DCT
1:03-cv-00185
Habasit Belting LLC v. Rexnord Industries
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Habasit Belting, Incorporated (Delaware)
- Defendant: Rexnord Industries, Inc. and Rexnord Corporation (Delaware)
- Plaintiff’s Counsel: Richards, Layton & Finger
- Case Identification: 1:03-cv-00185, D. Del., 03/06/2003
- Venue Allegations: Venue is based on Defendants' incorporation in Delaware.
- Core Dispute: Plaintiff alleges that Defendant’s modular conveyor belt products infringe patents related to the design of side-flexing, or "radius," conveyor belts.
- Technical Context: The technology involves modular plastic conveyor belts used in industrial applications, such as food processing, which must navigate curved paths without compromising stability or creating safety hazards.
- Key Procedural History: The complaint alleges infringement of U.S. Patents 6,330,941 and 6,523,680. According to the provided patent documents, both patents were subsequently the subject of inter partes reexamination proceedings. A certificate for the '941 patent, issued January 12, 2016, cancelled several claims, including independent claims 1 and 7, which are asserted in this complaint. A certificate for the '680 patent, issued April 30, 2013, cancelled all claims (1-14), including independent claims 1 and 8 asserted here. These post-filing events fundamentally affect the viability of the infringement claims as pleaded.
Case Timeline
| Date | Event |
|---|---|
| 2000-05-25 | Priority Date for '941 Patent |
| 2000-05-25 | Priority Date for '680 Patent |
| 2001-12-18 | '941 Patent Issued |
| 2003-02-25 | '680 Patent Issued |
| 2003-03-06 | Complaint Filing Date |
| 2013-04-30 | Reexamination Certificate Issued for '680 Patent (All Claims Cancelled) |
| 2016-01-12 | Reexamination Certificate Issued for '941 Patent (Asserted Claims Cancelled) |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,330,941 - "Radius Conveyor Belt," issued Dec. 18, 2001
The Invention Explained
- Problem Addressed: The patent describes issues with prior art modular plastic "radius belts," which are designed to travel along curved paths. These problems include a tendency for belts to rise out of their supports on turns, concentration of pulling load on the outer links causing failure, and transverse compression of the modules ('941 Patent, col. 1:40-66).
- The Patented Solution: The invention is a modular belt designed to improve stability and flexibility. Its key feature is an intermediate section with two distinct parts: an upper, transverse stiffening "web" and a lower, "corrugated portion" with a sinusoidal shape ('941 Patent, col. 2:10-22). This two-part structure allows the link ends of adjacent modules to nest together when the belt navigates a curve, permitting the belt to collapse on the inside of the turn and fan out on the outside, while the web provides structural stability ('941 Patent, col. 3:55-60; Fig. 2).
- Technical Importance: This design sought to provide a radius belt that was more resistant to compression and had better engagement with the drive sprocket, addressing common failure modes in high-speed or tightly tensioned conveyor systems ('941 Patent, col. 2:5-9).
Key Claims at a Glance
- The complaint asserts independent claims 1 (a belt module) and 7 (a radius conveyor belt comprising a plurality of modules).
- Essential elements of independent claim 1 include:
- An intermediate section with opposed first and second walls, comprising a web portion and a corrugated portion.
- The web portion extends partway through the module's thickness.
- The corrugated portion extends the rest of the way and has a sinusoidal shape with regularly spaced ridges and valleys.
- A first and a second plurality of link ends extending from the intermediate section and connected to the ridges of the corrugated portion.
- Transverse openings in the link ends.
- The complaint reserves the right to assert additional claims (Compl. ¶¶ 15, 21).
U.S. Patent No. 6,523,680 - "Radius Conveyor Belt With Structure For The Prevention Of Pinched Fingers," issued Feb. 25, 2003
The Invention Explained
- Problem Addressed: This patent, a continuation-in-part of the application leading to the '941 Patent, addresses a specific safety hazard. In radius belts with a large pitch (the distance between pivot rods), the grid openings created when the belt flexes can be large enough for an operator's fingers to penetrate, potentially leading to injury ('680 Patent, col. 1:46-56).
