Taizhou Tongchuang Maternal Child Products Co Ltd v. TOMY Intl Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Taizhou Tongchuang Maternal and Child Products Co., Ltd. d/b/a TPN-US and Hangzhou Mofeili Technology Co., Ltd. d/b/a kaibdun (People's Republic of China)
  • Defendant: TOMY International, Inc. (Delaware)
  • Plaintiff's Counsel: Holland & Knight LLP
• Case Identification: 1:26-cv-05032, N.D. Ill., 08/06/2026
• Venue Allegations: Venue is alleged to be proper in the Northern District of Illinois because the Defendant, TOMY International, Inc., is a corporate entity with its principal place of business in the district and is therefore considered to reside there.
• Core Dispute: Plaintiffs seek a declaratory judgment that their collapsible baby bathtubs do not infringe Defendant's patent and/or that the patent is invalid, and further allege that Defendant is engaging in false patent marking and false advertising.
• Technical Context: The technology relates to collapsible baby bathtubs, a consumer product category where portability and compact storage are significant design and marketing features.
• Key Procedural History: This declaratory judgment action follows Defendant's patent enforcement activities on Amazon.com, including the submission of Amazon Patent Evaluation Express (APEX) Agreements against Plaintiffs' products. The complaint heavily relies on statements made by the Defendant during a prior inter partes review (IPR) proceeding (IPR2021-01208) for U.S. Patent No. 9,545,176. Although the Patent Trial and Appeal Board (PTAB) denied institution of the IPR, Plaintiffs allege that Defendant's arguments to the PTAB, which distinguished the patent from prior art, now preclude Defendant's infringement positions and reveal that Defendant's own marked products do not practice the patent.

Case Timeline

Date	Event
2008-11-20	'176 Patent Priority Date
2017-01-17	'176 Patent Issue Date
2021-07-28	IPR Petition Filed against '176 Patent (IPR2021-01208)
2021-11-10	Defendant (Patent Owner) Filed Preliminary Response in IPR
2023-01-01	Defendant Filed Initial Patent Infringement Claim with Amazon.com
2023-12-04	Plaintiff kaibdun Sent Letter to Defendant Disputing Infringement
2023-12-11	Defendant Responded to kaibdun's Letter
2026-04-10	Defendant Submitted APEX Agreements to Amazon.com
2026-04-13	Amazon.com Notified Plaintiffs of APEX Agreements
2026-08-06	Complaint Filing Date

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

U.S. Patent No. 9,545,176 - "Bathtub"

• Patent Identification: U.S. Patent No. 9545176, "Bathtub," issued January 17, 2017 (the '176 Patent).

The Invention Explained

• Problem Addressed: The patent's background section notes that various bathtubs for children are "well known," including "collapsible bathtubs relying on a preexisting full size bathtub for support" ('176 Patent, col. 1:19-22). The implicit problem is the lack of a self-supporting, freestanding bathtub that is also conveniently collapsible for storage.
• The Patented Solution: The invention is a portable bathtub comprising a frame, a collapsible container, and leg assemblies ('176 Patent, abstract). The key innovation is that the leg assemblies are deployable to "support the container at an elevated location with respect to a support surface," creating a freestanding unit ('176 Patent, abstract; '176 Patent, col. 2:51-54). Both the legs and the tub container can be moved between collapsed and deployed positions, allowing the entire structure to become thin and compact for storage ('176 Patent, FIG. 5; '176 Patent, FIG. 6).
• Technical Importance: This design offers the convenience of a portable, collapsible bathtub without the limitation of needing to be placed inside a larger, standard bathtub for support.

Key Claims at a Glance

• The complaint asserts non-infringement of all claims and specifically discusses independent claims 1, 12, and 21 (Compl. ¶55).
• Independent Claim 1 of the '176 Patent includes the following essential elements:
  • A frame.
  • A container extending from the frame, including a "water impervious, rigid bottom surface."
  • A plurality of leg assemblies coupled to the frame, movable to a deployed position to "support the container at an elevated location with respect to a support surface."
  • The container is movable between a collapsed position and a deployed position "to form an open tub to receive a child to be bathed."

III. The Accused Instrumentality

Product Identification

• The Accused Products are Plaintiffs' "collapsible baby bathtubs" sold on Amazon.com under various Amazon Standard Identification Numbers (ASINs) (Compl. ¶12).

Functionality and Market Context

• The Accused Products are described as collapsible baby bathtubs that are in direct competition with the Defendant's products on the Amazon.com marketplace (Compl. ¶48; Compl. ¶50).
• The complaint alleges two key functional aspects. First, when in a deployed position, the container of the Accused Products "is designed to always rest directly on the support surface" and is not elevated (Compl. ¶57). The complaint provides a photograph purporting to show an Accused Product resting on a tabletop (Compl. p. 16). Second, the Accused Products "all have a perforation in the bottom to allow water to drain out" (Compl. ¶58).

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement. The core allegations of non-infringement are summarized below.

