DCT

1:24-cv-00399

Latham Pool Products Inc v. Sentry Covers LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00399, W.D. Mich., 04/18/2024
  • Venue Allegations: Venue is alleged to be proper in the Western District of Michigan because Defendant Sentry Covers, LLC resides in the district, maintaining its headquarters and principal place of business in Traverse City, Michigan.
  • Core Dispute: Plaintiff alleges that Defendant’s automatic pool cover systems, specifically its universal gear assemblies and its modular encapsulation track systems, infringe three of Plaintiff's patents.
  • Technical Context: The lawsuit concerns the mechanical systems for automatic swimming pool covers, focusing on the gear mechanisms that operate the cover and the track encapsulation systems that guide it.
  • Key Procedural History: The complaint alleges that Plaintiff sent a series of pre-suit notice letters to Defendant beginning on November 15, 2022, identifying the patents and the accused products. The complaint also alleges that a former Senior Vice President at Plaintiff Latham later became employed by Defendant's parent company and was involved in developing the accused product line.

Case Timeline

Date Event
2012-08-13 ’707 Patent Priority Date
2017-05-09 ’707 Patent Issue Date
2019-10-08 ’040 and ’419 Patents Priority Date
2022-06-19 Sentry Covers launch date alleged
2022-09-27 ’040 Patent Issue Date
2022-11-15 Latham sends first pre-suit notice letter to Sentry re: ’707 and ’040 patents
2023-02-08 Latham sends second pre-suit letter to Sentry with claim charts
2023-06-20 ’419 Patent Issue Date
2023-07-24 Latham sends third pre-suit letter to Sentry re: ’419 patent
2024-04-18 Complaint Filing Date

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

U.S. Patent No. 9,644,707 - "Universal Gear Assembly for Automatic Pool Covers," issued May 9, 2017

The Invention Explained

  • Problem Addressed: The patent addresses the drawback of prior art "double dog gear" mechanisms for automatic pool covers, which were side-specific. This meant installers had to order distinct left-side or right-side mechanisms depending on where the motor was located, leading to ordering confusion, delays, and potential installation errors (Compl. ¶23).
  • The Patented Solution: The invention is a "universal" gear assembly that can be installed on either the left or right side of a pool. This is achieved through a control gear with two different sets of elongated, spiraling pin slots. A locking pin engages one set of slots for a left-side installation and the other set for a right-side installation, allowing the same component to function correctly regardless of its position ('707 Patent, Abstract; col. 4:41-54).
  • Technical Importance: This universal design sought to provide a safer, more reliable, and easier installation process by eliminating the need for side-specific parts (Compl. ¶23).

Key Claims at a Glance

  • The complaint asserts at least independent claim 11 (Compl. ¶44).
  • Claim 11 is for a gear assembly, requiring:
    • A control gear with a body member, a hollow passageway for a drive shaft, and a locking pin.
    • A "first set of elongated pin slots formed in the body member... spiraling on the body member in a first direction."
    • A "second set of elongated pin slots formed in the body member... spiraling on the body member in a second direction, the second direction being different that the first direction."
    • The locking pin is configured to selectively engage one of the two sets of slots to cause the control gear to slide axially in response to motor actuation.
  • The complaint reserves the right to assert other claims (Compl. ¶42).

U.S. Patent No. 11,454,040 - "Pool Cover Assembly and Systems," issued September 27, 2022

The Invention Explained

  • Problem Addressed: The patent identifies challenges with conventional pool cover encapsulation systems, where the track for the cover's edge is shipped as a single, long piece. This practice is described as increasing shipping costs, creating handling difficulties, and risking damage to the components. Additionally, forming corners from these long pieces is described as a "labor and time intensive process" ('040 Patent, col. 1:29-47; Compl. ¶25).
  • The Patented Solution: The invention discloses a modular system where the full-length encapsulation is formed by coupling together shorter, separate sections using a "splice member." It also describes a "corner connection assembly" that includes a corner endcap member to join encapsulation sections at a 90° angle without requiring complex cutting or welding ('040 Patent, Abstract; col. 2:26-36).
  • Technical Importance: This modular approach permits easier and cheaper manufacture, shipment, and installation of pool cover track systems (Compl. ¶25).

Key Claims at a Glance

  • The complaint asserts at least independent claim 11 (Compl. ¶58).
  • Claim 11 is for a pool encapsulation assembly, requiring:
    • An encapsulation member comprising a "first encapsulation portion that is removably coupleable to a second encapsulation portion."
    • The first and second portions are "securable to each other via a splice member" such that they are longitudinally aligned.
    • Each encapsulation portion comprises a cover track recess and at least one splice recess adjacent to the cover track recess.
  • The complaint reserves the right to assert other claims (Compl. ¶56).

Multi-Patent Capsule: U.S. Patent No. 11,680,419

  • Patent Identification: U.S. Patent No. 11,680,419, "Pool Cover Assembly and Systems," issued June 20, 2023.
  • Technology Synopsis: As a continuation of the ’040 Patent, this patent also relates to pool cover encapsulation systems. It describes assemblies formed from multiple, interconnected encapsulation members that join to form the corners and sides of the pool cover track, aiming to simplify construction and installation (’419 Patent, Abstract; Compl. ¶22).
  • Asserted Claims: The complaint asserts at least independent claim 11 (Compl. ¶72).
  • Accused Features: The accused features are Sentry's "Encapsulation Assembly" products, which the complaint alleges are sold in 8-foot sections designed to be connected on-site (Compl. ¶32, ¶40).

