US Patent 10357103 Height adjustable desk

A height-adjustable desk has a base, having a support, a middle portion of a rear side of the support having a column disposed thereon and being upright, a front side of the column having a plurality of slots, the slots being spaced along the column. The desk has a shelf, having a frame, an upper desk top and a lower desk top, the frame disposed on and moveably surrounding the column, the frame having an insert corresponding to the slots, the insert configured to be inserted into one of the slots, the upper desk top located at the frame, the lower desk top located at the frame lower than the upper desk top.