Abstract: A dual-wheel differential system includes an in inner hub, an outer hub, and a differential assembly mechanically coupled between the inner hub and the outer hub to allow the inner hub and the outer hub to rotate at different angular speeds. A user-actuatable locking system is configured to mechanically lock the inner hub to the outer hub. The user-actuatable locking system may include at least one axially-translating or radially-translating locking pin configured to engage at least one of the inner hub and the outer hub. The locking system may be pneumatically, hydraulically, or electromechanically actuated.

Abstract: A dual-wheel differential system includes an in inner hub, an outer hub, and a differential assembly mechanically coupled between the inner hub and the outer hub to allow the inner hub and the outer hub to rotate at different angular speeds. A user-actuatable locking system is configured to mechanically lock the inner hub to the outer hub. The user-actuatable locking system may include at least one axially-translating or radially-translating locking pin configured to engage at least one of the inner hub and the outer hub. The locking system may be pneumatically, hydraulically, or electromechanically actuated.

Abstract: A belt tensioner comprises first and second pulleys, a main arm and a sub-arm. The first pulley is displacable relative to an engine, and the second pulley is displacable relative to the first pulley. The main arm is connected to the first pulley, and a first spring is connected to the main arm and resists displacement of the first pulley when the engine is started. The sub-arm is connected to the second pulley, and a second spring is connected between the main arm and the sub-arm and maintains the second pulley generally equidistant from the first pulley while the engine is running.