A vent for an axle housing includes a first body portion and a second body portion. A weight bearing member affixed to and extending between the pair of runners allows mounting of removable mount weights on a horn projecting therefrom. Accordingly, even if external force is applied to the canopy by bump, contact, putting some object or others, the driving mechanism will not continue or start to lower or raise the canopy while the external force is applied to the canopy because the driving mechanism will be rendered non-operational. A valve is movably received in the front channel. An elastic element includes a first end attached to the attachment side of the pawl and a second end attached to an anchor securely mounted in the transverse hole.