Apparatus and method for extending and storing jib of crane

摘要

PCT No. PCT/JP97/01141 Sec. 371 Date Oct. 5, 1998 Sec. 102(e) Date Oct. 5, 1998 PCT Filed Apr. 2, 1997 PCT Pub. No. WO97/37927 PCT Pub. Date Oct. 16, 1997The present invention relates to an apparatus and a method for extending and storing a jib of a crane which make it possible to simplify the operation of changing a wire rope. The apparatus includes an end sheave (23), which is detachably attached to the front lower end of a boom (3); a rotating device, (80) for rotating a rotary bracket (30); and a link (123), which vertically rotatably connects the end sheave (23) and the front upper portion of the boom (3) and positions the end sheave (23) above and in front of the boom (3) when the rotary bracket (30) is rotated in the forward direction of the boom (3).