PURPOSE: To provide a bolt pressing-down member by which co-rotation of a bolt can be prevented when a nut is fastened and which can be separated from a bolt head part by extremely easily releasing torque applied through the bolt after fastening is completed.
CONSTITUTION: A bolt pressing-down member is provided with a pressing plate 4 driven so as to vertically movable toward a bolt head part Bh, a socket part 3 connected to the pressing plate so as to be vertically movable toward the bolt head part and to be freely rotatable in the bolt shaft peripheral direction, a first contact block 14 fixedly arranged on the pressing plate and a second contact block 15 which mutually contacts with the first contact block on mutual slant faces 14a and 15a and is fixedly arranged in the socket part. Both slant faces 14a and 15a are opposed to each other so as to come into contact with each other when both slant faces 14a and 15a incline in the mutually separating direction to a perpendicular surface and the socket part is rotated in the nut fastening direction as both blocks vertically separate from each other.
WATANABE TOSHIO
MOCHIZUKI KAZUO
MIZUIDE SHIGEO
IIZUKA KAZUO
KAWASAKI HEAVY IND LTD
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