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Patent Searching and Data


Title:
TAPPING SCREW
Document Type and Number:
WIPO Patent Application WO/2013/080327
Kind Code:
A1
Abstract:
[Problem] To provide a tapping screw exhibiting high fastening strength to and resistance to withdrawal from resin moldings. [Solution] For this tapping screw (1), the intersection (P) of the root (10) with the clearance flank (8) of the thread crests (7) is set so that the first percentage of thread engagement (ρ1), which is the percentage of the actual thread engagement height (H1) in a pilot hole (6) with respect to a first thread crest height (H2) from the top of the thread crest (7) to said intersection (P), exceeds 50%. The intersection (Q) of the root (10) with the pressure flank (9) of the thread crests (7) is set so that the second percentage of thread engagement (ρ2), which is the percentage of the actual thread engagement height (H1) in a pilot hole (6) with respect to a second thread crest height (H3) from the top of the thread crest (7) to said intersection (Q), is 50% or more and less than the first percentage of thread engagement (ρ1). The roots of the thread crests form a tapered shape that extends from the intersections (P) to the intersections (Q) thus set. By setting the first percentage of thread engagement (ρ1) and the second percentage of thread engagement (ρ2) in this manner, the tapered roots (10) exhibit a high resistance to withdrawal and high fastening strength.

Inventors:
TORII SHINGO (JP)
NISHIMURA NAOKI (JP)
HAMANO SHINICHI (JP)
Application Number:
PCT/JP2011/077649
Publication Date:
June 06, 2013
Filing Date:
November 30, 2011
Export Citation:
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Assignee:
NITTO SEIKO KK (JP)
TORII SHINGO (JP)
NISHIMURA NAOKI (JP)
HAMANO SHINICHI (JP)
International Classes:
F16B25/06; F16B25/04
Foreign References:
JP2000074026A2000-03-07
JP2006336709A2006-12-14
JPS58178514U1983-11-29
JP2010019391A2010-01-28
JPH10103320A1998-04-21
JP2005127398A2005-05-19
JP2006177436A2006-07-06
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Claims: