I'd also ban the assigning of patents to corporations; they would only be owned by the original people who filed them. So corporations could only benefit from those patents as long as the patent-holders were employees (or at least one of the patent-holders if there's multiple), by being allowed to use the patent license-free.
>I understand that we can't just ban the selling of patents
Why not? We can ban anything we want as long as it's not unconstitutional. The question is if a ban of something has more negative effects than positive. I don't see how it would here.
Even if we accept patents, then you can be required to partner with a manufacturer within a certain period of time. This kind of thing might already exist if we compare it to the record labels for turning copywritten songs into fortunes for labels and authors. Similar middle-men would show up plus DIY kits, consultants, and advice on doing it yourself. The risks you face wouldn't be much different from the current market where trolls like Intellectual Ventures convince broke patent holders to give it to them for pennies using pressure of their bargaining power then make millions off them in law suits.
It is a long way from a patentable idea to a marketable product. So what happens when the patent originator lacks the competencies or capital to produce at scale? If selling a patent was banned, both the innovator and society would be denied any benefit from the innovation.