They have probably run into too many liars without degrees they have listed on their resume or something like that. Maybe they want to know how you did in your core (non-engineering) courses because patent work is different from typical technical engineering work. I don't know what your experience is in submitting patents (if that would be your new job).
My experience in submitting patents would not be reflected on my engineering school transcripts.
I could easily supply my diploma to prove my degrees.