There must be many ways to find numbers to search for. The way I do it anyway is firstly to go to the website:
http://www.google.com/patentsThere you can type in the patent number stamped into one of your locks and find out a lot about who thought of it, who made it, how it works, etc.
The main method I use though is to simply search for a name. A lot of maufacturers list their locks under the name of an individual, rarther than the company name. This makes searching for a specific patent quite difficult sometimes. However it is well worth doing anyway, searching for "medeco" for example pulls up a fascinating collection of ways of picking them.
When you click on the link at Google Patent search, it brings you to a summary page, where you can click on "Download PDF". You might want to look a little further down the page first, as you often get the Patent numbers of related inventions under "Citations" and "Referenced by" that are frequently of considerable interest as well.
