Found a 1906 patent :-)

https://www.google.com/patents/US860536?dq=roller+pinion+patent&hl=en&sa=X&ei=DGUlUuDvAciEjAKP34D4Aw&ved=0CDQQ6AEwAA


The epi and hypo scripts do not form this shape, I guess.

Still doing research...

-Brian