DCT
3:24-cv-13085
Quanzhou Fengze Daxiong Net Tech Co Ltd v. Ab Mill LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Quanzhou Fengze Daxiong Net Tech Co Ltd (China)
- Defendant: Ab Mill LLC (Massachusetts) and Michael H Domesick (Massachusetts)
- Plaintiff’s Counsel: Dinsmore & Shohl LLP
- Case Identification: 3:24-cv-13085, D. Mass., 12/13/2024
- Venue Allegations: Venue is alleged to be proper in the District of Massachusetts as Defendant Ab Mill, LLC is a Massachusetts limited liability company with its principal place of business in the state.
- Core Dispute: Plaintiff 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.
- Technical Context: The technology relates to exercise equipment designed to assist users in performing plank exercises by providing support for the forearms and hands.
- Key Procedural History: The lawsuit was precipitated by an infringement complaint filed by the Defendants with Amazon.com, which resulted in the removal of Plaintiff's products from Amazon's online marketplace. The complaint for declaratory judgment also includes an invalidity count asserting that the patent-in-suit is obvious in light of two prior art references not cited during prosecution.
Case Timeline
| Date | Event |
|---|---|
| 2000-11-23 | Chen Prior Art (DE 100 58 195 C2) Filing Date |
| 2000-12-07 | Smith Prior Art (U.S. 6,582,347) Filing Date |
| 2018-04-23 | ’364 Patent Priority Date |
| 2022-11-08 | ’364 Patent Issue Date |
| 2024-10-11 | Plaintiff receives infringement notice from Amazon.com |
| 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"
- Issued: November 8, 2022.
The Invention Explained
- Problem Addressed: The patent's background section describes drawbacks of conventional plank exercises, including significant discomfort and strain on a user's elbows and wrists, which bear the body's weight (Compl. ¶78; ’364 Patent, col. 1:12-38). It also notes that some existing exercise devices use unrestricted sliding movements, creating a risk of injury from overextension (’364 Patent, col. 2:5-10).
- The Patented Solution: The invention is an apparatus designed to redistribute bodyweight from the elbows to the forearms via arm support pads, used in conjunction with hand grips (’364 Patent, col. 2:56-65, Fig. 4). This apparatus is described as being "translationally static relative to a ground surface," which is intended to provide a more stable and controlled exercise experience than devices that slide freely (’364 Patent, col. 3:9-11).
- Technical Importance: The described solution aims to make plank exercises safer and more comfortable, potentially allowing for longer hold times and better form by mitigating common points of failure like elbow pain and wrist strain (’364 Patent, col. 2:20-24).
Key Claims at a Glance
- The complaint seeks a declaratory judgment of non-infringement for independent claims 1, 4, 8, 10, and 11 (Compl. ¶¶32, 52, 57, 62, 65).
- Independent Claim 1:
- An apparatus for facilitating a user to achieve a plank position.
- Comprising an arm support pad, a hand grip, and a frame member.
- A "contact surface configured to engage a ground surface."
- The contact surface is "configured to allow the apparatus to rest on the ground surface."
- When placed on the ground, the contact surface is in "level contact with the ground surface."
- Independent Claim 4:
- An apparatus with a left and right arm support pad portion.
- A frame having a first and second leg.
- The first and second legs are "connected with a hinge or pivot member."
- The hinge or pivot member allows "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 also states that because the independent claims are not infringed, neither are any of the dependent claims (Compl. ¶¶71-72).
III. The Accused Instrumentality
Product Identification
- Plaintiff's "Elbow Support Accessory" (ASINs B0DKT37LTP, B0DHP751N9), which is designed for use with a separate "Pilates Push-up Board" (Compl. ¶¶19, 31).
Functionality and Market Context
- The accused product is described as an accessory with eight wheels, not a standalone device (Compl. ¶33). These wheels are specifically designed for dynamic motion: one type slides along the top surface of the companion Push-up Board, while a second type slides within two recessed "chutes" on the board (Compl. ¶¶33-35).
- The complaint alleges the product's primary function is to facilitate "sliding Pilates exercises," which inherently involves motion, not static positioning (Compl. ¶34). The product's intended use is depicted in a photograph showing the accessory mounted on the board. This image shows the accessory's wheels resting on the top surface and within the chutes of the board (Compl. p. 6).
- Plaintiff alleges that its primary sales channel in the United States is the Amazon marketplace, making the delisting of its products a source of immediate and irreparable harm (Compl. ¶¶21, 24).
