Susan McKNIGHT Inc v. United Industries Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Susan McKnight, Inc. (Tennessee)
  • Defendant: United Industries Corporation (Delaware)
  • Plaintiff’s Counsel: Baker, Donelson, Bearman, Caldwell & Berkowitz, PC; McCormick, Paulding & Huber, LLP
• Case Identification: 2:16-cv-2534, W.D. Tenn., 06/30/2016
• Venue Allegations: Venue is alleged to be proper because Defendant has committed acts of infringement in the district, including selling or offering for sale the accused products.
• Core Dispute: Plaintiff alleges that Defendant’s "Hot Shot Bed Bug Interceptor" product infringes a patent related to a mechanical pitfall trap for capturing bed bugs.
• Technical Context: The technology addresses the market need for non-chemical methods to monitor and control bed bug infestations, which have seen a significant resurgence.
• Key Procedural History: The patent-in-suit was the subject of an Inter Partes Review (IPR) proceeding (IPR2017-01686) filed approximately one year after the complaint. The proceeding concluded with a certificate issued on March 30, 2021, cancelling all 17 claims of the patent. The cancellation of all asserted claims is a dispositive event for the litigation.

Case Timeline

Date	Event
2008-05-06	'973 Patent Priority Date
2009-01-01	Plaintiff began selling its patented trap (approximate)
2016-02-09	'973 Patent Issue Date
2016-06-30	Complaint Filing Date
2017-06-30	Inter Partes Review (IPR) Filed
2021-03-30	IPR Certificate Issued; All Claims of '973 Patent Cancelled

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

U.S. Patent No. 9,253,973 - "Crawling Arthropod Intercepting Device and Method"

• Issued: February 9, 2016.

The Invention Explained

• Problem Addressed: The patent describes a resurgence in bed bug infestations, partly due to the insects developing resistance to chemical pesticides (’973 Patent, col. 1:56-64). It notes that bed bugs can climb rough vertical surfaces using their tarsal claws but are unable to climb very smooth surfaces (’973 Patent, col. 2:9-24). This creates a need for effective, non-chemical trapping methods.
• The Patented Solution: The invention is a physical trap, typically a coaster-like device placed under furniture legs, designed to exploit the bed bugs' climbing limitations (’973 Patent, Abstract). The device features an outer wall with a rough, textured surface that bed bugs can easily climb, leading them inward. Inside this outer wall are one or more "pitfall traps" or moats, which are receptacles with smooth, slippery interior walls. Bed bugs that climb the outer wall and fall into a moat, or those that try to leave the furniture and fall into an inner receptacle, are trapped because they cannot gain traction to climb the slippery surfaces (’973 Patent, col. 4:52-67).
• Technical Importance: The device provides a poison-free, reusable tool for both detecting the presence of bed bugs and reducing their numbers by physically intercepting their movement to and from human hosts (’973 Patent, col. 3:38-44).

Key Claims at a Glance

• The complaint asserts independent claims 1 and 16 (Compl. ¶13).
• Independent Claim 1 requires:
  • A bed bug intercepting device for placement under a support leg of furniture.
  • An "upstanding, exterior climbable surface" that bed bugs can climb.
  • "First and second pitfall traps" located inwardly from the climbable surface.
  • The first trap is a "bait-free inner, support-leg receiving receptacle" with a "slippery" peripheral surface to prevent escape.
  • The second trap is a "bait-free outer receptacle" with "slippery" inner and outer peripheral surfaces to prevent escape.
  • The structure traps bed bugs traveling toward the furniture (in the outer receptacle) and away from the furniture (in the inner receptacle).
• Independent Claim 16 is similar but more structurally detailed, requiring:
  • An exterior climbable surface that "slopes upwardly at an angle to vertical."
  • A bait-free inner receptacle and a bait-free outer receptacle.
  • The outer receptacle is formed between an inner peripheral surface (connected to the inner receptacle) and an outer peripheral surface, both of which are "slippery."
  • The upstanding peripheral surfaces of both receptacles "ascend to a common peripheral rim."
• The complaint states infringement of "one or more claims... including at least Claims 1 and 16," which suggests the possibility that other claims may be asserted later (Compl. ¶13).

III. The Accused Instrumentality

Product Identification

• The "Hot Shot Bed Bug Interceptor" (Compl. ¶11).

