DCT
2:25-cv-02733
Huian County Mubing E Commerce Co Ltd v. Interlink Products Intl Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Huian County Mubing E-commerce Co., Ltd. (China)
- Defendant: Interlink Products International, Inc. (New Jersey)
- Plaintiff’s Counsel: Glacier Law LLP
- Case Identification: 2:25-cv-02733, W.D. Wash., 12/30/2025
- Venue Allegations: Plaintiff alleges venue is proper in the Western District of Washington because Defendant directed patent enforcement activities into the district, specifically by initiating Amazon’s “Patent Evaluation Express” process, which involves communications with Amazon personnel located in Seattle.
- Core Dispute: Plaintiff seeks a declaratory judgment that its rain shower head products do not infringe Defendant's patent related to multi-function showerheads with selectable spray modes, and/or that the patent is invalid.
- Technical Context: The technology at issue involves showerheads that provide both conventional showering functions and specialized spray patterns, such as high-pressure jets, intended for cleaning purposes.
- Key Procedural History: This declaratory judgment action was filed after Defendant accused Plaintiff of infringement through Amazon’s neutral patent enforcement program, threatening removal of Plaintiff’s product listings. The complaint also includes detailed invalidity contentions, citing four specific prior art references.
Case Timeline
| Date | Event |
|---|---|
| 2020-12-10 | '435 Patent Priority Date (via parent application) |
| 2024-05-16 | '435 Patent Application Filing Date |
| 2025-12-02 | U.S. Patent No. 12,485,435 Issues |
| 2025-12-10 | Defendant submits agreement for Amazon APEX proceeding |
| 2025-12-12 | Amazon notifies Plaintiff of Defendant's infringement report |
| 2025-12-30 | Complaint for Declaratory Judgment Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,485,435 - *"Showerhead Having Selector For Directing Water Flow In Independent Directions"*
- Issued: December 2, 2025.
The Invention Explained
- Problem Addressed: The patent’s background section notes that conventional showerheads are designed primarily for showering, and their resulting water pressure or spray patterns may be "undesirable for cleaning purposes" such as rinsing tiled walls or tubs (ʼ435 Patent, col. 1:20-29).
- The Patented Solution: The invention is a showerhead with a selector mechanism that allows a user to switch water flow between three distinct and independent nozzle groups. These include a "plurality of first nozzles" on the faceplate for conventional showering, a "second nozzle" configured to create one type of specialized spray (e.g., a fan shape), and a "third nozzle" for another different type (e.g., a jet stream). The second and third nozzles are configured to direct water "transverse to the first direction" of the main shower spray, facilitating targeted cleaning (ʼ435 Patent, Abstract; col. 4:12-21).
- Technical Importance: The claimed invention provides a single fixture that integrates standard showering functionality with specialized, selectable high-pressure or wide-coverage spray patterns designed for cleaning tasks.
Key Claims at a Glance
- The complaint indicates that Defendant asserted independent Claim 1 in the pre-suit Amazon APEX proceeding (Compl. ¶20).
- The essential elements of independent Claim 1 include:
- A showerhead with a head portion and a handle.
- A plurality of "first nozzles" for flow in a "first direction."
- At least one "second nozzle" for flow in a "second direction."
- At least one "third nozzle" adjacent to the second, for flow in a "third direction."
- A "flow selector moveable between a first position" (directing water to the first nozzles), a "second position" (directing water to the second nozzle), and a "third position" (directing water to the third nozzle).
- A requirement that the second and third directions are "substantially the same and transverse to the first direction."
- A requirement that the second and third nozzles create different "type[s] of the flow of water."
- A requirement that the flow selector can remain in a selected position without continuous external force (e.g., a detent mechanism).
- The complaint argues that because Claim 1 is not infringed, dependent claims which incorporate its limitations are also not infringed (Compl. ¶26).
III. The Accused Instrumentality
Product Identification
- Plaintiff’s "rain shower head" products sold on Amazon.com (Compl. ¶9, ¶23).
Functionality and Market Context
- The complaint describes the Accused Product as employing a "rotatable disc/faceplate mechanism" to switch between different spray modes (Compl. ¶23). This mechanism operates in "multiple discrete positions" and routes water through various internal passageways to different outlets (Compl. ¶23). The complaint further alleges that the Accused Product includes an "off" position where no water is discharged, a feature it contends is not recited in the asserted claim (Compl. ¶23).
