Info on strange linkage ?

Does anybody have a drawing or picture of the
torsion linkage used to drive the ailerons in
early Ventus or the rudder in Libelle ?
Or can tell me what that's called ?

Thanks !
Best Regards, Dave

PS: It was used to avoid external bellcranks,
with their associated fairings and drag. It's
out of favor because it is problematic
(cost, weight, stiction, etc), and it turns
out the fairings add negligible drag...