| 摘要 |
<p>PURPOSE:To reduce the cost by a method wherein a base arm, an intermediate arm and a front arm are connected through a support rope, a driven roller and driven sheaves, and a working tool is installed to the front arm. CONSTITUTION:As a driving drum 62 is driven clockwise, an intermediate arm 11b is pushed out by operation of a push-out rope 61b that is fixed at its one end to the front end of a base arm 11a and is wound round a driven sheave 64 provided to the bottom end of the intermediate arm 11b. At the same time, the rope 61b is unwound from the drum 62 in a length twice the pushed-out length of the arm 11b, and thereby a front arm 11n is pushed out through a support rope 52 in s length twice the pushed-out length of the arm 11b. As a working tool installed to the front end of the arm 11n lands on the ground, a force acting on the tool is borne with the arm 11a through the arm 11n, the rope 52, a driven roller 51, the arm 11b, the driven sheave 64, the rope 61b and a driven sheave 63.</p> |
