To prevent a large nut from dropping and to ensure safety of a worker with a simple and inexpensive way in screwing and unscrewing work of the large nut to be screwed to a large bolt.
An outer thread 16 of a center guide rod 12 is screwed in a threaded hole 104c provided in a lower end face 104a of the large stud bolt 104. When removing a lower nut 108, a nut reception base 14 is lifted near the lower nut 108 by operating a rotating handle 24. Then a tool is mounted to an outer circumference of a rotating tool mounting part 110, and the lower nut 108 is rotated to be lowered. According to the moving speed, the rotating handle 24 is rotated to lower the nut reception base 14. When the lower nut 108 comes off the stud bolt 104, the lower nut 108 is dropped on the reception base 20. When mounting the lower nut 108, an operation in reverse order to an operation when removing the lower nut 108 is performed.
IWASA NORIATSU
KASHIWABARA SHINICHI
SUZUKI TAKASHI
| JPH0787700A | 1995-03-31 | |||
| JPH0685734U | 1994-12-13 | |||
| JPH10184651A | 1998-07-14 | |||
| JPH0221319U | 1990-02-13 | |||
| JP2001009747A | 2001-01-16 |