Power Mobile Life LLC v. Shenzhen Shermon Technology Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Power Mobile Life LLC (Washington)
  • Defendant: Shenzhen Shermon Technology Co., Limited (People's Republic of China)
  • Plaintiff's Counsel: K&L Gates LLP; ScienBiziP, P.C.
• Case Identification: 2:26-cv-01723, W.D. Wash., 05/19/2026
• Venue Allegations: Plaintiff alleges venue is proper in the Western District of Washington because a substantial part of the events giving rise to the action occurred there, namely Defendant's patent enforcement activities directed at a Washington-based plaintiff. Alternatively, venue is alleged to be proper because the Defendant is not a U.S. resident and may be sued in any judicial district. The complaint also alleges Defendant consented to venue in King County, Washington by participating in Amazon's APEX program.
• Core Dispute: Plaintiff seeks a declaratory judgment that its robotic vacuum product does not infringe Defendant's patent related to a "dry-wet separation cleaning floor brush," and that the patent-in-suit is invalid.
• Technical Context: The technology concerns cleaning heads for vacuum cleaners designed to perform both dry debris collection and wet mopping, while keeping the collected dry refuse and wet sewage physically separated.
• Key Procedural History: This declaratory judgment action was filed in response to Defendant's assertion of patent infringement against Plaintiff through Amazon's Patent Evaluation Express (APEX) procedure, an extra-judicial process that can lead to the removal of product listings from Amazon's platform. The complaint's invalidity contentions rely on a Chinese patent application as prior art.

Case Timeline

Date	Event
2018-10-02	CN730 Prior Art Reference Publication Date
2020-03-26	'975 Patent Priority Date
2020-03-27	'975 Patent Application Filing Date
2022-11-22	'975 Patent Issue Date
2026-04-29	Defendant Executes Amazon APEX Agreement
2026-04-30	Plaintiff Receives APEX Notice from Amazon
2026-05-19	Complaint Filing Date

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

U.S. Patent No. 11,503,975 - "Dry-Wet Separation Cleaning Floor Brush"

• Patent Identification: U.S. Patent No. 11,503,975, "Dry-Wet Separation Cleaning Floor Brush," issued November 22, 2022.

The Invention Explained

• Problem Addressed: The patent's background section describes issues with contemporary cleaning robots that combine sweeping, vacuuming, and mopping functions. Specifically, it notes that storing collected dust and sewage together can lead to blockages and poor cleaning performance, and complicates maintenance. '975 Patent, col. 1:11-33
• The Patented Solution: The invention proposes a cleaning brush assembly featuring a housing internally divided by a "partition plate." This plate creates two distinct, "disconnected" chambers. A "first storage chamber" is designed for dry cleaning (sweeping and vacuuming) using a stiff roller brush, while a "second storage chamber" is for wet cleaning (mopping) with a soft roller brush. This physical separation is intended to keep dry debris and wet sewage apart throughout the cleaning process. '975 Patent, abstract '975 Patent, col. 1:59-65
• Technical Importance: By mechanically separating the collection of dry and wet waste, the invention aims to provide more effective and reliable cleaning in multi-function devices and simplify the process of emptying and maintaining the robot. '975 Patent, col. 2:55-62

Key Claims at a Glance

• The complaint identifies independent claims 1, 9, and 16 as being at issue in the dispute Compl. ¶26 Compl. ¶33
• The essential elements of independent claim 1 are:
  • A dry-wet separation cleaning floor brush comprising a housing, a stiff roller brush and a soft roller brush,
  • wherein the housing is provided with a partition plate dividing the inner part of the housing into a first storage chamber and a second storage chamber which are disconnected to each other,
  • wherein the stiff roller brush is partially contained in the first storage chamber, is movably connected to the housing, and partially protrudes the housing,
  • and wherein the soft roller brush is partially contained in the second storage chamber, is movably connected to the housing, and partially protrudes the housing.
• The complaint notes that Defendant asserted at least Claim 1 and may assert claims 9 and 16 Compl. ¶33

