based on the state of its inputs.
    • Evidence for a Narrower Interpretation: The patent’s detailed embodiments and figures consistently depict the selection logic as being driven by sensing voltage or current on the main AC power lines, L1C and L1H (’194 Patent, Figs. 6-8). A party may argue that "current inputs" refers specifically to these high-voltage power lines and not low-voltage control taps.

For the ’092 Patent:

  • The Term: "adjusting all the torque settings of the motor with the adjustment factor"
  • Context and Importance: The definition of this term is critical for determining whether the accused "auto-sizing" feature infringes. Practitioners may focus on this term because it contrasts a simple, global scaling operation with a more complex, adaptive programming function.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue that any method that results in a new, complete set of torque settings for the motor has effectively "adjusted all" of them.
    • Evidence for a Narrower Interpretation: The claim language "with the adjustment factor" and the subsequent requirement to "obtain proportionally reduced torque settings" strongly suggest a singular, multiplicative scaling operation is applied globally. The patent states that the purpose is to allow a single motor to be "customized" with a simple adjustment, rather than being reprogrammed based on complex environmental feedback like static pressure (’092 Patent, col. 6:5-18).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced and contributory infringement for all asserted patents. It claims Defendants provide materials such as training guides, installation guides, and advertisements that instruct and encourage customers and installers to use the accused products in an infringing manner (Compl. ¶¶ 121, 128-129, 138-139).
  • Willful Infringement: Willfulness is alleged for all four patents. The complaint bases this on Defendants’ alleged knowledge of the patents from at least 2013 and 2015 due to the long history of litigation between the parties. It alleges that Defendants continued their conduct despite an objectively high likelihood that their actions constituted infringement (Compl. ¶¶ 131, 142, 154, 165).

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

  • A primary issue for the ’194 patent will be one of technical equivalence and claim scope: Can Plaintiff prove that the accused motor's control system, which appears to use low-voltage signals to select speeds, is functionally the same as the claimed "multiplexing unit" that operates by sensing which high-voltage power line is active?
  • A key evidentiary and construction battle for the ’092 patent will concern the mechanism of adjustment: Does the accused product’s "auto-sizing" feature, which independently calculates torque for each tap based on system pressure, perform the claimed method of applying a single, global "adjustment factor" to "proportionally reduce" all settings? This dispute will also involve the factual question of whether the adjustment falls within the claimed 60-99% range.
  • Given the extensive and mixed results of the prior IPR and reexamination proceedings, a central theme will be the resilience of the surviving patent claims: The case will test whether the patents, having already withstood significant validity challenges at the PTAB and Federal Circuit, can hold up against what will likely be renewed invalidity arguments in a district court forum.