New Holland was the first manufacturer to integrate a metal detector and a corresponding sequencer into its forage harvesters to protect the chopper units.
Here is the related patent from 1973:
https://worldwide.espacenet.com/patent/search/family/023472937/publication/DE2430147A1?q=DE2430147
The automatic adjustment of the shearbar, which is now standard in all forage harvesters, was originally a New Holland invention. Here is the corresponding patent from 1987:
https://worldwide.espacenet.com/patent/search/family/021941082/publication/DE3855398T2?q=EP291216
This application is about a screen that is intended to prevent the cooler fan from sucking feed dust or corn juice emerging from the cracker into the cooler: