An actuator assembly comprised of: a first coil and a second coil, each with a bore and a producing a magnetic flux when subject to an electric signal; a tube extending through the bores such that coils are coaxial; a magnetic pole piece within the tube and generally between the first bore and the second bore; a magnetic ring set outside of the tube and between the coils, in which the magnetic flux paths both travel through the magnetic pole piece and the magnetic ring to complete their respective magnetic paths; and a first and second axially translatable movable member within the tube and wherein the movable members each axially translate towards the magnetic pole piece in the presence of the magnetic flux such that by controlling the electric signal, proportionality can be achieved.