DCT
3:25-cv-04135
Shenzhen Kelaisiman Trading Co Ltd v. Hyperice IP Subco LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Kelaisiman Trading Co Ltd and twelve other Chinese entities (China)
- Defendant: Hyperice IP Subco LLC and Hyperice IP Topco LLC (Delaware LLCs with principal place of business in California)
- Plaintiff’s Counsel: SHM Law Firm
- Case Identification: 3:25-cv-04135, N.D. Cal., 08/11/2025
- Venue Allegations: Plaintiffs allege venue is proper because Defendants' enforcement actions, specifically filing infringement complaints with Amazon, caused harm to Plaintiffs' business operations within the Northern District of California by causing the removal of product listings.
- Core Dispute: Plaintiffs seek a declaratory judgment that their percussive massage gun products do not infringe Defendants' patent related to a quick-connect system for attaching and removing massaging heads.
- Technical Context: The technology relates to handheld percussive massage devices, a popular category of consumer electronics for muscle therapy and recovery.
- Key Procedural History: The complaint alleges that Defendants obtained a favorable, non-binding decision through the Amazon Patent Evaluation Express ("APEX") procedure against non-party sellers and subsequently used that decision to file infringement complaints with Amazon against Plaintiffs' products, leading to their delisting. Plaintiffs also allege the patent-in-suit is not "patentably distinct" from a related patent that Defendants are asserting in separate district court litigations.
Case Timeline
| Date | Event |
|---|---|
| 2013-07-01 | '052 Patent Priority Date (via U.S. Provisional App. 61/841,693) |
| 2024-07-01 | '052 Patent Application Filing Date |
| 2025-01-28 | '052 Patent Issue Date |
| 2025-03-07 | First alleged Amazon notification/delisting of Plaintiffs' products |
| 2025-03-XX | Defendants allegedly initiate APEX procedure against third parties |
| 2025-05-09 | Second alleged Amazon notification/delisting of Plaintiffs' products |
| 2025-08-11 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,208,052 - "Massage device with a releasable connection for a massaging head," Issued January 28, 2025
- The Invention Explained:
- Problem Addressed: The patent background notes that prior art vibrating massagers can be "bulky, get very hot, are noisy and/or are difficult to use for extended periods of time" ('052 Patent, col. 1:30-34).
- The Patented Solution: The invention describes a handheld percussive massager featuring a "quick-connect system" that allows a user to attach or detach different massaging heads ('052 Patent, col. 10:11-18). This system is designed to allow the head to be swapped even while the device's piston is in motion, using magnetic force to secure the head to the piston ('052 Patent, col. 6:53-7:12). The specification also discloses a drive mechanism, a "Scotch yoke," that incorporates "spring bars" intended to reduce the noise and wear associated with the piston's change of direction ('052 Patent, col. 5:12-29).
- Technical Importance: A system for rapidly changing massaging heads enhances user convenience, allowing for different therapeutic applications during a single session without needing to power down the device ('052 Patent, col. 5:49-56).
- Key Claims at a Glance:
- The complaint seeks a declaratory judgment of non-infringement with respect to Claim 1, the sole independent claim of the patent (Compl. ¶51).
- Independent Claim 1 requires:
- A housing
- A handle portion on the housing
- A piston with a bore at its distal end
- A motor to reciprocate the piston at a first speed
- A drive mechanism that determines a predetermined stroke length
- A quick-connect system comprising the piston's distal end and a massaging head
- The quick-connect system must allow the massaging head to be inserted or removed from the bore while the piston reciprocates
- A flywheel operatively connected between the motor and piston
- The handle portion and motor must be on the same side of a plane along which the flywheel rotates
- The complaint does not explicitly reserve the right to address dependent claims but seeks a declaration of non-infringement of "any valid claim of the '052 Patent" (Compl. ¶68).
III. The Accused Instrumentality
Product Identification
- The "Non-Infringing Products" are various models of massage guns sold by the thirteen Plaintiffs on the Amazon marketplace under numerous storefronts and Amazon Standard Identification Numbers (ASINs) (Compl. ¶¶ 23-46).
