When looking at interesting mixers I came across a mechanical engineer that does animations.
Some may not be very practical, but it kinda cheered me up that there are still people out there thinking up interesting solutions.
Artofex like mixer. https://www.youtube.com/watch?v=6ktLcEOzY9o
https://www.youtube.com/watch?v=gYksowpfhFY
2 speed whip https://www.youtube.com/watch?v=ZJdrYD-DPnM
One arm reversing. https://www.youtube.com/watch?v=iNl0R_26HSE
One arm speed change. https://www.youtube.com/watch?v=E_QsGY1Rz7E