| 摘要 |
PROBLEM TO BE SOLVED: To provide a roof bolt capable of maintaining satisfactory tightening force without scratching overlapped platelike bodies when the platelike bodies are tightened and fixed. SOLUTION: This roof bolt consists of a bolt 1 having a large diameter part (a) at a tip and a washer 2, an enlarged sleeve 3, a collar 4, and a nut 5 which are attached to the bolt 1 in this order. By fixing the nut 5 and rotating the bolt 1, an inner peripheral face of the enlarged sleeve 3 is slidably engaged with an outer peripheral face of the collar 4, thereby tightening and fixing a plurality of platelike bodies A, B arranged between the enlarged sleeve 3 and the nut 5 so as to nip and hold them. A washer 2 is provided between the large diameter part (a) at the tip of the bolt 1 and the enlarged sleeve 3 sot that a bottom face of the enlarged sleeve 3 does not scratch a surface of the plate body B because the rotation of the bolt 1 is not transmitted to the enlarged sleeve 3.
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