Patent ID: 7789025

Claim:
A height adjustment arrangement for an upright member located adjacent a support structure, comprising: a guide arrangement for guiding vertical movement of the upright member relative to the support structure, the guide arrangement including a bracket arrangement attached to the support structure and having guide areas engaged with guide grooves formed in the upright member; and a constant force spring arrangement interposed between the guide arrangement and the upright member, the spring arrangement including a spring cylinder and a spring band extending from the spring cylinder and attached to the upright member to apply an upward biasing force on the upright member, the constant force spring arrangement including a mounting screw connected to the bracket arrangement and extending through a passage formed in a bushing located in the spring cylinder, wherein the spring cylinder is rotatable relative to the bracket arrangement about the bushing, the spring band being configured to counterbalance the weight of the upright member and hold the upright member in a plurality of desired vertical positions relative to the support structure without requiring any locking device.