An assembly for converting motion comprises a first arm rotatable about a first fixed pivot; a second arm rotatable about a second fixed pivot; a third arm pivotably connected to a second position on the second arm; a first connecting arm extending between the first and third arms; a second connecting arm extending between the first and second arms; a support arm extending from the connection between the second and third arms, the support arm linked to the connection between the first arm and the first connecting arm, wherein one of the connection between the second and third arms and the connection between the first arm and the first connecting arm is moveable relative to the support arm and the other of the connection between the second and third arms and the connection between the first arm and the first connecting arm is fixed relative to the support arm.