An extension and retraction arrangement for retaining a supported article, such as a monitor, in relation to a trolley structure that is retained for axial extension and retraction in relation to an elongate support arrangement. A support arm, which can be unitary, articulated, pivoting, or non-pivoting,...http://www.google.ca/patents/US7621489?utm_source=gb-gplus-sharePatent US7621489 - Extension and retraction arrangements
