ANSWER: (D) is the correct answer. See MPEP § 2173.05(c), under the heading “Open-Ended Numerical Ranges.” Paraphrasing the explanation therein, when an independent claim recites a composition comprising “at least 20% iron” and a dependent claim sets forth specific amounts of non-iron ingredients which add up to100%, apparently to the exclusion of iron, an ambiguity is created with regard to the “at least” limitation unless the percentages of the non-iron ingredients are based on the weight of the non-iron ingredients. On the other hand, a composition claimed to have a theoretical content greater than 100% (i.e., 20-80% of iron, 20-80% of gallium, and 1-25% of copper) is not necessarily indefinite simply because the claims may be read in theory to include compositions that are impossible in fact to formulate. Here, because the invention is a non-theoretical alloy, the sum of the claimed constituents cannot exceed 100% unless the percentage is based on weight. In (D), the sum of elements (B) and (C)is 81% by volume, leaving only 19% for iron. Claim 1, however, requires “at least 20% iron,” rendering Claim 2 ambiguous as to the percentage of element A. (A) is incorrect. The sum of gallium and copper components is 80%, leaving a possible 20% of the composition for element iron. Claim 1 requires “at least 20% iron,” which includes 20% iron. Therefore, the sum of iron, gallium and copper components in Claim 2 is 100%. (B) is incorrect. “At least 20% iron” includes 21% iron, “at least 10% gallium includes 11% gallium, and “at least 10% copper includes 10.01% copper. (C) is incorrect. “At least 20% iron” includes 20% iron, “at least 10% gallium includes 10% gallium, and “at least 10% copper” includes 10% copper. (E) is incorrect because Claim 1 uses the open transition phrase “comprising,” which permits additional elements to be added to the composition. Nothing in the problem indicates that an additional component, silver, cannot be added to the composition.
Q) Indefinite Claim (10.03.49a)
Test takers report a #49 from the October 2003 (AM) patent bar exam is in the current question pool.
49. Inventor files an application for a non-theoretical metal alloy. The application as originally filed contains the following Claim 1:
1. A metal alloy comprising at least 20% by volume of iron; at least 10% by volume of gallium, and at least 10% by volume of copper.
In accordance with the patent law, rules and procedures as related by the MPEP, which of the following claims would be properly held indefinite under 35 USC 112(2)?
(A) Claim 2: The alloy of claim 1 containing 66% by volume of gallium and 14% by volume of copper.
(B) Claim 2: The alloy of claim 1 containing at least 21% by volume of iron, 11% by volume of gallium, and 10.01% by volume of copper.
(C) Claim 2: The alloy of claim 1 containing 20% by volume of iron, 10% by volume of gallium, and 10% by volume of copper.
(D) Claim 2: The alloy of claim 1 containing 54% by volume of copper and 27% by volume of gallium.
(E) Claim 2: The alloy of claim 1 containing at least 1% by volume of silver.