Abstract: A door closing device of the type having a piston and cylinder is described, the piston being movable within the cylinder under the bias of a spring and being connected to an arm mechanism which is arranged to transmit movement of the piston into pivoting movement of a door and vice versa, the device including a number of by-pass channels arranged to bring portions of chambers separated by the piston into communication with one another, whereby to limit the speed of flow of a dampening medium contained in the cylinder and passing through the channels as the piston is reciprocated.