The group's motor-driven fourbar with a symmetrical coupler curve (L3 = L4 = BP). One crank revolution drives coupler point P around the oval. A rigid lazy arm with a weighted moist tip hangs from P on a free pin: it trails as it drags the top page toward the spine, and the page flips over once the tip has carried it past the spine.
Book: 13.5″ wide open (6.75″ pages), 9.5″ deep, pages curled to 0.75″. The arm is a rigid rod on a free pin with a weighted tip and some pin friction, so it swings but settles quickly. The oval sits so a hanging arm would reach 0.4″ below the top page curl, which makes it lean back while it drags. The page flip itself is animated, not a paper simulation.