| 摘要 |
The invention relates to a timber crane 1, comprising a column 2 which is rotatable about its vertical axis and to the upper end of which a lifting beam 3, 11 has been connected by means of a joint 12. In lifting cranes of this kind, pressure-medium-driven cylinders have been used to set in motion the extensions 3a, 3b of the lifting beam 3. In the lifting crane according to the invention, the extensions 3a, 3b are extended by gravitational force and retracted with the aid of a flexible pull member 4. <IMAGE> |
