Ritfit LLC et al. v. Ningbo Huayue Dianzi Shangwu Youxian Gongsi et al.

Competitive Home Gym Suppliers Clash Over Exercise Machine Patent

In a recent intellectual property dispute within the burgeoning home fitness market, U.S.-based Ritfit LLC and its Chinese partner, Ningbo Ruitefei Sports Technology Co Ltd, have filed a patent infringement lawsuit against Chinese competitors Ningbo Huayue Dianzi Shangwu Youxian Gongsi, which operates under the brand name LIONSCOOL, and an individual, Zhong YIN. The case, initiated on April 17, 2026, in the U.S. District Court for the Northern District of Illinois, centers on allegations that the defendants' leg exercise machine infringes on the plaintiffs' patent. Both Ritfit and LIONSCOOL are operating companies that manufacture and sell a range of home gym equipment, positioning them as direct competitors in a market that has seen a surge in intellectual property disputes.

The lawsuit targets LIONSCOOL's line of leg extension and curl machines, which are functionally similar to Ritfit's own "PLC01 Leg Extension and Curl Machine." These machines are designed for home gyms to allow users to perform exercises targeting the quadriceps and hamstrings. The complaint alleges that the defendants' products infringe on U.S. Patent No. 12,427,372. While the docket confirms the patent is at issue, its specific technical details, title, and claims are not available through public online search portals as of May 4, 2026, making a detailed technical summary of the asserted technology difficult. The plaintiffs are operating companies; Ritfit, founded in Delaware in 2015, designs and distributes a wide array of home fitness gear and holds over 30 patents. The defendants also appear to be operating companies based in Ningbo, China, with LIONSCOOL marketing a similar range of affordable strength training equipment.

The case has been filed in the Northern District of Illinois, a popular venue for patent litigation, particularly cases involving online retailers and design patents. The court's experience with patent disputes and established local patent rules make it a strategic choice for plaintiffs. Given the recent filing date, no judge has been publicly assigned, and there have been no substantive rulings. The lawsuit is notable as it reflects a broader trend of increasing patent enforcement within the competitive and innovative fitness technology industry. Companies like Peloton, iFIT, and TRX have engaged in significant patent litigation to protect their market share, signaling that intellectual property is a key battleground in the fitness sector. As of this date, there are no known parallel proceedings, such as an Inter Partes Review (IPR), before the Patent Trial and Appeal Board.

Litigation Remains in Infancy with No Substantive Developments

As of May 4, 2026, the patent infringement litigation between Ritfit LLC and Ningbo Huayue Dianzi Shangwu Youxian Gongsi is in its earliest procedural stage. The only significant legal event to have occurred is the filing of the initial complaint. Given the recent filing date of April 17, 2026, there have been no substantive responses from the defendants or any court rulings.

Chronological Developments:

• 2026-04-17: Complaint Filed
  The plaintiffs, Ritfit LLC and Ningbo Ruitefei Sports Technology Co Ltd, filed a complaint for patent infringement in the U.S. District Court for the Northern District of Illinois. The complaint (Dkt. 1) alleges that the "LIONSCOOL" brand leg extension and curl machine, sold by defendants Ningbo Huayue Dianzi Shangwu Youxian Gongsi and Zhong YIN, infringes upon U.S. Patent No. 12,427,372. The plaintiffs are seeking a jury trial.

• Current Status (2026-05-04): Awaiting Defendant's Response
  The case is currently open and active. Docket records indicate that no judge has been assigned to the case yet. The defendants have not yet filed an answer, a motion to dismiss, or any other responsive pleading. The deadline for a defendant to respond to a complaint is typically 21 days after service of the summons, or longer if service is made internationally. No significant discovery, claim construction, or motion practice has taken place.

• Parallel PTAB Proceedings: None
  A search of the U.S. Patent and Trademark Office's Patent Trial and Appeal Board (PTAB) records shows no Inter Partes Review (IPR) or Post-Grant Review (PGR) petitions have been filed challenging the validity of U.S. Patent No. 12,427,372 as of the current date. Consequently, there are no parallel administrative proceedings that could lead to a stay of the district court case.

The litigation is proceeding as expected for a case that is less than a month old. The next significant steps will be the formal service of the complaint on the defendants, their subsequent appearance in court, and the filing of their response to the allegations.

Plaintiffs' Counsel from Cross-Border IP Firm

The plaintiffs, Ritfit LLC and Ningbo Ruitefei Sports Technology Co Ltd, are represented by attorneys from Veritas Light Law Group, P.C., a firm that specializes in cross-jurisdictional legal services between North America and Asia, including international intellectual property protection.

Based on court filings, the following attorneys have appeared on behalf of the plaintiffs:

• Mingbo Ye

  • Role: Counsel for Plaintiffs. His specific role as lead or local counsel has not been formally designated in the initial filings.
  • Firm: Veritas Light Law Group, P.C. The firm has offices in California, Texas, and Shanghai.
  • Note on experience: Mr. Ye is admitted to practice in Texas and several federal courts, including the Northern District of Illinois. His practice areas are listed as Intellectual Property and Wills-Trusts-Probate, and he is fluent in Mandarin Chinese. Publicly available information does not detail his specific patent litigation history or notable past cases.

• Roumin Xie

  • Role: Counsel for Plaintiffs. A specific role has not been designated in the initial filings.
  • Firm: Veritas Light Law Group, P.C. (Newport Beach, CA office).
  • Note on experience: Mr. Xie is an active member of the State Bars of California and Texas. His self-reported practice areas include Immigration and Intellectual Property. Further details on his specific patent litigation experience are not publicly available.

The selection of Veritas Light Law Group, P.C. underscores the international dimension of this case, which involves U.S. and Chinese plaintiffs suing Chinese defendants over a U.S. patent. The firm's stated focus on "international IP protection" and its presence in both the U.S. and China align with the legal needs of the plaintiffs in this competitor lawsuit.

Defense Counsel Has Not Yet Appeared

As of May 4, 2026, no attorneys have filed a notice of appearance on behalf of the defendants, Ningbo Huayue Dianzi Shangwu Youxian Gongsi and Zhong YIN.

The case was filed on April 17, 2026. Under the Federal Rules of Civil Procedure, a defendant typically has 21 days to respond to a complaint after being served. However, for defendants located outside the United States, as is the case here, the time to respond is generally extended. The formal service of the complaint and summons on international defendants can be a lengthy process governed by international agreements such as the Hague Service Convention.

Given the recent filing date and the international status of the defendants, it is not unusual that counsel has not yet formally appeared on the docket. The next major step in the litigation will be the plaintiffs' filing of proof of service, followed by the appearance of defense counsel and a responsive pleading to the complaint.