Patent ID: 7624882

Claim:
A crane comprising: a generally vertical substantially A-shaped support frame comprised of a substantially vertical first leg and a second leg located at an angle with the first leg, an upper end of the second leg connected to an upper end of the first leg; a rotatable base supporting the support frame; a lifting arm having a lower end hingedly connected to the base at a hinge point, the lifting arm having first and second connection points; a movable displacement member supported by the upper end of the first leg, the displacement member comprising a tie connection device; a tie member connected with a first side to the tie connection device and a second side attached to a tie connection point situated at a horizontal distance from the support frame and at a height near a lower end of the support frame; a first cable guide means carried by the displacement member; first and second pulling devices; a first cable extending from the first connection point on the lifting arm along the first cable guide means to the first pulling device; a second cable guide means attached to an upper end of the support frame; a second cable extending from the second connection point on the lifting arm along the second cable guide means to the second pulling device; and a stop part located on the second leg of the support frame, the stop part situated near the displacement member, wherein, in a load transfer position, the displacement member engages with the stop part for transferring a load on the first cable guide means to the second leg of the frame, and in a tieback position, the displacement member is disengaged from the stop part by the tie member connected with the first side to the tie connection device and the second side attached to the tie connection point at the horizontal distance from the support frame at the height near the lower end of the support frame.