- All sections
- E - Fixed constructions
- E21D - Shaftstunnelsgallerieslarge underground chambers
- E21D 9/14 - Layout of tunnels or galleriesConstructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
Patent holdings for IPC class E21D 9/14
Total number of patents in this class: 75
10-year publication summary
|
2
|
2
|
4
|
6
|
2
|
9
|
7
|
7
|
8
|
4
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Changjiang Survey Planning Design and Research Co., Ltd. | 12 |
4 |
| Electricwaze LLC | 13 |
4 |
| Komatsu Ltd. | 4576 |
3 |
| Beijing Zhongkuang Innovation Alliance Energy Environment Science Academy | 5 |
3 |
| China University of Mining and Technology | 1266 |
2 |
| Electricite de France | 736 |
2 |
| Jack Kennedy Metal Products & Buildings, Inc. | 34 |
2 |
| Korea Railroad Research Institute | 177 |
2 |
| Shandong University | 1054 |
2 |
| China Railway 14th Bureau Group Co., Ltd. | 14 |
2 |
| Acciona Infraestructuras, S.A. | 13 |
1 |
| China University of Mining and Technology, Beijing | 95 |
1 |
| ESPROS Photonics AG | 30 |
1 |
| FCC Construccion S.A. | 7 |
1 |
| Hazemag & EPR GmbH | 23 |
1 |
| Line-x LLC | 47 |
1 |
| Metro de Madrid, S.A. | 9 |
1 |
| Ocean University of China | 193 |
1 |
| Politecnico di Torino | 363 |
1 |
| Queen's University at Kingston | 538 |
1 |
| Other owners | 39 |