DCT
1:24-cv-11277
Shenzhen Zhifu Network Technology Co Ltd v. Core Home Fitness LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Shenzhen Zhifu Network Technology Co Ltd, et al. (collectively "Plaintiffs") (China)
- Defendant: Core Home Fitness LLC (Nevada)
- Plaintiff’s Counsel: Venture Partner
- Case Identification: 1:24-cv-11277, N.D. Ill., 10/31/2024
- Venue Allegations: Venue is alleged to be proper based on Defendant’s operation of interactive e-commerce websites that target and sell products to consumers in Illinois.
- Core Dispute: Plaintiffs seek a declaratory judgment that their adjustable dumbbell products do not infringe and that U.S. Patent No. 7,614,983 is invalid, following Defendant’s patent infringement complaints on e-commerce platforms that resulted in the delisting of Plaintiffs' products.
- Technical Context: The lawsuit concerns the field of adjustable exercise dumbbells, where a single handle can be used with a variable number of weight plates to change the total weight.
- Key Procedural History: The action was precipitated by Defendant's patent infringement complaints filed with Amazon.com, eBay.com, and/or Walmart.com, which led to the removal of Plaintiffs' product listings. Plaintiffs allege they engaged U.S. patent counsel, who concluded the products do not infringe, but Defendant and the e-commerce platforms did not accept this conclusion, prompting the current lawsuit.
Case Timeline
| Date | Event |
|---|---|
| 2005-05-03 | ’983 Patent Priority Date (Provisional App. 60/677,150) |
| 2006-04-25 | Filing Date of Parent Application (11/410,774) |
| 2007-11-06 | Issue Date of Parent Patent (U.S. 7,291,098) |
| 2009-11-10 | ’983 Patent Issue Date |
| 2024-10-31 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,614,983 - "Apparatus for Adjusting Weight Resistance to Exercise," Issued November 10, 2009
The Invention Explained
- Problem Addressed: The patent identifies a need for continued improvement in the field of adjustable weight lifting equipment, specifically concerning the methods for selecting different combinations of weight plates for use with an exercise dumbbell (’983 Patent, col. 1:30-34).
- The Patented Solution: The invention discloses an exercise dumbbell system where a handle member is equipped with rotatable weight selectors. These selectors are designed to rotate into and out of engagement with notches in adjacent weight plates. By rotating the selector, a user can secure a desired number of weight plates to the handle for lifting (’983 Patent, Abstract; col. 2:30-35). The core mechanism involves a selector that rotates within a cavity formed by aligned notches in the weight plates, allowing it to engage or disengage specific plates based on its rotational position (’983 Patent, col. 5:5-15; FIG. 1).
- Technical Importance: The technology provides a mechanism for quickly and selectively adjusting the weight of a dumbbell without manually adding or removing individual plates and locking collars.
Key Claims at a Glance
- The complaint addresses independent claims 1, 9, and 11 (Compl. ¶20).
- Independent Claim 1:
- An exercise apparatus, comprising:
- a liftable member having at least one weight supporting section;
- weights sized and configured to be supported by the at least one weight supporting section;
- a weight selector rotatably mounted on the liftable member for rotation about an axis extending lengthwise between adjacent said weights,
- wherein the weight selector is configured for rotation through a cavity defined between adjacent said weights.
- Independent Claim 9:
- An exercise apparatus, comprising:
- a weight lifting member having at least one weight supporting section;
- weights sized and configured to be supported by the at least one weight supporting section, wherein notches in the weights cooperate to define a cavity having upwardly open sectors and upwardly closed sectors; and
- a weight selector rotatably mounted on the weight lifting member for rotation inside the cavity, wherein the weight selector defines a rotational axis, and includes a plate having a generally semi-circular shape when viewed axially.
- Independent Claim 11:
- An exercise apparatus, comprising:
- a weight lifting member having at least one weight supporting section;
- weights sized and configured to be supported by the at least one weight supporting section, wherein notches in the weights cooperate to define a cavity having upwardly open sectors and upwardly closed sectors; and
- a weight selector, rotatably mounted on the weight lifting member for rotation inside the cavity, wherein the weight selector is rotatable between a first orientation underlying only one of the weights, and a second orientation underlying only another of the weights.
- The complaint notes that dependent claims 2-8, and 10 are also not infringed (Compl. ¶¶ 36, 48).
III. The Accused Instrumentality
Product Identification
- Plaintiffs' adjustable dumbbells, identified in the complaint as "Plaintiffs' Products," with specific examples "Product 1" and "Product 2" (Compl. ¶¶ 9, 14).
Functionality and Market Context
- The complaint describes two distinct mechanisms. Product 1 is alleged to use a rotatable handle component that drives two "sliders" to move telescopically through a central hole in the dumbbell pieces. The extended sliders engage the dumbbell pieces to select the desired weight (Compl. ¶30). A visual provided in the complaint shows the "Dual Security Protection" of this product, highlighting a "Plate Lock System" and a "Tray Lock System" (Compl. p. 7). Product 2 is alleged to use a rotatable grip that drives a "limiting member" to translate, causing protrusions to insert into "clamping slots" on the weight plates to engage them (Compl. ¶37). The complaint provides an annotated diagram illustrating how rotation of the grip drives a protrusion into an insertion hole to connect a weight plate (Compl. p. 10).
- The complaint alleges these products were popular and competitive on e-commerce platforms before being delisted due to Defendant's infringement reports (Compl. ¶¶ 14, 18).
