Derivative works — US Patent 8627684

Defensive Disclosure Document for US Patent 8,627,684

This document outlines derivative variations of US Patent 8,627,684, "Pull roll apparatus and method for controlling glass sheet tension," to serve as defensive disclosures. The goal is to generate prior art that renders future incremental improvements by competitors obvious or non-novel, based on the core claims of the patent. This analysis focuses primarily on Independent Claim 1 (Apparatus), with implications for Independent Claim 14 (Method) and Independent Claim 19 (System) where relevant.

Derivatives Based on Independent Claim 1 (Apparatus)

Claim 1: A pull roll apparatus for controlling a cross-draw tension and a down-draw tension of a glass sheet while manufacturing the glass sheet, the pull roll apparatus comprising: a first stub roll pair having two vertically downtilted rolls, wherein a first edge portion of the glass sheet is drawn between the two vertically downtilted rolls associated with the first stub roll pair; a second stub roll pair having two vertically downtilted rolls, wherein an opposing second edge portion of the glass sheet is drawn between the two vertically downtilted rolls associated with the second stub roll pair; and a control device which controls the first stub roll pair and the second stub roll pair.

1. Material & Component Substitution

Derivative 1.1: Ceramic-Coated Rolls with Magnetic Levitation Drives

Enabling Description: The vertically downtilted rolls of the first and second stub roll pairs (450a/b, 452a/b) are constructed with a high-purity alumina (Al₂O₃) or silicon carbide (SiC) ceramic core, plasma-coated with a wear-resistant, low-friction composite layer (e.g., tungsten carbide-cobalt). Instead of conventional servo motors and gearboxes, each roll (450a, 450b, 452a, 452b) is independently driven by a three-axis active magnetic levitation system, eliminating physical bearings and contact friction. The magnetic actuators provide both rotational torque and precise non-contact positioning for downtilt and splay adjustments. Roll gap sensing is achieved via eddy current displacement sensors providing feedback to the control device (446) for maintaining a precise non-contact nip force. This arrangement reduces particulate contamination, enables higher operating temperatures, and improves responsiveness and precision of tension control by decoupling mechanical linkages.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446] --> B(Magnetic Levitation Drive 454a)
    A --> C(Magnetic Levitation Drive 454b)
    A --> D(Magnetic Levitation Drive 456a)
    A --> E(Magnetic Levitation Drive 456b)
    B --> F{Ceramic Roll 450a}
    C --> G{Ceramic Roll 450b}
    D --> H{Ceramic Roll 452a}
    E --> I{Ceramic Roll 452b}
    F -- Draws --> J[Glass Sheet Edge 305a]
    G -- Draws --> J
    H -- Draws --> K[Glass Sheet Edge 305b]
    I -- Draws --> K
    J -- Tension Feedback --> A
    K -- Tension Feedback --> A
    Sensors[Eddy Current Displacement Sensors] --> A
    Sensors --> F
    Sensors --> G
    Sensors --> H
    Sensors --> I

Derivative 1.2: Viscoelastic Polymer Roll Coverings with Piezoelectric Actuators

Enabling Description: The vertically downtilted rolls (450a/b, 452a/b) are equipped with a conformable, high-temperature viscoelastic polymer covering (e.g., a silicone-polyimide composite) engineered for optimal grip and minimal marking on the glass sheet. Instead of a single drive for each roll, a series of micro-piezoelectric actuators are embedded circumferentially within the roll structure, allowing for localized and dynamic adjustment of the roll's surface topography and effective diameter. This enables fine-tuning of the contact patch and localized shear forces, enhancing micro-level cross-draw tension control. The downtilt and splay angles are adjusted using precision linear piezoelectric stages, offering sub-micrometer positioning resolution. Force feedback is provided by integrated thin-film piezoelectric load sensors within the roll coverings themselves, reporting to the control device (446).
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446] --> B{Piezoelectric Actuators 450a}
    A --> C{Piezoelectric Actuators 450b}
    A --> D{Piezoelectric Actuators 452a}
    A --> E{Piezoelectric Actuators 452b}
    B -- Modifies Surface --> F[Viscoelastic Roll 450a]
    C -- Modifies Surface --> G[Viscoelastic Roll 450b]
    D -- Modifies Surface --> H[Viscoelastic Roll 452a]
    E -- Modifies Surface --> I[Viscoelastic Roll 452b]
    F -- Draws --> J[Glass Sheet Edge 305a]
    G -- Draws --> J
    H -- Draws --> K[Glass Sheet Edge 305b]
    I -- Draws --> K
    J -- Tension Feedback (Piezo Sensors) --> A
    K -- Tension Feedback (Piezo Sensors) --> A
    L[Piezoelectric Positioning Stages] --> F
    L --> G
    L --> H
    L --> I
    L --> A

