DCT
3:25-cv-00622
Radio Systems Corp v. Taizhou Xingyi Technology Co Ltd
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Radio Systems Corporation d/b/a PetSafe Brands (Delaware)
- Defendant: Taizhou Xingyi Technology Co., Ltd. d/b/a PET HAHA (China)
- Plaintiff’s Counsel: Merchant & Gould P.C.
- Case Identification: 3:25-cv-00622, E.D. Tenn., 12/30/2025
- Venue Allegations: Plaintiff alleges venue is proper in any U.S. judicial district because Defendant is not a resident of the United States.
- Core Dispute: Plaintiff alleges that Defendant’s disposable cat litter tray cartridges infringe a utility patent related to self-cleaning litter box systems and a design patent for a litter tray.
- Technical Context: The technology concerns automated self-cleaning cat litter boxes and disposable cartridges, a consumer product category focused on convenience and odor control for pet owners.
- Key Procedural History: The utility patent-in-suit, U.S. Patent No. 7,762,213, was subject to an ex parte reexamination that resulted in amended claims. This history may introduce arguments concerning claim scope and prosecution history estoppel during litigation.
Case Timeline
| Date | Event |
|---|---|
| 2003-09-30 | U.S. Patent No. 7,762,213 Priority Date |
| 2010-07-27 | U.S. Patent No. 7,762,213 Issued |
| 2012-01-17 | U.S. Patent No. 7,762,213 Reexamination Certificate Issued |
| 2016-04-22 | U.S. Patent No. D786,514 Application Filed |
| 2017-05-09 | U.S. Patent No. D786,514 Issued |
| 2025-12-30 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,762,213 - "Self-cleaning litter box"
- Patent Identification: U.S. Patent No. 7,762,213, "Self-cleaning litter box," issued July 27, 2010 (the “’213 Patent”).
The Invention Explained
- Problem Addressed: The patent describes prior art self-cleaning litter boxes as cumbersome, requiring frequent user intervention for cleaning and refilling, and having exposed drive mechanisms susceptible to contamination from litter and waste, leading to unreliability and failure (’213 Patent, col. 2:11-44).
- The Patented Solution: The invention claims a litter cartridge for use in a self-cleaning litter box that simplifies waste management. It features a single, non-compartmentalized tray where a rake moves solid waste from a general "waste receiving area" to a dedicated "waste storage area" at one end of the same tray. This storage area is covered by a hinged lid that is mechanically opened by the litter box system during a cleaning cycle to receive waste and then closed, containing the waste and odor within the disposable cartridge (’213 Patent, Abstract; col. 16:18-45).
- Technical Importance: This approach sought to improve the convenience and reliability of automated litter boxes by integrating waste storage into a simple, disposable cartridge, eliminating the need for separate waste receptacles and protecting the operating mechanism from contamination (’213 Patent, col. 2:46-54).
Key Claims at a Glance
- The complaint asserts independent claim 15 (’213 Patent, as amended by reexamination) (Compl. ¶19).
- The essential elements of asserted claim 15 include:
- A one-piece, generally non-compartmentalized litter cartridge tray with a floor, side wall, and top opening defining a single chamber.
- The tray is compatible with a litter box machine having a moveable rake that combs through litter.
- A waste lid that covers only a portion of the tray, defining a covered waste storage area and an uncovered waste receiving area within the single chamber.
- The waste lid has open and closed positions, where the open position allows the rake to deposit waste into the storage area.
- The waste lid includes a magnetic coupling element that enables the lid to be opened and closed by an external force.
- The complaint focuses its infringement count on this single independent claim (Compl. ¶35).
U.S. Design Patent No. D786,514 - "Reusable litter tray"
- Patent Identification: U.S. Design Patent No. D786514, "Reusable litter tray," issued May 9, 2017 (the “’514 Patent”).
The Invention Explained
- Problem Addressed: Not applicable. Design patents protect ornamental appearance, not functional solutions to technical problems.
- The Patented Solution: The patent claims the specific ornamental design for a litter tray as depicted in its figures (’514 Patent, Figs. 1-8). The design consists of the tray's specific shape, contours, and surface features, which create a distinct visual appearance (Compl. ¶25).
- Technical Importance: Not applicable. The value is in the product's aesthetic design rather than its technical function.
Key Claims at a Glance
- Design patents contain a single claim. The asserted claim is for "The ornamental design for a reusable litter tray, as shown and described" (’514 Patent, Claim).
- The complaint highlights several ornamental features: a rectangular basin with four outer walls, subdivided into two unequal areas by a ridge shorter than the outer walls, where the walls and ridge connect to the bottom surface with concave curves (Compl. ¶27).
III. The Accused Instrumentality
Product Identification
- Defendant’s "Crystal Cat Litter and Disposable Litter Tray" product, sold on Amazon (the "Accused Product") (Compl. ¶17-18).
Functionality and Market Context
- The Accused Product is a disposable cartridge pre-filled with cat litter, designed for use in compatible self-cleaning litter boxes (Compl. ¶18, ¶20a). The complaint alleges it is a one-piece, non-compartmentalized tray with a floor and walls defining a single chamber (Compl. ¶20b). A photograph included in the complaint shows the Accused Product, an empty tray with an integrated, hinged lid at one end (Compl., Image 7, p. 9).
- The product is alleged to have a lid covering a waste storage area, while another portion of the tray serves as a waste receiving area (Compl. ¶20c). Visuals in the complaint depict the Accused Product in operation with a rake that moves through the litter (Compl., Image 6, p. 8). The complaint alleges the Accused Product competes directly with Plaintiff’s own cartridges (Compl. ¶18).
IV. Analysis of Infringement Allegations
’213 Patent Infringement Allegations
| Claim Element (from Independent Claim 15) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a cartridge used with a litter box machine... the litter cartridge comprising a one-piece generally non-compartmentalized tray formed to be compatible with said litter box machine and being removable therefrom, said tray having a floor, at least one side wall and an opening on top to define a single chamber... | The Accused Product is a one-piece litter cartridge for use with a compatible machine. A provided image is annotated to show a "Single chamber with a floor and walls." (Compl., Image 4, p. 7). | ¶20a-b | col. 16:18-24 |
| a waste lid for covering only a portion of said tray defining a covered portion and an uncovered portion within the single chamber, said covered portion defining a waste storage area... said uncovered portion defining a waste receiving area, said waste lid having an open position and a closed position... | The Accused Product has a lid that defines distinct areas. An annotated image identifies a "Waste storage area" (covered by the lid) and a "Waste receiving area" (uncovered). (Compl., Image 6, p. 8). | ¶20c | col. 16:29-35 |
| wherein the open position allows the rake to travel at the constant height above the floor of the tray collecting the waste... wherein the rake is able to move waste and waste mixed with litter from said waste receiving area to said waste storage area... | The complaint includes an image depicting a rake traveling through the litter in the Accused Product to move waste from the receiving area to the storage area. (Compl., Image 6, p. 8). | ¶20c | col. 16:36-42 |
| wherein said waste lid includes a coupling element which enables said waste lid to be opened and closed under the influence of an external force, and wherein said coupling element is magnetic. | The complaint alleges the Accused Product’s lid has a magnetic coupling element. An annotated image highlights features labeled "Metallic coupling elements" on the lid. (Compl., Image 5, p. 8). | ¶20c | col. 16:46-51 |
’514 Patent Infringement Allegations
The complaint alleges that the ornamental design of the Accused Product is "the same or substantially the same" as the design claimed in the ’514 Patent (Compl. ¶24). The legal test for design patent infringement is whether an "ordinary observer," giving the level of attention a typical purchaser would, would be deceived into believing the accused product is the patented design (Compl. ¶28).
The complaint provides a photograph of the Accused Product, which shows a rectangular white plastic tray with an integrated partial lid (Compl., Image 7, p. 9). The complaint alleges specific points of similarity, including the rectangular basin shape, the presence of a short, traversing ridge that subdivides the basin into two unequal parts, and the use of concave curves where the walls meet the floor (Compl. ¶27). To support its infringement theory, the complaint also presents a table of prior art designs that were considered during the ’514 Patent’s prosecution, arguing these designs are visually distinct from the patented design, which may suggest a broader scope of protection for the ’514 Patent’s overall appearance (Compl. ¶29).
Identified Points of Contention
- Scope Questions: For the ’213 Patent, a question may arise regarding the preamble language "A cartridge used with a litter box machine... having a rake." The court may need to determine if this language limits the claim to a combination of the cartridge and the machine, or if the sale of a cartridge intended for such use constitutes direct infringement.
- Technical Questions: A primary technical question for the ’213 Patent infringement analysis may be whether the Accused Product's "Metallic coupling elements" (Compl., Image 5, p. 8) meet the claim limitation "wherein said coupling element is magnetic." The analysis may turn on whether the claim requires the element on the tray itself to be a magnet, or if a magnetically-attractable material (such as steel) that interacts with a magnet on the machine suffices.
V. Key Claim Terms for Construction
- The Term: "said coupling element is magnetic" (from ’213 Patent, claim 15)
- Context and Importance: This term is a specific technical limitation at the end of the independent claim. Infringement may hinge on its interpretation, as the complaint identifies the corresponding feature on the Accused Product as "Metallic" rather than explicitly "magnetic" (Compl., Image 5, p. 8). Practitioners may focus on this term because the distinction between a magnet and a material that is merely magnetically attractive is a potentially dispositive technical and legal issue.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification describes the interaction as occurring between "magnets 207" on the system lid and "magnet material 236" on the tray lid (’213 Patent, col. 16:46-51, col. 18:6-9). One could argue that "magnetic" in the claim should be interpreted consistently with the specification's reference to "magnet material," meaning any material capable of magnetic interaction.
- Evidence for a Narrower Interpretation: The specification draws a distinction between the terms "magnets" and "magnet material" (’213 Patent, col. 16:46-51). An argument could be made that the claim's specific use of the word "magnetic" to describe the element on the waste lid, rather than "magnet material," was a deliberate choice requiring the element to be an actual magnet that generates a magnetic field.
VI. Other Allegations
- Indirect Infringement: The complaint does not plead specific facts to support claims of induced or contributory infringement, such as knowledge or intent to cause infringement by third parties. The infringement counts focus on direct infringement (Compl. ¶34, ¶44).
- Willful Infringement: The complaint includes conclusory allegations that Defendant’s infringement is willful for both the ’213 and ’514 patents (Compl. ¶38, ¶48). However, the complaint does not provide a specific factual basis for these allegations, such as pre-suit knowledge of the patents.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: for the ’213 Patent, can the term "magnetic," as applied to the coupling element on the disposable tray, be construed to cover a magnetically attractive material like steel, or does it strictly require a permanent magnet? The outcome of this claim construction dispute may determine infringement.
- The central question for the ’514 Patent will be one of visual perception: under the "ordinary observer" test, is the overall ornamental appearance of the Accused Product substantially the same as the patented design? This will involve a visual comparison focused on whether alleged similarities in shape and contour are close enough to cause purchaser confusion, especially in light of the dissimilar prior art.
- A third key question will be one of claim interpretation: does infringement of the asserted apparatus claim for a "cartridge" require proof that the Defendant sells the cartridge in combination with an infringing litter box machine, or is the sale of the standalone cartridge, designed for such use, sufficient to prove direct infringement?