pic: Concentric Shifting Transmission Concept

[Gabe]

The solution could be to have not one, but two pins per spring. When you use one pin to lock you are essentially putting a shearing force on the pins. The problem arises when the pins retract and, as the pins wear down, they retract too far and shearing forces are applied to the springs which will damage them. By adding a very short pin segment with rounded ends in between the locking pin and the spring (shortened a bit), the transmission will unlock by splitting at the union between the pins. This concept is the same as the pin tumbler lock.
Notice that the ends of the pins are rounded to make the pins separate easily. When the lock is "locked", the inner cylinder can't turn because the pins aren't shearing. Study the image and apply the mechanism design to the shifting transmission. The simplest solution to the current design on the drawing board is to insert a ball bearing in between the locking pins and the springs, after having rounded over the end of the pin.