The design patent is the companion to the utility patent. Design patents protect the form of an “article of manufacture.” Design patents protect the effort to create aesthetic innovation. They are simpler to formulate than utility patents and are as vague as a utility patent is precise. The design patent is a sketch or two of a design. If another design looks like the one drawn in the figure, it is in violation of the patent. A design patent generally has a more subjective interpretation, relying on an aesthetic viewpoint. Because design patents are relatively simple to formulate and much less expensive than a utility patent, one technique that companies use is to not only protect the final design form, but to also protect a satellite of concepts used in the development of a product form. Every major form concept considered can be patented. This design patent protection strategy was a technique used by Black & Decker in protecting the snakeLight hands-free flashlight and proved effective in litigation against several knock-off products.
in contrast to a design patent, a utility patent is precise, and expert wordsmiths craft the claims. For example, if the claim includes a word such as handle, as with the Swiffer utility patent, a legal challenge might question what the definition of handle really is! Although it is much more expensive than a design patent, companies still create layers of protection through satellite patents, much more strategically and generally building off the main patent.
The Swiffer has two design patents on the dry mop and two more on the WetJet. The design patents for the dry Swiffer show the form of the entire mop system, including the textured handle, long pole, and flat head. The pivot function is not relevant to the design patent, but its integrated look is. The additional patents for the WetJet focus on the look of the grip and the reservoir.
Although in the United States, utility patents last for 20 years from the date of submission to the patent office, design patents last only 14 years from the time the design patent is granted. The courts seem to recognize that styles change quicker than technology. in some industries, such as clothing and fashion, both utility and especially design patents are used sparingly because every six months or less a new style is introduced, making it difficult for competition to remain current even without patent protection.
Once a patent expires, anyone can produce a product that functions or looks exactly like that described in the patent. Savvy companies will submit new patent applications constantly as they take an evolutionary approach to innovation surrounding a product, improving features and updating styles to maintain the competitive edge.