Derivative 1.3: Fiber Optic Strain Sensors for Real-time Tension Mapping

Enabling Description: The pull roll apparatus incorporates distributed fiber optic strain sensors (e.g., Fiber Bragg Grating sensors) integrated directly into the core structure of the downtilted rolls (450a/b, 452a/b) and the supporting shafts. These sensors provide a continuous, high-resolution spatial map of the strain exerted by the glass sheet across the contact length of each roll. This real-time strain data is fed into the control device (446), enabling it to calculate and adjust differential torque to individual rolls or localized sections of a roll, thereby optimizing cross-draw and down-draw tension distribution with unprecedented granularity. The traditional load cells (448a) are augmented or replaced by these distributed sensors for superior accuracy and resolution.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446] --> B(Motor Driver 454a)
    A --> C(Motor Driver 454b)
    A --> D(Motor Driver 456a)
    A --> E(Motor Driver 456b)
    B --> F{Downtilted Roll 450a}
    C --> G{Downtilted Roll 450b}
    D --> H{Downtilted Roll 452a}
    E --> I{Downtilted Roll 452b}
    F -- Fiber Optic Strain Sensors --> J[Sensor Data Acquisition]
    G -- Fiber Optic Strain Sensors --> J
    H -- Fiber Optic Strain Sensors --> J
    I -- Fiber Optic Strain Sensors --> J
    J --> A
    F -- Draws --> K[Glass Sheet Edge 305a]
    G -- Draws --> K
    H -- Draws --> L[Glass Sheet Edge 305b]
    I -- Draws --> L

2. Operational Parameter Expansion

Derivative 2.1: Ultra-High-Speed Micro-Sheet Drawing in Partial Vacuum

Enabling Description: The pull roll apparatus is scaled for manufacturing ultra-thin (e.g., <20 µm) glass micro-sheets at significantly increased drawing velocities, up to 100 m/min. The entire drawing zone, including the pull rolls, operates within a partial vacuum (e.g., 10⁻³ Torr) or inert gas atmosphere to minimize aerodynamic drag, thermal convection effects, and surface oxidation/contamination of the molten glass. The stub rolls (450a/b, 452a/b) feature active internal cooling systems using liquid nitrogen or helium, maintaining precise surface temperatures to prevent glass adhesion and ensure optimal friction characteristics at these high speeds. The control device (446) is enhanced with predictive algorithms to compensate for dynamic pressure differentials and subtle material property variations at accelerated draw rates.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446 with Predictive ML] --> B(High-Speed Motors)
    B --> C{Active Cooled Rolls 450a}
    B --> D{Active Cooled Rolls 450b}
    C --> E[Glass Micro-Sheet Edge]
    D --> E
    F[Vacuum Chamber] -- Encloses --> C
    F -- Encloses --> D
    F -- Encloses --> G{Glass Micro-Sheet}
    G -- Draw Velocity 100m/min --> E
    H[Vacuum Pump/Inert Gas Supply] --> F
    I[Cryogenic Cooling System] --> C
    I --> D

Derivative 2.2: Extreme Temperature Gradient Operation with Zonal Heating/Cooling

