Theory of Dependent Claims: Survey Results
Patent Law Blog (Patently-O):
Patent claims define the scope of an invention much like metes and bounds define real property boundaries or a statute delineates the difference between criminal and non-criminal activity. Often, patent applicants submit a series of claims all directed toward the same invention. Various independent claims allow an applicant to focus on various aspects of the invention. These broad aspects may be directed to various nodes of a larger system or regions of a compound, processes for creating or using various elements, etc. Dependent claims by definition add additional limitations. Thus, for instance disputed claim 1 and 2 from the recent Lovanex dispute reads as follows:
1. A heterogeneous intimate admixture of sulfated heparinic polysaccharides … consisting essentially of
from 9% to 20% of polysaccharide chains having a molecular weight less than 2,000 daltons
from 5% to 20% of polysaccharide chains having a molecular weight greater than 8,000 daltons, and
from 60-86% of polysaccharide chains having a molecular weight of between 2,000 and 8,000 daltons ….
2. The heterogeneous polysaccharide admixture as defined by claim 1, comprising less than 2% of dermatan sulfate.
Claim 2 is interpreted to include all the limitations of claim 1 with the additional limitation of “less than 2% of dermatan sulfate.” See 37 CFR 1.71(c).
Earlier this week, I polled Patently-O readers on why they file dependent claims and received just over 1000 responses. (Listed below).
Theory of Dependent Claims
Why do you file dependent claims?
Percent of Responses
Answer Options
Strongly Agree
Mostly Agree
Neither Agree nor Disagree
Mostly Disagree
Strongly Disagree
Rating Average
Dependent claims are backup in case the independent claim is rejected in prosecution.
59%
34%
4%
2%
0%
1.51
Dependent claims are backup in case the independent claim is found invalid in litigation.
59%
31%
6%
3%
1%
1.56
Claim…