Patent ID: 11414831

Abstract:
A pair of right and left supporting bases (10) provided on a sidewalk (9) of a revolving body (4) and both right and left sides (16) of a movable ladder (12) are connected by trajectory restricting members (22) in a swingable manner. In positions of the left supporting base (10) which are apart from each other, main body base ends (20a and 21a) of first and second hydraulic cylinders (20 and 21) are pivotally supported, and rod tip ends (20b and 21b) of the respective hydraulic cylinders (20 and 21) are pivotally supported in a common position of the left side (16) of the movable ladder (12). By operating the first and second hydraulic cylinders (20 and 21) in directions reverse to each other (extension and retraction), in-common pivotally supported parts (20b and 21b) are moved, thereby switching a position of the movable ladder (12) between an extended position and a retracted position.