| 摘要 |
A reinforcing washer for use in a mine roof bolt assembly comprising a roof bolt having a shaft portion, an embossed bearing plate having a surface which substantially contacts the mine roof, an opposite surface and an aperture through which the roof bolt extends, said washer comprising a rigid member having a first surface shaped to substantially contact and complement the opposite surface of the bearing plate, an opposite surface and an aperture through which the roof bolt extends. Preferably, the shape of the embossed bearing plate and the rigid member is a cup or donut. Most preferably, the washer has a substantially uniform thickness and is manufactured from hardened steel.
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