In the early 1980s Henry Juy, the owner and CEO of Simplex, was on a crusade to produce an effective but very cheap, very low-end, derailleur in up-market, high-wage-cost, France. His answer to this problematic contradiction was plastic injection moulding.
French Patent # 2,520,693 was all about moulded plastic pulley cage plates. This patent takes the next step, describing a variety of low cost designs for the parallelogram. It even features a plastic parallelogram formed in a single piece, with thinned flex-zones replacing pviot pins.
It's all so futuristically cool - but bike mechanics everywhere will thank God that none of it ever came to pass