Zhejiang Qili v. Core Home Fitness: Adjustable Dumbbell Patent Dismissed in 86 Days
Zhejiang Qili Health Technology filed suit against Core Home Fitness, LLC in the Northern District of Illinois asserting US7614983B1 — a patent covering adjustable dumbbell mechanisms — across products sold on Amazon, Walmart, and eBay. The case was voluntarily dismissed without prejudice just 86 days after filing, before the defendant was even served.
Pre-Service Voluntary Dismissal in an Adjustable Dumbbell Patent Dispute
On January 25, 2025, Zhejiang Qili Health Technology Co., Ltd. — a Chinese fitness equipment manufacturer — filed a patent infringement action in the U.S. District Court for the Northern District of Illinois against Core Home Fitness, LLC. The complaint asserted US7614983B1, a patent directed at adjustable dumbbell technology, against a broad range of competing products sold under multiple marketplace storefronts on Amazon, Walmart, and eBay, including brands such as LEEKEY DIRECT, Pooboostore, Rendpas Direct, Xddias Fitness Expert, ZYZHI, and lnowfitness.
On April 21, 2025, just 86 days after filing and before defendant Core Home Fitness, LLC had been served, plaintiff’s counsel filed a notice of voluntary dismissal without prejudice pursuant to Federal Rule of Civil Procedure 41(a)(1)(A)(i). Because service had not been completed and the defendant had not appeared or answered, plaintiff was entitled to dismiss as of right — without a court order and without prejudice to refiling. No cost or fee ruling was entered.
The speed and pre-service timing of this dismissal is notable. Voluntary dismissals filed before service are often associated with post-filing settlement discussions, a decision to refile in a different venue, or a reassessment of claim viability. The public record does not disclose whether any commercial resolution was reached. The without-prejudice designation preserves Zhejiang Qili’s right to refile the same infringement allegations, meaning Core Home Fitness and the named marketplace sellers remain potentially exposed to future enforcement action on US7614983B1.
Filing to Voluntary dismissal in 86 days
86 days — resolved before service of process, well short of the typical N.D. Illinois patent litigation timeline
Voluntarily dismissed: what the Rule 41 notice means for both parties
Rule 41(a)(1)(A)(i): dismissal as of right, no court order needed
Federal Rule of Civil Procedure 41(a)(1)(A)(i) permits a plaintiff to dismiss an action without a court order by filing a notice of dismissal at any point before the opposing party serves an answer or a motion for summary judgment. Because Core Home Fitness had not been served, Zhejiang Qili could exercise this right unilaterally. The dismissal is procedural — no court ruled on the merits of the patent infringement allegations.
Pre-service dismissal as of rightDismissed without prejudice — refiling remains possible
The notice expressly states dismissal is ‘without prejudice,’ meaning Zhejiang Qili retains the right to refile the same claims. This is distinct from a dismissal with prejudice, which would bar refiling permanently. The public record is silent on whether a commercial settlement or licensing arrangement was reached privately. Core Home Fitness cannot treat this dismissal as a final resolution — future enforcement action on US7614983B1 remains a live risk.
Refiling right preservedZhejiang Qili retains full enforcement options on US7614983B1
By dismissing without prejudice before service, Zhejiang Qili preserves maximum strategic flexibility. It may refile in the same district, elect a different forum, pursue additional defendants, or have resolved the dispute privately. The breadth of accused products — spanning Amazon, Walmart, and eBay storefronts — suggests an enforcement campaign targeting multiple sellers, not just Core Home Fitness.
Enforcement campaign may continueCore Home Fitness: no adjudication, but patent risk remains
Core Home Fitness was never served and did not incur litigation costs in this proceeding. However, the without-prejudice dismissal means no court has invalidated or limited US7614983B1. The company — and the other marketplace sellers named in the complaint — should treat this as a warning rather than a clearance. A freedom-to-operate analysis against US7614983B1 is advisable for any business selling adjustable dumbbell products in the U.S.
No invalidity ruling obtainedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Zhejiang Qili Health Technology Co., Ltd. | Company | Chinese fitness equipment manufacturer — holder of US7614983B1 (adjustable dumbbell technology)Search in Eureka ↗ |
| Defendant | Core Home Fitness, LLC | Company | Core Home Fitness, LLC — U.S. fitness equipment brand and alleged infringer of adjustable dumbbell patentSearch in Eureka ↗ |
| Plaintiff counsel | Weisun Rao | Attorney | Counsel for Zhejiang Qili Health Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Venture Partner, LLC | Law Firm | Representing Zhejiang Qili Health Technology Co., Ltd.Search in Eureka ↗ |
| Presiding judge | Judge Steven C. Seeger | Judge | Illinois Northern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The dismissal notice invokes Rule 41(a)(1)(A)(i) and expressly confirms that Core Home Fitness had not been served at the time of filing. This is a procedural exit, not a merits adjudication — the court made no finding on infringement, validity, or claim scope. The explicit ‘without prejudice’ language under Rule 41(a)(1)(B) is legally significant: it preserves Zhejiang Qili’s right to refile identical claims, and no estoppel or res judicata bar applies to future proceedings on US7614983B1.