Enabling Description: The pull roll apparatus is designed to operate with a substantial temperature gradient across the width of the glass sheet at the roll contact points, where the edge portions (305a, 305b) can be at vastly different temperatures. Each roll (450a, 450b, 452a, 452b) incorporates independent internal zonal heating elements (e.g., induction coils) and cooling channels to precisely control its surface temperature profile. This allows for deliberate manipulation of local glass viscosity and ductility at the pull points. The control device (446) integrates real-time thermal imaging feedback (IR thermography) to adjust individual roll temperatures and subsequently tailor cross-draw tension distribution to manage localized thermal stresses or induce specific material flow for forming non-uniform cross-sections.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446 (Thermal Stress Opt.)] --> B(Zonal Heater/Cooler 450a)
    A --> C(Zonal Heater/Cooler 450b)
    A --> D(Zonal Heater/Cooler 452a)
    A --> E(Zonal Heater/Cooler 452b)
    B --> F{Temp-Controlled Roll 450a}
    C --> G{Temp-Controlled Roll 450b}
    D --> H{Temp-Controlled Roll 452a}
    E --> I{Temp-Controlled Roll 452b}
    F -- Draws & Applies Temp Gradient --> J[Glass Sheet Edge 305a]
    G -- Draws & Applies Temp Gradient --> J
    H -- Draws & Applies Temp Gradient --> K[Glass Sheet Edge 305b]
    I -- Draws & Applies Temp Gradient --> K
    IR[IR Thermography Sensors] --> J
    IR --> K
    IR --> A

Derivative 2.3: Dynamic Oscillatory Splay and Downtilt for Active Flatness Correction

Enabling Description: The pull roll apparatus features high-frequency electromechanical actuators for independently adjusting the splay angle (θ) and downtilt angle (x) of each stub roll pair (442, 444) in a dynamic, oscillatory manner, with frequencies up to 50 Hz. The control device (446) uses real-time laser profilometry (e.g., structured light or scanning interferometry) of the glass sheet's surface downstream from the rolls to detect instantaneous deviations from target flatness. Based on this feedback, the control device (446) actively oscillates the splay and downtilt angles to generate transient cross-draw and down-draw tension pulses that counteract detected warpage, ripple, or other flatness defects in situ, effectively "ironing" the glass sheet as it forms.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446 (Adaptive Flatness Alg.)] --> B(High-Freq. Actuator 442 Splay)
    A --> C(High-Freq. Actuator 442 Downtilt)
    A --> D(High-Freq. Actuator 444 Splay)
    A --> E(High-Freq. Actuator 444 Downtilt)
    B --> F{Stub Roll Pair 442}
    C --> F
    D --> G{Stub Roll Pair 444}
    E --> G
    F -- Applies Oscillatory Tension --> H[Glass Sheet]
    G -- Applies Oscillatory Tension --> H
    I[Laser Profilometer] -- Detects Flatness Deviations --> H
    H -- Real-time Feedback --> I
    I --> A

3. Cross-Domain Application

Derivative 3.1: Tension Control in Technical Textile Production

Enabling Description: The pull roll apparatus is adapted for maintaining precise tension in delicate technical fabrics (e.g., carbon fiber weaves, medical textiles, smart fabrics) during continuous processing, such as coating, lamination, or heat-setting. The stub roll pairs apply controlled cross-draw and down-draw tension to the edges of the fabric web, preventing puckering, wrinkling, or distortion, especially in anisotropic materials. The downtilted rolls compensate for inherent material inconsistencies or variations in web width. The control device uses non-contact optical tension sensors and width measurement systems for feedback, adjusting pneumatic cylinder-driven splay/downtilt mechanisms and individual roll torques to maintain a flat, dimensionally stable fabric.
Applies to: Claim 1 (Apparatus), Claim 14 (Method - "manufacturing a textile web"), Claim 19 (System - "textile manufacturing system").

graph TD
    A[Control Device (Textile Tension)] --> B(Motor 1)
    A --> C(Motor 2)
    B --> D{Stub Roll Pair 1 (Downtilted)}
    C --> E{Stub Roll Pair 2 (Downtilted)}
    D -- Controls Tension --> F[Technical Fabric Web Edge 1]
    E -- Controls Tension --> G[Technical Fabric Web Edge 2]
    F -- Pulls --> H[Technical Fabric Web]
    G -- Pulls --> H
    I[Optical Tension Sensors] --> F
    I --> G
    I --> A
    J[Width Measurement System] --> H
    J --> A

Derivative 3.2: Edge Stress Control in High-Performance Polymer Film Extrusion

Enabling Description: The pull roll apparatus is reconfigured for precisely controlling edge stresses and maintaining uniform width in newly extruded, still-tacky polymer films (e.g., PTFE, PEN, PI films) at elevated temperatures after a die. The first and second stub roll pairs engage the thickened bead edges of the polymer film, which are subject to neck-in and differential cooling. The vertically downtilted rolls, possibly featuring specialized non-stick coatings (e.g., fluoropolymers) and differential temperature control, exert specific cross-draw and down-draw forces to counteract edge effects, minimize residual stresses, and ensure consistent film width and flatness as it cools. The control device integrates laser micrometers for real-time width and thickness measurements, adjusting roll parameters to prevent edge tearing or folding.
Applies to: Claim 1 (Apparatus), Claim 14 (Method - "extruding a polymer film"), Claim 19 (System - "polymer film extrusion system").

graph TD
    A[Control Device (Film Extrusion)] --> B(Motor 1)
    A --> C(Motor 2)
    B --> D{Stub Roll Pair 1 (Downtilted, Coated)}
    C --> E{Stub Roll Pair 2 (Downtilted, Coated)}
    D -- Applies Force to Edge Bead --> F[Polymer Film Edge 1]
    E -- Applies Force to Edge Bead --> G[Polymer Film Edge 2]
    F -- Draws --> H[Extruded Polymer Film]
    G -- Draws --> H
    I[Laser Micrometer (Width/Thickness)] --> H
    I --> A
    J[Die Exit] --> H
    K[Temperature Control System] --> D
    K --> E
    K --> A

Derivative 3.3: Thin Metal Foil Drawing and Annealing

Enabling Description: The pull roll apparatus is adapted for managing tension in thin metal foils (e.g., copper, aluminum, stainless steel) during drawing or continuous annealing processes, particularly for foils less than 50 µm thick. The stub roll pairs, constructed from hardened tool steel with precise surface finishes and possibly induction heated to match the foil temperature, engage the edges of the metal ribbon. The vertically downtilted orientation and adjustable splay/downtilt allow the control device to apply precise transverse and longitudinal tension, preventing edge curling, tearing, or buckling during thermal processing or high-speed drawing operations. Load cells and optical inspection systems provide feedback on edge tension and potential defects, enabling dynamic adjustments.
Applies to: Claim 1 (Apparatus), Claim 14 (Method - "drawing a metal foil"), Claim 19 (System - "metal foil processing system").

graph TD
    A[Control Device (Metal Foil Tension)] --> B(Motor 1)
    A --> C(Motor 2)
    B --> D{Stub Roll Pair 1 (Downtilted, Heated)}
    C --> E{Stub Roll Pair 2 (Downtilted, Heated)}
    D -- Engages Edge --> F[Metal Foil Edge 1]
    E -- Engages Edge --> G[Metal Foil Edge 2]
    F -- Draws --> H[Thin Metal Foil]
    G -- Draws --> H
    I[Load Cells / Optical Inspection] --> F
    I --> G
    I --> A
    J[Induction Heating System] --> D
    J --> E
    J --> A

