Patent ID: 9212671
Filing Date: 2015-12-15
Classification: F15B,F16K

Abstract:
1. A pneumatic actuator for setting a control armature, comprising: a first working chamber and a second working chamber, the first and second working chambers being pneumatically separated from each other by a movable dividing wall to which the control armature is coupled in a force-transmitting manner, said dividing wall in case of a pressure difference between the working chambers being displaced in a first control direction; a positioner adapted to output at least one pneumatic control signal to the first working chamber; the first and the second working chambers being pneumatically connected to each other via a pneumatic short-circuit duct and with a balancing valve disposed in the short-circuit duct for at least one of closing or opening the short-circuit duct, the balancing valve being drivable by the positioner such that, in case of a certain operating condition detected by said positioner, the balancing valve pneumatically short-circuits the first and the second working chambers for achieving a pressure balance which equalizes pressure between the chambers; and said certain operating condition comprises a stick-slip state of the control armature, the positioner being connected to sense a slipping movement of the control armature after a sticking of the control armature, said short-circuiting by the balancing valve occurring when the control armature slips.