DCT
2:25-cv-01564
Guangzhou Shirui Technology Co Ltd v. Hyperice IP Subco LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Guangzhou Shirui Technology Co., Ltd. (China)
- Defendant: Hyperice IP Subco, LLC (Delaware) and Hyper Ice, Inc. (California)
- Plaintiff’s Counsel: Glacier Law LLP
- Case Identification: 2:25-cv-01564, W.D. Wash., 08/15/2025
- Venue Allegations: Plaintiff, the accused infringer, alleges venue is proper because Defendant submitted patent infringement complaints to Amazon.com, Inc. in Seattle, and a substantial part of the events giving rise to this declaratory judgment action occurred within the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that its massage gun products do not infringe Defendant’s patent related to the mechanical design of percussive massagers, and/or that the asserted patent is invalid.
- Technical Context: The technology concerns handheld percussive massage devices, a product category within the consumer wellness and sports recovery market.
- Key Procedural History: This action was initiated after Defendant Hyperice allegedly reported Plaintiff to Amazon.com for patent infringement. The complaint characterizes this as "extra-judicial patent enforcement" that created a justiciable controversy, prompting Plaintiff to seek a declaratory judgment of non-infringement and invalidity. The complaint also identifies seven U.S. patents and two U.S. patent applications as exemplary prior art alleged to invalidate the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2013-07-01 | ’933 Patent Priority Date |
| 2025-02-04 | ’933 Patent Issue Date |
| 2025-08-15 | Complaint for Declaratory Judgment Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,213,933 - Massage device with a releasable connection for a massaging head
- Patent Identification: U.S. Patent No. 12,213,933, Massage device with a releasable connection for a massaging head, issued February 4, 2025. (Compl. ¶¶ 16-17).
The Invention Explained
- Problem Addressed: The patent's background section states that prior art vibrating massage devices were often "bulky, get very hot, are noisy and/or are difficult to use for extended periods of time" (’933 Patent, col. 1:29-34).
- The Patented Solution: The invention is a percussive massager designed to be more robust, quieter, and cooler. It describes a mechanical layout with a motor and handle on opposite sides of a reciprocating piston, driven by a "Scotch yoke" mechanism (’933 Patent, Abstract; col. 5:14-17). This mechanism may include a spring bar to reduce the noise and wear associated with the drive components changing direction at high speed (’933 Patent, col. 5:26-49). The design also incorporates a cooling system where a fan draws air over a heat sink in a cavity that is isolated from the motor and other internal components, intended to prevent overheating from dust and lint buildup (’933 Patent, col. 6:10-48).
- Technical Importance: The design attempts to solve key usability issues in handheld power devices—namely, operational noise, heat generation, and mechanical durability—which are significant factors for consumer adoption and satisfaction. (Compl. ¶ 16; ’933 Patent, col. 1:29-34).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claim 1. (Compl. ¶ 21).
- The essential elements of independent claim 1 include:
- A housing
- A piston with a bore at its distal end
- A motor to reciprocate the piston
- A drive mechanism that determines a predetermined stroke length of the piston
- A quick-connect system for a massage head, which allows the head to be inserted into or removed from the bore "while the piston reciprocates"
- A drive mechanism comprising a flywheel connected to the motor's output shaft and a crank pin extending from the flywheel to the piston
- The complaint notes that if independent claim 1 is not infringed, then dependent claims 2-15 are also not infringed. (Compl. ¶ 26).
III. The Accused Instrumentality
Product Identification
- Plaintiff’s "Massage Gun" products, identified in the complaint by six Amazon Standard Identification Numbers (ASINs). (Compl. ¶ 23).
Functionality and Market Context
- The complaint describes two specific functionalities of the Accused Product relevant to the dispute. First, its massage head connection is a "secure friction/interference and/or twist/press fit" that requires the device to be powered off and the piston to be at rest for a head to be changed safely and correctly. (Compl. ¶ 22). Second, the device’s stroke length is described as being "fixed by its internal geometry at the time of manufacture," with no mechanism for users to select or adjust the stroke length. (Compl. ¶ 23).
