XPATH is your friend! Something like this will get you the inventors name:

HtmlWeb w = new HtmlWeb();
HtmlDocument doc = w.Load("http://www.google.com/patents/US3748943");
foreach (HtmlNode node in doc.DocumentNode.SelectNodes("//div[@class='patent_bibdata']/br[1]/preceding-sibling::a"))
{
    Console.WriteLine(node.InnerHtml);
}