US Patent 11358257 Magnetic clamping device

A magnetic clamping device is provided that includes a housing in which a number of magnets are disposed. A magnetizable core extends through the housing between the magnets and is movable with respect to the housing and the magnets. The core can be moved using a suitable mechanism disposed on the housing between an extended position where the core is positioned in contact with the support surface and a retracted position where the core is spaced from the support surface. The position of the core relative to the housing and the support surface adjusts the magnetic holding force transmitted from the magnets through the core to attract and hold the core on the support surface.