IV. Analysis of Infringement Allegations
The complaint argues for non-infringement by asserting that Plaintiffs' Products lack key limitations of the asserted claims.
’983 Patent Infringement Allegations (Claim 1)
| Claim Element (from Independent Claim 1) | Alleged Non-Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a liftable member having at least one weight supporting section; | The complaint does not dispute this element. | ¶¶ 30, 37 | col. 2:36-40 |
| weights sized and configured to be supported by the at least one weight supporting section; | The complaint does not dispute this element. | ¶¶ 30, 37 | col. 2:32-35 |
| a weight selector rotatably mounted on the liftable member for rotation about an axis extending lengthwise between adjacent said weights, | Product 1 allegedly uses a rotatable handle to drive sliders, and Product 2 uses a rotatable grip to drive protrusions. Plaintiffs argue these are not "rotatably mounted on the liftable member" and that their axis of rotation extends through a dumbbell plate, not between adjacent weights. | ¶¶ 32-34, 39-41 | col. 5:48-54 |
| wherein the weight selector is configured for rotation through a cavity defined between adjacent said weights. | Plaintiffs allege their products lack a "cavity defined between adjacent weights." Instead, Product 1's sliders move through a central hole in each plate, and Product 2's protrusions insert into clamping holes on each plate. | ¶¶ 35, 42 | col. 5:48-54 |
- Identified Points of Contention:
- Scope Questions: A central dispute will be whether the claimed "weight selector" that "rotat[es]... between adjacent said weights" can be construed to read on the Plaintiffs' mechanisms, which allegedly involve rotation of a handle to actuate translating sliders or protrusions that engage weights individually through central holes or slots.
- Technical Questions: The complaint raises the question of whether the "central hole" in Product 1 or the "clamping holes" in Product 2 constitute a "cavity defined between adjacent said weights" as required by the claim. The complaint provides an annotated figure from the patent showing the claimed axis extending lengthwise within the space between two adjacent weights to support its interpretation (Compl. p. 15).
V. Key Claim Terms for Construction
The Term: "a weight selector rotatably mounted on the liftable member for rotation about an axis extending lengthwise between adjacent said weights" (Claim 1)
Context and Importance: The spatial relationship of the rotational axis ("between adjacent said weights") is a primary basis for Plaintiffs' non-infringement argument. Practitioners may focus on this term because Plaintiffs allege their products' rotational axis is fundamentally different—passing through a weight plate rather than in the space between two plates (Compl. ¶¶ 33, 40).
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's general description refers to a "weight selector rotatably mounted on the handle member for rotation into different sectors of a cylindrical cavity defined by aligned notches" without consistently specifying the axis must be between weights in every context (e.g., ’983 Patent, col. 1:52-56).
- Evidence for a Narrower Interpretation: The summary of the invention describes the handle extending "therebetween" first and second weight supporting sections, defining a "longitudinal axis" (’983 Patent, col. 1:47-50). FIG. 1 and the accompanying description show the handle member (110) and its grip (114) positioned between the two sets of weights (180, 190), which may support an interpretation that the relevant axis of rotation for the selector is also located in this space.
The Term: "notches in the weights cooperate to define a cavity having upwardly open sectors and upwardly closed sectors" (Claims 9 & 11)
Context and Importance: This term is critical for Claims 9 and 11. Plaintiffs contend their products, which use a "central hole with narrower opening groove" or "clamping slots," do not have the claimed "notches" that define a cavity with distinct open and closed sectors (Compl. ¶¶ 45, 51).
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party could argue that any opening that allows selective engagement could be considered a "notch" in a general sense.
- Evidence for a Narrower Interpretation: The specification explicitly shows and describes "upwardly open notch 183" and "upwardly closed notch 184" in weight plate 180 (FIG. 8) and similarly for plate 190 (FIG. 9). The description of four distinct sectors (A-D) through which the selector plate rotates further suggests a specific geometric arrangement is contemplated (’983 Patent, col. 4:66-col. 5:2; FIG. 2).
VI. Other Allegations
- Indirect Infringement: The complaint does not provide sufficient detail for analysis of indirect infringement, as its purpose is to seek a declaration of non-infringement. It makes a conclusory statement that no claims are infringed "either directly or indirectly" (Compl. ¶57).
- Willful Infringement: The complaint does not contain allegations that Plaintiffs (the accused infringers) acted willfully. Instead, it includes a count for "Damages to Plaintiffs Caused by Defendant's Fraudulent Reports of Patent Infringement," alleging that Defendant's actions in reporting infringement to e-commerce platforms were malicious and intended to eliminate competition (Compl. ¶¶ 61-63).
VII. Analyst’s Conclusion: Key Questions for the Case
This declaratory judgment action appears to center on fundamental disagreements over claim scope and the operation of the accused devices. The key questions for the court will likely be:
- A core issue will be one of claim construction: Can the phrase "rotation about an axis extending lengthwise between adjacent said weights" from Claim 1 be interpreted to cover a mechanism where the handle's rotation actuates a non-rotating component (like a slider or protrusion) that moves axially through the center of a weight plate?
- A second key issue will be structural interpretation: Do the "central hole" and "clamping slots" of the accused products meet the claim limitation of "notches...cooperat[ing] to define a cavity having upwardly open sectors and upwardly closed sectors," or is the claimed structure fundamentally different from the engagement mechanisms in Plaintiffs' dumbbells?
- A final determinative question will be one of functional difference: Does the disclosed invention, which relies on a single selector plate rotating within a common cavity formed by multiple weights, read on the accused products, which allegedly use separate engagement features (sliders or protrusions) for each weight plate?