When the ball rolls from the front side, they are supposed to swing up and lock out of the way. From the back they just let the ball roll through. When all 5 are locked up, the bank resets down. Get them in order, you add-a-ball. Get them all in any order and it jacks your spinner value and your bonus multiplier at the end.

I have a working SPeakeasy if you need any other help.

mark

Edit: only one other game has these targets. It's a baseball themed one called Grand Slam, I think.