Vanstar v. Dezhou Nange: Barbell Attachment Patent Case Closed Without Prejudice
Xiamen Vanstar Technology Co., Ltd. filed suit against four Chinese defendants — including Dezhou Nange Trading Co., Ltd. and Shenzhen Qiwei electronic commerce Co., Ltd. — over alleged infringement of US11648452B1, a patent covering a barbell attachment. After all defendants failed to respond following service, the Southern District of Florida administratively closed the case within 283 days, leaving the door open for refiling.
Default-driven closure after Chinese defendants go silent
On November 8, 2024, Xiamen Vanstar Technology Co., Ltd. — a Chinese fitness equipment company — filed an infringement action in the U.S. District Court for the Southern District of Florida against four defendants: Dezhou Nange Trading Co., Ltd., Shenzhen Qiwei electronic commerce Co., Ltd., and individuals Dan Sun and Hui Sun. The claim centred on US11648452B1, a U.S. patent covering an attachment for barbell fitness equipment.
Service of the summons and complaint on all four defendants was completed between May 20 and June 13, 2025. None of the defendants filed an answer or otherwise responded. Acting sua sponte, Judge Melissa Damian ordered Vanstar to file a Motion for Entry of Clerk’s Default by September 2, 2025, and simultaneously directed the Clerk to administratively close the case pending that filing. The closure is without prejudice, meaning Vanstar’s claims survive and can be reasserted.
The 283-day duration to administrative closure is consistent with patterns in cases involving Chinese e-commerce defendants who are served but do not engage U.S. proceedings. The public record does not disclose any settlement, licensing discussion, or substantive merits ruling. The outcome leaves Vanstar positioned to pursue a default judgment — or refile if circumstances change — without having litigated the infringement merits.
Filing to Dismissed without Prejudice in 283 days
Case resolved in 283 days — faster than many contested patent matters, driven by defendant non-response rather than merits adjudication.
Administrative closure without prejudice: what it means for both sides
Administrative closure ≠ final judgment — the case lives on
The court’s order administratively closes the docket for housekeeping purposes while Vanstar pursues a Clerk’s Default. A dismissal without prejudice means no final adjudication on the merits has occurred. Vanstar retains full rights to refile the same claims, and the administrative closure is explicitly conditional on the pending default motion process.
Without prejudice closureVanstar retains enforcement rights and a clear path to default
Because the dismissal is without prejudice, Vanstar’s infringement claims under US11648452B1 remain legally intact. The court’s September 2, 2025 deadline for filing a Motion for Entry of Clerk’s Default suggests the next logical step is a default judgment proceeding — which, if granted, could yield injunctive relief and damages without a contested trial.
Default judgment pathway openSilent defendants face heightened default judgment risk
All four defendants — Dezhou Nange, Shenzhen Qiwei, Dan Sun, and Hui Sun — failed to respond despite confirmed service. Their silence significantly raises the risk of a default judgment that could include monetary damages and injunctive orders affecting U.S. sales channels. Non-appearance typically forfeits any invalidity or non-infringement defences.
Non-appearance riskPattern enforcement: U.S. courts as tool against Chinese e-commerce infringers
This case is consistent with a broader enforcement strategy used by Chinese IP holders targeting competing Chinese sellers on U.S. e-commerce platforms. Filing in the Southern District of Florida — a court experienced with such matters — and seeking default judgments against non-appearing defendants can result in platform takedowns and account freezes, even without contested litigation.
E-commerce enforcement patternFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Xiamen Vanstar Technology Co., Ltd. | Company | Chinese fitness equipment manufacturer — holder of US11648452B1Search in Eureka ↗ |
| Defendant | Dezhou Nange Trading Co., Ltd. | Company | Chinese trading and e-commerce entities and two individual defendants alleged to infringe barbell attachment patent.Search in Eureka ↗ |
| Co-Defendant | Dan Sun | Individual | Search in Eureka ↗ |
| Co-Defendant | Hui Sun | Individual | Search in Eureka ↗ |
| Co-Defendant | Shenzhen Qiwei electronic commerce Co., Ltd. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Andrew Jonathan Palmer | Attorney | Counsel for Xiamen Vanstar Technology Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Palmer Law Group PA | Law Firm | Representing Xiamen Vanstar Technology Co., Ltd.Search in Eureka ↗ |
| Presiding judge | Judge Melissa Damian | Judge | Florida Southern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The court’s August 18, 2025 order reflects a sua sponte case management decision rather than any merits adjudication. The court noted confirmed service on all four defendants, their collective failure to respond, and directed Vanstar to formalise its default position by September 2, 2025. The administrative closure with an explicit warning that failure to file the default motion ‘may result in a dismissal without prejudice’ signals the court’s intent to maintain oversight while keeping the enforcement pathway open for the patent holder.
