Patent ID: 6751953
Filing Date: 2004-06-22
Classification: B61D,E05F,E05Y,F15B

Abstract:
Hydraulic actuating device for a closure assembly, which closure assembly comprises a closure element which is moveable between a closed position, in which the closure element closes off an opening, and an opened position, which hydraulic actuating device comprises:a hydraulic actuator for moving the closure element, which actuator has a housing having a cylinder space, in which a piston/piston rod assembly is moveable to and fro, which latter, in the cylinder space, delimits a closing chamber and opening chamber, the housing being provided in each of the chambers with an associated mouth, connecting to the cylinder space, for the supply and discharge of hydraulic fluid, a hydraulic pump having an associated electric pump motor, which pump has one or more delivery ports for the delivery of hydraulic fluid under pressure, a reservoir for hydraulic fluid, wherein, when hydraulic fluid is supplied to the closing chamber, the actuator delivers a force so as to make the closure element perform a closing motion towards the closed position and, when the supply is directed to the opening chamber, delivers a force so as to make the closure element perform an opening motion towards the opened position, wherein the hydraulic actuating device further comprises a first pressure-limit valve, which is connected to the opening chamber, and a second pressure-limit valve, which is connected to the closing chamber, and wherein electrical control means are further provided for controlling the supply of hydraulic fluid under pressure to the opening chamber or to the closing chamber of the actuator, wherein a hydraulic flow sensor connected to the electrical control means is provided at each pressure-limit valve, such that the one or more hydraulic flow sensors detect the presence of a flow of hydraulic fluid through the pressure-limit valve to the reservoir, and wherein the electrical control means are adaptedâ€”if a flow sensor detects a flow of hydraulic fluidâ€”to reverse the supply of hydraulic fluid under pressure to the actuator, so that the opening motion is changed to a closing motion or vice versa.