Dual Ratio Constant Mesh Gearbox

A dual ratio constant mesh gearbox, comprising:

• a housing;
• an input drive shaft coupled to a vehicle propulsion electric motor;
• a sun gear rigidly coupled to said input drive shaft;
• a ring gear;
• a set of planetary gears interposed between said sun gear and said ring gear, wherein said set of planetary gears are in constant mesh with said sun gear and said ring gear;
• a planetary gear carrier coupled to said set of planetary gears and to an output drive shaft, wherein said output drive shaft is at least partially contained within said housing;
• a sprag clutch assembly contained within said housing, wherein said sprag clutch assembly permits rotation of said ring gear in a first direction within said housing and prevents rotation of said ring gear in a second direction within said housing;
• a second clutch assembly separate and independent of said sprag clutch assembly, wherein engaging said second clutch assembly locks said ring gear to said sun gear, and wherein disengaging said second clutch assembly unlocks said ring gear from said sun gear;
• and
• a band brake translatable from at least a first position to a second position, wherein said band brake in said first position permits rotation of said ring gear within said housing, and wherein said band brake in said second position prevents rotation of said ring gear within said housing.