ELECTRONIC LIMITER OF WEIGHT-LIFTING CAPACITY

摘要

This invention relates to lifting and transportation machinery, and particularly to electronic load capacity limiters, which are used for switching off crane actuators and prevention of crane overturning if the weight load exceeds the allowed value. Its goal is to extend functionality of the electronic load capacity limiter. The proposed limiter (Fig. 1) consists of five units: a strain-measuring load converter (A1), an electronic control unit (A2), a mass indicator (A3), a control and indication desk (A4), and wind velocity pickup (A5). The electronic control unit (A2) consists of an analogue-to-digital converter (1) and a microprocessor (2) connected to a non-volatile memory device (3) and an actuating unit (4) as well as to a power supply (5).The electric signal generated by strain-measuring converter (A1) is led to analogue-to-digital converter (1). Control of the conversion process, computation of load capacity limiter switching points, calculation of weight with consideration of parameters measured by mass indicator (A3) and wind velocity pickup (A5), and conversion of these parameters into appropriate code are performed by microprocessor (2). The microprocessor also forms a signal for blocking the lifting mechanism by comparison between the measured parameters and the code values, which are stored in the non-volatile memory device (3) if such measured parameters exceed the allowed values. The control and indication desk (4) is provided for input of the initial data. The desk (A4) is used to input the operational values of automatic devices and other parameters of the crane, and to adjust the time delay value for operation of automatic systems in dynamic mode, as well as for the possibility when wind velocity exceeds the allowed value.