Abstract: A switchable magnetic apparatus has a first layer having one or more first-layer magnets, a second layer on a rear side of the first layer and having one or more second-layer magnets, and a third layer on a rear side of the second layer. The first and second layers are movable relative to each other between an ON position and an OFF position for switching the apparatus between an ON state and an OFF state. The third layer has one or more third-layer magnets for applying a first force to the one or more second-layer magnets when the second layer is at a position intermediate the ON and OFF positions, and the first force is at a direction opposite to a second force applied to the one or more second-layer magnets by the first-layer magnets when the second layer is at the position intermediate the ON and OFF positions.

Abstract: A magnetic unit for generating a directional magnetic field towards a target direction on a front side thereof. The magnetic unit has a pair of front magnetic structures and a rear magnetic structure. Each of the front magnetic structures and the rear magnetic structure has a first pole in a target area about a front edge of a target side. In a first state, the first poles of the front magnetic structures and the rear magnetic structure are a same pole thereby forming a target pole in the target area for engaging a work-piece about the front edge. Each of the front magnetic structures and the rear magnetic structure has a second pole opposite to the respective first pole, the second poles of the front magnetic structures and the rear magnetic structure are on a rear side of the front edge and at a distance thereto.

Abstract: A switchable magnetic apparatus has a first layer having one or more first-layer magnets, a second layer on a rear side of the first layer and having one or more second-layer magnets, and a third layer on a rear side of the second layer. The first and second layers are movable relative to each other between an ON position and an OFF position for switching the apparatus between an ON state and an OFF state. The third layer has one or more third-layer magnets for applying a first force to the one or more second-layer magnets when the second layer is at a position intermediate the ON and OFF positions, and the first force is at a direction opposite to a second force applied to the one or more second-layer magnets by the first-layer magnets when the second layer is at the position intermediate the ON and OFF positions.

Abstract: A switchable magnetic apparatus has a front layer, a rear layer, and a manipulating mechanism for changing the relative arrangement of the magnets to change the apparatus between ON and OFF states. The front layer has one or more front-layer magnets and a plurality of interleaved ferromagnetic components. The rear layer has one or more rear-layer magnets. When the magnetic apparatus is OFF, some or all of the rear-layer magnets overlap some or all of the ferromagnetic components, wherein the ferromagnetic components experience opposite poles between the adjacent front-layer magnets compared to the adjacent rear-layer magnet. When the magnetic apparatus is ON, some or all the rear-layer magnets overlap some or all the ferromagnetic components, wherein the ferromagnetic components experience the same magnetic pole from the adjacent front-layer magnets and the adjacent rear-layer magnet.

Abstract: A switchable magnetic apparatus has a front layer, a rear layer, and a manipulating mechanism for changing the relative arrangement of the magnets to change the apparatus between ON and OFF states. The front layer has one or more front-layer magnets and a plurality of interleaved ferromagnetic components. The rear layer has one or more rear-layer magnets. When the magnetic apparatus is OFF, some or all of the rear-layer magnets overlap some or all of the ferromagnetic components, wherein the ferromagnetic components experience opposite poles between the adjacent front-layer magnets compared to the adjacent rear-layer magnet. When the magnetic apparatus is ON, some or all the rear-layer magnets overlap some or all the ferromagnetic components, wherein the ferromagnetic components experience the same magnetic pole from the adjacent front-layer magnets and the adjacent rear-layer magnet.

Abstract: A switchable magnetic apparatus has a front layer, a rear layer, and a manipulating mechanism for changing the relative arrangement of the magnets to change the apparatus between ON and OFF states. The front layer has one or more front-layer magnets and a plurality of interleaved ferromagnetic components. The rear layer has one or more rear-layer magnets. When the magnetic apparatus is OFF, some or all of the rear-layer magnets overlap some or all of the ferromagnetic components, wherein the ferromagnetic components experience opposite poles between the adjacent front-layer magnets compared to the adjacent rear-layer magnet. When the magnetic apparatus is ON, some or all the rear-layer magnets overlap some or all the ferromagnetic components, wherein the ferromagnetic components experience the same magnetic pole from the adjacent front-layer magnets and the adjacent rear-layer magnet.