| 摘要 |
PROBLEM TO BE SOLVED: To provide a conveyance device capable of automatically lowering load when conveyance power failure occurs. SOLUTION: This conveyance device is provided with a hydraulic motor 44 driving an elevating mechanism 41, an electromagnetic selector valve (driving pressure change-over means) 65 for leading driving pressure into either of a first driving passage 63 and a second driving passage 64 selectively, and a boost pressure passage 71 for leading back pressure into the other of the first and second driving passages 63, 64 selectively to perform loading and unloading by lifting and lowering load. This conveyance device is provided with a bypass passage 68 connecting the first and second driving passages 63, 64 mutually, a self-weight lowering valve 69 for opening and closing the bypass passage 68, and an emergency pump 81 for leading back pressure into either of the first and second driving passages 63, 64 through the boost pressure passage 71 to adjust lowering speed of load through the self-weight lowering valve 69. COPYRIGHT: (C)2005,JPO&NCIPI
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