B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
B23Q3/00—Devices holding, supporting, or positioning work or tools, of a kind normally removable from the machine
B23Q3/15—Devices for holding work using magnetic or electric force acting directly on the work
B23Q3/154—Stationary devices
B23Q3/1546—Stationary devices using permanent magnets