Yu Chen v. Schedule A Defendants: Walker Design Patent Dismissed in 75 Days
Yu Chen filed a design patent infringement action in the Northern District of Illinois against a class of unnamed online marketplace sellers, asserting USD988941S covering a walker design. The case was voluntarily dismissed without prejudice under Rule 41(a)(1)(A)(i) just 75 days after filing — before any defendant appeared or answered.
Walker Design Patent: A Schedule A Action Ends Before It Begins
On July 21, 2024, Yu Chen filed a design patent infringement action in the U.S. District Court for the Northern District of Illinois (Case No. 1:24-cv-06135) against an unspecified group of online sellers collectively identified as ‘The Partnerships and Unincorporated Associations Identified on Schedule A.’ The asserted patent is USD988941S (Application No. 29/708547), which covers the ornamental design of a walker. The case was assigned to Judge Jeremy C. Daniel.
The case closed on October 4, 2024 — just 75 days after filing — when plaintiff Yu Chen filed a voluntary notice of dismissal pursuant to Federal Rule of Civil Procedure 41(a)(1)(A)(i), dismissing all Schedule A defendants without prejudice. A Rule 41(a)(1)(A)(i) dismissal is a unilateral plaintiff action available before any defendant has served an answer or motion for summary judgment, requiring no court order. Dismissal without prejudice means the claims are not extinguished and could theoretically be refiled.
The rapid resolution — before any defendant appeared on the record — is consistent with several dynamics common to Schedule A litigation: early out-of-court settlements with individual sellers, platform-level takedowns mooting the claims, or a strategic decision to refile against a narrowed defendant list. Because the dismissal was unilateral and no settlement terms are publicly recorded, the precise driver remains unknown from the public record. The without-prejudice designation preserves Yu Chen’s option to reassert the design patent against these or related parties.
Filing to Voluntary dismissal in 75 days
75 days — well below the median Schedule A case duration in N.D. Illinois
Voluntarily dismissed: what the Rule 41 exit means for both sides
Rule 41(a)(1)(A)(i): plaintiff’s unilateral exit right
Under Fed. R. Civ. P. 41(a)(1)(A)(i), a plaintiff may dismiss an action without a court order by filing a notice before the defendant serves an answer or a motion for summary judgment. No defendant in this case had appeared, so the right was available as of right. The court plays no gatekeeping role — the dismissal is self-executing upon filing.
No court order requiredPublic record is silent on whether claims are truly closed
A dismissal without prejudice does not extinguish the underlying patent claims — Yu Chen retains the right to refile against the same or related defendants. A dismissal with prejudice would have permanently barred re-assertion. The notice here expressly states ‘without prejudice,’ but the public record contains no settlement agreement, consent order, or indication of whether any resolution was reached privately before the filing.
Claims survive dismissalSellers dismissed — but no immunity from future action
Because the dismissal is without prejudice, the Schedule A defendants receive no preclusive protection. They cannot invoke res judicata or claim-splitting defenses if Yu Chen refiles. Any sellers who had product listings removed via preliminary injunction or TRO obtained before dismissal would retain that operational disruption even without a final judgment on the merits.
No res judicata protectionDesign patent enforcement via Schedule A: disruption without adjudication
This case is consistent with a broader enforcement pattern in which design patent holders use Schedule A complaints and early TRO filings to secure marketplace takedowns, then voluntarily dismiss once commercial objectives are achieved. For online sellers in the walker and mobility-aid product category, the case signals active monitoring of ornamental design rights — even where litigation does not proceed to a merits ruling.
Enforcement without final judgmentFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Yu Chen | Individual | Individual design patent holder — holder of USD988941S (ornamental walker design)Search in Eureka ↗ |
| Defendant | The Partnerships and Unincorporated Associations Identified on Schedule A | Individual | Anonymous online marketplace sellers identified collectively on Schedule ASearch in Eureka ↗ |
| Plaintiff counsel | Lance Y. Liu | Attorney | Counsel for Yu ChenSearch in Eureka ↗ |
| Plaintiff law firm | Lance Liu | Law Firm | Representing Yu ChenSearch in Eureka ↗ |
| Presiding judge | Judge Jeremy C. Daniel | Judge | Illinois Northern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The dismissal notice invokes Rule 41(a)(1)(A)(i) and expressly specifies dismissal ‘without prejudice,’ which is legally significant: it signals the plaintiff has not released its claims, no settlement has been recorded, and the patent’s enforceability is entirely intact. The absence of any defendant appearance on the docket means no invalidity arguments, claim construction positions, or affirmative defenses have been advanced — leaving the legal landscape around USD988941S unchanged by this proceeding.
