DCT
3:24-cv-13087
Quanzhou Fengze Daxiong Net Tech Co Ltd v. Ab Mill LLC
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Quanzhou Fengze Daxiong net tech Co., LTD. (d/b/a ZHOUBX) (China)
- Defendant: Ab Mill, LLC (Massachusetts) and Michael H. Domesick (Massachusetts)
- Plaintiff’s Counsel: Dinsmore & Shohl LLP
- Case Identification: 3:24-cv-13087, D. Mass., 12/13/2024
- Venue Allegations: Venue is alleged to be proper in the District of Massachusetts because Defendant Ab Mill, LLC is a limited liability company with its principal place of business in Massachusetts.
- Core Dispute: Plaintiff, a seller of exercise equipment, seeks a declaratory judgment that its "Elbow Support Accessory" does not infringe U.S. Patent No. 11,491,364 and that the patent is invalid, following an infringement complaint Defendants filed with Amazon that resulted in the delisting of Plaintiff's products.
- Technical Context: The technology relates to exercise equipment, specifically ergonomic devices designed to assist users in performing plank exercises by providing support for the forearms and hands.
- Key Procedural History: The action was precipitated by Defendants' submission of a patent infringement complaint to Amazon.com, which led Amazon to remove Plaintiff's products from its online marketplace and require a court order for reactivation. The complaint alleges the '364 Patent's claims are invalid in light of prior art that was not cited during prosecution.
Case Timeline
| Date | Event |
|---|---|
| 2000-11-23 | Filing date of German Patent DE 100 58 195 C2 ("Chen") prior art |
| 2000-12-07 | Filing date of U.S. Patent No. 6,582,347 ("Smith") prior art |
| 2018-04-23 | Earliest priority date for U.S. Patent No. 11,491,364 ('364 Patent) |
| 2022-11-08 | Issue date of '364 Patent |
| 2024-10-11 | Plaintiff receives notice from Amazon of product removal |
| 2024-12-13 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,491,364 - "Plank Support Exercise Apparatus and Related Methods"
- Patent Identification: U.S. Patent No. 11,491,364, "Plank Support Exercise Apparatus and Related Methods," issued November 8, 2022.
The Invention Explained
- Problem Addressed: The patent's background section identifies several shortcomings with conventional plank exercises and related devices. These include the significant discomfort from concentrating body weight on the elbows, the risk of injury from unrestricted sliding movements on some devices, and unergonomic hand grip positions that can cause wrist strain (’364 Patent, col. 1:12-2:41).
- The Patented Solution: The invention is a plank support apparatus featuring a hand grip and a separate arm support pad connected by a frame. This design purports to transfer the user's weight through the forearm to the pad, rather than concentrating it on the elbow (’364 Patent, col. 6:53-65). The apparatus is described as having a ground-interface surface that is "translationally static," providing a stable, non-sliding base to enhance safety and allow for controlled, destabilizing rotational movements for a more advanced exercise (’364 Patent, col. 3:7-10; Fig. 3).
- Technical Importance: The claimed invention seeks to make the popular plank exercise safer, more comfortable, and more effective by improving ergonomics and stability compared to performing the exercise on the floor or with prior art devices (’364 Patent, col. 2:42-53).
Key Claims at a Glance
- The complaint asserts non-infringement of independent claims 1, 4, 8, 10, and 11.
- Independent Claim 1 recites, in part:
- An apparatus with an arm support pad, a hand grip, and a frame member.
- A "contact surface configured to engage a ground surface" underneath the apparatus.
- The contact surface is configured to "allow the apparatus to rest on the ground surface" such that it is in "level contact with the ground surface."
- Independent Claim 4 recites, in part:
- An apparatus with a left and a right arm support pad portion and a frame with a first and second leg.
- The first and second legs are "connected with a hinge or pivot member."
- This connection allows for "a variation in a spacing" of the left and right arm support pad portions relative to one another.
- The complaint states that since the independent claims are not infringed, neither are any dependent claims (Compl. ¶72).
III. The Accused Instrumentality
Product Identification
- The "Elbow Support Accessory" sold by Plaintiff ZHOUBX on Amazon under ASINs B0DKT37LTP and B0DHP751N9 (Compl. ¶19, 31).
Functionality and Market Context
- The complaint describes the accused product not as a standalone device, but as an "accessory that is intended to slide in cooperation with a Pilates Push-up Board" (Compl. ¶31). Its core functionality is based on "eight highly customized wheels" designed for rolling motion (Compl. ¶33). These wheels are of two distinct types: one set slides along the top surface of the associated push-up board, while the other set slides within two opposing "chutes" on the board (Compl. ¶33-35). An image in the complaint shows a user performing a sliding exercise with the product. (Compl. p. 9).
- The complaint alleges that Amazon's online marketplace is the Plaintiff's "primary sales channel in the United States," making the delisting of its products a source of immediate and irreparable harm (Compl. ¶21, 24).
