by Robert M. Hunter, Registered Patent Agent

News about patents, licensing and seed capital sources for inventors and innovating organizations.


I. USING LINKING CLAIMS TO REDUCE PATENT COSTS--Experience has shown that using a simple claim drafting technique can reduce patent costs.

II. NEW USE INVENTIONS--If you have invented a new use for an existing product or process, learn how your invention can be protected.


Both U.S. patent laws and court decisions have made it clear that only one invention can be claimed in an issued U.S. patent. While 35 U.S.C. 121 allows the U.S. Patent and Trademark Office (USPTO) to restrict examination to a single “independent and distinct” invention, the position of the USPTO is that the law is “redundant” and that those two words mean the same thing. An entire chapter (Chapter 800) of the Manual of Patent Examining Procedure (MPEP) is devoted to explaining the USPTO position on the issue, which is a muddy issue at best.

A decision by a USPTO Examiner that an application contains claims to two or more inventions can have expensive consequences. Also, because the decision can be somewhat subjective, it hard to reverse. First, a response to the Office action containing such a requirement must usually be prepared, containing an election of the invention to be examined, as well as arguments that “traverse” the requirement. If that is not successful, a petition can be prepared and filed. If that is not successful, one or more divisional applications must be filed. The USPTO (small entity) filing fee alone is $355 for each application. Alternatively, a filing fee can be paid for each extra invention in the original application. More significantly, a separate series of maintenance fees must be paid for each issued patent, which can amount to over $3,000+ over the life of each patent.

While nothing can prevent an Examiner from issuing a restriction requirement, two techniques can be used to head off the problem. While one or both of these techniques are preferably used in the application as filed, they can also be used in a response to a restriction requirement.

One is to draft a “generic” or “genus” claim of sufficient breath that it covers all disclosed “species” (related variations) of the invention and, often, additional undisclosed species. For example, different claimed subcombinations (operable subassemblies) that are usable with each other may be species of a common, claimed generic invention that comprises all of the subcombinations. Another example would be species of chemical compounds that are related to one another as intermediate and final products. However, this approach does not work if distinction between the inventions is that each is in a different invention category, for example, product and process, because a claim can cover only a single “statutory class” of invention.

A second technique is to use one or more linking claims. While using linking claims may not avoid a restriction requirement, the requirement must be withdrawn if any linking claims are allowed. Types of linking claims include (1) a claim to a process of making a product which links process and product claims, (2) a claim to “means” for practicing a process which links apparatus and process claims, and (3) a claim to a product which links a process of making and a use (process of using). An example of a linking claim that links a method and an apparatus is: “A method for unloading nonpacked, nonbridging and packed, bridging flowable particle catalyst and bead material from the opened end of a reactor tube which comprises utilizing the nozzle of claim 7.” Note that the reference to the other claim must not be in the preamble, but rather must be in the body of the claim. (See my October, 2000, newsletter for an explanation of the parts of a claim.)

It is usually best to really tangle the situation up with complementary linking claims, because distinctness is tested both ways. The USPTO fee for each additional dependent linking claim is $15 and they are simple to write.

The disadvantage of using either of these techniques is that they deny the Examiner the two extra “counts” (“beans”) associated with the prosecution of each divisional application. In that his bonuses and raises are based on accumulating counts, as was explained in my January, 2001, newsletter, an unreasonable Examiner can get testy. Because playing beans-for-a-patent games is a bad idea, use of linking claims will usually be worthwhile.


U.S. patent law permits patents to be granted for “any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof” (U.S.C. 101). The term “process” is defined as “process, art, or method, and includes a new use of a known process, machine, manufacture, composition of matter, or material” (U.S.C. 100).

A new use is, therefore, a process of using an object or composition, which includes steps in the process. If the “newness” (or novelty) of the use resides solely in the use of an old thing for a new purpose, the test of patentability becomes obviousness of the new use. The novelty of a process step may also reside in the material being treated as well as in the nature of the treatment step itself. Of course, if the material being used in a new way is new itself, the new use may be patentable for that reason.

An example of a new use claim is as follows: “The process of (doing something) comprising: administering (composition Z) to the body (or object) in question.” (The careful reader will note that the claim quoted in the above article is also a new use claim.) Note that such claims are infringed by practicing the claimed process, not by selling the composition, assuming the used composition or apparatus has other (old) uses. Enforcing such claims is difficult because it is the end customers who are likely to be the direct infringers. Suing each of them is impractical, and who wants to sue a potential customer anyway?

Even though the above definitions have been around for decades, whether “new use” inventions can be claimed using composition or apparatus claim formats is still controversial. A composition claim in the form “an improved growth stimulating composition for animals which comprises: an animal feed and an effective amount of (old compositions) contained therein for growth simulation” has been allowed. Some court decisions have held that, as long as there is any change in the structure of the invention, patentability can reside in the realization of the non-obvious new use in the new article, with claims being directed to the article.

Of course, the objective of the claim drafter is always to get as many types of claims allowed as possible. So, it is reasonable to claim a “new use” invention in as many of the following ways as the prior art will allow: (1) a new composition per se, (2) intermediates in the manufacture of the composition, (3) processes for making the composition and its intermediates, (4) treatment preparations containing a certain amount of the composition, and, of course, (5) processes for using the composition. There is USPTO rule that states that "the discovery of a new property or use of a previously known composition, even when that property and use are unobvious from prior art, cannot impart patentability to claims to the known composition." So, in some cases, reliance on method claims, which can be much more difficult to enforce, is your only option.

It is well, however, for an applicant wishing to obtain new use claims to be aware that this part of U.S. patent law has been characterized as being “very confusing” and involving “hypertechnical consideration of apparent flyspecks.” The MPEP notes that “it is often difficult to draw a fine line between what is permissible, and what is objectionable. . . .” In such instances, achieving truly valuable patent claims can be time-consuming, that is, it might be fun for your patent practitioner, but it might get expensive for you.

Robert M. (Bob) Hunter, Ph.D.
Licensed Professional Engineer
Registered Patent Agent
65-1116 Hoku'ula Rd.
P.O. Box 1291
Kamuela, HI 96743
tel (808) 885-4194
fax (808) 885-4114
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