US Patent 7137311 Gearbox

A gearbox with an actuating device for automated shifting and selection of transmission ratios includes a gearbox operating element that is driven by an actuator. The actuator has a drive source with an output element. A swivel movement of the output element causes the gearbox operating element to shift into or out of a transmission ratio or to select one of the shift slots of a shift-gate pattern and to simultaneously apply a force to an energy-storing device. The energy-storing device acts on an intermediate element which acts on the gearbox operating element. At least one retaining element limits the actuation of the intermediate element to a predetermined position.