III. The Accused Instrumentality

  • Product Identification: The complaint identifies the "Sentry Products," which include the "Sentry Cover System" using a "universal double dog" gear assembly (the "Sentry Gear Assembly") and a "pool encapsulation assembly comprising 8-foot encapsulation sections" (the "Sentry Encapsulation Assembly") (Compl. ¶30-32).
  • Functionality and Market Context:
    • The "Sentry Gear Assembly" is advertised as using two "double dog" gears and allows an installer to "switch the threaded pin from one double dog gear over to the other, allowing the system to operate in the other direction." This is promoted as a benefit because "the same components are used between right and left mechanisms" (Compl. ¶39).
    • The "Sentry Encapsulation Assembly" is advertised as coming in "8' lengths, making transport and installation easier" and using a "self-aligning (vertically and horizontally) bracket" to ensure rigid alignment between sections (Compl. ¶40).
    • The complaint alleges that these products were designed to compete directly with Latham's products and that a former Latham executive was involved in their development after joining Sentry's parent company (Compl. ¶33-38).
    • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references non-limiting claim chart exhibits that were not attached to the pleading itself. The infringement theories are summarized below based on the complaint’s narrative allegations.

  • '707 Patent Infringement Allegations
    The complaint alleges that the Sentry Gear Assembly directly infringes at least claim 11 of the ’707 Patent (Compl. ¶44). The infringement theory appears to be that Sentry’s "universal double dog" gear performs the same function as the patented invention—selective coupling of a drive shaft to one of two output shafts for use in either a left- or right-side installation (Compl. ¶43). The allegation is supported by citations to Sentry's marketing materials, which describe a mechanism for switching operational direction by moving a pin, thereby enabling universal application with a single set of parts (Compl. ¶39).

  • '040 Patent Infringement Allegations
    The complaint alleges that the Sentry Encapsulation Assembly directly infringes at least claim 11 of the ’040 Patent (Compl. ¶58). The core of this allegation is that Sentry's system of connecting separate 8-foot encapsulation sections using a bracket meets the claim limitations of using a "splice member" to couple a "first encapsulation portion" to a "second encapsulation portion" (Compl. ¶57, ¶40). The complaint contends that Sentry’s system of providing shorter, connectable lengths embodies the solution patented in the ’040 Patent (Compl. ¶25, ¶40).

V. Key Claim Terms for Construction

  • For the ’707 Patent:

    • The Term: "a first set of elongated pin slots ... spiraling... in a first direction" and "a second set of elongated pin slots ... spiraling... in a second direction."
    • Context and Importance: This language defines the core "universal" feature of the patented gear. The infringement analysis will turn on whether Sentry’s mechanism, which allegedly allows an installer to "switch the threaded pin from one double dog gear over to the other" (Compl. ¶39), meets this structural requirement. Practitioners may focus on this term because the key dispute will be whether Sentry's allegedly reconfigurable pin is equivalent to the claimed two distinct, permanent, spiraling sets of slots.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent's background and summary emphasize solving the problem of needing side-specific parts ('707 Patent, col. 2:9-24). A party could argue the term should be construed broadly to cover any structure that achieves this universal function using different pathways for a pin.
      • Evidence for a Narrower Interpretation: The figures and detailed description show two physically distinct sets of angled slots machined into the body of the control gear (e.g., ’707 Patent, Figs. 7-9, col. 4:26-38). A party could argue the term is limited to this specific embodiment of two separate, permanent, spiral-cut slots.

  • For the ’040 Patent:

    • The Term: "splice member."
    • Context and Importance: The infringement case for the ’040 and ’419 patents hinges on whether Sentry’s "self-aligning... bracket" (Compl. ¶40) is a "splice member" under the patent's definition. The construction of this term will be critical to determining infringement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent states that "Various types of a splice members may be used," listing examples such as a "coping clip splice member, a snap button splice member, an expandable compression-fit splice member, a key-hole interlocking splice member, or other suitable splice members" ('040 Patent, col. 2:30-36). This suggests the term is not limited to a single structure.
      • Evidence for a Narrower Interpretation: The patent illustrates specific embodiments, such as an external coping clip that slides over the joint (Fig. 9A-D) and an internal member with snap buttons (Fig. 10A-C). A party may argue that Sentry’s bracket is structurally distinct from these disclosed examples and that the claim term should be narrowed to the disclosed embodiments or their equivalents.

VI. Other Allegations

  • Indirect Infringement: For all three patents, the complaint alleges both induced and contributory infringement. Inducement is based on Sentry allegedly providing "instructions, guides, and/or encouragement" to customers, citing its website (Compl. ¶49, ¶63, ¶77). Contributory infringement is based on allegations that the accused components are "specially made for use in a manner infringing" the patents and are not staple articles of commerce (Compl. ¶50, ¶64, ¶78).
  • Willful Infringement: Willfulness is alleged for all three patents. The allegations are based on Sentry's alleged pre-suit knowledge via notice letters sent by Latham, dated November 15, 2022 (for the ’707 and ’040 patents) and July 24, 2023 (for the ’419 patent). The complaint asserts that Sentry continued its allegedly infringing activities after receiving notice (Compl. ¶45-47, ¶59-61, ¶73-75).

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

  • A central issue will be one of claim construction and scope: for the ’707 patent, can the claim requirement for two distinct sets of "spiraling" pin slots be construed to cover Sentry's gear mechanism, which is described as using a reconfigurable pin to switch its direction of operation?
  • A second core issue will be one of structural identity: for the ’040 and ’419 patents, is Sentry's "self-aligning bracket" for connecting track sections the same as or equivalent to the "splice member" recited in the claims, or does it represent a technologically distinct, non-infringing design?
  • A key factual question, highly relevant to willfulness, will be the role of the former Latham executive named in the complaint. The court will examine the extent of his involvement in the conception and development of the accused Sentry products to determine if there is evidence of copying.