[bjimster1]

it's rather simple device.

1. globe motor is activated, which spins ellipse until next limit switch is pressed
2. the ellipse pushed on the bearing which is connected to a slide, which pushes on the shaft on which the gear cluster is.
3.there are two sets of springs on each side (they can't be seen because they are in between the CIMs.)
4. one spring puts pressure on the gear cluster to put it in high speed (as seen above)
5. when the ellipse spins it overcomes the force of that spring. the other spring now contracts (putting pressure) on to the gear cluster until it "catches" and slides in to low gear.
6. the ellipse is able to be horizontal (with respect to the robot; for low speed) and the gear cluster not engaged, but is being pressured to do so.

this system allows for mechanical shifting without fear of jamming anywhere. in the strange highly unlikely situation that something goes wrong, the shifter will default into high speed.

i hope that answers your question.