IV. Analysis of Infringement Allegations
U.S. Patent No. 11,491,364 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality (per Declaratory Judgment Complaint) | Complaint Citation | Patent Citation |
|---|---|---|---|
| a contact surface configured to engage a ground surface underneath the frame member or the arm support pad... | The product's contact surfaces are eight wheels specifically designed to roll and slide along a separate push-up board, not to engage a ground surface in a static manner (Compl. ¶33, 35). The complaint includes an annotated photograph identifying the "first type of wheels" for sliding on the board surface and the "second type of wheels" for sliding in a chute. (Compl. p. 7). | ¶33, 35, 38 | col. 22:41-43 |
| wherein the contact surface is configured to allow the apparatus to rest on the ground surface whereby when the apparatus is placed on the ground surface, the contact surface is in level contact with the ground surface. | The product is "intended for sliding motion" and cannot achieve a "static placement state" due to the rolling action of its wheels (Compl. ¶42-43). The complaint argues the term "rest on" indicates a static state, which is contrary to the product's function and design (Compl. ¶40-41). It further alleges that placing the device on the ground would cause damage from "sharply pointed heads of fastening bolts." (Compl. p. 8, ¶44). | ¶40, 42-44, 47 | col. 22:43-47 |
U.S. Patent No. 11,491,364 Infringement Allegations
| Claim Element (from Independent Claim 4) | Alleged Non-Infringing Functionality (per Declaratory Judgment Complaint) | Complaint Citation | Patent Citation |
|---|---|---|---|
| wherein the first leg and the second leg are connected with a hinge or pivot member allowing a variation in a spacing of the left arm support pad portion and the right arm support pad portion relative to one another. | The complaint alleges the two legs of the accessory are locked together by a joint and there is "no connection between the two legs" that would permit variable spacing (Compl. ¶53). It asserts that the distance between the legs is "fixed and unchangeable" and is instead "strictly and uniquely determined by the spacing between the two chutes on the board" where the accessory is used (Compl. ¶54-55). A photograph depicts this fixed structure. (Compl. p. 10). | ¶53-55 | col. 23:3-8 |
- Identified Points of Contention:
- Scope Questions: A primary question is whether claim terms such as "rest on" and "engage a ground surface," which the patent specification associates with a "translationally static" and stable apparatus, can be interpreted to cover a product with wheels designed for rolling motion. The plaintiff argues that its product's essential character is dynamic (sliding), while the patent describes a static support.
- Technical Questions: A key factual dispute concerns the structure of the accused product. Does the joint connecting the two halves of the accessory allow for "a variation in a spacing" as required by claim 4, or is the distance between them fixed and unchangeable as alleged in the complaint?
V. Key Claim Terms for Construction
The Term: "rest on" (Claim 1)
Context and Importance: This term is central to the non-infringement argument for Claim 1. The plaintiff contends its wheeled device, designed for motion, cannot "rest on" a surface in the static sense required by the patent. Practitioners may focus on this term because its construction could determine whether the entire category of wheeled or rolling exercise accessories falls outside the patent's scope.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A defendant could argue that any object making contact with a surface is "resting" on it, even if it has wheels and is capable of motion. The term itself is not explicitly defined in a limited way.
- Evidence for a Narrower Interpretation: The plaintiff may point to the specification's repeated emphasis on stability and overcoming the dangers of prior art sliding devices, suggesting "rest on" implies a stable, non-movable state (’364 Patent, col. 2:15-21). The patent also describes itself as "translationally static" (’364 Patent, col. 3:9-10), and the complaint notes the patent does not disclose wheels or rollers (Compl. ¶41).
The Term: "a variation in a spacing" (Claim 4)
Context and Importance: The plaintiff's non-infringement argument for Claim 4 hinges on the assertion that its product has a fixed, unchangeable spacing between its two arm supports. The interpretation of "variation" is critical; if it requires user-adjustability that the accused product lacks, the claim may not be infringed.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent holder might argue that any small amount of play or flexibility in the joint constitutes a "variation," even if not intended for user adjustment.
- Evidence for a Narrower Interpretation: The specification describes embodiments with a "hinge or pivot member" that explicitly allows for adjustment to "alter the lateral distance" and accommodate different user sizes or exercise types (’364 Patent, col. 12:59-65). This context suggests "variation" implies a functional, intended adjustability, which the plaintiff alleges its product lacks (Compl. ¶54-55).
VI. Other Allegations
- Invalidity Allegations: The complaint includes a count for a declaratory judgment of invalidity, alleging that all claims of the '364 Patent are invalid under 35 U.S.C. §§ 102 and/or 103 (Compl. ¶78). The complaint specifically identifies two prior art references: U.S. Patent No. 6,582,347 ("Smith") and German Patent No. DE 100 58 195 C2 ("Chen"). It is noted that the Chen patent was not cited during the prosecution of the '364 Patent (Compl. ¶78.b). The complaint provides an exemplary obviousness argument, asserting that Claims 1-3 are rendered obvious by combining the teachings of Chen and Smith (Compl. ¶79).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim construction and scope: can terms like "rest on" and "engage," which are described in the patent in the context of a static and stable support device, be construed to cover a product that is defined by its use of wheels for dynamic rolling motion? The outcome may depend on whether the patent's focus on stability imparts a narrow, static-only meaning to these terms.
- A second central question will be one of factual determination: does the accused product's structure, specifically the joint connecting its two halves, allow for "a variation in a spacing" as required by Claim 4? This will likely involve a direct comparison of the product's physical characteristics against the requirements of the claim language.
- Finally, a key validity question will be the impact of uncited prior art: does the German "Chen" patent, either alone or combined with the "Smith" patent, disclose or render obvious the key elements of the '364 patent's claims, particularly the combination of hand grips, arm pads, and a ground-engaging surface for a plank exercise apparatus?