Let me play devils advocate here for a minute..
You get a patent. You're beginning to knock out some "devices". I copy your device and start selling them while you're new venture is in its
infancy.. What do you do

What can you do
You send a cease and desist letter... That'll probably cost you.. I ignore it and keep making widgets.... Now what do you do? What can you do?
Now you have to go the court route.. I'm still making some widgets and selling them, and making money... Now you are paying a lawyer to do all
kinds of lawerly crap, instead of producing product.. I just bought a new machine to make your widget cheaper, you didn't because you had to
pay a lawyer.
2 years down the road, my company, which is an insulated shell and owns nothing, has made and sold a 1000 widgets and kept very careful records and booked
a total of $462 in profit. And just before trial time, I say "OK, I'll stop".. Are you going to throw another $10k out the door to go to trial and get that $462

?
Just pointing out that you can get a patent, and there is nothing wrong with that, its a cool thing to do, an accomplishment, you came up with something cool...
Even better, its something you want to actually make and sell, and that's really cool too. (that's actually cooler than a patent)..
Nobody is going to defend your patent for you.. Its YOUR patent, its YOUR job to defend it. You have to PAY to defend it. If you can't PAY to defend it,
then its not even worth the paper its written on.
Then we run into all the other patent BS.. If you start digging.. And digging... And Digging.. You will most likely find that your patent isn't all that original.
There has been well over 100 years of people patenting whacked out stuff to get gold... And then even if you do have an "original", a little tweak, or improvement,
and your patent is worthless.
I'm just pointing out that I believe going the patent route isn't going to protect your product in a way you think it will. Its really nothing more than a certificate
that allows you to PAY to sue other people.
Make your money with reputation and quality.. Maybe trade mark a catchy name, BAZOOKA gold trap and GOLD CUBE come to mind. Think Kleenex and Band Aids.
Nobody wants to buy a "Joe's Plastic fluid bed sluice".. They want a BAZOOKA!!!!
I hope it all works out for you, and if your "widget" doesn't require naturally running water, I might even buy one.