IV. Analysis of Infringement Allegations
’364 Patent Infringement Allegations (Claim 1)
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a contact surface configured to engage a ground surface underneath the frame member or the arm support pad... | Plaintiff alleges its product has eight wheels designed to slide on a separate Push-up Board, not to engage a "ground surface" like a floor. It is argued the wheels provide sliding contact, not engagement in the static sense. A photograph shows the accessory's wheels positioned for sliding on the board (Compl. p. 6). | ¶¶33-38 | col. 22:41-43 |
| ...wherein the contact surface is configured to allow the apparatus to rest on the ground surface... | Plaintiff argues that the term "rest on" implies a static state, which is contrary to the function of its product's wheels, which are designed for sliding motion. | ¶¶40-42 | col. 22:43-44 |
| ...whereby when the apparatus is placed on the ground surface, the contact surface is in level contact with the ground surface. | Plaintiff contends that if its product were placed on a ground surface like a floor, the sharp heads of the wheel-fastening bolts would make contact, potentially damaging the floor and the bolts themselves, and preventing level contact or the intended sliding exercise. | ¶¶44-45, 47, 50 | col. 22:44-47 |
’364 Patent Infringement Allegations (Claim 4)
| Claim Element (from Independent Claim 4) | Alleged Non-Infringing Functionality | 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. | Plaintiff alleges that while its product's frame has two legs connected by a joint, this joint does not allow for a variation in spacing. Instead, the distance between the legs is "fixed and unchangeable" during use, as it is "strictly and uniquely determined by the spacing between the two chutes on the board." A photograph illustrates this configuration (Compl. p. 10). | ¶¶53-55 | col. 23:66-col. 24:6 |
Identified Points of Contention
- Scope Questions: A central dispute will be the interpretation of "ground surface." Plaintiff argues it means the floor, whereas Defendants may argue it can encompass the top surface of the companion "Push-up Board." The patent's focus on a "translationally static" apparatus may support the Plaintiff's narrower interpretation (’364 Patent, col. 3:9-11).
- Technical Questions: The case raises the question of whether a device designed with wheels for dynamic sliding can meet claim limitations requiring it to "engage" and "rest on" a surface in a "level contact" state. The complaint provides visual evidence showing the pointed heads of fastening bolts on the wheels, arguing this design feature makes stable, level contact on a floor impractical and damaging (Compl. p. 8).
- Functional Questions: Regarding Claim 4, the dispute will likely focus on whether the accused product's joint functions as a "hinge or pivot member allowing a variation in a spacing." Plaintiff's position is that any variation is not enabled by the joint itself but is dictated and fixed by an external component (the push-up board's chutes), which may not satisfy the claim language.
V. Key Claim Terms for Construction
The Term: "rest on the ground surface" (Claim 1)
- Context and Importance: This phrase is critical because the accused product uses wheels for sliding motion. Plaintiff argues "rest on" implies a static state, which its product is not designed for (Compl. ¶40). The outcome of this construction could be dispositive for infringement of claims 1 and 10.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A defendant might argue that "rest on" simply means to be supported by, without precluding the ability to move. The term itself is not explicitly defined as static.
- Evidence for a Narrower Interpretation: The patent specification states that one embodiment of the invention is "translationally static relative to a ground surface" (’364 Patent, col. 3:9-11). The summary also describes maintaining a "static position" (’364 Patent, col. 1:49-50). This context suggests the invention was conceived as a stable, non-moving platform, supporting a narrower, static definition of "rest on."
The Term: "a hinge or pivot member allowing a variation in a spacing" (Claim 4)
- Context and Importance: Plaintiff's product has two legs connected by a joint, but it alleges the spacing is fixed by the external push-up board, not by the joint itself (Compl. ¶¶54-55). Practitioners may focus on whether "allowing a variation" requires the hinge to be the active mechanism for adjustment, or if it is met so long as variation is possible in the overall system.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A defendant could argue that as long as the hinge facilitates a change in spacing (even if constrained by another part), it "allows" for it.
- Evidence for a Narrower Interpretation: The patent describes adjustability as a way to match a user's body size, for example, by varying the distance between arm pads to accommodate different shoulder widths (’364 Patent, col. 10:30-34). This suggests an intended purpose of active, user-defined adjustment via the hinge mechanism, which may not be met if the spacing is rigidly fixed by an external constraint during use.
VI. Other Allegations
- Invalidity: The complaint includes a declaratory judgment count for invalidity of all claims of the ’364 Patent under 35 U.S.C. §§ 102 and/or 103 (Compl., Count II). The invalidity argument is based on the combination of U.S. Patent No. 6,582,347 ("Smith") and German Patent No. DE 100 58 195 C2 ("Chen") (Compl. ¶¶78-79). Plaintiff alleges Chen, which was not cited during prosecution, teaches most elements of Claim 1, and that it would have been obvious to a person of ordinary skill in the art to combine Chen's device with teachings from Smith, such as a tubular frame member and a destabilization device (Compl. ¶¶79c-e).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can claim terms like "rest on" and "engage," which are described in the patent in the context of a "translationally static" device, be construed to read on a product specifically designed with wheels for dynamic sliding motion on a separate board?
- A key functional question will be one of operative mechanism: does the accused product's joint, whose inter-leg spacing is rigidly dictated by an external board's chutes, meet the claim 4 requirement of a "hinge... allowing a variation in spacing," or is there a fundamental mismatch in how adjustability is achieved?
- A central validity question will be the strength of the uncited prior art: does the German "Chen" reference, either alone or in combination with "Smith," disclose or render obvious the claimed invention, particularly given that Chen was not before the examiner during the prosecution of the ’364 Patent?