4. Integration with Emerging Technologies

Derivative 4.1: AI-Driven Predictive Tension Optimization with Digital Twin

Enabling Description: The control device (446) is augmented with an embedded Artificial Intelligence (AI) module, specifically a deep reinforcement learning agent. This AI agent continuously processes real-time sensor data (e.g., glass temperature profile, thickness, actual tension values from load cells, downtilt/splay angles, motor torques) from the pull roll apparatus and a downstream optical inspection system (flatness, stress). A high-fidelity "digital twin" of the entire glass forming and drawing process runs in parallel, simulating various control parameter changes. The AI agent, trained on historical data and through continuous interaction with the digital twin, predicts optimal adjustments to downtilt, splay, and roll torques to minimize residual stress and maximize flatness, even in anticipation of process disturbances (e.g., changes in melt viscosity, environmental fluctuations). These optimized parameters are then applied to the stub roll pairs by the control device (446).
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Physical Pull Roll Apparatus] --> B(Sensors: Temp, Thickness, Tension, Flatness)
    B --> C{Control Device 446 (AI Module)}
    C --> A
    C -- Control Commands --> A
    D[Digital Twin (Process Simulation)] --> C
    C -- Simulation Feedback/Training --> D
    C -- Data Logging --> E(Cloud/Historical Data)
    E -- Training Data --> C
    A -- Real-time Data --> D

Derivative 4.2: IoT-Enabled Remote Monitoring and Predictive Maintenance

Enabling Description: The pull roll apparatus incorporates a network of miniaturized, ruggedized IoT sensors (e.g., wireless accelerometers, embedded temperature sensors in rolls, bearing vibration monitors) connected via a low-power wireless protocol (e.g., LoRaWAN, Zigbee) to a local gateway. This gateway securely transmits aggregated sensor data to a cloud-based IoT platform. The platform employs machine learning algorithms to analyze operational parameters, detect anomalies, predict component failures (e.g., roll bearing wear, motor degradation, refractory coating delamination), and trigger alerts for predictive maintenance. This enables remote diagnostics, proactive scheduling of roll changes, and optimization of maintenance intervals, reducing unscheduled downtime and improving overall equipment effectiveness.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Pull Roll Apparatus] --> B(IoT Sensors: Vibration, Temp, Accel.)
    B -- Wireless (LoRaWAN/Zigbee) --> C[IoT Gateway]
    C -- Secure IP --> D[Cloud IoT Platform]
    D --> E(ML for Anomaly Detection)
    D --> F(Predictive Maintenance Dashboard)
    F --> G[Maintenance Team / Operators]
    E -- Alerts --> G
    H[Control Device 446] -- Operational Data --> C

Derivative 4.3: Blockchain-Verified Supply Chain for Roll Materials and Performance Metrics

Enabling Description: Each stub roll (450a/b, 452a/b) and critical component (e.g., motors, sensors, roll coverings) within the pull roll apparatus has a unique digital identity and lineage recorded on a private blockchain network. Supply chain data, including raw material origin, manufacturing process parameters, quality control measurements, and certification details for each component, are immutably logged as transactions. During operation, key performance metrics (e.g., actual roll wear rates, downtilt adjustment history, accumulated run-time, maintenance records) are also recorded to the blockchain, linked to the specific roll's identity. This provides verifiable transparency for component provenance, authenticity, and long-term performance, enhancing traceability, quality assurance, and enabling trusted data sharing with suppliers or regulatory bodies.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Component Manufacturer] --> B(Log Material Cert. to Blockchain)
    B --> C[Blockchain Network]
    C --> D(Supply Chain Participants)
    D --> E[Pull Roll Apparatus Assembly]
    E --> F(Log Assembly & QC to Blockchain)
    F --> C
    G[Control Device 446] -- Operational Metrics --> H(Log Roll Performance to Blockchain)
    H --> C
    I[Maintenance Logs] --> J(Log Service History to Blockchain)
    J --> C
    C -- Immutable Records --> K[Auditors / Quality Assurance]
    C -- Verifiable Data --> L[Optimized Procurement / Lifetime Tracking]

