| 摘要 |
PROBLEM TO BE SOLVED: To provide a tightening nut for a framework, which makes a flange piece engaged and locked into a framework material by cutting the framework material in a short period of time, and which enables the smooth performance of the operation of tightening the framework material. SOLUTION: The circular flange piece 4 for being locked to the framework material undergoing the insertion of a bolt 2 for the framework is provided on the one side of a main tubular body 1 in which a female screw 3 to be screwed to the bolt 2 is formed. The backside of the flange piece 4 is composed of an inside curved surface 4'a which gradually gets close to a surface 4" of the flange piece 4 toward a peripheral end from the side of the main tubular body 1, and an outside inclined surface 4'b which continues from the inside curved surface 4'a. Additionally, inner and outer cutting blades 5 and 6 for cutting the framework material 7 are provided in the inside and outside curved surface 4'a and 4'b in such a manner as to be arranged alternately in a circumferential direction, respectively. The respective cutting blades 5 and 6 are provided in such an inclined manner that the other-side ends 5" and 6" on the peripheral end-side of the flange piece 4 are positioned in the rear in the direction of screwing the female screw 3 to the bolt 2, with respect to the one-side ends 5' and 6' on the side of the main tubular body 1. COPYRIGHT: (C)2009,JPO&INPIT
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