Apparatus for the extension and retraction of a peripheral device

摘要

The present invention provides an extendible support mechanism in which a counterbalance system allows extension and retraction of the arm to be carried out with the same level of mechanical effort. Embodiments of the present invention allow the system to be used in a plurality of orientations, and thus the invention has particular utility in the extension and retraction of peripheral devices for radiotherapy systems, where use of a rotatable gantry is common.