It is odd to be part of a program designed to promote fluid power yet find myself tasked with reducing the weight and size of an entirely mechanical linkage in order to translate linear displacement into rotational motion.
So, the basics of this particular Ankle Foot Orthosis: Two pneumatic cylinders are extended & retracted under about 100 - 150psi. This linear motion must then be transferred into rotational motion at the ankle to facilitate an assistive torque for both dorsiflexion and plantarflexion.
The set of gears above (not to scale) should reduce the weight and size of the current gear system by increasing the size of the large, rack-driven cog (green) and decreasing size of the sector gear (blue). This should also allow for the same degree of rotation which the model currently accomplishes with a cluster gear (green) comprised of two small, equally sized gears along with a very large sector gear.
It is exciting to work with a design at such an advanced stage. In school projects, I have rarely gotten past a second, let alone third iteration, and this is where some polishing work comes in, it seems. It has been a pleasure to piggyback on the countless hours of work of everyone has put in on this AFO. It's an impressive machine, with impressive design components -- all the result of talented engineers.