Title:
SCREW FASTENER
Document Type and Number:
Japanese Patent JP2020204343
Kind Code:
A
Abstract:
To provide a screw fastener that is hard to loosen as compared with conventional screws, and rich in flexibility.SOLUTION: A pair of recessed grooves 8a, 8b along a spiral line are formed in parallel between a mountain-side part and a valley-side part of a pressure-side flank 7 of a fastening bolt 1, and the part between the pair of recessed grooves 8a, 8b are in a flat shape. With this constitution, pressure-side flanks 7, 14 of a male screw 4 and a female screw 13 are not in contact with each other at sites of the recessed grooves 8a, 8b in a fastened state, so that the stress concentrating on the sites is dispersed to equally load flat parts 9a, 9b other than the recessed groove parts 8a, 8b. Consequently, screw threads become hard to plastically deform and harder to loosen than the conventional constitution.SELECTED DRAWING: Figure 4
Inventors:
TERAO TAKAHIRO
Application Number:
JP2019111240A
Publication Date:
December 24, 2020
Filing Date:
June 14, 2019
Export Citation:
Assignee:
TERAO KIKAI KK
International Classes:
F16B39/30
Attorney, Agent or Firm:
Yasutoshi Iwata
Kitao Matsuura
Yu Yamamoto
Kitao Matsuura
Yu Yamamoto