US Patent 8657246 Movable base with control surface

In a further embodiment, a method of controlling a base assembly can be provided. An actuation member can be pumped to deploy one or more wheels to lift a base assembly on said wheels. Further, a pin can be received in a holding portion on a semi-planar contoured surface in response to the pumping of the actuation member. The wheels can be held in a deployed position via the pin being held in the holding portion. Further pumping of the actuation member can separate the pin from the holding portion and retract the wheels from the deployed position.