DCT
8:25-cv-00450
Plenums Of Florida Inc v. VIB ISO LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Plenums of Florida Inc. (Florida)
- Defendant: VIB-ISO, LLC (Ohio) and James Pooler (Ohio)
- Plaintiff’s Counsel: Carlson IP Law, LLC
- Case Identification: 8:25-cv-00450, M.D. Fla., 02/21/2025
- Venue Allegations: Plaintiff Plenums alleges venue is proper in the Middle District of Florida because the harm, stemming from patent enforcement activities directed at a Florida resident, occurred in the district.
- Core Dispute: Plaintiff seeks a declaratory judgment that its vibration isolation rails do not infringe the Defendant’s patent and/or that the patent is invalid, following receipt of a cease-and-desist letter.
- Technical Context: The technology concerns vibration absorption systems, specifically mounting rails or curbs used to isolate large rooftop HVAC units from building structures to reduce noise and vibration.
- Key Procedural History: The parties had a prior business relationship where Plaintiff purchased products from Defendant. After Plaintiff began manufacturing its own products, a dispute arose, leading to Plaintiff signing an NDA in November 2024. Defendant sent a cease-and-desist letter on February 5, 2025, alleging patent infringement and demanding payment, which prompted this declaratory judgment action.
Case Timeline
| Date | Event |
|---|---|
| 2011-10-10 | ’901 Patent Priority Date |
| 2015-05-12 | ’901 Patent Issue Date |
| 2020-01-01 | Plenums began manufacturing its own vibration isolation rails (approximate start date) |
| 2024-11-01 | A Plenums project experienced issues with its rails (approximate start date) |
| 2024-11-20 | Plenums executed the "2024 NDA" with VIB |
| 2024-12-17 | Plenums requested additional information from VIB |
| 2025-01-17 | Plenums ceased production and sale of its accused vibration isolation rails (on or before this date) |
| 2025-02-05 | VIB's counsel sent a cease-and-desist letter to Plenums |
| 2025-02-10 | Plenums responded to the cease-and-desist letter |
| 2025-02-14 | VIB responded to Plenums, alleging willful infringement |
| 2025-02-21 | Complaint for Declaratory Judgment filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,027,901 - "Rooftop Air Conditioning Vibration Absorption System", issued May 12, 2015
The Invention Explained
- Problem Addressed: The patent seeks to improve upon prior art HVAC mounting systems that, while modular, required significant on-site assembly, such as bolting sections together before they could function as intended (’901 Patent, col. 1:19-29). This on-site work could be inefficient.
- The Patented Solution: The invention is a pre-packaged, modular vibration absorption system designed to be delivered to a work site ready for installation with minimal assembly (’901 Patent, col. 2:1-6). It consists of an upper rail to support the HVAC unit and a lower rail to mount on the roof, separated by biasing devices (e.g., springs). A key feature is a fastener assembly with an adjustable nut that allows for pre-loading and varying the compression of the springs to tune the system's stiffness (’901 Patent, Abstract; Fig. 2).
- Technical Importance: This approach aims to simplify and speed up the installation of large HVAC units by "obviating some installation steps required of these prior systems" (’901 Patent, col. 2:4-6).
Key Claims at a Glance
- The complaint identifies independent claims 1 and 10 as being at issue (Compl. ¶27).
- Independent Claim 1 requires:
- an upper rail and a lower rail
- at least one biasing device between the rails
- a fastener with a head interconnecting the rails
- a "restraint stiffener" that encircles the fastener, is clamped to the lower rail with a first nut, and is capable of reducing the fastener's bending moment
- a "second nut releasably engaged with said fastener," which is "adjustably positionable" to vary the compression of the biasing device
- Independent Claim 10 is similar to claim 1, but adds more specific geometric details about the rails, describing the upper rail as forming a "channel" and the lower rail as forming a "corner cross-section" (’901 Patent, col. 6:4-15).
- The complaint does not mention any dependent claims.
III. The Accused Instrumentality
Product Identification
The accused products are "Plenums' vibration isolation rails and curbs" (Compl. ¶23).
Functionality and Market Context
The complaint states that Plenums began making its own vibration isolation rails after 2020, following a period of purchasing similar rails from Defendant VIB (Compl. ¶11, ¶14). These rails are used to "dampen the sound that comes from the vibration that occurs while HVAC units are in use" (Compl. ¶11). A photograph of the Plenums vibration isolation rail is included in the complaint. (Compl. p. 5). Plenums alleges it ceased production and sale of these specific rails prior to January 17, 2025 (Compl. ¶22).
IV. Analysis of Infringement Allegations
This is a declaratory judgment action where the Plaintiff, Plenums, is alleging non-infringement. The "allegations" below reflect Plenums' contentions that its products lack key elements of the asserted patent claims.
