| 摘要 |
A compressible support used to support mine roofs. The compressible support generally includes a male member which adjustably engages a collar and may further include a cap and a wooden base. A post may also be provided. The male member defines ridges and grooves and the collar defines corrugations, each preferably in the form of modified buttress threads, which yield, fracture, or strip when the compressible support is subjected to additional force, decreasing the overall length of the compressible support.
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