DCT

3:14-cv-00866

Tsann Kuen Zhangzhou Enterprises Co Ltd v. Amazon.com Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:14-cv-00866, W.D. Wis., 12/15/2014
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants conduct regular business and have systematic contacts within the Western District of Wisconsin, including offering for sale and selling the accused products within the district.
  • Core Dispute: Plaintiff alleges that the "Chef Buddy 82-1233C Electric Non-Stick Grill," sold by Defendants, infringes a patent related to the design of electric clamshell-style grills.
  • Technical Context: The technology concerns electric countertop grills designed to cook food while simultaneously draining away grease and other liquids into a collection area.
  • Key Procedural History: The complaint notes that Plaintiff is the owner of the patent-in-suit by assignment from the original inventors. No other procedural history is mentioned.

Case Timeline

Date Event
1995-01-11 ’905 Patent Priority Date (Filing Date)
1997-03-04 ’905 Patent Issued
2014-12-15 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

  • Patent Identification: U.S. Patent No. 5,606,905, Device for Cooking Foodstuffs, issued March 4, 1997.

The Invention Explained

  • Problem Addressed: The patent seeks to address the desire to cook food without added fats or oils, to remove grease that emanates from the food during cooking, and to accomplish this without drying out the food, which was a noted disadvantage of conventional broiling ('905 Patent, col. 1:11-18). It also notes the difficulty of grilling small or ground foodstuffs on existing devices ('905 Patent, col. 1:21-24).
  • The Patented Solution: The invention is a clamshell-style cooking device with a lower cooking plate positioned at an angle to the horizontal. This slope causes liquids like grease to drain away from the food into a "downwardly extending portion" of the plate, which can include an opening for collection in a separate tray ('905 Patent, Abstract; col. 4:25-38). The upper and lower plates form a "cooking chamber" that "substantially restrains the escape of vapor," thereby retaining moisture in the food during cooking ('905 Patent, col. 2:53-57).
  • Technical Importance: The design combines the fat-draining benefit of grilling with the moisture-retaining benefit of a closed cooking chamber, addressing a key trade-off in consumer cooking appliances of the era.

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 10 ('905 Patent, col. 6:46-6:65, 7:47-8:13).
  • Independent Claim 1 requires:
    • A first cooking plate positioned at an angle, supporting grilling members.
    • The grilling members have "upwardly curved end portions" at their lower marginal end to retain foodstuffs.
    • A second, movable cooking plate that forms a "cooking chamber which substantially restrains the escape of vapor."
    • A heating element.
    • The first cooking plate includes a "downwardly extending portion for collecting liquid."
  • Independent Claim 10 is similar to Claim 1 but further specifies:
    • The "downwardly extending portion" is "positioned at approximately the lowest point of said first cooking plate, whereby liquid emitted...is directed to the said at least one downwardly extending portion."

III. The Accused Instrumentality

Product Identification

  • The "Chef Buddy 82-1233C Electric Non-Stick Grill" (Compl. ¶20).

Functionality and Market Context

  • The complaint identifies the accused product as an "electric non-stick grill" but provides no specific technical details about its operation, design, or features (Compl. ¶20). No probative visual evidence provided in complaint.
  • The complaint alleges the accused grill is sold and distributed by national retailers Amazon, Home Depot, Wal-Mart, and Sears, suggesting broad commercial availability (Compl. ¶¶ 11-14, 20-23).

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart or detailed infringement allegations. It makes the conclusory assertion that the accused "Chef Buddy 82-1233C Electric Non-Stick Grill contains each of limitations contained within claims 1 and 10 of the ’905 Patent" (Compl. ¶¶ 20-23). Because the complaint does not map specific product features to claim elements, a claim chart summary cannot be constructed.

  • Identified Points of Contention: The lack of detail in the complaint means any potential disputes must be inferred from the claim language itself.
    • Scope Questions: A central question may be the proper construction of "substantially restrains the escape of vapor." The degree of sealing required to be "substantial" will be a likely focus of claim construction.
    • Technical Questions: A key factual question for the court will be whether the accused grill's cooking surface possesses "upwardly curved end portions" that perform the specific function of "retaining" foodstuffs, as required by claim 1. Similarly, for claim 10, a question will be whether the grill's liquid collection area is located at "approximately the lowest point" of the angled cooking plate.

V. Key Claim Terms for Construction

  • The Term: "substantially restrains the escape of vapor" (from claim 1).

  • Context and Importance: This term defines the required performance of the "cooking chamber." Its construction will be critical, as nearly all cooking devices permit some vapor to escape. Practitioners may focus on this term because the degree of sealing in the accused product will be compared against the court's definition of "substantially."

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification states that the design "acts to substantially restrain the vapor within the chamber," which could suggest that the mechanism does not need to be perfectly efficient or create a full seal ('905 Patent, col. 6:9-11).
    • Evidence for a Narrower Interpretation: The patent describes "peripheral rims configured to contact each other in a shingled overlapping configuration to enclose the cooking chamber," which could be argued to require a specific and effective sealing structure, not merely a loose closure ('905 Patent, col. 3:4-8).

  • The Term: "upwardly curved end portions" (from claim 1).

  • Context and Importance: This structural limitation is tied to a specific function: "whereby foodstuffs placed on said grilling members are retained by said upwardly curved end portions" ('905 Patent, col. 6:57-60). The dispute will likely center on whether the accused grill has this structure and, if so, whether it performs the claimed retaining function.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The claim language itself does not specify the degree or angle of the curve, potentially allowing any upward turn at the end of the grilling ridges to meet the limitation.
    • Evidence for a Narrower Interpretation: The specification explicitly states that these portions "prevent foodstuffs from sliding or otherwise moving down and off of inclined grilling members" ('905 Patent, col. 4:17-19). This may support an interpretation that the structure must be pronounced enough to actually achieve this food-retaining function, rather than being merely an incidental or decorative feature.

VI. Other Allegations

  • Indirect Infringement: The complaint includes a boilerplate allegation of contributory and induced infringement but offers no specific facts to support the required elements of knowledge and intent, such as citations to user manuals, advertisements, or other instructional materials (Compl. ¶¶ 20-23).
  • Willful Infringement: The complaint alleges that Defendants' infringement "is and has been willful" (Compl. ¶28). However, it provides no factual basis for this allegation, such as evidence of pre-suit knowledge of the ’905 Patent or its infringement.

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of claim scope: can the term "substantially restrains the escape of vapor," a term of degree, be construed in a way that reads on the seal created by the upper and lower halves of the accused grill? The case may turn on how much vapor escape is permissible under the patent.
  • A key evidentiary question will be one of functional performance: does the physical structure of the accused grill’s cooking surface, particularly any "upwardly curved end portions," actually perform the food-retaining function recited in Claim 1, or is there a fundamental mismatch between the product's design and the patent's functional requirements?