Patent ID: 8235230

Claim:
Method for motorized control of a slewing movement of a rotary upper part of a tower crane, the rotary part comprising a jib and a counterjib, the rotary part being associated with an electric slewing mechanism comprising at least one geared electric motor unit with an electric motor and reduction gearbox, the method comprising: powering the electric motor electrically in such a way as to produce a slewing torque transmitted to the rotary part of the crane, the slewing torque having a first torque value corresponding to a first period of use and a second torque value corresponding to a second period of use, wherein the first torque value is a maximum amount of the slewing torque transmitted to the rotary part of the crane during the first period; wherein the second torque value is a maximum amount of the slewing torque transmitted to the rotary part of the crane during the second period; wherein the first period of use is a time period in which a windspeed is less than or equal to a given value; wherein the second period of use is a time period in which a windspeed is greater than the given value, and wherein the second torque value is greater than the first torque value.