Jib crane for farm use - has jib derricking on support which derricks on slewing platform with ring mounted on top of e.g. silo

摘要

The jib crane is for use on farms, having a slewing ring inside a building for a jib equipped with a grab etc. at the free end. The jib (12) derricks on a support (10), in turn derricking at the other end on a platform (6) mounted on the slewing ring. The support is coupled to the jib in the rear third of the length of the latter. The angle (L) between centre lines and support in the retracted position is less than 90 deg., and the jib angle is controlled by a tie bar (17) coupled to its rear end, and whose other end works in a curved track (20) on the platform, and which can be shaped to suit the shape and angle of the roof.