Canon 7 How To Use Manual page 10

The lever will return automatically when released. It will not return
to the original position, i. e. close to the body. It will be about 1/4"-1/2"
from the body. But you can advance the film from this position. When
the camera is not in use return the lever to its original position against
the body.
Several short strokes, instead of one full stroke, can be used to
wind the film. The lever locks when winding is complete.
When the film is loaded, sometimes winding is not completed in
one full stroke for the first film wind. If such is the case, the shutter locks and cannot be depressed. To obviate this
situation, it is advisable to wind the lever twice for the first film wind.
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