摘要 |
A stack of ferromagnetic sheets is gripped, lifted, and transported by first engaging with an uppermost sheet of the stack a plurality of magnet assemblies of a magnetic grab, each assembly having at least one electromagnet, then electrically energizing the electromagnets and lifting the stack with the grab while monitoring a magnetic flux of each electromagnet. A controller then compares the fluxes of the electromagnets, and varies the electrical energization of at least one of the electromagnets such that the fluxes of all the electromagnets are generally equal. The system has at least one flux sensor on each of the magnet assemblies and connected to the controller. |