Differential gear drive mechanism

A differential gear drive mechanism comprising

• a drive gear mounted for free rotation on an output shaft, said drive gear including
• an outer ring gear element mounted coaxial to, and captured by, and adjustably interlocked with,
• an inner ring portion which is rotatably mounted on said output shaft, said adjustable interlock permitting relative rotation between said inner and outer ring members for a few degrees of limited rotation in either direction around said output shaft,
• a first driven spur gear mounted coaxial to said drive gear on said output shaft and engaged therewith,
• a mirror image second driven spur gear disposed on the opposite side of said drive gear and mounted on and engaged with a second output shaft mounted coaxial to said first output shaft,
• a multiplicity of first drive pawls pivotally secured to said drive gear inner ring portion and spring biased to alternately engage said driven spur gear teeth in coordinated action to rotate said driven gear in the same direction as said drive gear unless a counter torque imposed on said output shaft overcomes said spring bias to reverse the engagement of said pawls and to permit said drive gear to impose a counter-torque on said output shaft, said pawls being rocker shaped and pivoted at the centers thereof whereby the opposite ends thereof alternately engage the teeth of the driven spur gear depending on which direction of rotational torque is imposed on the drive gear, said pawls being biased by a spring mechanism which individually interconnects each pawl to said outer ring element whereby said rocker pawl alternately engages said driven gear depending upon the direction of torque applied to said outer ring element,
• a second set of drive pawls identical to said first set mounted on the opposite side of said drive gear and formed to engage said second driven gear in the same manner as said first set of drive pawls engages said first driven gear,
• a multiplicity of radially inward projecting stops formed on said outer ring element of said drive gear,
• a multiplicity of radially outward projecting stops formed on said inner ring portion of said drive gear, the projecting stops from one of the ring members being captured between pairs of stops from the other ring member permitting limited relative rotational motion of one ring member with respect to the other based on the distance the captured stop of the one ring member can move between the stops of the other ring member,
• a multiplicity of partial circumferential cavities formed between said ring members by said stops,
• a multiplicity of ball bearings disposed in said cavities but not filling them, and
• said inner ring portion of said drive gear including spring biased ball bearings biased outward from said drive gear towards the adjacent surfaces of said driven spur gears, said adjacent surfaces including a washboard surface for engaging said ball bearings.