Functionality and Market Context

• The complaint alleges the product is a "pitfall trap" designed for "intercepting and capturing bed bugs climbing onto and off of the legs of furniture" (Compl. ¶11). It is sold in a box that illustrates and describes its use under furniture legs as a pitfall trap (Compl. ¶12). No further technical details about the product's construction or materials are provided in the complaint.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or provide specific factual allegations mapping elements of the accused product to the patent's claim limitations. The infringement theory is stated in a conclusory manner.

Narrative Infringement Theory

• The complaint alleges that Defendant directly infringes the ’973 Patent by making, using, selling, and offering for sale the "Hot Shot Bed Bug Interceptor" (Compl. ¶17). The basis for this allegation is the product's function as a "pitfall trap" used under furniture legs to capture bed bugs, which Plaintiff contends practices the inventions of at least claims 1 and 16 (Compl. ¶¶ 11-13).

Identified Points of Contention

Given the lack of detail, any dispute would likely center on the fundamental characteristics of the claimed device.

• Scope Questions: A central question would concern the scope of the terms "climbable" and "slippery." Do the surfaces of the accused interceptor possess the distinct tactile properties required by the claims? For instance, does the product's exterior have a "bed bug tarsal claw-engageable surface roughness" as recited in dependent claim 2, and do its interior moats have surfaces that are "slippery to prevent bed bugs from climbing out" as required by claim 1?
• Technical Questions: What evidence demonstrates that the accused product's surfaces meet the functional requirements of the claims? The patent specification provides quantitative metrics for surface roughness (Ra) to distinguish "climbable" (greater than 300 microinches) from "slippery" (about 100 microinches or less) surfaces (’973 Patent, col. 5:26-28, 47-48). The infringement analysis would turn on whether the accused product exhibits a comparable differentiation in surface texture.

V. Key Claim Terms for Construction

The Term: "slippery to prevent bed bugs from climbing out" (Claim 1)

• Context and Importance: This term defines the core trapping mechanism of the invention. Its construction is critical because it determines the standard for what constitutes an effective, infringing pitfall trap surface. Practitioners may focus on this term because infringement hinges on whether the accused product's inner surfaces meet this functional requirement.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language itself is functional, suggesting that any surface which, in practice, prevents a bed bug from climbing out would meet the limitation, regardless of its specific physical properties.
  • Evidence for a Narrower Interpretation: The specification provides specific examples, stating that the slippery surfaces can be made of "polymer, glass, or polished metallic material" and may have a "surface roughness Ra of about 100 microinches or less" (’973 Patent, col. 5:42-48). A party could argue these disclosures limit the scope of "slippery" to surfaces with these specific, measurable characteristics.

The Term: "exterior climbable surface" (Claim 1)

• Context and Importance: This term defines the entry point for bed bugs into the trap. Its scope determines what kinds of external textures on an accused device would be considered infringing.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The plain language suggests that any exterior surface that a bed bug can, in fact, climb would satisfy the limitation.
  • Evidence for a Narrower Interpretation: The specification discloses achieving this property via a "bed bug tarsal claw-engageable surface roughness" with an Ra "greater than about 300 microinches" or by covering the surface with "fabric, sawdust, sandpaper or paper pulp" (’973 Patent, col. 5:26-28; col. 11:49-51). A defendant might argue the term should be construed as being limited to these disclosed methods of creating a rough, climbable texture.

VI. Other Allegations

Willful Infringement

• The complaint alleges that Defendant’s infringement is "knowing and willful" (Compl. ¶19). This allegation is made "upon information and belief" and is not supported by specific factual assertions, such as prior correspondence or knowledge of the patent (Compl. ¶19).

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

1. The Impact of IPR: The primary and dispositive question for this case is the legal effect of the Inter Partes Review, which resulted in the cancellation of all claims of the '973 patent. As IPR cancellation is effective retroactively, a central issue is whether the Plaintiff's case for infringement and damages is rendered entirely moot, including for any alleged infringement that occurred prior to the IPR certificate's issuance.

2. Claim Construction Scope: If the claims were to survive, a core issue would be one of definitional scope: would the terms "climbable" and "slippery" be construed broadly based on their observed function (i.e., whether a bed bug can or cannot scale the surface), or would they be limited more narrowly to the specific surface roughness (Ra) values and materials disclosed in the patent's specification?

3. Evidentiary Proof of Infringement: The case would present a key evidentiary question of technical fact: does the accused "Hot Shot Bed Bug Interceptor" actually have the differentiated surface properties required by the claims? The outcome would depend on factual evidence, likely from competing expert analyses of the product’s material composition and surface topography.