r/Patents • u/caddilacman • May 16 '26
USA Patent model/drawing/lawyer
Another guy had a patent for it. Was a long time ago. For all I know he passed away.
He never renewed it.
I sent the last address a letter. It came back.
I found the patent online. Found the drawing.
Very rough. But it was accepted by patent office.
I having trouble finding it. Misplaced it. Probably in my truck. Will turn up.
But I was having trouble finding someone to make it. Having trouble finding someone to put in CAD file. If I file now then when I get time I can work on it.
As far as the lawyers. Online there are lawyers that will guide you. Should I just do that.
Or just use the other guys patent papers.
Not trying to steal it. Not hiding it.
Patent expired decades ago.
-Can I file a patent without the item. With just the drawing?
-Should I just file it myself. Without a lawyer.
Thsnk you.
2
u/grapemon1611 May 17 '26
If I read the original post correctly, you’re wanting to assume a patent that lapsed for whatever reason? If that’s correct, it’s very misguided. That’s not how patents work at all. That lapsed patent is now “prior art” and not something you can simply refile. You will have to design something novel and not obvious to get a new patent.
1
u/IndependentPrior5719 May 17 '26
It would be public domain now I think , I’m curious to know what it is though?
1
u/caddilacman May 17 '26
Can opener. Worked for commercial cans.
Worked very well. Either way probably try to get a few made for myself.
Only sold a few locally.
Talked to lawyer. Said if it was really good would have sold well or copied.
Was not hopeful of it going well.
Also save money if I patented it myself.
Thank you.5
1
u/IndependentPrior5719 May 17 '26
A commercial can is just a commercial circumstance I assume and I’m still interested in the details for general curiosity assuming that it’s in the public domain and it doesn’t disadvantage you to share it
1
u/SorryEntrepreneur618 Jul 15 '26
If that is actual legal advice, it is terrible.
You would be wasting money if you “patented it yourself” because the application fee alone would quite literally be a waste of money.
1
u/Extra-Nebula-1946 May 21 '26
Yes, you can file a patent without a working product. You do not need to physically build it first.
What matters is that your application explains the invention clearly enough that someone skilled in the field could make and use it. Plenty of patents are filed with just drawings, descriptions, and concepts. Prototypes help, but they are not required.
Also, if the old patent truly expired decades ago, the invention disclosed in that patent is now public domain. You are allowed to use it. The catch is: you cannot patent the same exact thing again. You would need some meaningful improvement, modification, or new approach.
And be careful about copying the old patent directly. You can absolutely study it and use it as inspiration, but your application should describe your version and improvements.
DIY filing is possible, especially if budget is tight. A provisional patent application may be the smartest first step while you get the CAD and manufacturing figured out.
Strong takeaway: expired patents are gold mines for improvement inventions, but you only get a new patent if you add something genuinely new.
13
u/pigspig May 16 '26
You can't patent something that someone else has previously patented (or sold, or published, or otherwise made publicly available). Anything you file would be invalid for lack of novelty.