Who's copying whom?

The 'Atkinson' engines used in the Prius aren't real Atkinsons, but Otto cycle engines, modified to use a Miller combustion cycle.

James Atkinson gave his name to a combustion/valve-opening cycle he developed in the late 19th century, having observed and talked to the valve-operators, on the four stroke engines used in pumping out mine water in the later Victorian period. These were fueled by stuff like finely-ground coal dust, blown into the combustion chamber using belllows, and had a very slow rotation rates. It had long been known that a perfect rhythm, in hauling on the valve levers, to open and close them, would lead to the best power output from such engines, and a good valve operator (who knew the rhythm) was a highly prized man.

Atkinson's interest was spurred by this, and he went on to study the effect, described the maths involved, in an idealised valve-overlap system, for a four stroke engine back in 1882: the Atkinson cycle. So good was this work, that the effects, first seen in engines with rotations as low as 1 rpm, still hold true for modern four strokes, of 18,000 rpm.

In order to evade certain patents, held over the Otto cycle engine, however, Atkinson used an ingenious tripple crank mechanism to achieve just one turn of the primary drive crank, per four strokes of the engine. It was totally superfluous to the actual effect, but did get around getting sued by the patent holders. This is why the 'Atkinson' engines in modern cars are not true Atkinsons, but Ottos, that use the Atkinson cycle.

Ralph Miller's idea, of 1940, was to supercharge the inlet of an Otto engine, running an Atkinson cycle, overcoming the low power-density of the Atkinson engine. His engines were intended for Marine and static power-generation use, and were heavily patented. This led to the automotive industry largely disregarding this type of engine for road use - just as Rudolph Diesel's successful patenting of the compression-ignition engine, meant that the less efficient carburated Otto engines were used in most car and motorcycle engines for much of the last century.

So there you go: if you like (and many of you will, of course) we can conclude that patents are so evil, they actually lead to global warming (unless your names happen to be 'Lewis Page' or 'Andrew Orlowski', of course - in which case global warming is caused by Stephen Fry).