Patio door tandem roller 30410 or patent number 4194266

There are a lot of possible matches for that patent. To be honest, patent numbers aren't the best way to identify a part, since they can cover a wide range of hardware. Start by looking at our 81-018, 81-149, 81-141 and 81-137 and carefully compare each one to your own part. If none match, please remove your roller from the door and show us pictures of it so that we can find a better match.