While cleaning up the hard drive on my laptop, I came across a list of patents I’d found via Google’s Patent Search. Only one of them has anything to do with hollowbody basses, but they’re fun to look at.
If you find any cool/historic/unique patents that I missed, post a link in the comments!
Up first, “Electric Bass Guitar and Elastomeric Bridge Therefor“:

Gibson/Epiphone/Norlin Patents:
Peavey Patents:
Fender Patents:
The Classic – 1959 Precision Bass
Modulus:
Mosrite:
Kent:
Patent art can sometimes be crudely drawn, or in some cases, drawn well but just plain ol’ funny. Check out this image from Patent #7030304:

