An on-off switchable magnet assembly is disclosed which has first and second magnets. The poles of the first magnet are aligned to first and second ferrous members. The second magnets move to align its poles to the first and second ferrous members so that flux from the same or different pole flows through the first and second members to switch the assembly on or off as a magnet assembly.

Magnetic coupling devices are disclosed which may be configured in at least three states. The various states may be provided through one or more of altering a position of a permanent magnet relative to another permanent magnet and altering a current level in a coil surrounding a permanent magnet.

Magnetic coupling devices are disclosed which may be configured in at least three states. The various states may be provided through one or more of altering a position of a permanent magnet relative to another permanent magnet and altering a current level in a coil surrounding a permanent magnet.

Provided, in one aspect, is a downhole magnetic debris removal apparatus. The downhole magnetic debris removal apparatus, in one aspect, includes a housing having a longitudinal axis, and a plurality of magnets arranged as one or more Halbach arrays of magnets coupled to the housing, the one or more Halbach arrays of magnets having a strong side and a weak side.

Provided is an electromagnetic chuck mounting structure capable of tightly and fixedly mounting an electromagnetic chuck on a table without fluctuation, having light weight, and making a low profile when an electromagnetic chuck is mounted on the table. The structure includes: a mounting groove recessed on an upper surface of the table and located inward of an edge of the table; a plurality of mounting holes formed at regular intervals on the mounting groove to fix the electromagnetic chucks to be mounted; and an adhesive filled and cured on the mounting groove and between the mounted electromagnetic chucks, wherein each of the electromagnetic chucks is fixedly fastened to each of the mounting holes by one fastening bolt, such that an upper surface of each electromagnetic chuck is aligned on a same plane with the upper surface of the table or protrudes from the upper surface of the table.

An on-off switchable magnet assembly is disclosed which has first and second magnets. The poles of the first magnet are aligned to first and second ferrous members. The second magnets move to align its poles to the first and second ferrous members so that flux from the same or different pole flows through the first and second members to switch the assembly on or off as a magnet assembly.

A mounting jig for manufacturing a tiling display device can include a supporting member, a plurality of jig magnets fixed to the supporting member, a hinge structure configured to rotate the plurality of jig magnets, and a guard rail configured to rotate in response to a rotation of the plurality of jig magnets, to reduce damage caused during detachment or attachment. The tiling display device includes a plurality of display devices disposed in the form of tiles. Each of the plurality of display devices includes a plurality of display elements, a plurality of circuits, a plurality of lines and a plurality of parts. The plurality of display elements can be a light emitting diode (LED) or a micro-LED including an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting layer.

A magnetic substance holding device includes: a first pole piece assembly including a first N-pole piece, a first S-pole piece, and a first permanent magnet; a second pole piece assembly including a second N-pole piece, a second S-pole piece, and a second permanent magnet; at least one first coil; at least one second coil; and a control device controlling current applied to the first coil and the second coil so as to control magnetic fluxes passing through the first coil and the second coil, thereby allowing the first pole piece assembly and the second pole piece assembly to switch between the first arrangement and the second arrangement, to control magnetic fluxes passing through the holding faces of the first pole piece assembly and the second pole piece assembly.

A grasp and release mechanism for carrying a load. The grasp and release mechanism includes a frame; a grasp mechanism attached to the frame and including plural permanent magnets configured to magnetically attach to a ferrous load; a release mechanism attached to the frame, wherein the release mechanism includes a drop plate; and an actuator mechanism attached to the frame and configured to apply a force F to the drop plate. The drop plate is configured to suddenly move relative to the frame to apply the force F to the load.

A magnetic apparatus (1) comprising a magnetizable surface (2) configured to anchor a one or more ferromagnetic elements in a removable manner and a plurality of magnetic poles (3), each provided with a free surface (4) thereof, the magnetizable surface (2) being at least partially defined by the free surfaces (4) of said plurality of magnetic poles (3) placed side by side; one part of said magnetic poles (3) has at least two measuring areas (5) on the free surface thereof, each measuring area (5) being associated with at least one sensor (6) adapted to detect a magnetic flux exiting from said area.