Yellow rack is stationary and engages with pink small pinion of a block of two ones.

Tooth number of large pinion is twice that of the small one.

This mechanism is not good solution for synchronously sliding windows however it can be applied for other cases where the gears are driving (actuator must be on the left panel).

► In case two pinions are of equal tooth numbers:

- If the pinion block or left panel are driving, only the left panel moves, the right one is immobile.

- If right panel is driving, both panels are stuck.