| 摘要 |
<p>A hydraulic pilot valve has a joystick which is normally maintained in a neutral position by coil springs acting on plungers which engage corresponding first cam surfaces of a cam fixed to the joystick. The plungers are each connected to respective valve members which are stroked to open the pilot valve when the plungers are depressed. When the joystick is pivoted to depress one of the plungers so as to stroke one of the valve members, that valve member is held stroked by an magnetic detent. The joystick may then be released and the valve member will remain in its stroked position. When the joystick is moved back towards a neutral position, a second cam surface on the joystick engages an outer end portion of the depressed plunger and applies an axial force to the plunger. This disengages an armature component of the magnetic detent from an electromagnetic component. A spring then pushes the plunger to its neutral position where the plunger holds the valve member operated thereby closed. In accordance with one embodiment, one joystick operates two or more valve members and, in accordance with another embodiment, the pilot valves are stacked.</p> |
