Facilitated tightening device

A fastening device, comprising:

• (1) a base, comprising
• (a) a bolt-insertion hole whose one portion is a bolt-insertion face, and
• (b) a slope portion whose radius is gradually reduced toward the bolt-insertion face under the condition that it connects with the bolt-insertion hole,
• (2) a running screw, comprising
• (a) a tapered, slide face that slides on said slope portion,
• (b) two lateral faces, and
• (c) an inclined portion that is inclined in the same direction as said slope portion and is formed on an end opposite to the bolt-insertion face, and which slides along said slope portion and is engaged with an inserted bolt, as it moves in its axial direction,
• (3) a pressing member for pressing the running screw downward, toward the bolt-insertion face,
• (4) a cover, on which an engagement portion engageable with the inclined portion of the running screw is formed, in which an insertion hole for inserting said bolt is formed, and which is mounted at the end opposite to the bolt-insertion side of said base,
• (5) a groove for said running screw, which is formed on said base, in which said running screw is slideably inserted, and which supports both of the two lateral faces of the running screw of the inserted running screw so as to prevent said running screw from wobbling in the circumferential direction,
• wherein, when said running screw moves toward said cover due to insertion of a bolt into said base, said engagement portion and said inclined portion become engaged with each other so as to prevent the running screw from slipping in a direction opposite to direction in which the bolt is inserted into said base.