| 摘要 |
PROBLEM TO BE SOLVED: To provide a jib crane which can use an I-section steel for general use as a new movable side beam even when the movable side beam is damaged. SOLUTION: A rib 18a extending in its longitudinal direction is projected on each face of a movable side beam 18. At least two lifting members 16 having upper and lower rollers 22, 24 for holding the ribs 18a provided on right and left side faces of the movable side beam 18 from upper and lower sides are provided on a base part side beam 14 with the predetermined spacing therebetween. At least one roller 22 (or 24) out of the upper and lower rollers 22, 24 provided on the lifting member 16 is mounted on the other roller 24 (or 22) in an approaching/separating manner. A stopper 26 for regulating the upward movement of the upper roller 22 or the downward movement of the lower roller 24 is mounted on the lifting member 16. COPYRIGHT: (C)2012,JPO&INPIT |
