Attempting to Rely on Claim Preambles is Still a Bad Idea

Ken Salen | August 1, 2012

In re Taylor (nonprecedential)

June 14, 2012

Panel:  Lourie, Dyk, Wallach.  Opinion by Lourie.


Taylor appealed from a decision of the Board of Patent Appeals and Interferences (BPAI) affirming the rejections of all pending claims of its U.S. Patent Application No. 11/429,507 as anticipated and obvious.

On appeal, the CAFC affirmed that the BPAI correctly construed the pending claims of the ’507 application and did not err in finding those claims unpatentable in view of the cited prior art. Of note, the BPAI and the CAFC held that Taylor could not rely on its preamble to limit its claim over the cited references.


The application at issue discloses cellulose-based dough that “can be used to form a variety of low-calorie foods.” Instead of flour, which significantly contributes to the caloric/ carbohydrate content of conventional baked goods, the claimed dough contains a mixture of cellulose, hydrocolloids (methylcellulose, xanthan gum, and hemicellulose), and other ingredients. The specification defines “low-calorie” as “a ≥50% caloric reduction as compared to the traditional version of the food per unit weight.”

Claim 1 is representative and reads as follows:

1. A mix for making low-calorie, palatable food or food components comprising by dry weight at least about 30% of fiber that is at least 50% cellulose, and an effective amount of hydrocolloids to help bind said mix to water.

The Examiner rejected the pending claims as anticipated or obvious over U.S. Patent 5,976,598 (“Akkaway”), which relates to a coated cellulose that, for purposes of this portion of the discussion, is not for making a “low-calorie, palatable food”.

On appeal to the Board of Patent Appeals and Interferences, the BPAI affirmed the substantive rejections and held that the terms “low-calorie” and “palatable” found in the preambles of the claims are non-limiting because they merely reflect intended uses or purposes without imposing any structural limitation on the claimed compositions.

With only the two remaining body ingredients (“at least about 30% of fiber that is at least 50% cellulose” and “an effective amount of hydrocolloids to help bind said mix to water”) at issue, the BPAI concluded that anticipation/obviousness had been satisfied here because Akkaway disclosed a cellulose fiber and bulking agent.

Taylor appealed to the Federal Circuit, arguing that the preamble could not be ignored.

The bulk of Taylor’s arguments against the cited Akkaway presumed patentable weight for the terms “palatable” and “low-calorie” in the preambles of the claims.

Thus, the primary dispute centered on whether the terms “low-calorie” and “palatable,” as recited in the preambles of the claims of the Application are limiting. Citing Catalina Marketing International, Inc. v., Inc., 289 F.3d 801 (Fed. Cir. 2002) and related cases, Taylor argued that those terms must be afforded patentable weight because they were introduced and relied upon during prosecution expressly to distinguish the pending claims from Akkaway.

The CAFC disagreed that such reliance on the preamble during prosecution resulted in extra weight being given to the preamble. The court noted that in contrast to district court proceedings involving an issued patent (i.e., during litigation), claims under examination before the PTO (i.e., during prosecution) are given their broadest reasonable interpretation consistent with the specification. The CAFC emphasized that the broader interpretive standard does not prejudice Applicant, who has the ability to correct errors in claim language and to adjust the scope of claim protection as needed during prosecution by amending the claims*.

In general, the preamble limits a claim if it recites essential structure or is otherwise “necessary to give life, meaning, and vitality” to the claim, Pitney Bowes, Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305 (Fed. Cir. 1999), while the preamble is not limiting when the claim body defines a structurally complete invention and the preamble states only a purpose or intended use. The CAFC asserted that in the present case, the bodies of the claims define the requisite components of the claimed compositions – specified proportions of fiber and hydrocolloid – and the CAFC held that it is not clear how stating that such compositions are “for making low-calorie, palatable foods” further limits the scope of protection sought, i.e., excludes compositions that would otherwise satisfy the recited structural requirements.

The CAFC concluded that the terms “low-calorie” and “palatable” are not limiting as used in the claims.

The CAFC distinguished Catalina by asserting that it is held to merely set forth “some guideposts” for evaluating whether a particular claim’s preamble limits claim scope. Among those, the CAFC has included the general proposition that “clear reliance on the preamble during prosecution to distinguish the claimed invention from the prior art transforms the preamble into a claim limitation because such reliance indicates use of the preamble to define, in part, the claimed invention.”

Taylor emphasized that “guidepost” as categorically determinative, arguing that Catalina compels the Examiner to construe the disputed preamble terms as limiting because he sought to distinguish Akkaway before the Examiner based in part on those terms.

The CAFC held that Catalina and “all of the other decisions that Taylor cites” arose in the context of infringement litigation, where prosecution is closed and the court’s task is to divine the meaning of issued claims under a narrower interpretive standard.

The CAFC emphasizes that the only time a preamble limits the claim is when the preamble is necessary for understanding of the claim body.

The CAFC distinguished such situation from the present case, where prosecution remains open and Taylor retains the option of amending the claim as needed.

Here, however, one could fully understand and compose the claim body elements of cellulose fiber and hydrocolloid without needing to know anything about their use in low-calorie, palatable foods. It did not matter that Taylor had clearly relied on the preamble to distinguish prior art; according to the panel, such reliance matters only when construing a claim at litigation, as in Catalina.

Thus, the CAFC held that the BPAI correctly rejected Taylor’s rigid reading of Catalina to conclude that the preambles of the claims of the ’507 application are not limiting under the broadest reasonable interpretation of those claims.


Preambles can introduce non-claimed features with which the main claim elements interact (In re Rehrig Pacific, CAFC 2012), and preambles can help define the relevant field for the non-analogous art test (In re Klein (CAFC 2011) under §103.

However, the weight accorded to preambles is uncertain. Thus, Applicant should ensure that all important structures or steps are in the claim body. Applicant should not rely on arguing that a preamble “breathes life” into the claim and is thus entitled to weight.

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