US7614983B1 — Adjustable Dumbbell Mechanism Technology
US7614983B1 is a U.S. utility patent directed to adjustable dumbbell technology — specifically the mechanisms by which a user selects and locks discrete weight increments within a compact dumbbell housing. The application number on record is US11/983213. Adjustable dumbbell patents of this type typically protect the selector dial, weight plate engagement system, and safety retention features that allow rapid weight changes without separate free weights, a design feature that became commercially significant during the home fitness boom.
For the fitness equipment sector, US7614983B1 represents a commercially sensitive asset given the proliferation of adjustable dumbbell SKUs across e-commerce marketplaces. The breadth of accused products in this action — spanning at least eight distinct seller storefronts — suggests the patent holder views its claims as covering widely adopted design patterns rather than a niche variant. Competitors and OEM manufacturers supplying the U.S. market should assess whether their selector and locking mechanisms fall within the claim scope before listing new products.
Should your product team run an FTO against US7614983B1?
Any business manufacturing, importing, or selling adjustable dumbbell products in the United States — particularly through Amazon, Walmart, or eBay storefronts — should consider a freedom-to-operate review against US7614983B1. The original complaint named products from at least seven distinct marketplace seller identities, suggesting the patent holder is actively monitoring competing listings. A pre-launch or pre-import FTO analysis can identify design-around opportunities before products reach the U.S. market.
PatSnap Eureka’s FTO Search Agent can map the claim landscape of US7614983B1 against your product specifications, surface prior art that may support invalidity arguments, and identify related continuation or family patents that could extend enforcement risk. For marketplace sellers or brands sourcing adjustable dumbbell products from Chinese OEMs, Eureka can also surface the supplier’s own patent portfolio — helping teams assess whether upstream IP ownership complicates enforcement or provides a licensing defence.
Run a freedom-to-operate analysis on US7614983B1 to assess your product’s exposure
Run FTO in Eureka →Similar Adjustable Fitness Equipment Patent Cases in N.D. Illinois
Browse comparable patent infringement actions involving fitness equipment and adjustable dumbbell technology filed in the Northern District of Illinois.
What this case signals for the fitness equipment IP landscape
A pre-service voluntary dismissal rarely signals the end of an enforcement story — for adjustable dumbbell sellers, this case warrants close attention.
Pre-service dismissals are often a strategic pause, not an exit
When plaintiffs dismiss before serving a defendant, it frequently indicates ongoing settlement talks, a venue reassessment, or a decision to consolidate claims. Zhejiang Qili’s without-prejudice election preserves every enforcement option. Businesses selling competing adjustable dumbbell products should not interpret this dismissal as IP clearance.
US7614983B1 remains active — FTO review is advisable for the sector
No court has ruled on the validity or scope of US7614983B1. Any company manufacturing or distributing adjustable dumbbell mechanisms in the U.S. — particularly via Amazon or Walmart marketplaces — should conduct a freedom-to-operate analysis against this patent before assuming clearance. The named product list in the original complaint signals broad enforcement intent.
Zhejiang v Core — key questions answered
Zhejiang Qili Health Technology Co., Ltd. filed a patent infringement action against Core Home Fitness, LLC in the Northern District of Illinois on January 25, 2025, asserting US7614983B1 covering adjustable dumbbell technology. The case was voluntarily dismissed without prejudice on April 21, 2025 — 86 days after filing — before the defendant was served, pursuant to Rule 41(a)(1)(A)(i).
A dismissal without prejudice means Zhejiang Qili retains the right to refile identical patent infringement claims in the future. No court ruled on the merits of the infringement allegations, and US7614983B1 has not been invalidated. Core Home Fitness and the other marketplace sellers named in the complaint — across Amazon, Walmart, and eBay — remain potentially exposed to future enforcement action.
The asserted patent is US7614983B1 (application number US11/983213). It is directed to adjustable dumbbell technology, specifically the mechanisms allowing users to select and lock discrete weight increments within a compact dumbbell housing. The patent is held by Zhejiang Qili Health Technology Co., Ltd., a Chinese fitness equipment manufacturer.
Pre-service voluntary dismissals under Rule 41(a)(1)(A)(i) are typically associated with several strategic scenarios: private settlement or licensing negotiations concluded before service, a decision to refile in a different jurisdiction or with a revised complaint, or a reassessment of claim strength following pre-filing diligence. The public record in this case does not disclose the specific reason for the early dismissal.
The complaint named adjustable dumbbell products sold under the CORE FITNESS, LEEKEY DIRECT, Pooboostore, Rendpas Direct, Xddias Fitness Expert, ZYZHI, and lnowfitness storefronts across Amazon, Walmart, and eBay, identified by specific ASIN and item numbers. This breadth of accused products across multiple marketplace platforms is consistent with a systematic enforcement campaign targeting competing sellers.
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