Multi-stage telescopic arm device and deep digging excavator equipped with multistage telescopic arm device

摘要

An extendable arm (12) comprising an outer cylinder (13) and a plurality of inner cylinders (21, 23) is provided on the distal end side of the boom (4). A telescopic cylinder (25) and a fixed sheave unit for extension (31, 31 ') are provided in the outer cylinder (13). A sheave attachment (30) is attached to the telescopic cylinder (25), and movable sheave units (33, 33 ') for extension and retraction are provided on the sheave attachment (30). An extendable and contractible rope (34) is hung four times between each sheave (31 A, 31 B) of the extendable sheave fixed sheave unit (31) and each sheave (33 A, 33 B) of the expanding and contracting movable sheave unit (33) I turn it. Between each sheave (31 A ', 31 B') of the extendable sheave fixed sheave unit (31 ') and each sheave (33 A', 33 B ') of the expanding and contracting movable sheave unit (33'), 34 ') four times.