2:26-cv-01828
Black Cat Inc v. 4C's Spray Equipment Rental LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Black Cat Inc. d/b/a Panther East (Pennsylvania)
- Defendant: 4C's Spray Equipment Rental, LLC (Pennsylvania)
- Plaintiff's Counsel: Panitch Schwarze Belisario & Nadel LLP
- Case Identification: 2:26-cv-01828, E.D. Pa., 03/20/2026
- Venue Allegations: Venue is asserted as proper in the Eastern District of Pennsylvania because a substantial portion of the Plaintiff's alleged infringement occurs in the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that it does not infringe, and that the Defendant's patents are invalid, unenforceable, and subject to intervening rights, following a patent dispute that included cease-and-desist letters and ex parte reexaminations of the patents-in-suit.
- Technical Context: The patents relate to systems and methods for dispensing two-component adhesives, a technology widely used in the construction and roofing industries for applying materials over large surfaces.
- Key Procedural History: This declaratory judgment action follows a prior dismissed case between the parties. After receiving cease-and-desist letters, Plaintiff initiated litigation, which was stayed and later dismissed pending ex parte reexaminations of both patents-in-suit. The patent owner, 4C's, amended the claims of both patents during reexamination. Plaintiff now alleges that 4C's committed inequitable conduct during the reexaminations by failing to disclose a material prior art reference ("Hammerlund") to the U.S. Patent and Trademark Office. Plaintiff also asserts intervening rights based on the claim amendments made during reexamination.
Case Timeline
| Date | Event |
|---|---|
| 2017-07-19 | Priority Date for '820 and '858 Patents |
| 2023-01-24 | U.S. Patent No. 11,559,820 Issues |
| 2023-03-10 | 4C's sends cease-and-desist letter to Black Cat regarding '820 Patent |
| 2023-03-31 | Black Cat responds to cease-and-desist letter |
| 2024-05-28 | U.S. Patent No. 11,992,858 Issues |
| 2024-08-23 | 4C's sends second cease-and-desist letter regarding both patents |
| 2024-10-16 | Black Cat files original declaratory judgment action (2:24-cv-05494) |
| 2025-04-15 | Black Cat serves Initial Invalidity/Noninfringement Contentions |
| 2025-04-29 | 4C's requests ex parte reexamination of both patents |
| 2025-05-09 | 4C's files motion to stay the original litigation |
| 2025-05-15 | USPTO orders reexamination of both patents |
| 2025-05-16 | Black Cat serves Supplemental Contentions identifying Hammerlund |
| 2025-06-13 | Court orders stipulated dismissal of original litigation |
| 2026-01-12 | USPTO issues Reexamination Certificate for '820 Patent |
| 2026-02-20 | USPTO issues Reexamination Certificate for '858 Patent |
| 2026-03-20 | Black Cat files current Complaint (2:26-cv-1828) |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 11,559,820 - "Adhesive Dispensing System and Method"
The Invention Explained
- Problem Addressed: The patent's background describes two conventional methods for applying two-component adhesives in construction: high-pressure sprays and low-pressure beads ʼ820 Patent, col. 1:44-48 High-pressure systems are expensive and difficult to control, leading to overspray and contamination ʼ820 Patent, col. 1:49-60 Low-pressure bead systems provide poor control over adhesive uniformity and coverage ʼ820 Patent, col. 1:61-2:6 Additionally, mixed adhesives can harden and create blockages in equipment ʼ820 Patent, col. 2:9-12
- The Patented Solution: The invention is a dispensing system that injects pressurized air into the two separate adhesive component fluids before they are combined in a mixing tip ʼ820 Patent, abstract ʼ820 Patent, col. 2:16-22 This "aeration" creates a low-pressure spray that allows for uniform adhesive application without the cost and control issues of high-pressure systems ʼ820 Patent, col. 2:30-44 The pre-mixing aeration is also described as improving the chemical reaction and creating a cured adhesive with a finer, stronger cell structure ʼ820 Patent, col. 6:29-38
- Technical Importance: The technology purports to offer a "best of both worlds" solution, achieving the uniform surface coverage of a spray application with the lower cost and greater control of a bead application, a significant consideration in fields like commercial roofing ʼ820 Patent, col. 2:35-44
Key Claims at a Glance
The complaint challenges the validity and infringement of claims that were amended during an ex parte reexamination, including independent claims 1, 13, and 32 Compl. ¶65 Claim 1 is representative of the core method:
- Providing a first and second adhesive component fluid.
- Providing a dispensing head with two separate head passages.
- Providing a mixing tip where the outlets of the head passages join.
- Flowing the first and second fluids through their respective passages to the mixing tip.
- "aerating" at least one of the fluids upstream of said mixing tip passage outlet.
- mixing the fluids within the mixing tip passage to form an adhesive.
- dispensing the adhesive.
U.S. Patent No. 11,992,858 - "Adhesive Dispensing System and Method"
The Invention Explained
- Problem Addressed: As a continuation of the application leading to the ʼ820 Patent, the ʼ858 Patent addresses the same technical problems: the operational and cost drawbacks of conventional high-pressure spray and low-pressure bead adhesive application systems ʼ858 Patent, col. 1:41-2:4
- The Patented Solution: The ʼ858 Patent discloses the same solution as its parent patent: a system that aerates at least one of the two adhesive components with pressurized air before they are mixed and dispensed ʼ858 Patent, abstract This process is intended to create an improved low-pressure aerated spray, enabling better control and more uniform coverage ʼ858 Patent, col. 2:21-38 The specification similarly describes how this pre-mixing aeration leads to a superior cured adhesive structure ʼ858 Patent, col. 6:20-36
- Technical Importance: The technology aims to provide the construction industry with a more efficient and controllable method for applying two-part adhesives, improving upon existing high- and low-pressure systems ʼ858 Patent, col. 2:5-7
Key Claims at a Glance
The complaint challenges claims amended during reexamination, including independent claims 1, 5, and 10 Compl. ¶97 Claim 5 is a representative method claim:
- Providing a dispensing head with two separate head passages.
- Providing a mixing tip connected to the outlets of the head passages.
- Providing a first and second adhesive component fluid.
- "aerating" at least one of the fluids in its respective head passage or in the mixing tip.
- dispensing the adhesive from the mixing tip.
III. The Accused Instrumentality
Product Identification
The complaint identifies a line of adhesive-dispensing products collectively referred to as the "VEE AIR Products" Compl. ¶13 Ten specific products are enumerated, including various spray guns, applicators, and related kits Compl. ¶18
Functionality and Market Context
The complaint alleges that the VEE AIR Products operate differently from the patented method Compl. ¶59 Compl. ¶91 Specifically, it claims the VEE AIR products aerate the adhesive components only after they have been combined in a mixing chamber Compl. ¶59 This mixing chamber is described as being located between the separate component passages and a subsequent mixing tip, meaning the components begin to mix before aeration and before entering the final tip Compl. ¶59 No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint does not contain claim charts from the Defendant, but it articulates a detailed non-infringement position, which is summarized below for the ʼ820 Patent. The core of the non-infringement argument is a dispute over the timing and location of aeration and mixing. A similar non-infringement argument is made for the ʼ858 Patent Compl. ¶91
The complaint does not provide sufficient detail for analysis of infringement allegations on a claim-by-claim basis beyond the arguments summarized for the independent claims.
Identified Points of Contention
- Scope Questions: The central dispute appears to be one of claim scope. Does the claim limitation "aerating at least one of said first adhesive component fluid or said second adhesive component fluid upstream of said mixing tip passage inlet" require aeration to occur while the two fluids are still in their separate passages? Or can the phrase be read more broadly to cover aeration of the fluids after they have already been combined, so long as that aeration occurs before the combined stream enters the final mixing tip? The complaint advocates for the narrower interpretation Compl. ¶59
- Technical Questions: A related technical question is where "mixing" begins. The complaint alleges that claims of the ʼ820 Patent require mixing to occur "within" the mixing tip passage, whereas the accused VEE AIR products allegedly begin mixing upstream of that passage Compl. ¶59 The court may need to determine the precise technical definitions of the "dispensing head," "mixing chamber," and "mixing tip" as used in the patent versus the accused products.
V. Key Claim Terms for Construction
- The Term: "aerating at least one of said first adhesive component fluid or said second adhesive component fluid upstream of said mixing tip passage inlet" ʼ820 Patent, claim 1
- Context and Importance: This term is central to the non-infringement dispute. Plaintiff's position is that its products do not meet this limitation because they aerate the fluids only after they have been combined, whereas the patent allegedly requires aeration while the fluids are still separate Compl. ¶59 The construction of "upstream" will be critical.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The plain language of the claim requires aeration merely "upstream" of the mixing tip inlet. An argument could be made that any location prior to the inlet-including a chamber where the fluids have already combined-satisfies this spatial requirement.
- Evidence for a Narrower Interpretation: The complaint argues that the patent's specification supports a narrower reading. It alleges the patent "only shows and describes embodiments where air is injected into the separate passages within the dispensing head" Compl. ¶54 The complaint also points to specification language stating that "aeration of the fluids prior to mixing... provides an improved process and product" Compl. ¶54 ʼ820 Patent, col. 2:19-22 ʼ820 Patent, col. 6:21-24, which may suggest that aeration of separate fluids is a key feature of the invention.
VI. Other Allegations
Inequitable Conduct
The complaint makes a significant allegation of inequitable conduct during the ex parte reexaminations of both patents (Compl. ¶69; Compl. ¶70; Compl. ¶71; Compl. ¶72; Compl. ¶73; Compl. ¶74; Compl. ¶75; Compl. ¶76; Compl. ¶77; Compl. ¶78). Plaintiff alleges that it provided Defendant with the "Hammerlund" prior art reference during the prior litigation Compl. ¶71 Compl. ¶103 It further alleges that Defendant and its counsel, despite knowing this reference was material to the patentability of the claims, intentionally withheld it from the USPTO examiner during the reexaminations with an intent to deceive Compl. ¶72 Compl. ¶77 Compl. ¶104 Compl. ¶109 If proven, this could render both patents entirely unenforceable.
Intervening Rights
Plaintiff asserts that it is protected by the doctrine of intervening rights (Compl. ¶63; Compl. ¶64; Compl. ¶65; Compl. ¶66; Compl. ¶67; Compl. ¶68). It argues that the claims of both patents were substantively amended during reexamination and are not "substantially the same as the claims originally issued" Compl. ¶65 Compl. ¶97 If the court agrees, Plaintiff may be shielded from liability for any infringement that occurred before the reexamination certificates were issued.
VII. Analyst's Conclusion: Key Questions for the Case
- A core issue will be one of claim construction: does the term "aerating... upstream of said mixing tip passage inlet," when read in light of a specification that exclusively depicts aeration of separate fluid components, require that aeration must occur before the components are mixed? Or is the term broad enough to cover aeration of a combined fluid stream?
- A critical question will be one of inequitable conduct: can the plaintiff prove by clear and convincing evidence that the defendant and its counsel withheld the Hammerlund reference from the USPTO during reexamination with the specific intent to deceive the patent examiner? The outcome of this inquiry could be case-dispositive.
- A key issue for damages will be intervening rights: were the claims substantively narrowed during reexamination? If so, the plaintiff's potential liability for activities that occurred before the reexamination certificates issued could be extinguished, significantly limiting any potential damages award.