Patent ID: 8827300

Claim:
A coupling device for coupling a first vehicle to a second towed vehicle, the coupling device including: a pillar for mounting to a towbar attached to the first vehicle, said pillar having a semi-spherical head with an equator, a neck and a body with a part-hemispherical portion where the body meets the neck; a connector for connection to the second towed vehicle; a sleeve linked to the connector that engages with the pillar by fitting over the pillar; and a collar that fits over and engages with a portion of the sleeve for movement with respect to the sleeve; wherein the collar is movable with respect to the sleeve between a first unlocked position in which the sleeve is removable from the pillar and a second locked position in which the sleeve is not removable from the pillar; wherein further the relationship between the semi-spherical head, the body and the part-hemispherical portion is such that, under draw-bar weight, a substantially continuous smooth engagement of the sleeve over the body of the pillar is achieved; wherein the sleeve has at least one aperture extending through the wall of the sleeve and a locking element positioned in each aperture of said at least one aperture; wherein in the second locked position each locking element has a portion that protrudes inwardly beyond an internal face of the sleeve wall and in the first unlocked position each locking element resides at least partially within a respective aperture such that no portion of each locking element protrudes inwardly be and the internal face of the wall of the sleeve to enable the sleeve to slide freely over the pillar; wherein the collar has at least one recess and the collar is movable to a position where a recess of said at least one recess is aligned with an aperture of said at least one aperture in the sleeve to enable movement of each respective locking element; and further including a biasing means connected to the collar and to the sleeve, the biasing means being biased at substantially all times to move the collar to a position where each recess is not aligned with a respective aperture in the sleeve.