Patent ID: 7252203
Filing Date: 2007-08-07
Classification: B66C

Abstract:
1. A mobile crane, comprising: a carrier; a superstructure arranged on said carrier such that said superstructure is rotatable about a substantially vertical axis; a boom device for lifting a load, said boom device being articulated at said superstructure and swivelable about a horizontal axis; a counterweight arrangement comprising a counterweight for increasing a lifting capacity of said mobile crane, said counterweight arrangement being connected to said superstructure such that said counterweight is liftable from the ground for allowing said counterweight to follow slewing movements of said superstructure, wherein a slewing radius of said counterweight is adjustable; actuating drive units for rotating said superstructure, adjusting said boom device, and adjusting the slewing radius of said counterweight; a sensor arrangement for determining crane parameters; and an electronic control device having a processor connected to a display and an input device for the mobile crane operator to input data, and a memory device connected to said processor and storing a program, said program including computer-executable instructions for determining an operating field for a display parameter selected from the group of display parameters consisting of load size, load radius, size of said counterweight and slewing radius of said counterweight and displaying the determined operating field on said display, the operating field includes an upper limit and a lower limit defining an adjustable range of the selected display parameter in which said counterweight is safely liftable from the ground while the remaining display parameters remain constant, said program further comprising instructions for determining and displaying actual quantities of the displayed parameters during crane operation using said sensor arrangement.