How did Linus Yale adapt the ancient Egyptian pin-tumbler principle?

Linus Yale Jr. evolved the ancient Egyptian pin-tumbler principle into the modern cylinder lock by miniaturizing the mechanism and introducing a small, flat key with a serrated edge.12

While the original Egyptian design utilized a large wooden bolt and a bulky, toothbrush-shaped key to lift pins, Yale’s adaptation refined this into a compact metal cylinder. In his design, the serrations on the edge of the key raise a series of internal pins to the exact height required to align with the cylinder's shear line. Once these pins are properly positioned, the cylinder is free to revolve, allowing the lock to be operated. This innovation, combined with the varying heights of the pins and the warding effect of the key's shape, created a highly secure mechanism that remains the most common lock and key system in use today.123