An actuator arrangement comprises a first screw shaft, a first nut
cooperating with the first screw shaft such that rotation of the first
screw shaft causes the first nut to translate thereon, a second screw
shaft, a second nut cooperating with the second screw shaft such that
rotation of the second screw shaft causes the second nut to translate
thereon, and first and second linkages connecting the first and second
nuts, respectively, to an output member, rotation of the first and second
screw shafts to cause translation of the first and second nuts towards
one another causing extending movement of the output member and rotation
of the first and second screw shafts to cause translation of the first
and second nuts away from one another causing retracting movement of the
output member.