For me the Dahon Curl is not a clone, even if its a derivative of the Brompton, its really a new tri-fold design with major differences in its frame design, not just some other components mounted a frame almost identical to the one of the Brompton like almost all Chinese Brompton clones.

For the patent issue, the Patent Pending claims and suing a competitor for patent infringement, many companies do that for many products knowing very well that at the end there will be no patent issued for the claimed Patent Pending nor any patent infringement judgement. Its just a manner to slow down the introduction of a new competitor product.

Brompton now knows that it won't work again and took another approach to fight against competition, i.e. developing real new bikes, first the T-line which is a real new titanium Brompton and not a classic Brompton frame built with titanium tubes instead of steel tubes like the Chinese titanium clones, second the G-line which is not a classic Brompton slightly enlarged to fit 20" wheels like the for 20" Chinese clones.