- All sections
- E - Fixed constructions
- E21F - Safety devices, transport, filling-up, rescue, ventilation, or drainage in or of mines or tunnels
- E21F 1/12 - Devices for automatically opening air doors
Patent holdings for IPC class E21F 1/12
Total number of patents in this class: 4
10-year publication summary
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1
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0
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0
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0
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0
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0
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0
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0
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0
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1
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| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Jack Kennedy Metal Products & Buildings, Inc. | 32 |
2 |
| Evapco, Inc. | 304 |
1 |
| Jack Kennedy Metal Products and Buildings, Inc. | 1 |
1 |
| Other owners | 0 |