Thousandshores Inc v. Yes4all LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Thousandshores, Inc. (California) and FANG HU (China)
  • Defendant: Yes4all LLC (California)
  • Plaintiff's Counsel: Gca Law Partners LLP
• Case Identification: 3:26-cv-03250, N.D. Cal., 04/16/2026
• Venue Allegations: Venue is alleged to be proper in the Northern District of California because a substantial part of the events giving rise to the claims occurred in the district and the Defendant is subject to personal jurisdiction there.
• Core Dispute: Plaintiffs allege that Defendant's balance boards infringe a patent related to an exercise balance board with an adjustable component system for modifying the range of motion.
• Technical Context: The technology relates to the field of exercise equipment, specifically balance boards that can be configured to offer varying levels of difficulty for fitness training and rehabilitation.
• Key Procedural History: The complaint alleges that Plaintiffs provided Defendant with notice of the asserted patent and the alleged infringement in February 2025, prior to filing the lawsuit.

Case Timeline

Date	Event
2022-06-16	'836 Patent Priority Date
2023-04-28	'836 Patent Application Date
Sometime in 2024	Alleged launch of Accused Products
2024-03-12	'836 Patent Issue Date
2025-02-01	Alleged pre-suit notice of infringement to Defendant
2026-04-16	Complaint Filing Date

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

U.S. Patent No. 11,925,836 - "Balance Board for Training and Fitness"

• Patent Identification: U.S. Patent No. 11,925,836, "Balance Board for Training and Fitness," issued March 12, 2024.

The Invention Explained

• Problem Addressed: The patent addresses the limitations of existing balance boards, which are described as having a fixed structure where the moving range of the rolling ball or roller cannot be adjusted ʻ836 Patent, col. 1:19-22 This requires users to purchase multiple different boards to accommodate various training requirements, leading to increased cost, storage space, and cleaning time ʻ836 Patent, col. 1:22-29
• The Patented Solution: The invention provides a single balance board with a detachable "adjusting component" that allows users to alter the board's range of motion, or "swing amplitude" ʻ836 Patent, col. 2:1-4 This component consists of two "arc-shaped adjusting parts" and two "vertical adjusting parts" ʻ836 Patent, abstract These parts can be configured in different combinations on the board's surface to create distinct "movable spaces" for either a rolling ball or a cylindrical roller, thereby adjusting the difficulty level ʻ836 Patent, col. 1:44-51 ʻ836 Patent, FIG. 1 ʻ836 Patent, FIG. 3 ʻ836 Patent, FIG. 4
• Technical Importance: The invention offers a modular and versatile balance board system, intended to provide a convenient and cost-effective solution for users with different training needs and skill levels.

Key Claims at a Glance

• The complaint asserts infringement of "one or more claims" of the ʼ836 Patent without specifying them Compl. ¶13 Independent claim 1 is the broadest claim.
• Independent Claim 1: The essential elements are:
  • A balance board body.
  • A rolling ball or a roller.
  • An adjusting component comprising two arc-shaped adjusting parts and two vertical adjusting parts.
  • The capability to form a first movable space for the rolling ball by coupling the arc-shaped parts to the vertical adjusting parts.
  • The capability to form a second movable space for the rolling ball by coupling the two arc-shaped adjusting parts to each other.
  • The capability to form a third movable space for the roller by longitudinally coupling the two vertical adjusting parts on the board's surface.

III. The Accused Instrumentality

Product Identification

The complaint identifies the accused instrumentalities as "balance boards" sold by Defendant YES4ALL, collectively referred to as the "ACCUSED PRODUCTS" Compl. ¶11 Compl. ¶26

Functionality and Market Context

• The complaint alleges that Defendant markets, offers for sale, and sells these infringing balance boards through various outlets, including Amazon.com and Walmart.com Compl. ¶22
• The complaint does not provide specific model numbers, technical descriptions, or any visual evidence of the Accused Products' functionality. It makes only a general allegation that they infringe the ʼ836 Patent Compl. ¶13
• No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that the Accused Products directly and/or indirectly infringe one or more claims of the '836 Patent Compl. ¶13 However, it does not provide a claim chart or any specific factual allegations mapping the features of the Accused Products to the limitations of any asserted claim. The complaint makes only conclusory statements of infringement. Therefore, a detailed claim chart summary is not possible based on the provided document.

• Identified Points of Contention:
  • Evidentiary Question: The primary issue will be factual: do the Accused Products sold by YES4ALL incorporate an "adjusting component" with both "arc-shaped adjusting parts" and "vertical adjusting parts" as recited in claim 1? The complaint offers no evidence on this point, making it a central focus for discovery.
  • Scope Question: A key legal question may be whether the Accused Products, if they have an adjustment mechanism, meet the specific structural and functional requirements of claim 1. For instance, the analysis will turn on whether the accused device is capable of forming the three distinct "movable spaces" as defined in the claim ʻ836 Patent, col. 6:45-54

V. Key Claim Terms for Construction

• The Term: "adjusting component"

• Context and Importance: This term is the central feature of the invention, defining the modular system that distinguishes it from the prior art. The scope of this term will be critical to the infringement analysis, as it dictates what structures constitute the claimed configurable system.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party might argue that "adjusting component" should encompass any set of detachable parts that adjusts the rolling path, not limited to the exact shapes shown. The claim language itself describes the component by its constituent parts ("comprises two arc-shaped adjusting parts and two vertical adjusting parts") rather than by a single, monolithic structure '836 Patent, col. 6:42-44
  • Evidence for a Narrower Interpretation: A party could argue the term is limited to the specific combination of parts disclosed in the specification that work together to create the three enumerated "movable spaces." The specification repeatedly describes the component as comprising these specific parts, which are shown in detail in figures like FIG. 1, FIG. 3, and FIG. 4, suggesting this complete system is what was invented and claimed '836 Patent, col. 3:23-28

• The Term: "movable space"

• Context and Importance: Claim 1 requires the ability to form three distinct types of "movable spaces" based on how the adjusting component's parts are arranged. Whether an accused product infringes will depend on whether it can create spaces that meet these functional and structural definitions.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term could be interpreted broadly to mean any confined area on the board that limits the travel of the ball or roller. The patent summary refers to forming "a plurality of movable spaces with different ranges" '836 Patent, col. 1:65-col. 2:2
  • Evidence for a Narrower Interpretation: A party may contend that the term is defined by its creation through the specific couplings recited in the claim: (1) arc and vertical parts together, (2) arc parts together, and (3) vertical parts together ('836 Patent, col. 6:45-54). The specification provides distinct figures corresponding to the first, second, and third movable spaces, arguably tying the term to these specific configurations ʻ836 Patent, FIG. 1 ʻ836 Patent, FIG. 3 ʻ836 Patent, FIG. 4

VI. Other Allegations

• Indirect Infringement: The complaint includes a conclusory allegation of indirect and induced infringement Compl. ¶13 However, it does not plead any specific facts to support the knowledge and intent elements required for such claims, such as referencing user manuals, advertisements, or other materials that instruct users on how to perform the infringing configurations.
• Willful Infringement: The complaint alleges willful infringement, stating that Defendant "has been fully aware of the '836 patent since at least February 2025 when Plaintiffs contacted it" Compl. ¶14 The allegation of willfulness is based on this alleged pre-suit notice and Defendant's subsequent continued sale of the Accused Products Compl. ¶14 Compl. ¶17

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

1. A central evidentiary question will be one of structural identity: does discovery reveal that Defendant's accused balance boards possess an "adjusting component" comprising the claimed "two arc-shaped adjusting parts" and "two vertical adjusting parts," or is there a fundamental structural difference? The complete absence of product-specific allegations in the complaint makes this the primary unresolved issue.
2. The case will likely involve a significant dispute over functional capability: assuming the accused products have some form of adjustable limiters, can they be configured to form the three distinct "movable spaces" required by claim 1? The infringement analysis will depend on whether the accused products meet the specific coupling and resulting spatial configurations recited in the claim.