Don't have name for this or know who invented it. This device was in a Fine Woodworking article a while back so I can't take credit for the invention. This weekend was the first time that it got a good workout. I have seen a similar device made from a sheet of plywood with varied slots but chose this style since it can be knocked apart and stored in the bottom of my bench. It can be adjusted easily to fit snug to fit inside a drawer. Knock the tapered wedges out, adjust to the desired width and whack the wedges home again. Built from maple and birch.
The contraption below is what I refer to as my sandplane. I have the 150 grit blade attached. It makes quick work of smoothing dovetail end grain. I fit drawers bass ackwards compared to what I have seen online. First I make the front and rear boards "line to line" with the carcase opening and cut the front and rear dovetails ever so slightly deeper than the side thickness. After glue up I sand the front and rear board end grain down to meet the sides.