SUPPORT ARM FOR OPTICAL ACCESSORIES

摘要

MID 072 P2 The present invention provides a support arm for optical accessories such as are used during the examination of eyes for determining the corrective eyeglass lens required. The support arm is supported by a vertical support post which defines a first axis about which the arm may be pivot. The support arm further includes a first hub portion adjacent to the support post and a second hub portion distal from the support post wherein a vertical mounting shaft extends from the second hub portion for supporting an optical accessory. A parallelogram structure extends between the first and second hub portions such that the second hub portion may be moved vertically relative to the first hub portion about a second horizontal axis located at the first hub portion while maintaining the mounting shaft in a vertical position. Further, the mounting shaft for the optical accessory maybe rotated about a third axis along the longitudinal axis of the shaft to position the optical accessory at different locations around the second hub portion. The weight of the optical accessory is counterbalance by a tension spring which biases the parallelogram structure to a horizontal position and thus counteracts the weight of the optical accessory. The support arm is further provided with a locking lever mounted to the second hub portion for simultaneously locking the support arm against movement about the first, second and third axes.