Multiple drive variable transmission ratio system with selective actuator engagement

A multiple drive variable transmission ratio system, comprising:

• a reference structural element;
• a differential subsystem including an output port coupled to a load, a first input port, and a second input port, wherein the load is moveable with respect to the reference structural element;
• a first drive actuator coupled to the first input port with a first speed reducer having a first transmission ratio;
• a second drive actuator selectively coupled to the second input port with a second speed reducer having a second transmission ratio;
• and
• a locking mechanism coupled to the second drive actuator and the second input port, wherein the locking mechanism is configured to couple the second drive actuator to the second input port in a first state and couple the second input port to the reference structural element in a second state, the locking mechanism comprising:
• a plurality of engaging elements in contact with the reference structural element and movable with respect to the reference structural element
• a plurality of receiving cavities fabricated into a portion of a structural element that couples the locking mechanism to the second input port of the differential;
• and
• a sliding frame element in contact with the plurality of engaging elements, the sliding frame element is movable with respect to the reference structural element, an engaging movement of the sliding frame element causes the plurality of engaging elements to move into contact with the plurality of receiving cavities at a first position of the sliding frame element with respect to the reference structural element and at an index position of the structural element with respect to the reference frame element, a disengaging movement of the sliding frame element causes the plurality of engaging elements to move out of contact with the plurality of receiving cavities at a second position of the sliding frame element with respect to the reference structural element.