PISTON ACTUATOR CONTROLLING A VALVE AND METHOD FOR OPERATING THE SAME

摘要

Piston actuators and methods of its operation are described. The piston actuators include a housing defining a chamber having a piston therein and a spring seated against the piston to bias it into a starting position. The piston includes a ferromagnetic material, a magnet or both and a secondary magnet or ferromagnetic material, forming a first magnetic/ferromagnetic pair with the piston, is positioned to maintain the piston in a secondary position. A tertiary magnet or ferromagnetic material, forming a second magnetic/ferromagnetic pair with the piston, may assist the spring in maintaining the piston in the starting position. During operation, introduction into or removal from the chamber of an amount of fluid sufficient to overcome the force of the spring (and the tertiary magnet or ferromagnetic material) enables the attraction between the members of the first magnetic/ferromagnetic pair to move the piston to the secondary position as a snap movement.

主权项

1. A piston actuator comprising:
a housing defining a chamber and comprising a port in fluid communication with the chamber; a piston at least partially comprising a ferromagnetic material, a magnet or both thereof, the piston disposed within the chamber; a spring seated against the piston to bias the piston into a starting position; and a secondary magnet or ferromagnetic material forming a first magnetic/ferromagnetic pair with the piston and positioned to maintain the piston in a secondary position once the piston moves to the secondary position; wherein, when the introduction of fluid into or the removal of fluid from the chamber via the port overcomes the force of the spring holding the piston in the starting position, the attraction between the members of the first magnetic/ferromagnetic pair moves the piston to the secondary position as a snap movement and thereafter maintains the piston in the secondary position.