Help with windup/pull back toy mechanism floating gear placement

[gearsrwellhard]

Hi,

I'm trying to design a windup baby toy (think toy stuck on wall rotating) with a gearing mechanism that works similar to a pull back toy car. Essentially I want to do a three quarter turn of the front of the unit anticlockwise to wind a coil spring via a gear train. When the front of the unit is released/let go, I want the first 'winding' gear to disengage via floating gears and gravity and engage the secondary gear train which causes the front of the unit to spin round as many times as possible. The aim is for around two minutes of slow turning.

I can't fathom the correct position of the moving gears to engage/disengage correctly without locking up. Has anybody experience in this, I would really appreciate it. Prototyping is VERY expensive so I need to figure this out correctly. Even if it's just a point in the right direction.

If you know of any decent reference material on the web I could use for guidance that would be awesome as I can't find anything. I'm not just expecting somebody to do all the hard work for me - although feel free! :)

I'm designing it in Solidworks

Many Thanks

 

[Danger]

Have you considered just pulling or pushing the rotating face in order to switch from one gear train to another? (Think about how a spring-operated watch works; turn the stem to wind, or pull it out and turn to set the time.)