Magnetically operated actuator employing permanent and electro-magnets - is monostable or multistable and moves slide valve which may be made of magnetic

摘要

The valve plunger (10) can move axially in its cylindrical casing (11). Attached to the plunger are magnetic elements (12, 13), or alternatively the whole plunger may be made from a magnetic material. Attached to the ends of the cylinder are permanent magnets (14, 15) one of each end for a bistable case, and each such magnet is also provided with a winding (16, 17). With the winding de-energised the plunger is attracted to the permanent magnet and is in a stable state. By exciting the winding (16) the permanent magnet flux is overcome and a force is exerted on the plunger which moves it into the other operating position. In the bistable case the permanent magnet (15) at the opposite end then takes over and attracts the plunger. The original setting can be restored by energising the winding (17) associated with this second magnet (15). The arrangement can be adapted to several forms, and several intermediate stable positions can be achieved by a suitable coil and magnet configuration.