Patent ID: 6904642

Claim:
A closing device for a hinged gate and having a body portion and pivotal arms for respective connection directly or indirectly to a gate and gate post through respective mounting means being relatively rotational about an axis which is adapted to be parallel to the axis of hinging of the gate, the body portion and the arms being relatively rotational through a range of positions extending from a gate closed position through to a fully open position, one of the pivotal arms having mounting means adjacent to form a pivotal connection to a mounting arm which is adapted to be connected to either the gate or a gate post, the body portion having a cylindrical piston with an external grooved profile with a helical groove pattern and an axial groove pattern, a first of the pivotal arms having a helical ribbed mounting portion for mounting the pivotal arm for rotation of the arm about the piston as the piston moves axially and the second of the pivotal arms having an axially ribbed mounting element to engage the piston and guide its axial displacement during relative rotation of the pivotal arms, the body portion further providing a cylindrical housing for the piston with fluid chambers on each side of the piston, resilient dosing means to cause the gate to close when released in the open position and speed control means for controlling the speed of closure of the gate by controlling fluid flow between opposite sides of the piston.