USD988941S — Ornamental Design for a Walker
USD988941S (filed under Application No. 29/708547) is a U.S. design patent protecting the ornamental appearance of a walker — a mobility aid product widely sold through e-commerce platforms. Design patents protect the way a product looks, not how it functions. Infringement is determined by the ‘ordinary observer’ test: whether an ordinary consumer would find the accused design substantially similar to the patented design. The patent’s drawings define the full scope of protection.
In the online marketplace context, design patents covering consumer mobility products like walkers are commercially significant because visual differentiation among competing SKUs is often minimal. A single design patent can sweep across multiple third-party sellers offering functionally equivalent but visually similar products. For manufacturers and private-label sellers in the walker category, USD988941S represents an active enforcement risk — particularly given the plaintiff’s willingness to initiate Schedule A litigation and the availability of ex parte TRO relief in N.D. Illinois.
Should your product team run an FTO against USD988941S?
Any company manufacturing, importing, or selling walkers or visually similar mobility aids through U.S. e-commerce channels should assess its exposure to USD988941S. Design patent infringement does not require copying or knowledge of the patent — an independently created product can still infringe if it is substantially similar in appearance to the claimed design under the ordinary observer standard. Given the active enforcement history, an FTO review is advisable before launching new walker SKUs.
PatSnap Eureka’s FTO Search Agent can rapidly map the ornamental claim scope of USD988941S against your product drawings, surface prior art that may limit the patent’s enforceability, and identify related design filings in the same patent family or by the same applicant. R&D and sourcing teams can use Eureka to run design-around analysis and flag visual similarity risk before products reach the marketplace — reducing the cost and disruption of a Schedule A complaint.
Run a freedom-to-operate analysis on USD0988941S to assess your product’s exposure
Run FTO in Eureka →Similar Design Patent Schedule A Cases in N.D. Illinois
Cases involving design patent enforcement against Schedule A defendants in the Northern District of Illinois, covering consumer product and mobility aid categories.
What this case signals for the mobility aid design patent landscape
Schedule A design patent actions in N.D. Illinois are increasingly used as enforcement tools independent of final adjudication.
Without-prejudice dismissals preserve a plaintiff’s full enforcement optionality
Yu Chen’s Rule 41(a)(1)(A)(i) exit preserves every claim. Competitors and sellers in the walker and mobility product category should not treat this dismissal as a clean bill of health. The patent remains in force and the door to re-litigation is open. Companies sourcing or selling walker products should maintain active FTO monitoring on USD988941S.
Schedule A tactics routinely achieve commercial outcomes before any hearing
The 75-day case cycle — filed, no defendant appearance, voluntarily dismissed — is a recognizable pattern in N.D. Illinois Schedule A litigation. Marketplace sellers in consumer product categories should assume that TRO and preliminary injunction risk exists from the moment a complaint is filed, even if the case never reaches a merits ruling.
Chen v Partnerships — key questions answered
It means Yu Chen unilaterally ended the case before any defendant appeared, and the dismissal is without prejudice — the underlying patent claims are not extinguished. Yu Chen retains the right to refile the same infringement claims against the same or related defendants at any time within the applicable statute of limitations.
The asserted patent is USD988941S, a U.S. design patent filed under Application No. 29/708547. It covers the ornamental design of a walker. Design patents protect appearance, not function, and infringement is assessed under the ordinary observer test for substantial similarity.
Based on the public record, no defendant filed an answer, motion, or notice of appearance before the case was voluntarily dismissed. The Rule 41(a)(1)(A)(i) dismissal is only available before a defendant serves an answer or summary judgment motion, which confirms no defendant had responded at the time of dismissal.
Yes. A without-prejudice dismissal does not bar refiling. Yu Chen may reassert USD988941S against the same Schedule A defendants or new parties, subject to the applicable statute of limitations for design patent infringement (six years under 35 U.S.C. § 286). The defendants receive no preclusive protection from this dismissal.
Schedule A litigation is a common enforcement technique in N.D. Illinois where a plaintiff sues a large group of anonymous online sellers — identified only on an attached schedule — in a single complaint. It enables plaintiffs to seek ex parte temporary restraining orders and asset freezes against marketplace sellers quickly. It is frequently used for design and trademark infringement involving products sold on platforms like Amazon, eBay, and AliExpress.
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