| 摘要 |
A roof-engaging assembly for a mine roof support having prop or jack means to engage and support the roof-engaging assembly, comprises a rigid part to engage said prop or jack means, and a roof-engaging part positioned over and resiliently urged away from the rigid part. Preferably the rigid part has a roof-engaging face and a relatively stepped or recessed face below the roof-engaging face, the roof-engaging part being positioned over and resiliently urged away from the stepped or recessed face and towards positions above the roof-engaging face of the rigid part.
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