The rotational permanent magnetic lifters have two magnetic systems, rotational and fixed. The magnetic circuits of rotational permanent magnetic lifters are in the lifting or unloading state by rotating magnetic system.
Here are two kinds of situations about magnetic lifters:
First, by a rotation of system, when the magnetic circuit is on, the magnetic lifters will be part of magnetic circuit, which is the lifting state; when the magnetic circuit of magnetic lifters is off, which is the unloading state.
Second, by a rotation of system, the state will make the magnetic circuit on and the magnetic circuit nestification, which is lifting state; another state will make the magnetic circuit produce reversed magnetic field, which is the unloading state.
When magnetic lifters mounted permanent magnet position vector to Figure 2a, forming a magnetic line of force was lifting steel parts by the main magnetic circuit. This time magnetic lifters for lifting the state, when the carrier to Figure 2b position. After the magnetic lifters format the magnetic field lines without lifting the sub-magnetic material, this time is unloading heavy state. Of course, vector must be achieved by external rotation.
In general, when the starting weight of magnetic lifters is not too large, we can use leverage principle with the handle to operate; when lifting is heavy, we should use motor to drive the magnetic lifters.