METHOD AND DEVICE FOR AUTOMATICALLY STRETCHING AND STORING A SUB-JIB FOR A CRANE

摘要

The present invention relates to method and device for automatically stretching and storing a sub-jib for a crane which needs fewer man-hours for preparation and less manual work and which enables a sub-jib to be stretched and stored within a short period of time in an easy, secure and safety fashion. To this end, the device comprises a laterally holding device for oscillating a sub-jib (6) in a lateral direction, a rotational bracket portion (30) for separating or connecting the sub-jib from to a top boom (5), first locking device (40) and second locking device (60) for locking the top boom and the rotational bracket portion and a rotating device (50) for rotational bracket portion relative to the boom.