The curvy metal paddle and the squarish lever operate in tandem, to press down on or release pressure from the bobbin, whilst winding. Pressing the[ATTACH=CONFIG]416066[/ATTACH][ATTACH=CONFIG]416066[/ATTACH] squarish lever causes the curving metal paddle to snap down onto the bobbin, keeping it in place and causing an even winding of the thread. Then, when finished winding, one touches a finger to the underside of the metal paddle and it releases up. As it does this, the square metal lever also returns to its original position. None of these motions affect the position one way or another of the bobbin winder itself, which has all the time been in contact with the handwheel. Here are two closer photos, which show the bobbin winder paddle in up and down position:[ATTACH=CONFIG]416065[/ATTACH]