CLAIM STRUCTURE - Patent law

Each claim in an issued U.S. patent application will be numbered, and each claim is exactly one sentence long.8 The structure of a typical claim contains three parts,which are, in the order of their usual appearance, the preamble, the transition, and the claim body (Figure below identifies the three parts of the composition claim 1 and the process claim 2).
The preamble to the claim is found at the beginning of a claim, and it will usually start by reciting the type of subject matter (e.g. process, machine, manufacture, or composition of matter) and sometimes will go further by summarizing the invention that is subsequently claimed, such as describing the inventions intended use or properties and possibly even how the invention is distinguished over the prior art (e.g., a compound with improved properties). The primary issue encountered with a claim’s preamble is whether part or all of the language of a preamble will be used in limiting the scope of the claim itself. If it does, then the words of the claim’s preamble areas important as the rest of the claim since those words will help define the “mete sand bounds” of the claim. It is not always easy to know whether the preamble affects the scope of the claim. There is no general litmus test for making this determination,which can be “resolved only on review of the entire . . . patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim.”

Where the preamble simply states the intended use, asserted benefits or purpose of the claimed subject matter then the preamble will not be found to affect the claim Enablement and the written description requirement will be covered in Later.

FIGURE :Compound and process claims with claim parts labeled.

scope. However, where the preamble “when read in the context of the entire claim,recites limitations of the claim, or, if the claim preamble is ‘necessary to give life,meaning, and vitality’ to the claim, then the claim preamble should be construed as if in the balance of the claim.”

FIGURE :Claim with non limiting preamble.

For illustrative purposes, an example of a claim with a descriptive preamble is shown in Figure above. The preamble to the claim tells one that the claim is to a compound and not, for example, to a method of using the compound for the alleviation of anxiety. The “anxiety-alleviating effects” of the compound describe a property of the compound and so the question here is whether that property materially limits the claim. If it did limit the claim, we would need to read into the claim some further requirement of the claim, such as a minimum amount of the compound necessary so that it could fulfill its required property of “anxiety-alleviating effects.” However,the compound being claimed is completely defined by structural formula I, and the anxiety-alleviating effect is simply one of the inherent properties (and potential uses) of that compound. In this case, the claim is complete even without the description of the anxiety-alleviating effects of the compound, and the description of that property is not “necessary to give life, meaning, and vitality” to the claim. Since the preamble appears merely to describe one of the properties attributable to the compound and is not required to make sense of the claim, the phrase anxiety-alleviating likely does not act to limit the claim.

However, the distinction can sometime be very subtle. Consider a patent containing a very similar claim 1 (Figure below) except that the term compound has been changed to “A pharmaceutical tablet” and the compound of formula I is the “sole active ingredient” of the pharmaceutical tablet. In this case, a “pharmaceutical tablet” is what is being claimed instead of only the compound. The question again is whether the phrase anxiety-alleviating effects further limits the claim. In other words, would a pharmaceutical tablet that did not have anxiety-alleviating effects but contained a compound of formula I as the sole active ingredient still be covered by the claim?

Without having the patent specification to read we can still manage a little detective work. We do know that the claim requires a pharmaceutical tablet. We also know that the claim requires a compound of formula I. We further appreciate that a pharmaceutical tablet is used for the administration to a subject for a pharmaceutical purpose. In this example, the pharmaceutical tablet being claimed contains the compound of formula I as its sole active ingredient. The purpose of the tablet, as inferred

FIGURE :Claim with limiting preamble.

from the preamble is to have an anxiety-alleviating effect in a human. How much of the compound of formula I needs to be in the tablet? Since the claim is directed to a tablet, and the tablet’s purpose is “anxiety-alleviating effects,” then the compound of formula I needs to be present in an amount sufficient to alleviate anxiety in a human; anything less would eviscerate the function of the tablet. In this example, the portion of the preamble describing the purpose also would serve as a limitation, at least as to the minimal amount of a compound of formula I that needs to be in the pharmaceutical tablet.

This does not resolve the question of specifically how much of the compound of formula I is required in the pharmaceutical tablet. Normally, the person drafting the claim would have drafted additional dependent claims further narrowing the invention to increase its clarity and limit its scope. For example, claims 2 and 3 give much clearer picture as to how the pharmaceutical tablet of the previous claim could be further delineated. Notice that claim 1 is independent and claims 2 and 3are dependent claims since claim 1 can stand alone but claims 2 and 3 borrow all of the limitations from the claim they depend from and then limit the scope further.

Finally, to think further about the importance of determining whether the preamble is limiting, just as a thought experiment let’s consider a number of hypothetical questions with regard to the set of claims in Figure 5.6 assuming the phrase “with anxiety-alleviating effects in humans” is indeed construed as a limitation. For the following questions, assume an anxiety-alleviating amount of compound I is at least5mg. (1) If another manufacturer sells a tablet containing1mg of compound I for the treatment of colds, would the claims be infringed? (2) How about if they sold a tablet containing 6 mg of compound I for the treatment of colds? (3) Finally, how about if they sold a tablet containing 3 mg of compound I for the treatment of colds, but a person had to take two tablets at the same time for the treatment to be effective?