The driving mechanism of the Mercedes model 8

The disengagement of the Mercedes Euklid 8 numeral wheels differs from the one of the 29 model. The gears at the top are forced away by the toothed rack. their thickness is half of the thickness of the gears below attached on a bar that oscillates from top to bottom.

The thickness of numeral wheels gears (not visible on the movie) is also the half of those of the oscillating bar. They are placed close to the top gears (the axis are in prolongation each to each). the total thickness of these two gears is equal to the thickness of the toothed rack gears.

When the toothed racks goes, the oscillating bar is in the upper position and his gears are engaged with the toothed racks ones. Being given there thickness, these gears are also engaged with those of the numeral wheels.
When the toothed racks comes back, the oscillating bar is in the lower position and his gears are disengaged. Then the numeral wheels stay at rest.