DCT
2:25-cv-12610
Keller North America Inc v. Earth Tech LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Keller North America, Inc. (Delaware)
- Defendant: Earth Tech, LLC d/b/a Earth Tech Menard (Delaware) and DGI-Menard, Inc. (Delaware)
- Plaintiff’s Counsel: Thrive IP® Intellectual Property Law Firm
- Case Identification: 2:25-cv-12610, D.S.C., 09/17/2025
- Venue Allegations: Plaintiff alleges venue is proper in the District of South Carolina because Defendants have committed acts of infringement and maintain a regular and established place of business within the district.
- Core Dispute: Plaintiff alleges that Defendants' mobile apparatus used for the on-site fabrication and installation of geotechnical "Earthquake Drains" infringes a patent related to a mobile system for field fabrication of socked perforated drains.
- Technical Context: The technology concerns mobile equipment for creating custom-length drainage pipes at construction sites, which are used in ground improvement projects to mitigate soil liquefaction during seismic events.
- Key Procedural History: The complaint alleges that Plaintiff provided Defendant Earth Tech with a "Notice of Infringement" on October 25, 2024, nearly eleven months prior to filing suit, and that Defendant failed to respond.
Case Timeline
| Date | Event |
|---|---|
| 2018-01-10 | ’588 Patent Priority Date |
| 2018-08-20 | ’588 Patent Application Filing Date |
| 2019-07-11 | ’588 Patent Application Publication Date |
| 2021-04-06 | ’588 Patent Issue Date |
| 2022-04 | Defendant Earth Tech acquired by Menard USA |
| 2024-10-25 | Plaintiff sent "Notice of Infringement" to Defendant |
| 2025-09-17 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 10,968,588 - Method and Apparatus for Field Fabrication of Socked Perforated Drains
The Invention Explained
- Problem Addressed: The patent’s background section notes that pre-manufacturing drainage systems at a factory is not cost-effective due to "unforeseeable variability in installation length requirements," which leads to material waste when pre-cut drains are too long or too short for on-site needs (’588 Patent, col. 2:14-20).
- The Patented Solution: The invention is a "mobile fabrication solution" that allows for the on-site assembly of socked drains to a precise, desired length (’588 Patent, col. 2:16-20). The apparatus is mounted on a trailer and features a large, rotating "despooling carousel" that feeds stock corrugated tubing into an "extrusion head unit." This head unit contains "counter-rotating wheels" that grip the tubing and actively drive it into a fabric "filter sock," creating the finished drain product which can then be cut to length. (’588 Patent, col. 2:35-52).
- Technical Importance: This on-site fabrication approach is described as "far more convenient and economical" because it eliminates waste and the logistical challenges of transporting bulky, pre-fabricated drains to a job site (’588 Patent, col. 2:16-20).
Key Claims at a Glance
- The complaint alleges infringement of "one or more claims" of the ’588 Patent (Compl. ¶33). The factual allegations most closely track independent claim 1.
- Independent Claim 1:
- An apparatus for mobile fabrication of socked drains, comprising:
- a wheeled trailer frame;
- a despooling carousel rotatably mounted on the trailer frame and configured for despooling plastic tubing; and
- an extrusion head configured for extruding plastic tubing despooled from said carousel into a filter sock, said extrusion head comprising a pair of counter-rotating wheels for gripping and controllably extracting plastic tubing from said despooling carousel and extruding it between said pair of counter-rotating wheels into a filter sock.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
- An apparatus, referred to as the "Infringing Apparatus," used by Defendants to assemble and install "Earthquake Drains" at project sites (Compl. ¶¶27-29).
Functionality and Market Context
- The complaint alleges that Defendants utilize a mobile system for the on-site fabrication of their Earthquake Drains, which are described as "corrugated pipe wrapped in tightly fitting filter fabric" (Compl. ¶27). A screenshot from Defendant's website states that "Each Earth Quake Drain is assembled on site" (Compl. p. 7). The complaint includes a photograph of the accused apparatus, depicting a large spool of black corrugated tubing mounted on a wheeled trailer (Compl. p. 8). A second, close-up photograph shows an internal mechanism that appears to contain two textured wheels positioned to engage a pipe passing between them (Compl. p. 8). The complaint alleges this apparatus is used in ground improvement services offered for sale in the United States, including at specific construction sites in South Carolina (Compl. ¶¶30, 31).
