- All sections
- E - Fixed constructions
- E21D - Shaftstunnelsgallerieslarge underground chambers
- E21D 9/02 - Driving inclined tunnels or galleries
Patent holdings for IPC class E21D 9/02
Total number of patents in this class: 11
10-year publication summary
|
2
|
0
|
1
|
2
|
0
|
1
|
0
|
0
|
1
|
2
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| China Railway Engineering Equipment Group Co., Ltd. | 46 |
1 |
| Minrail Inc. | 5 |
1 |
| Vermeer Manufacturing Company | 639 |
1 |
| Sigma S.A. | 3 |
1 |
| Chang'an University | 169 |
1 |
| Caldon Mining Pty. Limited | 1 |
1 |
| Hajduk Group Sp. z o.o. | 1 |
1 |
| Shanghai Investigation, Design & Research Institute Co., Ltd. | 35 |
1 |
| China Railway Beijing Engineering Group Co., Ltd | 6 |
1 |
| China Three Gorges Construction Engineering Corporation | 13 |
1 |
| The No. 1 Engineering Co., Ltd of China Railway Beijing Engineering Group | 1 |
1 |
| Other owners | 0 |