Some of you out there may already be familiar with this search feature, but for everybody else, it's just a hidden goldmine waiting to be explored. Google Patents searches within a library of currently 7 million patents. Almost all of these have more or less detailed drawings included. Perfectly suited as blueprints or references for 3D modeling!
From the Google Patent Search FAQ:
All patents available through Google Patent Search come from the United States Patent and Trademark Office (USPTO). Patents issued in the United States are public domain government information, and images of the entire database of U.S. patents are readily available online via the USPTO website.
Google Patent Search covers the entire collection of patents made available by the USPTOâ€”from patents issued in the 1790s through those issued in the middle of 2006. We don't currently include patent applications, international patents, or U.S. patents issued over the last few months, but we look forward to expanding our coverage in the future.
The range of things you can find with Google Patents is huge, and the included blueprints are often extremely suitable as blueprints for 3D modeling. Here are a few quick examples of what one can find with Google Patents:
Go to Google Patents and try it out for yourself. It's an instant bookmark!
... So, who can find the most crazy blueprints? (Like underwear, for instance!)