Input: orange shaft.

Yellow and blue shafts receive rotary motion from orange input shaft through two worm drives.

The green worm has prismatic joint (sliding key) with the orange shaft.

Turn violet screw for moving pink slider and green worm to adjust relative positioning angle between yellow and blue rollers.

The adjustment can be performed even during transmission.

The self-locking of the violet screw preserves the adjusted angle from accidental motion of the green worm.