- Plaintiff alleges that the Amazon marketplace is its "primary sales channel in the United States," and Defendant’s enforcement actions threaten to cut off this channel (Compl. ¶14).
IV. Analysis of Infringement Allegations
As this is a complaint for declaratory judgment of non-infringement, the following chart summarizes the Plaintiff's asserted points of non-infringement for the sole claim identified as asserted in pre-suit communications.
'435 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a flow selector moveable between a first position in which water flow is directed through the plurality of first nozzles, a second position in which water flow is directed through the at least one second nozzle, and a third position... | The Accused Product uses a "rotatable disc/faceplate mechanism" operating in "multiple discrete positions," which is alleged to be a "materially different flow-selection structure." | ¶23 | col. 9:12-18 |
| a first position in which water flow is directed through the plurality of first nozzles... | The complaint alleges that the Accused Product's selector routes water to "selected subsets of faceplate nozzles" rather than through the entire "plurality of first nozzles" as claimed. | ¶23 | col. 9:13-15 |
| [Implicit limitation to three positions] | The Accused Product is alleged to include an additional "off" position in which no water is discharged from any nozzle, which the complaint contends is a configuration not recited in Claim 1. | ¶23 | col. 9:12-18 |
No probative visual evidence provided in complaint.
Identified Points of Contention
- Scope Questions: A primary dispute may center on whether the claim term "a flow selector moveable between a first position..., a second position..., and a third position" can be construed to read on the accused "rotatable disc/faceplate mechanism," which allegedly operates in "multiple discrete positions" and includes an "off" setting not explicitly recited in the claim (Compl. ¶23).
- Technical Questions: The complaint raises a factual question regarding the operation of the accused product: does its selector, in any position, direct water flow "through the plurality of first nozzles" as required for the claimed "first position," or does it only ever direct water through a "subset" of those nozzles (Compl. ¶23)?
V. Key Claim Terms for Construction
- The Term: "a flow selector moveable between a first position..., a second position..., and a third position"
- Context and Importance: This term is central to the non-infringement dispute. Plaintiff argues its "rotatable disc mechanism" with "multiple discrete positions" and an "off" setting is structurally and functionally different from the claimed three-position selector (Compl. ¶23). The construction of this term will determine whether a device with more than three functional states falls within the scope of the claim.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patentee (Defendant) may argue that the claim language does not explicitly use preclusive terms like "only" or "consisting of," potentially allowing for additional, unrecited positions. The specification’s description of the "flow selector 116" is functional, configured to "selectively direct flow" (ʼ435 Patent, col. 4:31-37), which could be argued as the core inventive concept regardless of other available positions.
- Evidence for a Narrower Interpretation: The Plaintiff may argue that the explicit recitation of three specific positions, each corresponding to a unique and enumerated nozzle group, defines a closed set of required functionalities. The detailed description repeatedly links the selector's movement to these three specific outcomes, arguably defining the complete scope of the claimed selector's operation (ʼ435 Patent, col. 5:1-6; col. 5:36-41; col. 5:47-53).
VI. Other Allegations
- Indirect Infringement: The complaint makes a preemptive denial of indirect infringement, stating that it has not encouraged or intended for customers to practice every limitation of the asserted claims and that the Accused Product is a "staple article of commerce suitable for substantial non-infringing uses" (Compl. ¶25).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of structural definition: Is the claimed "flow selector moveable between a first position..., a second position..., and a third position" limited to a mechanism with exactly three corresponding functional states, or can it be construed to cover a multi-position "rotatable disc" that includes those three states among others, such as an "off" position?
- A key evidentiary question will be one of operational correspondence: Does the accused product's mechanism, in its primary showering mode, direct water "through the plurality of first nozzles" as required by Claim 1, or does it, as alleged by the plaintiff, direct water only to a "subset" of those nozzles, potentially creating a factual basis for non-infringement?
- A third area of focus will be validity: Plaintiff has presented multiple prior art references, raising the question of whether the combination of different nozzle types (shower, jet, fan) and a selector mechanism on a single showerhead would have been obvious to a person of ordinary skill in the art at the time of the invention (Compl. ¶34-39).