Abstract: A magnetic worktable includes a worktable body and a plurality of magnetic devices disposed at a worktable body. Positions of the magnetic devices at the worktable body are variable. The magnetic devices are electrically connected to each other via a circuit, such that the magnetic devices can generate a magnetic attraction force when magnetized. The total area of the magnetic devices accounts for a small portion of the worktable body area, allowing a user to change the arrangement and quantity of the magnetic devices by modularization and according to the shape and processing method of a workpiece. Therefore, any workpieces can be fixed to the magnetic devices by magnetic attraction. Accordingly, the magnetic worktable incurs a low manufacturing cost and advantageously features high practicability.

Abstract: A permanent electromagnetic indexing apparatus includes a chassis, a carrier pivoted to the chassis, and a plurality of magnetic sets. Each of the magnetic sets includes a first permanent magnet, a magnetic-conductive member, a second permanent magnet, and a magnetizing coil. Each of the first permanent magnets is mounted to the magnetic-conductive member. Each of the magnetic-conductive members is mounted onto the second permanent magnet. Each of the magnetizing coils surrounds the second permanent magnet. The magnetic sets are mounted to the carrier to enable the magnetic-conductive members to become a working surface for placing a workpiece thereon. When each of the magnetizing coils is electrically conducted, the polarity of each of the magnetic-conductive members can be changed and then the workpiece can be fixed to or removed from the working surface. In this way, the workability can be enhanced to enable preferably flexible and variable processing.

Abstract: A magnetic retaining device for attaching a work piece to a machine tool includes a magnetic housing having two housing members secured together and having different magnetic poles, and a magnetic core rotatably received in the magnetic housing and having two core members having different magnetic poles. The magnetic force of the housing members may be offset by the core members when the core members are received in the housing members of different magnetic poles, and may be increased when the core members are received in the housing members of the same magnetic poles, in order to selectively and stably retain the work piece to the machine tool.