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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2019/131685
Kind Code:
Provided is a nut in which, by moving the fastening force in bolt-nut fastening toward the open side of the nut and increasing the load sharing among the threads from the third thread on, it is possible to reduce the load on the first engaged thread, which bears the maximum load, and extend the fatigue life of the bolt with respect to crack-axis fracturing. A first embodiment of the nut is configured such that, with regard to the shape of the nut in a longitudinal sectional view, a space having a convex shape on the top is formed concentrically, centering on the thread axis, on the fastening-side nut face. The convex space is a structure in which a convex space is formed as a shape connected by straight lines, curved lines, or a combination of both. By forming said space such that, when L2 is the depth of the convex space from the nut face and L1 is the axial-direction length of the nut from the first root of a complete thread portion to the nut face, said convex space depth L2 is in the range of L1 < L2 ≤ L1 + 5 lengths of the thread pitch, more of the stress on the threads of the nut during fastening is moved to the third thread on toward the open side of the nut and load concentration on the first engaged thread of the nut and the bolt is reduced.

MATSUO, Makoto (18-13 Omorinishi 4-chome, Ota-k, Tokyo 15, 〒1430015, JP)
HAYASHIDA, Tatsuaki (1-24-15, Ushikubo-higashi Tsuduki-ku, Yokohama-sh, Kanagawa 14, 〒2240014, JP)
IWAMOTO, Yoshinao (16-12 Azaminominami 3-chome, Aoba-ku, Yokohama-sh, Kanagawa 12, 〒2250012, JP)
Application Number:
Publication Date:
July 04, 2019
Filing Date:
December 25, 2018
Export Citation:
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MATSUO INDUSTRY CORPORATIONS (18-13, Omorinishi 4-chome Ota-k, Tokyo 15, 〒1430015, JP)
IMOTT INC. (16-12, Azaminominami 3-chome Aoba-ku, Yokohama-sh, Kanagawa 12, 〒2250012, JP)
International Classes:
F16B31/02; F16B33/06; F16B37/00
Foreign References:
Attorney, Agent or Firm:
AOKI, Atsushi et al. (SEIWA PATENT & LAW, Toranomon 37 Mori Bldg. 5-1, Toranomon 3-chome, Minato-k, Tokyo 23, 〒1058423, JP)
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