Maybe it's for bearing efficiency? Note that the spur gears are rigidly attached to, respectively, the crank and the shaft. So they don't require bearings at their centres. There is a link arm which pulls the gears together, and that rotates. But the key is that this arm is not transmitting the cranking power; it just holds the parts together. So its bushings/bearings don't have to be so hefty. (Their load is going to be proportional to the transmitted power; obviously the bigger the crank and more horsepower going through it, the more tightly you have to hold the gears together. But it's going to be some fraction compared to a bearing that is directly driven.)
The note only alludes to this mechanism being used to elude a patent claim, not mentioning any advantages. Someone had patented cranks in such a way that you can weasel your way out with this arrangement. I'm guessing that the patent's drawings and descriptions specifically indicated a rotating bushing on the crank wheel where the arm is attached, and this has no such arm attachment.