Link 4 slides along axis x-x in a fixed guide. Link 2 slides along axis y-y and has, at its end, wedge-shaped tooth spaces a-a. Rack 1 slides along axis z-z and has wedge-shaped teeth b. Link 3 slides along axis q-q and has wedge-shaped tooth spaces c. Rack 1 is traversed by advancing link 2 into engagement with teeth b and retracting link 3 out of engagement with teeth b. Then link 4 can be pushed to the right with rack 1.
$2182$WL,SD$