III. The Accused Instrumentality

Product Identification

• The accused product is a "Eufy branded robot vacuum," sold on Amazon under the Amazon Standard Identification Number (ASIN) B0FK2HPNCB Compl. ¶13

Functionality and Market Context

• The complaint identifies the product as part of the "Eufy" line of smart-home products, which is associated with Anker Innovations Limited Compl. ¶12 The complaint provides a printout of the Amazon product listing for the accused Eufy robot vacuum, which shows the product's external appearance and marketing information Compl. ¶13 The central technical allegation made by the Plaintiff is that the accused product's design does not include the specific separated and disconnected chamber structure claimed by the '975 Patent Compl. ¶20 Compl. ¶28

IV. Analysis of Infringement Allegations

The complaint is for a declaratory judgment of non-infringement. The core of the non-infringement argument is that the Accused Product fails to meet a specific limitation common to all independent claims.

'975 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
wherein the housing is provided with a partition plate dividing the inner part of the housing into a first storage chamber and a second storage chamber which are disconnected to each other	Plaintiff alleges the Accused Product does not contain this feature. The complaint states the product does not have a partition plate that divides the housing into a first storage chamber and a second storage chamber that are disconnected from each other.	¶20; ¶28	col. 1:59-65

• Identified Points of Contention:
  • Technical Question: The primary factual dispute will concern the physical construction of the Accused Product. The key question is whether its internal components for handling dry debris and wet liquid can be characterized as a "partition plate" creating two "disconnected" storage chambers.
  • Scope Questions: The case raises a clear question of claim scope: what is the meaning of the term "disconnected to each other"? The plaintiff's non-infringement position hinges on a reading of this term that the Accused Product's design does not satisfy Compl. ¶28

V. Key Claim Terms for Construction

• The Term: "disconnected to each other"
• Context and Importance: This term appears in all three independent claims Compl. ¶27 and is the explicit basis for the Plaintiff's non-infringement argument Compl. ¶28 The interpretation of "disconnected" will therefore be a dispositive issue for the infringement analysis. Practitioners may focus on this term because its interpretation-whether it means absolute physical and fluidic isolation or allows for some incidental or indirect connection-will determine if the Accused Product's design falls within the claim's scope.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent does not explicitly define "disconnected." A party arguing for a broader meaning (e.g., functionally separate for the primary purpose of waste collection, even with some shared airspace or minor connection) would need to argue that the overall context of the invention supports such a reading, though the specification provides little direct support for this.
  • Evidence for a Narrower Interpretation: The patent repeatedly uses the phrase "disconnected to each other" without qualification '975 Patent, abstract '975 Patent, col. 1:62-63 '975 Patent, claims 1, 9, 16 The stated goal of preventing the sewage inlet from being "blocked by dust" further supports an interpretation requiring strict separation between the dry and wet collection systems '975 Patent, col. 3:18-22 This consistent language suggests an intended meaning of complete or near-complete physical and fluidic isolation.

VI. Other Allegations

• Indirect Infringement: The Plaintiff seeks a declaration that the Accused Product does not infringe "directly or indirectly" Compl., prayer B However, the complaint does not contain specific factual allegations regarding inducement or contributory infringement for analysis.
• Willful Infringement: As a declaratory judgment action filed by the accused infringer, the complaint does not allege willfulness. However, the Defendant's filing of the APEX complaint serves as pre-suit notice of the patent to the Plaintiff Compl. ¶¶15-16 This fact would be a necessary predicate for the patentee (Defendant) to later assert a claim for willful infringement if infringement is found for any sales occurring after the notice.

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

The resolution of this case will likely depend on the court's answers to two fundamental questions:

• A core issue will be one of claim construction and factual analysis: What is the required degree of separation for the two storage chambers to be considered "disconnected to each other" under the patent's claims, and does the physical design of the accused Eufy robot vacuum meet this standard?
• A parallel issue will be one of validity: Does the cited prior art (the "CN730 Reference") disclose all elements of the asserted claims, including a cleaning brush with a partitioned housing for separate, disconnected dry and wet storage, thereby rendering the '975 Patent's invention anticipated and invalid?