A device for closing a closure member hinged on a support, which closing device comprises an actuator mechanism having a resilient member which is arranged to urge the hinged closure member towards its closed position and a hydraulic damper mechanism for damping the closing movement of said hinged closure member under the action of said resilient member, which actuator mechanism comprises: - a frame; - a reciprocating pushrod which is slidably mounted on said frame to translate between an extended and a retracted position when opening and closing the hinged closure member; and - said resilient member which is arranged between said pushrod and said frame to urge the pushrod towards its extended position, and which hydraulic damper mechanism comprises: - a cylinder barrel defining a closed cylinder cavity; - a reciprocating piston placed within said cylinder barrel so as to divide the cylinder cavity into a first side and a second side; - a first motion converting mechanism for converting the translational motion of said pushrod into a rotational motion of a first pinion, which first motion converting mechanism comprises a first rack and pinion gearing (15, 39) having a first rack on said pushrod which engages said first pinion; - a transmission, including a second motion converting mechanism (34, 35), between said first pinion and said piston for transmitting and converting the rotational motion of said first pinion into a translational motion of the piston; - a one-way valve allowing fluid flow from said first side to said second side of the cylinder cavity when opening the hinged member; and - at least one restricted fluid passage (29, 43) between said first and second sides (26, 27) of the cylinder cavity, characterised in that the hydraulic damper mechanism comprises a piston rod fixed to said piston to reciprocate together with the piston in the cylinder cavity; in that said second motion converting mechanism comprises a second rack and pinion gearing (34, 35) arranged within said cylinder cavity and having a second rack formed by said piston rod and a second pinion engaging said second rack; and in that said transmission provides together with said first and second pinions (39, 35) a reduction gearing between said pushrod and said piston so that said piston reciprocates over a smaller distance than said pushrod. - a frame; - a reciprocating pushrod which is slidably mounted on said frame to translate between an extended and a retracted position when opening and closing the hinged closure member; and - said resilient member which is arranged between said pushrod and said frame to urge the pushrod towards its extended position, - a cylinder barrel defining a closed cylinder cavity; - a reciprocating piston placed within said cylinder barrel so as to divide the cylinder cavity into a first side and a second side; - a first motion converting mechanism for converting the translational motion of said pushrod into a rotational motion of a first pinion, which first motion converting mechanism comprises a first rack and pinion gearing (15, 39) having a first rack on said pushrod which engages said first pinion; - a transmission, including a second motion converting mechanism (34, 35), between said first pinion and said piston for transmitting and converting the rotational motion of said first pinion into a translational motion of the piston; - a one-way valve allowing fluid flow from said first side to said second side of the cylinder cavity when opening the hinged member; and - at least one restricted fluid passage (29, 43) between said first and second sides (26, 27) of the cylinder cavity,