IV. Analysis of Infringement Allegations
U.S. Patent No. 10,968,588 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a wheeled trailer frame | Defendant utilizes an apparatus that includes a wheeled trailer frame. | ¶29 | col. 3:12-14 |
| a despooling carousel rotatably mounted on the trailer frame and configured for despooling plastic tubing | Defendant's apparatus includes a despooling carousel rotatably mounted on the trailer frame. | ¶29 | col. 3:47-49 |
| an extrusion head configured for extruding plastic tubing despooled from said carousel into a filter sock... | Defendant's apparatus includes an extrusion head. | ¶29 | col. 3:23-24 |
| ...said extrusion head comprising a pair of counter-rotating wheels for gripping and controllably extracting plastic tubing... and extruding it... into a filter sock. | The extrusion head of Defendant's apparatus comprises a pair of counter-rotating wheels. The complaint includes a photograph of this component. | ¶29; p. 8 | col. 4:41-44 |
- Identified Points of Contention:
- Functional Questions: A central question may be whether the accused "pair of counter-rotating wheels" performs the specific functions recited in the claim: "gripping and controllably extracting" the tubing from the carousel. The complaint alleges the presence of these components (Compl. ¶29) and provides a supporting photograph (Compl. p. 8), but the court will need to examine evidence on how the accused device actually operates to determine if it "controllably extracts" tubing in the manner claimed.
- Scope Questions: The analysis may focus on whether the accused mechanism constitutes an "extrusion head" as the term is used in the patent. While the complaint makes this conclusory allegation, a dispute could arise over whether the term implies a specific structure or set of components beyond merely having a pair of wheels.
V. Key Claim Terms for Construction
The Term: "extrusion head"
Context and Importance: This term defines the core active component of the claimed apparatus. The infringement analysis will depend heavily on whether the Defendants' mechanism for feeding the tubing into the sock qualifies as an "extrusion head." Practitioners may focus on this term because the defendant could argue its apparatus is a simpler "feeder" or "guide" that does not meet the structural or functional complexity implied by "extrusion head."
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent abstract describes the "head unit" as containing "counter-rotating wheels that grip and drive the tubing out through a collet into a filter sock" (’588 Patent, Abstract). This functional description could support a construction covering any device that performs this action.
- Evidence for a Narrower Interpretation: The detailed description discloses a specific embodiment of the "extrusion head unit 20" that includes not just wheels but also a housing (21), a hydraulic motor (121), and an input chute (102) (’588 Patent, col. 4:41-49). This could support an argument that the term is limited to a more complex assembly and does not cover a simple wheel-pair mechanism alone.
The Term: "controllably extracting"
Context and Importance: This phrase describes the action performed by the counter-rotating wheels on the plastic tubing. Its construction is critical because it distinguishes an active, powered feeding mechanism from a passive guide system. The dispute will likely center on what level of "control" is required by the claim.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states the wheels "grip and drive the tubing out" (’588 Patent, col. 2:42-43), suggesting that any powered, active pulling of the tubing from the carousel could meet the limitation.
- Evidence for a Narrower Interpretation: The patent describes a system powered by a hydraulic pump connected to a "2-spool directional control valve 29," which an operator uses to control the "speed and direction of automated despooling" (’588 Patent, col. 3:30-34, col. 6:45-47). This detailed control scheme could support a narrower construction requiring more than simple on/off power, potentially including variable speed or directional control.
VI. Other Allegations
- Indirect Infringement: The complaint includes a boilerplate allegation of induced and contributory infringement, asserting that Defendants provide "components, equipment, services, and instructions for the practice of the patented inventions" (Compl. ¶44). The complaint does not, however, provide sufficient detail or specific facts to analyze the basis for these claims, such as identifying the specific instructions or third-party actors involved.
- Willful Infringement: The complaint alleges that Defendants' infringement has been willful, knowing, and deliberate (Compl. ¶39, 45). The basis for this allegation is both constructive notice (via the patent's publication and issuance) and alleged actual notice. Specifically, the complaint states that Plaintiff sent a formal "Notice of Infringement" to Defendant Earth Tech on October 25, 2024, and that Defendant failed to respond before the suit was filed (Compl. ¶37).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of functional equivalence: Does the evidence show that the accused apparatus's counter-rotating wheels perform the dual functions of "gripping and controllably extracting" the tubing from the carousel, as required by the claim, or do they perform a more limited function, such as merely guiding the tubing?
- A second key question will be one of definitional scope: Can the term "extrusion head," as described in the ’588 Patent with its specific motor and housing embodiments, be construed broadly enough to read on the specific design of the Defendants' accused mechanism?
- Finally, a central question for damages will be willfulness: Given the allegation that Defendants received and did not respond to a notice of infringement nearly a year before the complaint was filed, the court will likely examine Defendants' conduct and intent following that notice to determine if any infringement was willful, which could lead to enhanced damages.