TOWER CRANE THREE-MEMBER MAST WITH FOLDING AND UNFOLDING DEVICE Russian patent published in 2002 - IPC

FIELD: tower crane with automatic folding and unfolding device. SUBSTANCE: tower crane mast 5 consists of three members, namely, lower member 6, intermediate mast folding member 7 and upper member 8. Mast lower member 6 is hinge connected by base to slewing chassis 3. Intermediate mast folding member 7 is hinge connected to top of lower member 6. Mast upper member 8 is hinge connected to intermediate member 7. Load-lifting boom 13 of crane installed on top of mast upper member 8 carries mast folding and unfolding device. This device has at least one strut 23, tension member 30 and mechanized drive means 27, 34. Strut is hinge connected to slewing chassis 3 and to intermediate member 7 of mast 5. Tension member 30 is hinge connected to mast intermediate member 7 and to upright 19 installed on load-lifting boom 13. Mechanized drive means can include drive lift 27 hinge connected to slewing chassis 3 and to lower member 6 of mast 6 of mast 5, and crank mechanism 34 installed at level of mast intermediate member 7. EFFECT: possibility of transportation by motor roads in folded state. 7 cl, 6 dwg