It's not a patent infringement case, it a trade-dress case, Basically, Ruger is saying that the shape and appearance of the 10/22 are a 'trademark' and T/C's copy is too much of a copy.
Yes, there are some Rugers that are copies, the Blackhawk, the SR1911, and Mini 14 come to mind. A few things are different in these cases, 1) the 1911 was produced by many companies in the past, so trademark exclusivity is almost impossible to prove, 2) Colt's never bothered to sue anyone over the issue of copies of the Model 1873 Single Action Army Pistol, because the SAA was not a big part of their revenue, and there are quite a few visual differences between the initial Blackhawks and SAAs, and 3) the Mini 14 is actually not a very accurate copy of an M14, and in any case the design of the M14 is Government property.