Alignment characteristics of magnetic fields have been used to achieve precision movement and positioning of objects. A key principle of operation of an alternating-current (AC) motor is that a permanent magnet will rotate so as to maintain its alignment within an external rotating magnetic field. This effect is the basis for the early AC motors including the “Electro Magnetic Motor” for which Nikola Tesla received U.S. Pat. No. 381,968 on May 1, 1888. On Jan. 19, 1938, Marius Lavet received French Patent 823,395 for the stepper motor which he first used in quartz watches. Stepper motors divide a motor's full rotation into a discrete number of steps. By controlling the times during which electromagnets around the motor are activated and deactivated, a motor's position can be controlled precisely. Computer-controlled stepper motors are one of the most versatile forms of positioning systems. They are typically digitally controlled as part of an open loop system, and are simpler and more rugged than closed loop servo systems. They are used in industrial high speed pick and place equipment and multi-axis computer numerical control (CNC) machines. In the field of lasers and optics they are frequently used in precision positioning equipment such as linear actuators, linear stages, rotation stages, goniometers, and mirror mounts. They are used in packaging machinery, and positioning of valve pilot stages for fluid control systems. They are also used in many commercial products including floppy disk drives, flatbed scanners, printers, plotters and the like.
Moreover, commercial, consumer, and industrial products and fabrication processes abound with a myriad of fasteners, latches, hinges, pivots, bearings and other devices that are conventionally based on mechanical strength and shape properties of materials rather than magnetic field properties because the magnetic field properties have been inadequate or otherwise unsuitable for the application.
Therefore there is a need for new magnetic field configurations providing new magnetic field properties that can improve and extend the operation of existing magnetic field devices and potentially bring the benefits of magnetic field operation to new devices and applications heretofore served only by purely mechanical devices.