self aligning/mating shaft coupling

Hi People,

I'm looking for a shaft coupling that will automatically align when a
removable component is placed onto our unit. (So the shafts can be 'out
of phase' while connecting )

At the moment I'm using a spider coupling with a rubber mating grommet
(shaped like an 'X'), which sometimes needs a bit of help, otherwise the
rubber can get pinched and the component won't sit correctly.

I guess an example is a blender: Put the jug on the base unit and press
  start. Nothing else needed. (except of course a mop and cloth because
you forgot the lid.)

A blender drive isn't reversible however.

I'd strongly prefer to use a ready made component - I've checked through
most of the major catalogs, and haven't seen anything ideal. If anyone
has any ideas, I'd love to know.

Cheers
Marc