Internally injected replacement support room-type coal pillar recovery method
US-11313226-B2 · Apr 26, 2022 · US
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Non-telescopic props
Non-telescopic props · Cooperative Patent Classification (CPC)
Building, mining, and civil engineering structures.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | E21D15/02 |
| Official title | Non-telescopic props |
| Display label | Non-telescopic props |
| Total patents | 4 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity appears stable based on the most recent years.
| Year | Patents |
|---|---|
| 2019 | 2 |
| 2020 | 1 |
| 2022 | 1 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Internally injected replacement support room-type coal pillar recovery method
US-2020378255-A1 · Dec 3, 2020 · US
Apparatus and method for pre-loading mechanical constant-resistance single prop
US-10385692-B2 · Aug 20, 2019 · US
Apparatus and method for pre-loading mechanical constant-resistance single prop
US-2019085690-A1 · Mar 21, 2019 · US