5. The "Inverse" or Failure Mode

Derivative 5.1: Controlled De-tensioning and Gap Widening for Crackout Recovery

Enabling Description: The pull roll apparatus is designed with a rapid-response de-tensioning system. Upon detection of a "crackout" (glass sheet break) by optical sensors or a sudden drop in motor torque, the control device (446) instantly commands the stub roll pairs (442, 444) to: 1) reduce their applied torque to near-zero, effectively de-tensioning the remaining glass sheet in the setting zone, and 2) rapidly increase the gap between the upper and lower rolls of each pair (450a/b, 452a/b) via high-speed pneumatic actuators. This rapid disengagement prevents further propagation of the crack, minimizes damage to the rolls, and creates a wider opening to facilitate quicker and safer re-threading of a new glass ribbon, significantly reducing downtime.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

stateDiagram-v2
    [*] --> Normal_Operation
    Normal_Operation --> Crackout_Detected : Optical/Torque Sensor
    Crackout_Detected --> Rapid_De_Tension : Control Device 446
    Rapid_De_Tension --> Gap_Widening : High-Speed Actuators
    Gap_Widening --> Rolls_Open : Facilitates Re-threading
    Rolls_Open --> Standby_for_Rethread
    Standby_for_Rethread --> Normal_Operation : Sheet Re-threaded & Re-engaged
    Normal_Operation --> Emergency_Stop : Catastrophic Failure
    Rapid_De_Tension --> Emergency_Stop

Derivative 5.2: Low-Power Diagnostic Mode with Simulated Load

Enabling Description: The pull roll apparatus incorporates a "low-power diagnostic mode" for calibration, troubleshooting, and preventative maintenance without engaging a glass sheet. In this mode, the stub roll pairs (442, 444) operate at minimal angular velocity and torque. Each roll is fitted with an internal or external electromagnetic brake/clutch system that can selectively apply a calibrated, simulated drag or resistive load. This allows the control device (446) to test motor responses, verify sensor accuracy, and diagnose electrical or mechanical issues under controlled, light-load conditions, using significantly less energy than full production, and without risking damage to actual glass material.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Control Device 446] --> B(Power Management Unit)
    A -- Selects --> C{Operational Mode}
    C -- Normal Production --> D[High Velocity/Torque]
    C -- Diagnostic Mode --> E[Low-Power/Simulated Load]
    E --> F{Stub Roll Motors}
    E --> G{Sensors}
    F --> H(Rolls 450a/b, 452a/b)
    H -- Engages --> I(Electromagnetic Brakes/Clutches)
    I -- Applies --> J[Simulated Load]
    G -- Feedback --> A
    J -- Load Feedback --> A

Derivative 5.3: Integrated Edge Shredding and Recycling System

Enabling Description: The pull roll apparatus is integrated with a system for immediate processing of the glass sheet's waste edge portions. Instead of simply drawing the waste edges, a set of additional, smaller driven stub rolls (or a modified design of 450a/b, 452a/b) located immediately downstream from the primary tensioning rolls are equipped with hardened, serrated surfaces. These "shredder rolls" actively score and fracture the waste edge portions (e.g., outside the product width 305c, 305d) into cullet. The control device (446) coordinates the speed and gap of these shredder rolls with the main pull rolls to ensure controlled fragmentation without impacting the product region. The resulting cullet is then immediately collected by an integrated pneumatic conveying system for recycling. This reduces manual handling of waste, improves safety, and streamlines the recycling loop.
Applies to: Claim 1 (Apparatus), Claim 14 (Method), Claim 19 (System).

graph TD
    A[Glass Sheet 305 (Product & Waste Edges)] --> B{Primary Pull Roll Pairs 442, 444}
    B -- Draws & Tension Control --> C[Glass Sheet (Post-Tensioning)]
    C -- Waste Edge Portions --> D{Integrated Shredder Rolls}
    D -- Fragmentation --> E[Glass Cullet]
    D -- Coordinated Control --> A
    E --> F[Pneumatic Conveying System]
    F --> G[Cullet Collection/Recycling]
    H[Control Device 446] --> B
    H --> D

Combination Prior Art Scenarios with Open-Source Standards

Here are three scenarios combining the principles of US8627684 with existing open-source standards to enhance defensive publishing.

