Blind Double Dovetail Joint

I used this joint once in the past for a student's project. I stumbled across a need to use it again while iterating on an end table design. It allows dovetailing a board into the face of another board with no obvious entry point. Drop in.  Slide over and the board won't pull out. Dovetailed sections with a slight taper do the job. 

The taper of the dovetail keys makes them easy to insert but wedge up tight when slid over. 

Cherry 4" wide into mahogany face 

I'm toying with a way to lock the joint in place when assembled.  Of course gluing them would work. This is to connect them without using glue.  First idea would be to use a spring loaded pin that would pop out and prevent the joint from sliding back to remove. Another idea is a pop-up plate that blocks the dovetail section from backing up once passed. Conical springs behind the plate would allow it to be pressed down out of the way when the board is first inserted, but then pop up when it slides over.  

Drop in, slide over for a snug connection.

Should I come up with a locking idea it'll mean the boards will need to be sanded and a finish applied before final assembly as they won't come back apart. The fit can be tested before the locking pin or plate is put in place. 

I used a 1/8" spiral end mill to removed most of the area before the dovetail bit undercut the edges. 1/2"d 14° dovetail bit.  On the cherry board end a 1/4" spiral end mill was use to pocket cut the areas between the dovetail section. 

As the joint is only 1/4" deep it could be done on the opposite side as well. You could simulate a board that passes through another board.  Using my angle clamping jig and some careful layout the board could intersect at any angle up to 15 degrees or so from perpendicular. Rotate the joint intersection for a compound angle appearance. 

4D