Magic Lever is Seiko’s trademarked name for a pallet lever mechanism: a small, scissor-shaped part that winds the mainspring in a self-winding watch. It winds whichever way the oscillating weight turns. It does this with fewer parts than the reverser or planetary gear systems other makers used when it appeared in 1959.
How does the Magic Lever work?
The lever sits on an off-centre, or eccentric, pin. As the rotor spins, that pin moves the lever up and down. It does so whether the rotor turns clockwise or anticlockwise. The lever has two arms, each carrying a spring-loaded pawl. The two pawls have different shapes and face opposite ways. One pushes the transmission wheel and the other pulls it, and they take turns. So every movement of the lever drives the wheel. This makes it a bidirectional winding system: the rotor winds the mainspring in both directions.
Where it comes from
Seiko developed the Magic Lever in 1959. Grand Seiko credits Suwa Seikosha, the company now called Seiko Epson. At the time, self-winding watches, Swiss ones among them, turned rotor motion into winding with reverser or planetary gear systems. Those were more complicated and more costly. The Magic Lever did the same job with fewer parts, and it proved simple and reliable. Seiko later refined the original design and fitted it to its Five watches.
Which watches use the Magic Lever?
Grand Seiko automatic watches of the 1960s used it, including the 62GS and the 61GS. It is found in many Seiko automatic movements, both vintage and current. For the 9RA calibres, Grand Seiko created a variant called the Offset Magic Lever. In this version the crank wheel sits away from the centre of the movement.
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