US11648452B1 — Attachment for Barbell
US11648452B1 is a U.S. utility patent held by Xiamen Vanstar Technology Co., Ltd. covering an attachment for barbell equipment. Filed under application number US17/994032, it relates to the mechanical design or functional configuration of accessories used with barbells — a product category that spans commercial gym equipment and consumer fitness markets. As a granted U.S. patent, it carries a presumption of validity unless successfully challenged.
The patent’s strategic significance lies in the competitive dynamics of the Chinese-origin fitness equipment market targeting U.S. consumers through e-commerce platforms. By securing a U.S. patent, Vanstar can pursue enforcement not only in federal court but potentially through USITC proceedings or platform takedown mechanisms. The fact that no invalidity challenge has been mounted — owing to defendant non-appearance — means the patent’s claims remain unchallenged and commercially potent for the foreseeable future.
Should you run an FTO analysis against US11648452B1?
Any company designing, manufacturing, importing, or selling barbell attachment products into the U.S. market should assess their exposure to US11648452B1. Vanstar’s active enforcement posture — filing suit in a U.S. federal court and pursuing default judgment — signals a willingness to use patent rights offensively. Products sold via Amazon, eBay, or other U.S. e-commerce channels are particularly exposed if they fall within the scope of the asserted claims.
PatSnap Eureka’s FTO Search Agent can map the claim scope of US11648452B1 against your product specifications, identify prior art that could support an invalidity argument, and surface related patent families or continuation applications that may extend Vanstar’s coverage. Given the absence of any claim construction record in this case, an independent FTO analysis is the only reliable way to assess your clearance position before entering or expanding in this product category.
Run a freedom-to-operate analysis on US11648452B1 to assess your product’s exposure
Run FTO in Eureka →Similar barbell and fitness equipment patent cases in U.S. district courts
Cases involving Chinese-held fitness equipment patents enforced in U.S. district courts — particularly the Southern District of Florida — against non-appearing e-commerce defendants.
What this case signals for the fitness equipment IP landscape
Non-appearing Chinese defendants, Southern District filings, and U.S. patent enforcement are converging into a recognisable playbook.
Administrative closure without prejudice keeps all claims alive
Competitors and distributors of barbell attachment products should not treat this closure as a vindication. Vanstar’s patent claims under US11648452B1 are unresolved on the merits. A default judgment motion is anticipated, and if granted, it could trigger platform-level enforcement actions affecting third-party sellers.
Default judgment in patent cases can be commercially devastating for defendants
When defendants fail to appear in U.S. patent actions, courts may enter default judgments that include permanent injunctions and damages. For e-commerce sellers, this typically means account suspension on major U.S. platforms. Sellers of similar barbell accessories should monitor this docket closely through the September 2025 default deadline.
Xiamen v Dezhou — key questions answered
Xiamen Vanstar Technology filed a patent infringement suit in the Southern District of Florida against Dezhou Nange Trading, Shenzhen Qiwei electronic commerce, Dan Sun, and Hui Sun over US11648452B1, a barbell attachment patent. After all defendants failed to respond following service, the court administratively closed the case without prejudice on August 18, 2025, directing Vanstar to file for clerk’s default by September 2, 2025.
A dismissal without prejudice means no final judgment on the merits was entered. Vanstar’s infringement claims under US11648452B1 remain legally intact and can be reasserted. In this case the closure is administrative and explicitly conditional — the court ordered a default motion deadline, indicating the enforcement pathway remains open rather than terminated.
US11648452B1 is a U.S. utility patent held by Xiamen Vanstar Technology Co., Ltd., filed under application number US17/994032. It covers an attachment for barbell fitness equipment. As a granted U.S. patent it carries a presumption of validity. No invalidity challenge was raised in this proceeding due to defendant non-appearance.
Acting sua sponte, Judge Melissa Damian reviewed the record and noted that all four defendants had been served but failed to answer or respond. The court administratively closed the case as a case management measure while directing Vanstar to file a Motion for Entry of Clerk’s Default by September 2, 2025. Administrative closure pending a default motion is a recognised procedural mechanism in the Southern District of Florida.
US11648452B1’s claims have not been adjudicated or narrowed in this proceeding. Competing sellers of barbell attachment products — especially those selling into the U.S. via e-commerce platforms — face unquantified infringement exposure. If Vanstar obtains a default judgment, platform-level enforcement actions such as account suspensions may follow. Independent FTO analysis against US11648452B1 is advisable for any company active in this product category.
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