METHOD AND DEVICE FOR MANUFACTURING BOLT, SCREW ROLLING DIE USED THEREFOR, AND MULTIPLE SCREW BOLT

Title:

METHOD AND DEVICE FOR MANUFACTURING BOLT, SCREW ROLLING DIE USED THEREFOR, AND MULTIPLE SCREW BOLT

Document Type and Number:

WIPO Patent Application WO/2004/085093

Kind Code:

A1

Abstract:

A method and a device for manufacturing bolts capable of mass-producing multiple screw bolts such as double screw bolts at low cost and a screw rolling die used therefor, the bolt manufacturing device comprising a pair of screw rolling dies (1) disposed opposite to each other at a specified interval and bolt supporting parts (2) supporting a cylindrical bolt material (3) at specified positions. The screw rolling dies (1) further comprise transfer patterns (4) having coarse screw thread ridge parts (5) as a part of the coarse screw threads formed by expanding a coarse screw and projections (6) as a part of fine screw threads (6a) cyclically formed at the thread root parts (5a) of the coarse screw threads according to the phase shift of the fine screw threads (6a) shown by imaginary lines formed by expanding a fine screw from the coarse screw threads.

Inventors:

TAKEMASU TERUIE (JP)
MIYAHARA HIROSHI (JP)

Application Number:

PCT/JP2004/003788

Publication Date:

October 07, 2004

Filing Date:

March 19, 2004

Export Citation:

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Assignee:

KYUSHU TLO CO LTD (JP)
TAKEMASU TERUIE (JP)
MIYAHARA HIROSHI (JP)

International Classes:

B21H3/02; B21H3/04; B21H3/06; (IPC1-7): B21H3/02; B21H3/04; B21H3/06

Foreign References:

JP2003260532A	2003-09-16
JP2003232326A	2003-08-22

Other References: