What are you asking...??
If you build a two pulley twist clutch set up...AND...get the slack and leverage right it will operate smoothly...
It "looks" reasonable from the picture, ...your on the right track...but you will have "some" tweaking to do to it (especially if this is your first one)...
Suggest drilling a couple holes in bar for hinge point adjustmen and having a couple different size pulleys (or belts) available to "fine tune" the action once you get it built and installed...
You may also have to experiment with a couple different spring sizes and strengths...as well as playing with pedal length and leverage...