1. Combination with OPC UA (Open Platform Communications Unified Architecture)

Scenario: A pull roll apparatus (as per Claim 1) is integrated into a factory-wide distributed control system using the OPC UA standard for data exchange. The control device (446), typically a PLC, acts as an OPC UA server, exposing real-time process variables (e.g., individual roll speeds, torques, calculated cross-draw and down-draw tensions 448a, 448b, downtilt and splay angles, roll gap, glass temperature at nip) as OPC UA nodes. Higher-level Manufacturing Execution Systems (MES), Supervisory Control and Data Acquisition (SCADA) systems, or cloud-based data analytics platforms (acting as OPC UA clients) securely access this data for holistic process monitoring, quality control, and long-term historical data analysis. This standardization facilitates interoperability, making it easier for various vendors' equipment and software to communicate with the pull roll system.
Enabling Description: The PLC (446) is configured with an embedded OPC UA server stack, implementing common profiles such as Data Access and Alarms & Conditions. All critical operating parameters, calculated tension values, and diagnostic statuses of the first and second stub roll pairs (442, 444), including individual motor setpoints and actual feedback values, are mapped to OPC UA variables with appropriate data types and access rights. A certificate-based security model, inherent to OPC UA, is employed for secure communication with client applications across the production network. This enables real-time visualization of tension profiles, remote parameter adjustments, and historical data logging to a plant historian, allowing for root cause analysis of flatness or stress defects in the glass sheet 305 in a standardized, vendor-neutral manner.

2. Combination with ROS (Robot Operating System)

Scenario: A glass manufacturing system (as per Claim 19) utilizes the pull roll apparatus (as per Claim 1) in conjunction with robotic manipulators for automated tasks such as crackout recovery or automated roll changeouts. The control device (446) interfaces with a robot controller, both communicating via ROS messages and services. Upon detection of a crackout event (e.g., loss of tension, as described in the "Inverse" derivatives), the pull roll apparatus enters a safe state (e.g., rolls open, motors stopped). The ROS-enabled robot, receiving commands and status updates from the pull roll control system, then executes a pre-programmed sequence for glass sheet re-threading or roll replacement, enhancing automation and reducing manual intervention.
Enabling Description: The control device (446) is equipped with a ROS bridge or directly implements a ROS client library. It publishes relevant state information (e.g., "system_status," "roll_positions," "tension_fault") as ROS topics and exposes services for critical commands (e.g., "open_rolls," "retract_actuators"). A dedicated robot controller, running ROS, subscribes to these topics and invokes services to coordinate its actions. For a crackout event, the pull roll's state transition to "Rolls_Open" triggers the robot to move to a designated re-threading position, extending a specialized gripper or guide mechanism. The robot's vision system (also ROS-integrated) could provide feedback on glass sheet alignment, which is then fed back to the pull roll control for fine-tuning roll engagement.

3. Combination with ANSI/ISA-88 Batch Control Standard

Scenario: The method for manufacturing a glass sheet (as per Claim 14) is implemented within a batch-oriented or semi-continuous production environment, where the pull roll apparatus (as per Claim 1) functions as a "Unit Procedure" or "Operation" within a larger ISA-88 compliant batch process. The control device (446) of the pull roll apparatus adheres to the ISA-88 Physical Model, acting as a "Control Module" that encapsulates the logic for controlling the downtilted rolls, splay, and torque. Higher-level "Procedure" and "Operation" layers (e.g., managed by an MES) dictate the specific tension profiles and drawing sequences needed for different glass product recipes, coordinating the pull roll operation with other upstream (melting, forming) and downstream (scoring, separation) units.
Enabling Description: The control device (446) implements the control logic for the first and second stub roll pairs (442, 444) according to ISA-88 Control Module definitions, exposing a standardized interface (e.g., "StartPull," "StopPull," "SetTensionProfile," "AdjustDowntilt") to its parent "Operation" module. Each specific glass sheet recipe defines a unique "TensionProfile" parameter set, including target cross-draw and down-draw tensions (448a, 448b), downtilt angles, and splay angles, which are passed to the pull roll control module. This modular approach allows for flexible recipe management, simplified scaling of production, and reuse of control code across different glass products or even different pull roll apparatuses within an ISA-88 compliant plant. The pull roll apparatus's response to these recipe parameters, including actual vs. target tension, is reported back to the ISA-88 supervisory layer for batch reporting and exception handling.