US Patent 7841570 Keyboard support mechanism

A keyboard support mechanism containing a novel articulating arm mechanism for permitting vertical movement of the keyboard shelf. The articulating arm mechanism has six major components: (1) a mounting bracket, (2) a mounting bracket support in combination with a swivel bracket, (3) a shelf bracket, (4) an upper arm, (5) at least one side arm, and (6) at least one stopping surface. The upper arm links the shelf bracket and the mounting bracket; the side arm and the stopping surface cooperate to keep the shelf bracket (and hence the keyboard shelf) at a constant angle relative to the ground.