SCREW WITH BIT ENGAGING HOLE, COMBINATION OF GROUP OF SCREW WITH BIT ENGAGING HOLE AND DRIVER BIT, AND GEOMETRY SETTING MEANS OF BIT ENGAGING HOLE

• Main Author: OKAMURA YOSUKE
• Format: Patent
• Language: English
• Published: 23.10.2008
• Subjects: BLASTING; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

PROBLEM TO BE SOLVED: To provide a screw with a bit engaging hole having a shape that remarkably extends a punching life for forming steps in wing engaging grooves, in which there is no buckling in fiber flow, and having an excellent biting property. SOLUTION: The screw has a central hole 5 in which the bit engaging hole 4 is formed along a central axis N passing through a central axis of a shaft 1, and a plurality of the wing engaging grooves 6 extending radially from the central hole 5. The groove end wall 7 of the wing engaging groove 6 is formed with an inclined face 71 inclined in a direction approaching the central axis N toward the bottom 51 of the central hole 5, and a parallel part 73 connected to the inclined face 71 via an inclined step 72 and extending toward a head top face 3a. The inclined step 72 is inclined in the direction in which an inner end is deeper than an outer end with respect to an orthogonal line orthogonal to the central axis N. COPYRIGHT: (C)2009,JPO&INPIT