| 摘要 |
PROBLEM TO BE SOLVED: To provide a jack capable of pressing up an object to be supported through a light operation without damaging the object to be supported and also setting a stroke thereof large, and enabling leveling adjustments to be easily and precisely made.SOLUTION: A jack is so constituted that a first elevation screw lever 3 in a barrel shape provided with an operation head 5 atop is threadably engaged with a male screw part 2 provided to a cylindrical body 1, and a second elevation screw lever 7 which has a smaller pitch than the first elevation screw lever 3 is threadably engaged with a female screw part 6 provided at a center part of the first elevation screw lever 3, and also configured to elevate a support head part 9 of an object to be supported, provided at an upper end of the second elevation screw lever 7, by a difference in pitch as the barrel part 5 is rotated.SELECTED DRAWING: Figure 2 |