- The Patented Solution: The invention adds a safety feature to the design of the '941 Patent. It specifies that the central "cross-rib" (analogous to the intermediate section) has a web that is extended in the direction of belt travel. This extension is sized to ensure that even when the belt is at its maximum collapsed state on a curve, the resulting gap between modules is less than 10 mm, which is too small for a finger to enter ('680 Patent, col. 2:61-66; col. 5:6-15; Fig. 9).
- Technical Importance: This design aimed to improve the safety of large-pitch radius belts without sacrificing the necessary collapsibility for navigating turns ('680 Patent, col. 5:26-34).
Key Claims at a Glance
- The complaint asserts independent claims 1 (a radius conveyor belt) and 8 (a conveying system).
- Essential elements of independent claim 1 include:
- A plurality of belt modules with a cross-rib having a web and a corrugated portion.
- Link ends disposed on the modules.
- A pivot rod connecting adjacent modules.
- A functional limitation: "the web on the cross-rib extends in the direction of belt travel such that, when the belt is at its maximum extension..., a space bounded by the web, an outer end of the first link end and the sidewalls of second links ends has a diameter less than 10 mm."
- The complaint reserves the right to assert additional claims (Compl. ¶¶ 15, 21).
III. The Accused Instrumentality
Product Identification
- The complaint accuses radius conveyor belts and belt modules sold by Rexnord, including those under the "Rex® MatTop® Chains" and "Rex 7856" names (Compl. ¶13).
Functionality and Market Context
- The accused products are modular, side-flexing conveyor chains used for applications requiring curved conveyor layouts (Compl., Ex. C, p. 35). The complaint includes a Rexnord product brochure as Exhibit C, which describes the "Rex® Metric 7526/7856 MatTop® Chain with Positrack™ Tracking Guides" (Compl., Ex. C, p. 35). This brochure includes a photograph showing the interlocking modular design of the accused chain (Compl., Ex. C, p. 35). The brochure also provides conveyor layout guidelines, illustrating the product's use in "S" bend configurations, which require the side-flexing capability at the core of the dispute (Compl., Ex. C, p. 36). The complaint alleges that Plaintiff and Defendant are direct competitors in this market (Compl. ¶12).
IV. Analysis of Infringement Allegations
'941 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| an intermediate section having opposed first and second walls... compris[ing] a web portion... and... a corrugated portion... wherein the corrugated portion has a sinusoidal shape comprising a series of regularly spaced ridges and valleys | The accused Rexnord modules allegedly have an intermediate section with a web portion and a corrugated portion with a sinusoidal shape, including regularly spaced ridges and valleys. | ¶15(a) | col. 2:15-22 |
| a first plurality of link ends extending outwardly from the intermediate section including the web portion and being connected to the regularly spaced ridges of the first wall of the corrugated portion | The accused modules allegedly have first link ends that extend from the intermediate section and are connected to the ridges of the corrugated portion. | ¶15(b) | col. 2:23-26 |
| a second plurality of link ends extending outwardly from the intermediate section... in a direction opposite the first link ends | The accused modules allegedly have second link ends extending from the intermediate section opposite the first link ends. | ¶15(c) | col. 2:27-31 |
| transverse openings provided in each of the first and second link ends | The accused modules allegedly have transverse openings in their link ends to receive a pivot rod. | ¶15(d) | col. 2:31-34 |
- Identified Points of Contention:
- Structural Questions: The central dispute will likely concern whether the accused product's structure meets the specific two-part "intermediate section" claimed in the patent. A key question is whether the accused modules contain both a distinct "web portion" and a "corrugated portion" with a "sinusoidal shape" as those terms are defined and illustrated in the patent specification.
- Scope Questions: The analysis may turn on how broadly the term "corrugated portion" is construed. Does any undulating surface for enabling collapse meet this limitation, or must it conform to the specific structure with "essentially parallel walls" described in the '941 Patent's summary of the invention? (col. 2:19-22).
'680 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a plurality of belt modules having... a cross-rib disposed between the first and second link ends and having a web, and a corrugated portion disposed adjacent to the web | The accused Rexnord modules are alleged to have a cross-rib with a web and an adjacent corrugated portion. | ¶21(a) | col. 5:45-49 |
| a pivot rod extending transverse to the direction of belt travel through... openings | The accused belts allegedly use a pivot rod to connect modules. | ¶21(b) | col. 5:63-65 |
| wherein the web on the cross-rib extends in the direction of belt travel such that, when the belt is at its maximum extension..., a space bounded by the web, an outer end of the first link end and the sidewalls of second links ends has a diameter less than 10 mm | The complaint alleges that the web on the cross-rib of the accused modules extends to reduce the gap between adjacent modules to prevent fingers from penetrating the grid. | ¶21(c) | col. 6:5-12 |
- Identified Points of Contention:
- Functional/Dimensional Questions: A primary question is empirical: do the accused products actually meet the dimensional limitation of creating a space with a "diameter less than 10 mm" when fully extended? The complaint alleges this functionality but does not provide measurements or test data.
- Structural Questions: Infringement will depend on whether the accused product achieves this safety feature using the claimed structure—specifically, an "extended web on the cross-rib." The court would need to determine if the accused product's design for reducing the gap is structurally equivalent to the one claimed in the patent.
V. Key Claim Terms for Construction
'941 Patent
- The Term: "corrugated portion"
- Context and Importance: This term is the structural heart of the '941 Patent's claimed invention for enabling side-flexing. Its construction will determine whether a wide range of undulating belt designs infringe or if infringement is limited to designs closely matching the patent's specific embodiment. Practitioners may focus on this term because the allegation of infringement hinges on the accused product having this specific two-part structure (web and corrugated portion).
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself describes the feature by its shape ("sinusoidal shape") and components ("ridges and valleys"), which could be argued to cover various wave-like structures that perform the same function (col. 6:39-41).
- Evidence for a Narrower Interpretation: The summary of the invention describes it more specifically as a "thin, corrugated strip having a pair of essentially parallel walls" ('941 Patent, col. 2:19-21). The detailed description and figures show a very specific alternating ridge and valley structure (Fig. 2; Fig. 5), which could support an interpretation limiting the term to that embodiment.
'680 Patent
- The Term: "a space... has a diameter less than 10 mm"
- Context and Importance: This functional limitation is the key inventive concept of the '680 patent, differentiating it from the prior art by adding a specific safety dimension. The entire infringement case for this patent rests on proving the accused product meets this precise numerical threshold.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent defines "critical opening width or diameter" as "the distance of the opening across its smallest dimension" ('680 Patent, col. 5:12-15). This provides a clear definition but leaves open questions about the measurement conditions (e.g., "maximum extension").
- Evidence for a Narrower Interpretation: Figure 9 explicitly illustrates this concept, showing a 10 mm cylindrical member that cannot fit into the space (200) created by the extended cross-rib ('680 Patent, Fig. 9). A defendant might argue that the claim should be limited to the specific geometry and conditions depicted in that figure.
VI. Other Allegations
- Indirect Infringement: The complaint alleges that Rexnord's acts of making, using, and selling the accused products constitute inducement of and contribution to infringement by others (Compl. ¶¶ 16, 22). The pleading does not, however, provide specific facts detailing how Rexnord's customers are directed to infringe or how the accused products are a material part of the invention with no substantial non-infringing use.
- Willful Infringement: The complaint alleges willful infringement for the '941 Patent, stating that Rexnord "had actual notice" of the patent "at least as of the filing of the original Complaint in this action" (Compl. ¶16). This allegation is based on post-suit knowledge. Willfulness is not explicitly alleged in the count for infringement of the '680 Patent (Count II, ¶¶18-22).
VII. Analyst’s Conclusion: Key Questions for the Case
- Case Viability: The central issue for the court is the legal status of the complaint itself. Given that the inter partes reexamination proceedings subsequent to the filing of this complaint resulted in the cancellation of all asserted claims from both the '941 and '680 patents, a threshold question is whether Plaintiff has any remaining basis for its infringement action as pleaded.
- Structural Equivalence: Assuming the claims were valid, a key technical question would be one of structural definition: do the accused Rexnord modules incorporate the specific two-part "intermediate section" comprising a "web portion" and a "corrugated portion" as required by the '941 Patent, or do they achieve side-flexing through a different, non-infringing structure?
- Dimensional Infringement: For the '680 Patent, the dispute would center on a question of fact and function: does the accused product's design, under conditions of maximum extension, actually create a gap with a "diameter less than 10 mm" as strictly required by the claim? Proving this would require specific evidence and measurement, which is not presented in the complaint.