- The complaint alleges that the Amazon marketplace is the Plaintiff's "primary sales channel in the United States" and that Defendant's infringement report threatens to remove the Accused Product from this channel. (Compl. ¶ 14).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
The complaint for declaratory judgment outlines Plaintiff’s theories of non-infringement.
’933 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a quick-connect system ... wherein the quick-connect system allows a proximal end of the first massaging head to be inserted into or removed from the bore while the piston reciprocates the predetermined stroke length at the first speed | The Accused Product must be powered off to change heads. Its friction-fit connection requires static alignment and attempting removal during reciprocation would cause misalignment and be contrary to safety guidance. | ¶22 | col. 6:51-56 |
| a drive mechanism that determines a predetermined stroke length of the piston | The Accused Product's stroke length is immutable and fixed by its geometry at manufacture. It lacks a mechanism that "determines" the stroke length in the sense of setting or selecting it, as allegedly contemplated by the patent's specification. | ¶23 | col. 7:22-31 |
Identified Points of Contention
- Scope Questions: A primary dispute may concern the claim phrase "while the piston reciprocates." The question is whether this limitation requires a specific mechanical design that is inherently tolerant of motion during head replacement, or if it can be read more broadly. The complaint suggests the Accused Product’s friction-fit system is fundamentally incompatible with this requirement. (Compl. ¶ 22).
- Technical Questions: A key technical question is whether the Accused Product's fixed-stroke drive mechanism performs the function of a "drive mechanism that determines a predetermined stroke length" as claimed. The complaint argues that the patent's specification discloses a variable-stroke embodiment, suggesting the term "determines" should be construed to mean "sets or adjusts," a feature the Accused Product allegedly lacks. (Compl. ¶ 23).
V. Key Claim Terms for Construction
Term: "while the piston reciprocates"
- Context and Importance: This term is central to one of the two primary non-infringement arguments. Plaintiff contends its product requires the piston to be static to change heads, and thus does not meet this limitation. (Compl. ¶ 22). The construction of this phrase may be dispositive of literal infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patentee may argue the term "allows" indicates a capability, not a mandatory mode of operation. The specification, in describing a magnetic quick-connect embodiment, states it may be "used without turning off the massaging device 100," which could be framed as an optional benefit rather than a structural requirement. (’933 Patent, col. 6:53-56).
- Evidence for a Narrower Interpretation: Plaintiff may argue that the language requires a specific type of connection system (like the magnetic one disclosed) that is structurally designed to function during motion, which it alleges its friction-fit mechanism is not. (Compl. ¶ 22).
Term: "determines a predetermined stroke length"
- Context and Importance: This term is the basis for Plaintiff's second main non-infringement theory. Plaintiff argues its fixed-stroke device does not "determine" a stroke length in the manner allegedly required by the patent. (Compl. ¶ 23). Practitioners may focus on this term because its construction will dictate whether the claim covers only adjustable-stroke devices or also fixed-stroke devices.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patentee may argue that "determines" simply means "sets" or "establishes," and that a fixed-stroke mechanism (e.g., via crank offset) inherently "determines" the stroke length. Dependent claim 8, which recites that an "offset... determines the predetermined stroke length," may support this reading. (’933 Patent, col. 10:45-48).
- Evidence for a Narrower Interpretation: Plaintiff argues that the specification’s disclosure of a "lost motion system" for adjusting the stroke length informs the meaning of "determines." (Compl. ¶ 23). The detailed description of this variable-stroke embodiment in Figure 7 and the accompanying text could be used to argue that the patentee contemplated "determines" to mean providing for the selection of a stroke length. (’933 Patent, col. 7:22-col. 8:4).
VI. Analyst’s Conclusion: Key Questions for the Case
This declaratory judgment action will likely focus on claim construction, with two questions being central to the non-infringement analysis.
- A core issue will be one of functional scope: does the claim limitation requiring that the quick-connect system "allows" head replacement "while the piston reciprocates" mandate a specific motion-tolerant design, or does it describe a broader, optional capability that could be read onto the accused friction-fit system?
- Another key issue will be one of definitional scope: can the term "determines a predetermined stroke length" be construed to cover a mechanism with a single, immutable stroke fixed at manufacture, or does the patent's disclosure of a variable-stroke embodiment limit the claim's scope to devices offering user-selectable stroke lengths?