US Patent 7938612 Battery-changing vehicle with cantilevered boom

A battery-changing vehicle includes a mobile carriage, a frame disposed above the mobile carriage, and a boom assembly connected to the frame. The mobile carriage defines a loading deck for receiving and transporting a battery. The boom assembly includes a lift hoist that lifts a battery to and from the loading deck. The lift hoist is capable of lateral movement between an extended disposition, at which the lift hoist is cantilevered away from the loading deck, and a withdrawn disposition, at which the lift hoist is disposed above the loading deck. The battery-changing vehicle may also include a transfer arm capable of transferring a battery to and from the loading deck.