I got my company's truck stuck the other day. Lucky it was at a school so a few of the boys pushed me to freedom. It was a light-ish truck and they are trainee builders. I was then stimulated into thinking about how I would have done on my own. Can a tire iron be attached to a hub?
How about an adjustable length bar with a ratchet lever point at each end. The bar is placed across the circumference of the wheel. At each point is an L shape pivoted at the corner of the L . The two small L arms hold onto the tire and the large acts as the paddle on the slippery earth . As the wheel rotates the paddle spades into the earth to gain grip but also tightens the device to the wheel.
Because you leave the dirt to go back on the hard, the paddle would be made of high density rubber similar to small digger tracks. And because wheel wells may be tight the paddle arms have to be offset outside the wheel wells.
Caution: Driving on the roads with mud spoons may cause damage to shocks but laughter to small kids strapped in the back.-- wjt, Aug 09 2014 Animal toy truck https://www.youtube...watch?v=4cq9GN1X1Qc [EnochLives, Aug 09 2014] Riiiiiip http://i00.i.aliimg...7/477974387_800.jpg [rcarty, Aug 15 2014] It is a good idea and I've not seen anything like it.
I wouldn't have it adjustable, though, because any adjustment mechanism is going to be a weak point, and the thing will have to be strong because of the high torque.
Better to have one model for each vehicle. I don't know how you planned to attach it to the wheel - I presume you'd remove two (opposite) wheel nuts, then use them to bolt it across the hub. You might need longer nuts to do the job, which would be supplied with the paddle.
[+]-- MaxwellBuchanan, Aug 09 2014 There is an older RC toy with wheels that sprout spoon shapes when the tires lose traction, but I can't remember the name of the toy and I'll be danged if I can find it using generic terms.-- 2 fries shy of a happy meal, Aug 09 2014 I had one of those [2 fries]. See link.-- EnochLives, Aug 09 2014 That's the one!Thank you. It's been bugging me all morning.-- 2 fries shy of a happy meal, Aug 09 2014 What if you just used tire chains? Get the type that can be fully attached without moving the vehicle.-- scad mientist, Aug 14 2014 How is this more convenient than a winch?-- bs0u0155, Aug 14 2014 Wenches can be challenging...-- normzone, Aug 15 2014 What kind of truck how many axles we talking about? I can't image why any rear wheel drive truck, which is typical could get the front wheels stuck.-- rcarty, Aug 15 2014 Was the ass end of the truck in the air? Anyway, I've seen every fuck up possible with trucks working as a mechanic. The worst thing I did was tear the entire length of a trailer cover on the side of a bay door. It was an expensive one, but the shop covered it. like this link but more expensive than pvc.-- rcarty, Aug 15 2014 //stuck// A drop from the apron to the ground - 6-7" will do it: the drive wheels on an unloaded arse end can't get near enough traction to pull the front end almost straight up half a foot by pulling backwards.-- FlyingToaster, Aug 15 2014 [flyingtoaster] is right. Now that I think about it, there's no way it has enough weight to counterbalance the block in the front end. Turning the wheels would actually kick the back end off the ground. But it does seem obvious that your solution to tow the truck out would work.-- rcarty, Aug 15 2014 random, halfbakery