| 摘要 |
PROBLEM TO BE SOLVED: To use a jack manually even in such emergency that a power source fails or driving energy is cut off by making a manual handle fittable to a driving force transmission mechanism between the power source and a screw shaft. SOLUTION: An external thread is carved by the sufficient length required for the lift action of a jack from a tip section on the screw shaft 5 of the jack, an annular projection 51 exerting a release stop function when the screw shaft 5 is inserted into a through hole 9b is provided on the other end side, and a square coupling hole 52 coupled and fixed to a manual handle coupling end section H1 having the same square as the square fixed shaft G3 of a connecting gear G3 forming a power transmission mechanism is formed. In such emergency that a power source fails or driving energy is cut off, the connecting gear G3 coupled with the square coupling hole 52 of the screw shaft 5 is extracted, and the square coupling section H1 of a handle H is coupled with the square coupling hole 52 in place of the connecting gear G3, thereby the jack can be manually driven without removing an electric motor M.
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