A valve means has a valve housing, in which an inlet duct for pressure fluid extends, the duct opening into a valve chamber, in which a valve member is held by spring means in a closed position engaging a valve seat, the valve member opening at a predetermined opening pressure of the pressure fluid present so that pressure fluid arrives by way of an opening cross section at a fluid outlet and flows from it, and the valve means comprises a control duct by way of which pressure fluid flows into a control chamber, in which a control member is held clear of a control seat by spring means in an open position, the control chamber being connected by way of a connecting duct with the valve chamber; and in which the control member so controls the exit flow of the pressure fluid that the control member is able to be shifted, prior to opening of the valve member at a control pressure below the opening pressure into engagement with its control seat so that the passage of fluid between the control chamber and the valve chamber is shut off and that in the open position of the valve member and during exit flow of the pressure fluid via the control chamber the control member, with a fall in pressure below the control pressure, shifts into its open position and the connection duct is opened with the result that pressure fluid can leave via the control chamber.

Claims data not available