Abstract: The present invention relates to a swivel arrangement comprising a first holder unit and a second holder unit, where the first holder unit (1) is assigned a first plane (11) and the second holder unit (2) is assigned a second plane (21). The first plane (11) is parallel to the second plane (21) upon a relative movement between the holder units (1, 2). The invention also concerns an arm structure (3) joining the first holder unit (1) to the second holder unit (2). The second holder unit (2) can be controlled, via the arm structure (3), in a complete or partial circular plane-parallel movement in relation to the first holder unit (1). A first reference direction, which is fixed in relation to, and coincides with, the first plane (11) is parallel to, or in each case essentially parallel to, a second reference direction, which is fixed in relation to, and coincides with, the second plane (21) during the whole of the plane-parallel circular movement.