Patent ID: 8955702
Filing Date: 2015-02-17
Classification: B66C

Abstract:
1. A luffing-jib tower crane, comprising: a tower, a jib connected to the tower via a joint, and a luffing cable holding the jib, wherein a drawing-in unit is configured to adjust a length of the luffing cable by winding the luffing cable onto a cable drum of the drawing-in unit or unwinding the luffing cable from the cable drum, wherein an angle of the jib with respect to the horizontal plane is measured by a first sensor attached to the jib, the angle having a first angle value, wherein a measuring device measures a length of an unwound part of the luffing cable so as to calculate a minimum angle of the jib with respect to the horizontal plane based on the length of the unwound part of the luffing cable, the calculated angle having a second angle value, and wherein the measuring device facilitates comparison of the first angle value and the second angle value.