| 摘要 |
A magnetic device is formed from a permanent magnet generating magnetic flux, an armature which can occupy two positions between four poles and an electromagnet winding to which current can be supplied to produce a magnetic flux in one direction or the other, the flux from the winding causing the armature to move into one position and continue to remain in that position after the current flow ceases. The device can be incorporated into a fluid valve to act as a drive for opening and closing the valve. It may also serve as the drive for opening and closing electrical contacts. Monostable operation can be achieved by locating a magnetic flux shunt at one end of the armature travel. A holding solenoid may be incorporated. A pivoting armature in a fluid tight chamber comprises a fluid flow controlling device. It can adopt either of two home positions in contact with two magnetic poles and is retained by magnetic flux from a permanent magnet. Fluid can flow into and out of the chamber via a first passage. A second passage extends through one of the poles to an opening in the pole face which is covered by the armature when the latter occupies one home position but is uncovered when the armature occupies its other home position. A third fluid passage extends through and leads to a second opening in another pole, which is covered when the armature occupies its said other home position. Passages in the poles house energy storing springs each of which is compressed as the armature approaches the pole. A push rod can extend through a passage in one of the poles for conveying armature movement externally of the device.
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