Search Patents
Patents are a rich and readily available source of teclmical information containing detailed drawings and explanations of how many products work. The main disadvantage of patent searches is that concepts found in recent patents are protected (generally for 20 years from the date of the patent application), so there may be a royalty involved in using them. However, patents are also useful to see what concepts are already protected and must be avoided or licensed. Concepts contained in foreign patents without global coverage and in expired patents can be used without payment of royalties. See Chapter 16, Patents and In tellectual Property, for an explanation of patent rights and how to understand patent claim .
The formal indexing scheme for patents is difficult for novices to navigate. Fortunately, several databases contain the actual text of all patents. These text databases can be searched electronically by key words. Key word searches can be conducted efficiently with only modest practice and are remarkably effective in finding patents relevant to a particular product. Copies of U.S. patents including illustrations can be obtained for a nominal fee from the U.S. Patent and Trademark Office and from several suppliers. ( ee the Web site www.ulrich-eppinger.net for a current list of online patent databases and up pliers of patent documents.)
A U.S. patent search in the area of nailers revealed several interesting concepts. One of the patents described a motor-driven double-fly wheel nailer. One of the illustrations from thai patent is shown in Exhibit 7-5. The design in this patent uses the accumulation of rotational kinetic energy in a flywheel , which is then suddenly converted into translational energy by a fi-ictionclutch. The energy is then delivered to the nail with a single impact of a drive pin.