Functionality and Market Context
- The complaint alleges that the Plaintiffs' products are handheld percussive massage guns sold in the U.S. primarily through the Amazon marketplace (Compl. ¶47).
- The complaint does not provide technical details on how the accused products operate. Instead, it makes conclusory allegations that the products lack specific features required by the claims of the '052 Patent (Compl. ¶¶ 60-61, 69-70). The complaint alleges that Defendants' infringement reports to Amazon have resulted in the delisting of Plaintiffs' products, causing "immediate and substantial harm" (Compl. ¶47, 65).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
The complaint seeks a declaratory judgment of non-infringement. The table below summarizes the Plaintiffs' core allegations of why their products do not meet the limitations of the asserted patent claim.
'052 Patent Non-Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a drive mechanism that determines a predetermined stroke length of the piston | The complaint alleges the Non-Infringing Products do not include such a drive mechanism. | ¶¶60, 69 | col. 5:1-12 |
| 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 complaint alleges the Non-Infringing Products do not include a quick-connect system with this specific functional capability. | ¶¶61, 70 | col. 10:13-18 |
- Identified Points of Contention:
- Technical Questions: The complaint's allegations of non-infringement are conclusory and lack specific factual support describing the actual design of the Plaintiffs' products. A central question will be what evidence exists to demonstrate that the accused products' head-attachment mechanisms do not perform the function of allowing insertion or removal while the piston is reciprocating.
- Scope Questions: The dispute may turn on the definition of a "quick-connect system" that functions "while the piston reciprocates." Does this require full functionality at operating speed, or does it cover a system that works only if the piston is moving slowly? The claim language "at the first speed" suggests a demanding standard that may be a focal point of litigation.
V. Key Claim Terms for Construction
- The Term: "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"
- Context and Importance: This limitation defines the core functionality of the patented invention and is a primary basis for Plaintiffs' non-infringement allegations (Compl. ¶¶ 61, 70). Its construction will be dispositive. The requirement that the system functions "while the piston reciprocates... at the first speed" sets a specific, and potentially high, functional bar for infringement.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's summary section describes the invention more generally as including a "quick-connection mechanism" for releasably connecting heads, without repeating the "while reciprocating" limitation in that initial description ('052 Patent, col. 1:40-44). A party could argue the claim's functional language is merely illustrative of one capability.
- Evidence for a Narrower Interpretation: The plain language of Claim 1 explicitly requires the system to function "while the piston reciprocates... at the first speed" ('052 Patent, col. 10:15-18). The specification further describes the quick-release connection in the context of user convenience, noting the end of the head can be tapered "to allow it to easily slip into the opening 608 even while the piston 608 is moving" ('052 Patent, col. 7:10-12). This provides strong intrinsic support for a narrow construction tied to this specific operational capability.
VI. Other Allegations
- Indirect Infringement: Plaintiffs seek a judgment of non-infringement for both direct and indirect infringement (Compl. ¶68). However, the complaint pleads no specific facts related to indirect infringement, focusing its substantive allegations on the features of the products themselves.
- Willful Infringement: This allegation is not applicable, as the complaint is a declaratory judgment action filed by the accused infringers.
VII. Analyst’s Conclusion: Key Questions for the Case
This declaratory judgment action appears to center on the following key questions:
- A question of definitional scope and function: Can the claim limitation requiring a "quick-connect system" that works "while the piston reciprocates... at the first speed" be read to cover attachment mechanisms that may be "quick" but do not permit the exchange of heads while the device is operating at speed? The resolution of this construction issue may be case-dispositive.
- An evidentiary question of product operation: As the complaint provides no technical details about the accused products, the case will depend heavily on evidence developed in discovery. A core factual dispute will be whether Plaintiffs' products actually possess the "swap-while-reciprocating" functionality required by the claim, or if they lack this specific feature as alleged.
- A question of litigation strategy and conduct: The complaint heavily emphasizes Defendants' alleged "abuse" of the Amazon APEX system and its concurrent litigation strategy involving a related patent (Compl. ¶¶ 64, 75-79). This suggests the case may involve disputes beyond literal infringement, potentially extending to the propriety of Defendants' pre-suit enforcement activities under theories of unfair competition or tortious interference.