US 8627684

US Patent 8627684, titled "Pull roll apparatus and method for controlling glass sheet tension," was granted to Corning Inc.

Summary of US8627684:

• Title: Pull roll apparatus and method for controlling glass sheet tension
• Assignee: Corning Inc.
• Inventors: Michael George Shultz, George Clinton Shay, David John Ulrich, James Gary Anderson, Liam Ruan De Paor, Lewis Kirk Klingensmith, Patrick Aaron Parks
• Filing Date: 2007-10-29
• Issue Date: 2014-01-14
• Abstract: The patent describes a pull roll apparatus and method for controlling both cross-draw tension (across the width) and down-draw tension (along the length) of a glass sheet during manufacturing. In a primary embodiment, the apparatus features a first driven stub roll pair and a second driven stub roll pair, along with a control device (e.g., a PLC). This control device manages these stub roll pairs as the first and second opposing edge portions of the glass sheet are drawn between two vertically downtilted rolls associated with each pair. The apparatus can optionally include a pulling roll assembly or additional sets of driven stub roll pairs located beneath the primary stub roll pairs.

Plain-Language Overview of Independent Claims:

• Independent Claim 1 (Apparatus): This claim describes a physical device, a "pull roll apparatus," designed to control the tension in a glass sheet both across its width (cross-draw) and along its length (down-draw). The apparatus comprises:

  1. A "first stub roll pair" with two vertically downtilted rolls, between which one edge of the glass sheet is drawn.
  2. A "second stub roll pair" with two vertically downtilted rolls, between which the opposite edge of the glass sheet is drawn.
  3. A "control device" (such as a programmable logic controller) that manages the operation of both the first and second stub roll pairs.

• Independent Claim 14 (Method): This claim outlines a manufacturing process for creating a glass sheet, which involves:

  1. Melting raw materials to form a glass sheet.
  2. Transporting the formed glass sheet to a pull roll apparatus.
  3. Utilizing the pull roll apparatus to draw the glass sheet. The pull roll apparatus used in this method functions as described in Claim 1, including the first and second stub roll pairs with their vertically downtilted rolls and the controlling device for managing both cross-draw and down-draw tension.

• Independent Claim 19 (System): This claim describes a complete glass manufacturing setup, referred to as a "glass manufacturing system," which includes:

  1. At least one container (vessel) for melting raw materials to produce molten glass.
  2. A forming tool (isopipe) that receives the molten glass and shapes it into a glass sheet.
  3. A pull roll apparatus that takes the glass sheet from the isopipe and draws it. This pull roll apparatus is configured as described in Claim 1, featuring the first and second stub roll pairs with vertically downtilted rolls and the control device to manage glass sheet tension.

Litigation Status:

The patent US8627684B2 is currently marked as "Active" and expires on 2029-04-17. It is also noted that the "Family has litigation". Specific litigation instances include:

• PTAB case IPR2025-01137 filed (Not Instituted - Procedural) by "Unified Patents PTAB Data".
• US case filed in International Trade Commission, case 337-TA-3795.
• US case filed in International Trade Commission, case 337-TA-1433.
• First worldwide family litigation filed, as tracked by Darts-ip.

As of the current date (April 26, 2026), no additional CAFC 2026 dockets specifically for US8627684 were found beyond what is indicated in the provided Google Patents data, which is already comprehensive regarding litigation history.