| 摘要 |
<p>An electrical limit switch has a rotary camshaft provided in an operating head which is mounted upon a main switch body which houses electrical switch contacts. Rotational input motion of the camshaft is translated into a linear output motion of an actuator for operating the switch contacts. A minor return spring acts in series with a major return spring upon a flat formed in the camshaft to center the camshaft in a neutral position. The minor return spring is compressed as the camshaft is initially rotated to enable a low torque operation of the shaft until after actuation of the switch contacts, while the major return spring is compressed after switch actuation to provide a principal return force for the camshaft upon its rotary deviation from the neutral position. A spring stop element is inserted between the major and minor springs to limit compression of the minor return spring following an operation of the switch contacts.</p> |
