There are rocking wheelchairs on the market but I can find no mention of using this rocking motion to actually propel a chair.
A simple ratchet mechanism would convert a forward rock into forward movement while the energy from rocking backwards could be stored to augment the next forward motion or saved to help with ascents.
Incorporate a gear system and these things could get up some serious speed on level ground.
"Outta my way you whippersnappers!"-- 2 fries shy of a happy meal, Nov 11 2013 Davinci Awards http://www.davinciawards.org/ [JesusHChrist, Nov 12 2013] Changemakers http://www.changemakers.com/ [JesusHChrist, Nov 12 2013] United Cerebral Palsy Life Labs http://lifelabs.ucp.orgThey might be into it too [JesusHChrist, Nov 14 2013] This idea wheely rocks!-- pashute, Nov 11 2013 Wheely?You're not just swaying that are you?-- 2 fries shy of a happy meal, Nov 11 2013 2fries, do you allow me to open a design challenge on changemaker.com, so we can design and prototype?
Or could u?-- pashute, Nov 12 2013 If you two form a joint venture, 2fries is chairman. Great idea. [+]-- AusCan531, Nov 12 2013 You certainly may do the design challenge thing [pashute] since I haven't heard of Changemaker.com before.-- 2 fries shy of a happy meal, Nov 12 2013 Submit it to the Davinci Awards.-- JesusHChrist, Nov 12 2013 [+] Just for fun can I also have a spinning propeller on the back of it? Very cool!-- xandram, Nov 12 2013 OK, will do, and will post back here.-- pashute, Nov 13 2013 Waiting, pashute. + For the fun idea.-- blissmiss, Nov 13 2013 Alternatively, instead of a chair it could be one of those rocking cradles. To generate power simply pinch the baby.-- rcarty, Nov 14 2013 random, halfbakery