This feature was also existing in some Borg-Warner transmissions made over the fifties. It fell outside of favor in subsequent decades because of its further complexity and value. In the late 1970s lock-up clutches started to reappear in response to needs for improved fuel economy, and are actually practically common https://angelopomml.blogsvila.com/34124016/new-step-by-step-map-for-torque-converter-clutch