Patent attributes
An armrest includes an armrest support and a subassembly supported thereon for vertical adjustment by a height adjustment device having a rotatable high-lead-angle threaded shaft, a mating nut, and a trigger. The shaft member is rotatable upon a vertical force being placed on the subassembly, and the trigger engages the shaft to prevent rotation and fix a selected height position. The subassembly includes a housing, an armrest cap, and a pair of swing arms pivoted to each of the housing and cap for adjustably supporting the armrest cap for rotational and translational horizontal movement. Horizontal adjustment is controlled by choice of materials, a frictional wave spring and dampener. Optionally, the armrest cap includes a keyhole slot and one of the links includes a configured protrusion shaped to selectively linearly slide along a long part of the slot . . . or rotate in the circular end of the keyhole slot.