Breguet 2-Pin Stop-Work
The left animation below changes δ to 11° and, consequently, the center distance also changes.
The right animation uses a small annulus. My interpretation of Breguet's notes makes a small annulus impossible and that design can only wind the mainspring 3 turns. However, if I am wrong then a small annulus can be used if the arbor wheel is changed appropriately. This animation is based on the shape of the arbor wheel illustrated in Daniels "The Art of Breguet" and achieves about 3 1/4 turns, not a big improvement!