| 摘要 |
PURPOSE:To prevent loosening of a bolt-nut device when a timber tightened by the device is dried and contracted by engaging both ends of a coil spring interposed between the two nuts screwed onto a bolt with lateral arms provided to these nuts, thereby allowing the coil spring to retighten the nuts. CONSTITUTION:Nuts 2, 3 provided with respective lateral arms 4 are screwed onto one end of a bolt 1 tightening a timber 10, and a coil spring 5 is interposed between the nuts 2, 3 with a clearance maintained with the outer periphery of the bolt 1. The extension parts 6 of the coil spring 5 are then engaged with coil spring engaging holes 15 provided on the heads of the lateral arms 4. When the tightened timber 10 is dried and contracted, the tortional force of the coil spring 5 automatically turns the nut 2 to prevent loosening of the nut. |
