by sevesteen » 23 Sep 2019 5:27
Had it explained to me elsewhere, then confirmed by disassembly of my 930. The center actuator (the part with cutouts for the balls) is spring loaded. When you operate the key, it is biased towards closing, but when the shackle is open it is blocked by the balls. When the shackle is fully closed the balls move into the shackle cutouts and no longer block rotation.