- All sections
- E - Fixed constructions
- E21D - Shaftstunnelsgallerieslarge underground chambers
- E21D 9/01 - Methods or apparatus for enlarging or restoring the cross-section of tunnels, e.g. by restoring the floor to its original level
Patent holdings for IPC class E21D 9/01
Total number of patents in this class: 11
10-year publication summary
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1
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2
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0
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0
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0
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1
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1
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1
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0
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2
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| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Komatsu Ltd. | 4703 |
2 |
| Deutsche Bahn AG | 231 |
1 |
| Fuzhou University | 339 |
1 |
| Nanjing University of Aeronautics and Astronautics | 498 |
1 |
| Shenzhen University | 1725 |
1 |
| Sun Yat-sen University | 732 |
1 |
| China Railway Construction Heavy Industry Co., Ltd | 25 |
1 |
| The Third Construction Co., Ltd of China Construction Third Engineering Bureau | 22 |
1 |
| Guangzhou Metro Group Co., Ltd. | 24 |
1 |
| China Construction Third Engineering Bureau Group (Zhejiang) Co., Ltd. | 5 |
1 |
| Other owners | 0 |