A claim in a patent application or issued patent should express not only the building blocks of an invention but also the relationships among the building blocks. Understanding and expressing these relationships clearly in a claim is vital for all types of claims. Without the relationships, claims would merely express an unorganized set of elements, such as building blocks. As an analogy, compare a pile of bricks, cinderblocks, steel girders or lumber to a finished building. A claim set without relationships among the elements would be comparable to a list of construction materials. A claim set with relationships among the elements would be comparable to an architectural set of building plans. Continuing with the analogy, the specification would provide a description of the building, giving context to the claim elements. Likewise, the entirety of the claims gives context to each of the claim elements.
Relationships are important in structural claims, but can be elusive in method claims. Often, we wish steps or actions in a method to be broadly claimed so that the steps can be performed in various orders and are not limited to being performed in the order recited in the claims. Other times, the order is specific and the method claim is written to recite steps, in sequence, such as with letters or numerals indicating such a sequence, or with specific mention in each step as to one or more steps that precede that step or follow that step. Other relationships in method claims can describe how some of the physical elements relate to the actions or to other physical elements recited in the claim.
Where the context and the relationships in the claims are clearly, unambiguously developed, there is firm ground to be argued during patent prosecution. When an Examiner from the USPTO issues an obviousness rejection under 35 USC §103, there is no single cited reference which shows all of the elements in the claimed relationship. So, the Examiner and the rejection rely on showing each of the elements in one or more of the multiple references cited. But, if we can show that an element in one of the references does not show that element in the same relationship or the same context as the present claims under examination, we can argue that not all aspects of the claims are shown in the cited references. This is particularly powerful if the reference, which shows the element in question, teaches to use that element in a different manner or different relationship to other elements than what is presently claimed. Both structural claims and method claims, which may have different approaches to describing the invention, are applicable in this type of analysis. Sometimes, an argument developed with reference to a method claim will guide amendments to a structural claim, and vice versa.
To finish up with the analogy, suppose we are comparing a particular bridge to a particular skyscraper. Both structures use steel girders, rivets, connections of one girder to another, and triangulation in their construction. But, if one says that the existence of skyscrapers predicts all bridges, one is wrong. A showing of a collection of steel girders and rivets in a skyscraper does not show steel girders and rivets in the same relationship and context as shown in a bridge. Relationship and context among elements in patent claims are part of the art of patenting.