- All sections
- E - Fixed constructions
- E21D - Shafts; tunnels; galleries; large underground chambers
- E21D 5/04 - Lining shafts; Linings therefor with brick, concrete, stone, or similar building materials
Patent holdings for IPC class E21D 5/04
Total number of patents in this class: 24
10-year publication summary
2
|
1
|
1
|
0
|
4
|
1
|
3
|
4
|
0
|
0
|
2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |