Tony,
I think I kind of figured out ratchet type design but based on princi[;e pof rotating ratchet linked to your idea...with next salary I will buy CCT to work with, but basically there is 2 variants:
1. Ratchet piece of ratchet screwdriver + bit that usually goes into screw goes into rod
2.Or: "external" rotating ratchet right on top of CCT...but that one easier to draw than to explain...
Only problem is limited set of tools I have - libing as expat in Belgium can not really setup workshop in rented house
I will try to get you draft drawings on weekend - have a look, may be you will find it uuseful...