Input: green helical gear.
Output: yellow rack slider having rotary and linear motions at the same time.
Blue helical gear is fixed to the blue carrier. The latter has small satellite spur gear (in pink) which is in mesh with grey stationary face gear.
Large spur gear (fixed to the shaft of the small satellite gear) is in mesh with the yellow rack.
The mechanism can be self-locking if transmission ratio of the helical gear drive is large enough.
This video was made on request of a YouTube viewer.