摘要 |
The crane comprising a fixed arm with a movable counterweight (29) and mounted on a pedestal, at least two movable arms (2, 3, 4) advancing telescopically from the fixed arm (1) and a rope-driving mechanism for driving the movable arms. The rope-driving mechanism of the second and next movable (3, 4) arms constitute a first (11) and a second (12) winding drum, a first (13) and a second (14) rope pulley and four sections (17, 19, 21, 23) of a substantially inextensible driving rope. The winding drums (11, 12) of the rope-driving mechanism of the specific driven movable arm (3) are fastened in swivel fashion to the movable arm (2) preceding in relation to the driven movable arm (3) . The first and the second (14) rope pulleys are fastened to the said preceding movable arm (2) close to its corresponding external and internal ends accordingly. The first section (17) of the driving rope links the first winding drum (11) with arm (1) that precedes the preceding movable arm (2) , while the second section (19) of the driving rope links the first winding drum (11) with the driven movable arm (3) . The third section (21) of the driving rope links the second winding drum (12) with the driven movable arm (3) , with the forth section (23) of the driving rope links the second winding drum (12) with the fixed arm (1) that precedes the preceding movable arm (2). |