3/3
Furthermore, depending on the scope of claims, the preferred embodiment device MUST cover the claims as scoped, or you must have the ability to easily modify the device to cover the full scope of claims. You can kinda slide on this part of the requirement as some modifications are taken to be self-evident to a "person trained in the art" - i.e. an expert. if you are not able to furnish such a device, the legal reasoning that would follow in a court decision would be the same as for the method patent.
consequently, unless you plan on patenting the theory/formula itself, you cannot merely describe a device by formula and create a defensible/enforceable patent.
Now the reality is that the USPTO and the PCT collectively receive millions of patent applications a year.Once you apply for a patent, some poor put-upon bastard has to read all of this drivel, a process that can take days, and then has to fill out a rather obscene amount of paperwork on all of it, and then has to send that paperwork to you, giving you a chance to reply and re-scope or submit arguments and so on that same examiner has to read all the stuff you send back, reread the patent paperwork (which has likely been languishing on his desk in the 6 months it took you to reply) then do it all again. this process can take literally dozens of iterations, though an examiner can choose to cut it off with a final office action. even then, however, you have options and can continue making his life a living hell.
Because of this, the vast majority of examiners simply don;t read patents that carefully. if a device for, let's say free energy, comes across his desk, instead of doing his due diligence, an examiner will usually just go "eh, fuck it, they'll never actually make it, I don't want to do the paperwork" and submit the patent to grant.
This is the reason, the ONLY reason, patents like that get granted.
the problem is, if the patent does end up going somewhere one day, perhaps in the hands of a different party than the original inventor, then you end up with a court case, where paperwork that the examiner barely glanced at is suddenly getting literally thousands of man-hours of reading and analysis time by acute and well trained lawyers looking for holes and problems, and as soon as they ask the question of "well, did you build it?" and you can't answer yes, then they can point and say " that asshole had no idea if the device would work, he never built it!" and get your ownership revoked. of course, doing this puts it in the public domain, which prevents them from patenting the same thing, but generally they're hoping to claim something else and your patent is seen as a "stepping stone" to the newer tech, and it has to be in public domain before they can move forwards with theirs.
hope this makes a little more sense.