I don't know all the details of the Voit - Aqualung relationship, but if I recall it goes something like this. Voit was a significant supplier of rubber goods to Aqualung, and some arrangement was made where AL would share regulator patents as part of the financial trade agreements. What I don't know is if Voit had the regs manufactured, or if Aqualung manufactured them for Voit. I tend to think Aqualung built them since they already had the setup to do so. It would cost Voit a bundle to do that. Also, I don't see Aqualung letting someone else build the equipment to manufacture regs on their patents, thus potentially losing control. Hopefully someone on the forum can give us better details!
"I get plenty of excercise just pushing my luck!"