'176 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Non-Infringing Functionality	Complaint Citation	Patent Citation
a plurality of leg assemblies ... to support the container at an elevated location with respect to a support surface	The container of the Accused Products is designed to rest directly on the support surface and is not elevated when in its deployed position.	¶57	col. 8:21-24
a container ... including a water impervious, rigid bottom surface	The Accused Products contain a perforation or drain hole in the bottom, which Plaintiffs allege renders the bottom surface not "water impervious."	¶58	col. 8:16-17

• Identified Points of Contention:
  • Scope Question (Estoppel): A primary issue appears to be whether the claim term "at an elevated location" requires the bathtub's container to be fully suspended above the support surface, without any contact. The complaint alleges the Defendant argued for this exact narrow construction during the prior IPR proceeding to distinguish the patent from prior art (Compl. ¶26; Compl. ¶28), which may give rise to a prosecution history estoppel argument limiting the scope of the term. The complaint includes a figure from Defendant's IPR response illustrating this "elevated" concept, where a dashed line representing the support surface is drawn below the entire tub container (Compl. p. 7).
  • Technical Question: The complaint alleges that when Defendant's own marked products are used as intended, the container "rests directly on and is fully supported by the support surface" (Compl. ¶36). A photograph is provided showing Defendant's "Sure Comfort® Collapsible Baby Bathtub" in use, appearing to rest on the bottom of a larger tub (Compl. p. 9). This raises the factual question of whether either the Plaintiffs' or the Defendant's own products meet the "elevated" limitation as construed by the Defendant itself.
  • Scope Question: A secondary issue is whether the term "water impervious" can read on a surface that includes a drain hole, even if it has a plug. The complaint argues this feature defeats the limitation (Compl. ¶58).

V. Key Claim Terms for Construction

• The Term: "at an elevated location with respect to a support surface"

• Context and Importance: This term is central to the non-infringement argument. Plaintiffs allege their products, and indeed Defendant's own marked products, rest directly on the support surface and are therefore not "elevated" (Compl. ¶57; Compl. ¶36). The construction of this term, particularly in light of Defendant's alleged statements to the PTAB, appears critical.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself does not explicitly forbid any contact between the container bottom and the support surface ('176 Patent, claim 1). One could argue that as long as the legs bear some of the load and provide some clearance, the container is "supported at an elevated location."
  • Evidence for a Narrower Interpretation: The complaint alleges that during IPR proceedings, Defendant argued that "elevated position means that the bottom surface 45 of the collapsible container 25 exists at an elevation higher than any underlying support surface on which the legs 21 rest" (Compl. ¶26). This statement, if proven, provides strong evidence for a narrow construction requiring complete separation between the container bottom and the support surface. The complaint further alleges Defendant argued that a tub resting on a surface was "exactly the conventional bathtub ... which the '176 Patent sought to solve" (Compl. ¶28).

• The Term: "water impervious"

• Context and Importance: Plaintiffs allege their products have a drain hole, which they contend makes the bottom surface not "water impervious" (Compl. ¶58). This provides a second, independent basis for their non-infringement claim.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A party could argue that "water impervious" refers to the properties of the material from which the bottom surface is made, not the absolute absence of any designed openings like a plugged drain.
  • Evidence for a Narrower Interpretation: The specification describes the container as forming an "open tub, vessel, or basin" to be "at least partially filled with water" ('176 Patent, col. 2:57-62). This functional description may support an interpretation that the entire surface must contain water without leaking, which an un-plugged hole would prevent.

VI. Other Allegations

• False Patent Marking (35 U.S.C. § 292): Plaintiffs allege that Defendant engages in false marking by marking its "Sure Comfort®" and "Boon® Naked" bathtubs with the '176 Patent number (Compl. ¶82). The basis for this claim is that Defendant's own products allegedly do not practice the patent for the same reasons as the Accused Products: their containers rest on the support surface and they contain drain holes (Compl. ¶¶84-85). The complaint alleges the requisite intent to deceive by pointing to Defendant's own statements in the IPR proceeding, which articulated a narrow claim scope that its own marked products purportedly fail to meet (Compl. ¶¶90-92).
• False Advertising (Lanham Act § 43(a)): Plaintiffs allege that Defendant makes false and misleading representations in commerce by advertising its products with phrases like "patented pop-open design" and "Designed with a patented mechanism" on packaging, its own website, and e-commerce listings (Compl. ¶¶42-45; Compl. ¶¶108-111). Plaintiffs assert these claims are false because the products are not covered by the '176 Patent, and that these representations are material to consumers (Compl. ¶¶46-47).

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

• Prosecution History Estoppel: A core issue will be whether the Defendant's arguments to the PTAB during the IPR proceeding estop it from now asserting a broader interpretation of the term "at an elevated location." The court will need to decide if Defendant is bound by its prior statements that an "elevated" tub must be fully suspended above the support surface, a position that Plaintiffs allege neither their products nor Defendant's own marked products can satisfy.
• Intent for False Marking: For the false marking and false advertising claims, a central question will be one of intent. Can Plaintiffs prove that Defendant marked and advertised its products with an intent to deceive the public? The allegation that Defendant's own counsel authored the IPR arguments that allegedly exclude its own products from the patent's scope will be a key piece of evidence in this inquiry.
• Definitional Scope: The case will also turn on a classic claim construction question: does a "water impervious" surface cease to be impervious if it includes a designed feature like a drain hole with a plug? The resolution of this secondary issue could provide an independent basis for a non-infringement finding.