| 摘要 |
PURPOSE:To turn a crawler crane without a turn ring by independently providing crawlers and mounting jack-up devices. CONSTITUTION:A travelling body 1 is so held on axles 2a, 2b, 3a, 3b which radially extend four-way from a center point at approximately the same angle, that the body may be turned in the horizontal direction by crawlers 4a, 4b, 5a, 5b. An upper mechanism 6 is directly mounted on the body 1 without a turn ring. A plurality of jack-up devices 10a, 10b, 10c is mounted thereon. If the directions of the crawlers 4a, 4b, 5a, 5b is changed for making a forward, rear, turn, left or right travel, crawler travelling gears are stopped and the jack-up devices 10a, 10b, 10c are actuated to lift the crawlers from the ground. Under the condition, hydraulic cylinders for turning the crawlers are driven. |
