Patent No. EP3909682 (titled "Method And Roller Mill For Thermomechanically Activating A Clay Mixture") was filed by Gebr Pfeiffer on May 14, 2020. The application was issued on Apr 6, 2022.

Patent oppositions filed by competitors challenge the validity of a granted patent. These oppositions are typically based on claims of prior art, lack of novelty, or non-obviousness. They are a key part of the process for determining a patent's strength and enforceability.
| Company | Opposition Date | Representative |
|---|---|---|
| THYSSENKRUPP POLYSIUS | Dec 1, 2022 | TETZNER |
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
Date
Description
Get instant alerts for new documents
Dec 3, 2025
Nov 28, 2025
Nov 28, 2025
Nov 28, 2025
Jul 29, 2025
Jul 24, 2025
Jul 24, 2025
Jul 24, 2025
May 27, 2025
May 27, 2025
May 27, 2025
May 22, 2025
May 22, 2025
May 22, 2025
May 22, 2025
May 22, 2025
May 22, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 27, 2025
Mar 11, 2025
Mar 7, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Feb 28, 2025
Jan 17, 2025
Jan 16, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 10, 2025
Jan 9, 2025
Jan 9, 2025
Jan 9, 2025
Apr 3, 2024
Apr 3, 2024
Apr 3, 2024
Apr 3, 2024
Apr 3, 2024
Apr 3, 2024
Apr 3, 2024
Mar 18, 2024
Mar 15, 2024
Aug 14, 2023
Aug 8, 2023
Aug 8, 2023
Aug 8, 2023
Aug 7, 2023
Aug 7, 2023
Aug 7, 2023
Jun 5, 2023
May 26, 2023
May 26, 2023
May 26, 2023
May 26, 2023
May 26, 2023
Jan 20, 2023
Jan 20, 2023
Dec 8, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Dec 1, 2022
Apr 21, 2022
Mar 11, 2022
Feb 28, 2022
Feb 28, 2022
Feb 28, 2022
Feb 28, 2022
Dec 9, 2021
Dec 9, 2021
Dec 9, 2021
Dec 9, 2021
Dec 9, 2021
Nov 22, 2021
Oct 20, 2021
Oct 18, 2021
Oct 18, 2021
Oct 18, 2021
Oct 18, 2021
Oct 18, 2021
Apr 8, 2021
Apr 8, 2021
Mar 23, 2021
Dec 23, 2020
Dec 23, 2020
Dec 23, 2020
Dec 23, 2020
Dec 23, 2020
Dec 23, 2020
Dec 23, 2020
Oct 15, 2020
Oct 15, 2020
Oct 15, 2020
Oct 15, 2020
Oct 9, 2020
Oct 1, 2020
Jul 7, 2020
Jul 7, 2020
Jul 7, 2020
Jul 7, 2020
May 14, 2020
May 14, 2020
May 14, 2020
May 14, 2020
May 14, 2020
May 14, 2020
May 14, 2020