No matter how well I wipe my feet at the mat, I still manage to bring the outside in, thanks to the deep treads in my sneaker.

Imagine, though, if you will, a sneaker sole made from two separate, interlocking treads. A dial on the side of the shoe retracts the first while simultaneously extending the second. two passes on the mat, and your clean as a whistle!
-- dbsousa, Jan 20 2004

What about if the 'tread' was above a smooth flexible membrane. You then dial in/out the knobbly bits when you want grip and dial them back in to make the surface flat. The membrane is there so all that dog-do, fag-butt, sticky-bud and chewing gum will not get stuck between the two sets of tread.

Alternatively, in my house shoes are not allowed in past the hall. BOOTS OFF! A very sensible practice from the East (I am amazed watching Friends etc when they lie on the sofa or bed with skanky sneakers on! - yuck!)
-- timbeau, Jan 20 2004


Imagine two combs, tines facing each other, but out of sync so that the tines of one line up with the gaps ofr the other. The same mechanical action raises one comb and lowers the other, so that when one comb is the positive tread, the other is the negative tread.

Or is that even more obtuse? I can't tell anymore...
-- dbsousa, Jan 20 2004


while I think this is an amusing concept, I think those loose-ish tines would wear away quite quickly. make 'em metal.
-- po, Jan 20 2004


Better still, wear platform shoes with thick treads within the platform. As the treads wear down, use a lip-stick-like screw to feed more out. Also retractable for cleaning purposes.
-- lostdog, Jan 20 2004



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