Quick engage/disengage mechanism for gear trains

Due to the challenging design of this year's Robot Energizing objects, many teams have come up with pretty interesting designs to carry the resources (i.e coal, bio-fuel, and esp. solar). One of the biggest challenge the teams face is to design some mechanism which can grab and lift the object by using only 1 motor as the other 2 have been used up for navigation.

So, some of the more successful teams have employed the grab & lift mechanism similar to the one shown below,

This is a brilliant solution for grabbing & lifting the Solar rescource off the ground, but there's a slight drawback to this design when the gear reduction ratio is too big - you need to turn the motor many rotations to reset it to the original position everytime the robot misses. So one the solution the teams come up with is to attach another knob/wheel along the driving axle for manual reset. However, this still takes up an awful amount of time, especially if your robot miss more than once :S

Recently i came across a very interesting mechanism that can engage/disengage a gear train with relative ease and i thought it would be an useful add-on to the grab & lift mechanism for quick engage/disengage in the event the robot misses the object.

I have uploaded the videos showing how the quick engage/disengage mechanism work along with the grab & lift mechanism without the quick engage/disengage mechanism for comparison.

Grab & lift with quick engage/disengage

Grab & lift without quick engage/disengage

This mechanism can even be applied to grabbers which uses wormscrews, which can save even more time on resetting the grabber.