摘要 |
<p>PURPOSE:To provide the drum having high durability, which can raise head tension, and also, can execute easily positioning of a tightening bolt to a head tightening nut, and generates no damage with regard to their screw parts. CONSTITUTION:To both ends of a cylindrical barrel main body 11, suspension rings 12, 13 are attached fixedly. These rings 12, 13 are connected by a support 31. Openings 14, 15 of these rings 12, 13 are covered with drum heads 16, 17. By screwing a bolt 22 into a lug nut 23, outside peripheral edges 16A, 17A of the drum heads 16, 17 are inserted and pressed between tightening frames 19, 20 and collars 12A, 13A of the rings 12, 13. The bolt 22 is inserted through an insert-through hole 21 of the tightening frames 19, 20, and on the other hand, the lug nut 23 is fitted loosely into the insert-through hole of the rings 12, 13. At the time of screwing the bolt 22 into the lug nut 23, an automatic aligning function works, and they are screwed exactly.</p> |