| 摘要 |
Apparatus and method of setting access covers to grade wherein the apparatus includes rubblizing bits and a vacuum, the first rubblizing bit having a central core with attached carriers for teeth to grind the underlying material into small pieces, a second rubblizing bit to rubblize below the ring of the access, a third bit for trimming a step for a T-lock, and a fourth bit for milling around an access ring for resurfacing and the steps of rubblizing down to the area of the bottom of the ring and sucking out the material by vacuum, settting the height of the ring and cover, trimming a step for a T-lock, and milling around the ring and cover a selected distance.
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