’901 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a restraint stiffener that encircles said fastener and which is clamped to said lower rail with a first nut, wherein said restraint stiffener is positioned such that said first portion of said lower rail is pressed... | Plenums alleges that its accused product does not contain a "restraint stiffener." (Compl. ¶27). The complaint reproduces a side-by-side visual comparison from the cease-and-desist letter which purports to show the products are identical. (Compl. ¶25, p. 7). Plenums counters that this visual comparison is insufficient for a utility patent infringement analysis (Compl. ¶26). | ¶27 | col. 5:8-14 |
| a second nut releasably engaged with said fastener... said second nut adjustably positionable along a length of said fastener wherein adjustment of said second nut... varies an extent of compression of said at least one biasing device. | Plenums alleges its product lacks a "second nut releasably engaged with [a] fastener," with "said second nut adjustably positionable." (Compl. ¶27). The complaint includes a close-up photo of the VIB product, which allegedly incorporates the patented features. (Compl. p. 4). Another photo shows the accused Plenums product, allowing for a visual comparison of the fastener mechanisms. (Compl. p. 5). | ¶27 | col. 5:15-21 |
Identified Points of Contention
- Technical Questions: A primary issue is factual and technical: does the Plenums product, as manufactured between 2020 and 2025, actually incorporate the "restraint stiffener" and "adjustably positionable" second nut structures as defined in the patent? The complaint explicitly denies the presence of these elements (Compl. ¶27).
- Scope Questions: The dispute may turn on the interpretation of what constitutes a "restraint stiffener." The patent provides a specific functional definition—"capable of reducing the fastener's bending moment"—and structural context, which will likely be central to claim construction and the infringement analysis (’901 Patent, col. 5:13-14).
- Evidentiary Questions: The complaint highlights a potential evidentiary conflict by contrasting VIB's alleged reliance on a high-level "identical" visual comparison with the element-by-element analysis required for utility patent infringement (Compl. ¶25-26). The case may question what level of evidence is sufficient to create a justiciable controversy and support an infringement claim.
V. Key Claim Terms for Construction
"restraint stiffener"
Context and Importance: This term is a specific structural element that Plenums expressly alleges is absent from its product (Compl. ¶27). The definition of this term will be dispositive for the infringement analysis of both independent claims 1 and 10. Practitioners may focus on this term because its presence or absence appears to be a bright-line factual dispute.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint does not provide sufficient detail for analysis of arguments for a broader interpretation.
- Evidence for a Narrower Interpretation: The patent specification describes the stiffener in detail, stating it "encircles the fastener 48," can be "clamped to the lower rail 34 with a nut 76," and that horizontal movement "is resisted by the fastener 48 and restraint stiffener 74" (’901 Patent, col. 4:20-27). Claim 1 itself defines the term functionally as being "capable of reducing the fastener's bending moment" (’901 Patent, col. 5:13-14). This language may support a narrower construction tied to these specific structural and functional characteristics.
"second nut ... adjustably positionable"
Context and Importance: This is the second element Plenums alleges is missing from its product (Compl. ¶27). Its construction is critical because it relates to the core inventive concept of tuning the system's vibration absorption characteristics.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint does not provide sufficient detail for analysis of arguments for a broader interpretation.
- Evidence for a Narrower Interpretation: The claim language links the adjustability of the nut directly to the function of "varie[s] an extent of compression of the at least one biasing device" (’901 Patent, col. 5:19-21). The specification reinforces this, stating "adjustment of the nut 52 along the length of the fastener 48, by turning the nut 52 relative to the fastener 48, varies an extent of compression" (’901 Patent, col. 3:23-27). This suggests a narrow construction requiring a nut that is specifically designed and used for tuning spring compression.
VI. Other Allegations
Willful Infringement
The complaint states that VIB's February 14, 2025 correspondence alleged willful infringement (Compl. ¶29). Plenums appears to preemptively counter this by noting it "ceased production and sale of its vibration isolation rails" before VIB's first cease-and-desist letter (Compl. ¶22), which may raise questions about the timing and basis of any willfulness claim. Plenums also alleges that VIB failed to mark its products with the patent number, which could limit pre-suit damages under 35 U.S.C. § 287 (Compl. ¶13).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be a factual determination of structure: Does discovery reveal that the accused Plenums product, manufactured from 2020-2025, incorporates the specific "restraint stiffener" and "adjustably positionable...second nut" assemblies as described and claimed in the ’901 patent? The complaint frames this as a clear factual mismatch.
- A key legal question will be one of claim scope: How will the court construe the term "restraint stiffener"? The case will likely depend on whether this term is interpreted narrowly to require the specific structure shown in the patent's embodiment, or more broadly to cover other potential stiffening components.
- The litigation may also raise threshold questions of standing and damages limitation: Plenums raises the question of whether VIB has proper assignment of the patent (Compl. ¶24) and alleges a failure to mark patented products (Compl. ¶13), issues that could affect VIB's ability to enforce the patent or collect pre-suit damages, respectively, should infringement be found.