However, the modern hybrid as implemented by Toyota, Ford, Honda, GM and others has its origins in the 1960s. The basic premise of combining an electric motor/generator with an internal combustion engine and a geared torque blending mechanism was born not in Japan or Germany but in southern California.
Dr. Baruch Berman, Dr. George Gelb, and Dr. Neal Richardson of TRW Inc. Power Systems division devised the first working example of hybrid electric drives we see today. Patent #3566717 was issued in March 1971 and several other patents were ultimately issued on related technology. The first working example was installed in a 1962 Pontiac Tempest in order to satisfy the patent examiners. It wasn't until a quarter century later that electronic control and battery technology advances allowed Toyota and Ford to finally develop systems robust enough to withstand daily use. You can check out the 1971 patent here.
[Source: Automotive Design and Production]