A magnetic chuck has a piston assembly that contains a cylindrical permanent magnet and a core yoke. The piston assembly is movable inside a cylinder tube. The permanent magnet is provided on the outer periphery of the core yoke and is magnetized in the radial direction.

An electrostatic chuck apparatus is provided that is capable of effectively reducing temperature imbalance of a wafer substrate that is heated to a high temperature. The electrostatic chuck apparatus includes a base including a cooling flow path through which a refrigerant may flow, an adiabatic layer on the base, a uniform heating plate on the adiabatic layer, a heating element between the adiabatic layer and the uniform heating plate, an insulating layer on the uniform heating plate and including a ceramic, a conductive layer on the insulating layer and having an area smaller than an area of the insulating layer, and a dielectric layer on the conductive layer and including a ceramic.

An electrostatic chuck apparatus is provided that is capable of effectively reducing temperature imbalance of a wafer substrate that is heated to a high temperature. The electrostatic chuck apparatus includes a base including a cooling flow path through which a refrigerant may flow, an adiabatic layer on the base, a uniform heating plate on the adiabatic layer, a heating element between the adiabatic layer and the uniform heating plate, an insulating layer on the uniform heating plate and including a ceramic, a conductive layer on the insulating layer and having an area smaller than an area of the insulating layer, and a dielectric layer on the conductive layer and including a ceramic.

A magnetic device for magnetically coupling to a ferromagnetic body, comprises a housing having a central bore. A plurality of pole sectors arranged within an envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced-apart pole portions arranged at respective distances, wherein a recess of a plurality of recesses separates each pole portion of the plurality of pole portions, wherein a first sector forms a first pole of the magnetic device and a second sector forms a second pole of the magnetic device. A first permanent magnet. A second permanent being moveable relative to the first permanent magnet. And, an actuator operatively coupled to the at least one second permanent magnet to move the at least one second permanent magnet relative to the at least one first permanent magnet.

A magnetic device for magnetically coupling to a ferromagnetic body, comprises a housing having a central bore. A plurality of pole sectors arranged within an envelope of the central bore and forming a workpiece contact interface of the magnetic device, each of the plurality of pole sectors comprising a plurality of spaced-apart pole portions arranged at respective distances, wherein a recess of a plurality of recesses separates each pole portion of the plurality of pole portions, wherein a first sector forms a first pole of the magnetic device and a second sector forms a second pole of the magnetic device. A first permanent magnet. A second permanent being moveable relative to the first permanent magnet. And, an actuator operatively coupled to the at least one second permanent magnet to move the at least one second permanent magnet relative to the at least one first permanent magnet.

Provided is a magnetic holder which may be easily moved even after being released. The magnetic holder includes a fixed permanent magnet extending in one direction, a rotating permanent magnet extending in the one direction and rotatably fixed at both ends, first and second yokes covering both sides of the fixed permanent magnet and the rotating permanent magnet and extending in an up-down direction, and a coil wound around the first and second yokes, wherein, in a cross-section perpendicular to the one direction, the first yoke is in contact with an N pole of the fixed permanent magnet and the second yoke is in contact with an S pole of the fixed permanent magnet, and the coil, the rotating permanent magnet, and the fixed permanent magnet are arranged successively along the first and second yokes from an attachment surface of the first and second yokes attached to the attachment object.

Disclosed is a magnetic force control device improved to be installed even in a narrow space having a small height. The magnetic force control device includes a first pole piece having a first interaction surface, a second pole piece having a second interaction surface, a third pole piece connected to the second pole piece, a coil wound around at least one of the second pole piece and the third pole piece, a stationary magnet fixed between the first pole piece and the second pole piece and a rotary magnet disposed between the first pole piece and the third pole piece and configured to be rotatable by controlling a current flowing through the coil.

An overhead hoist transport system includes a vehicle, a wafer box and a controller. The vehicle includes a combiner. The combiner includes at least one magnetic module. The magnetic module is fixed to a base plate. The magnetic module is downwardly protruded. The wafer box includes a header. The header includes a combining member configured to correspond to the magnetic module. The controller is configured to generate a control signal for controlling attachment and detachment operations between the combiner and the wafer box. The magnetic module includes a frame, a first permanent magnet, a second permanent magnet and a magnetic switch. The frame has an annular cross-sectional shape. The first permanent magnet is fixed to the frame. The second permanent magnet is rotatably arranged in the frame. The magnetic switch is configured to rotate the second magnet in response to the control signal.

A magnetic chuck includes a cylinder tube including a workpiece attraction surface to which a workpiece is attracted, a piston assembly including a permanent magnet and being movable in an internal space of the cylinder tube, the piston assembly separating the internal space of the cylinder tube into a first pressure chamber and a second pressure chamber, a first supply/discharge port formed in the cylinder tube and communicating with the first pressure chamber, a second supply/discharge port formed in the cylinder tube and communicating with the second pressure chamber, and a communication passage configured to allow the first pressure chamber and the second pressure chamber to communicate with each other.

A magnetic base for an electric power tool, in particular for a magnetic core drilling machine. The magnetic base having a base body, in which at least one first solenoid coil forming an electromagnet is accommodated in a receiving space, whose magnetic force is switchable between a maximum resulting holding force and a minimum resulting holding force. A first side that is adapted to be coupled with the electric power tool. An oppositely situated second side, which is adapted to be placed on a workpiece to be processed. The receiving space is designed such that an insertion of the at least one solenoid coil into the receiving space is possible only from the first side.