Engaging Gears Perpendicular to Shaft Direction?

[Matt Adams]

Many teams, most with reasonable success, have made shifting transmissions by engaging gearsets by sliding gears along an axle with the proper distance between the gears for the correct mesh. This is shown as a top view on my fast sketch below.

What I'm wondering is if there have been any teams that have attempted, with or without success, to engage gear sets in a direction perpendicular to that, as shown as a side view in the sketch below.




1. I am aware this is more difficult
2. I am aware that you need to be careful about backlash and proper spacing
3. I am aware that you run the risk of stripping teeth due to the possibillity of teeth prematuring engaging on the outter-most edges instead of at the pitch diameter.

All that aside, has it been done?

Thanks in advance.

Matt