摘要 |
<p>Apparatus to vary the effective spring rate of diaphragm actuators are described. An example spring assembly for use in a diaphragm actuator includes a first spring operatively coupled to a diaphragm plate and an actuator stem, and a second spring operatively coupled to the actuator stem and configured to be serially operative with the first spring. Additionally, a movable spring seat is disposed between the first and second springs.</p> |