Patent ID: 7158292

Claim:
An apparatus for retaining an optical viewing device on a stand, the apparatus comprising: a parallelogram carrier arm for supporting and positioning the optical viewing device, the carrier arm having four carrier links pivotable relative to one another; a brake operable to prevent pivoting of the carrier links relative to one another; and a support element that is modifiable in length when the brake is applied to brace the parallelogram carrier arm by applying a force to distort the geometric properties of the carrier arm, wherein the force is independent of a load imposed by the optical viewing device, wherein the support element is a strut arranged to have a line of action extending through a point of pivotal connection between first and second pivotally coupled carrier links and through an intermediate point along a third carrier link, whereby the strut is approximately diagonal with respect to the carrier arm, and wherein the support element is modifiable in length in motorized fashion and the apparatus includes a remotely controllable drive system for changing the length of the support element.