Title:
TABULAR ROCK BOLT
Document Type and Number:
Japanese Patent JP2019044949
Kind Code:
A
Abstract:
To attain detection of metallic fatigue of a bolt and its stopping against looseness under utilization of a fact that a substantial difference occurs between a force in which the bolt is extended under its metallic fatigue and a force in which the bolt is loosened.SOLUTION: An L-shaped metal 4 stored in a groove 2 arranged to be open at a bolt 1 of this invention along its axis of rotation is taken out in advance. Material 10 is held at the bolt 1 and fastened with a nut 3. The L-shaped metal is inserted at the nut 3. A metallic tip 7 out of a head part 5 is bent with a hammer into such a shape as one in which it may be horizontal in respect to a hexagonal plane. In Fig.3, the metallic extremity end 7 is bent toward an operator's side. This bending action completes its stopping against looseness. The section of the opened groove is less than 5% of the cross section of the opened groove. Then, the bolt showing metallic fatigue therein is slightly elongated by several millimeters to cause the L-shaped metal 4 bent in horizontal in respect to the hexagon plane to be pulled out. An interface with respect to the hexagon plane becomes a fulcrum 8 under a principle of lever to cause the metallic extremity end 7 to be returned widely, resulting in that its metallic fatigue can be visually confirmed and further it can be detected.SELECTED DRAWING: Figure 3
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Inventors:
TADA TSUGUNAGA
Application Number:
JP2017180677A
Publication Date:
March 22, 2019
Filing Date:
September 01, 2017
Export Citation:
Assignee:
TADA TSUGUNAGA
International Classes:
F16B31/00; F16B39/02