looking at that ilustration seems quite simple. it free spining small diameter sprockets are installed every 120 degrees, 60 degrees out of sink with the drive sprockets, then apon rotation, no 2 drive sprockets are going to touch the chain, eliminating the possibility of lockup.
the way that i think that on the fly shifting could be acomplished is if:
- free spining small diameter sprockets are installed every 120 degrees, 60 degrees out of sink with the drive sprockets
- the distance from center of input shaft to the point of contact of the sprockets with the chain is the same for all 3 speeds/dear ratios
- the angle the chain makes around the transmission assemly would be increased to 140 deg (current design seems to propose something in the range of 90 deg)
- transmission is placed closer to the middle of each side of the robot
- tensioners installed on the free spinning sprockets to take up slack, ortensioners installed on both sides of the transmission along the chain
any comments on my proposal greatly apreciated, sorry if i veered too far away from simplicity in design as the goals.