Title: Self-extruding fastener

Abstract: A self-extruding fastener having a head provided with a cross groove, a stem having two screw threads and a tapering portion terminating at a sharp pointed forward end adapted to form a guide opening in a thin sheet of metal. A third screw thread generates in a position midway between said two screw threads and in a portion where the stem ends and the tapering portion begins, and extends to the pointed forward end, while the two screw threads disappear in the tapering portion. Therefore, the self-extruding fastener according to the invention comprises three sections, that is, two screw thread section, three screw thread section and one screw thread section.

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Other info:

Inventors: Shimizu, Mituo (Kyoto, JP)
Miyake, Hidenori (Kyoto, JP)

Application Number: 014919
Filing Date: 1979-02-26
Publication_date: 1980-12-30
Assignee: Kabushiki Kaisha Yamashina Seikosho (JP)
Primary Class(es): 411/386 411/412, 411/413
Other Classes:
US Patent Ref:

1749903	Mar, 1930	Cannon	85/46.
1802668	Apr, 1931	Newton	85/44.
2314391	Mar, 1943	DeVellier	85/46.
3277769	Oct, 1966	Lippmeier	85/44.
3541918	Nov, 1970	Johnson	85/46.
3942405	Mar, 1976	Wagner	85/46.
4027573	Jun, 1977	Laverty	85/46.

Other Refs:
Primary Examiner: Britts, Ramon S.
Assistant Examiner:
Attorney: Swabey; Alan, Mitchell; Robert E., Houle; Guy J.