U.S. patent law Edit
An apparatus claim is a patent claim that describes define a device or system that usually has active components. An apparatus claim defines the invention in terms of the components of the invention, that is, in terms of what the invention is as opposed to what the invention does. The Patent Act also permits an apparatus claim to be defined with means-plus-function elements.
An apparatus claim can be identified by the terms in the preamble. Although apparatus claims have more variation in the terminology used in the preamble than method claims, the preamble of an apparatus claim frequently includes one of the following terms: “apparatus,” “device,” or “system.”
An apparatus claim is different than a method claim because an apparatus claim generally describes the components of the device or system in terms of physical or structural characteristics. An apparatus claim is infringed by the actual device or system.