Unit 2 Patent Application Preparation

Schematic example of drafting a set of claims

The procedure for drafting a set of patent claims is a sophisticated undertaking, significantly shaped by several variables:

Inventor Input: The fundamental information and innovative concepts furnished by the inventors.
Prior Art Landscape: Awareness of existing patents and publications pertinent to the invention.
Business Objectives: The commercial interests and strategic aims of the applicant.
Drafter’s Expertise: The proficiency, experience, and available time of the patent drafter.
Figure 8: (a) No infringement of Claims 1 to 5; (b) Claims 1 to 3 are infringed, but not Claims 4 and 5 The drafting process typically commences with a collaborative brainstorming session involving the patent drafter and the inventor(s). The principal aims of this initial engagement are to (at least provisionally):

The evaluation of novelty requires a comparison between the scope of a patent claim and the relevant prior art. In Figures 7a and 7b, prior art documents are illustrated as small circles labeled P1 and P2, respectively.

Figure 7a: Depicts a scenario in which prior art reference P1 is positioned entirely outside the scope of the independent claim (Claim 1). Accordingly, Claim 1 is novel over P1. A substantial simplification follows: by definition, every claim dependent on Claim 1 (Claims 2-5) is likewise novel over P1. If this situation applies to all identified prior art references, then all claims (1-5) may be regarded as novel.
Figure 7b: Shows prior art reference P2 located within the scope of Claim 3. Because Claim 3 falls within the scopes of Claims 1 and 2, P2 renders Claims 1, 2, and 3 not novel. However, P2 lies outside the scope of Claim 4. Consequently, Claim 4 is novel over P2. In the same manner, P2 is also outside the scope of Claim 5, and therefore Claim 5 is novel.

A frequent misconception among non-specialists is that invalidation of an independent claim automatically leads to invalidation of all dependent claims. This assumption is incorrect. Moreover, even if Claim 4 is novel, this alone does not ensure its validity; additional patentability requirements, such as inventive step, must also be satisfied.

Let us now examine the assessment of literal infringement using the dependency groups depicted in Figures 8a and 8b, on the assumption that all claims are valid. A finding of infringement requires two essential determinations:

1.Prohibited Act: That at least one infringing act (for example, making, using, or selling the claimed invention without the authorization of the patent proprietor) has taken place. For the purpose of this analysis, this element is presumed to be established.

2.Scope Comparison: That the “accused embodiment” (the product or process attributed to the alleged infringer) falls within the scope of at least one valid patent claim. This necessitates a direct comparison between the scope of the claims and the accused embodiment.

Figure 8a: Illustrates an accused embodiment (Q1, represented by a small circle) that lies outside the scope of the independent claim (Claim 1). As a result, Claim 1 is not infringed. This considerably simplifies the analysis, as it follows that none of the claims dependent on Claim 1 are infringed either.
Figure 8b: Depicts an accused embodiment (Q2) situated within the scope of Claim 3. This indicates that all elements specified in Claim 3 are present in Q2. Since Claim 3 depends on Claims 1 and 2, the elements of Claims 1 and 2 must likewise be present in Q2. Therefore, Claims 1, 2, and 3 are all infringed by Q2. Conversely, Q2 lies outside the scope of Claim 4, meaning that not all elements of Claim 4 are present in Q2; accordingly, Claim 4 is not infringed. In the same example, Claim 5 is also not infringed by Q2.

It is often mistakenly believed that infringement of an independent claim automatically entails infringement of all dependent claims. As demonstrated in Figure 8b, this is not necessarily the case.

Schematic example of drafting a set of claims

Drafting a coherent and strategically robust set of patent claims depends on several factors:

Inventor Input: The technical information and inventive concepts provided by the inventor(s).
Prior Art Landscape: Knowledge of relevant existing patents and publications.
Business Objectives: The applicant’s commercial and strategic goals.
Drafter’s Expertise: The patent drafter’s knowledge, experience, and available time.

Figure 8: (a) No infringement of Claims 1-5; (b) Claims 1-3 are infringed, but not Claims 4 and 5

The drafting process usually begins with a brainstorming session between the patent drafter and inventor(s). The primary objectives are to:

Identify the invention(s) and core inventive concept(s).
Select the most appropriate type of first independent claim, recognizing that additional independent claims may be added later.
Choose a suitable preamble that reflects the desired level of generality for the claim group.

This preparation should consider:

Specific embodiments, drawings, and examples.
The closest prior art.

The independent claim is the foundation of patent protection. It should define the essential elements required to achieve the technical effect that solves the problem addressed by the invention.

To maximize protection:

The independent claim should include all elements necessary for the invention’s core functionality.
These elements should be defined as broadly as possible while remaining consistent with the invention and prior art.

For both independent and dependent claims, a sound inventive-step strategy is required to show that the invention is non-obvious or provides an unexpected technical advantage.

Product Claims: Focus on the technical features that create the advantage, not the advantage itself.
Avoiding Mere Desideratum: Claims should specify the technical means of achieving a result rather than merely stating a desired outcome.

While independent claims provide the broadest protection, dependent claims define more specific embodiments.

Structure of Dependent Claims

One Element Per Claim (Generally): A dependent claim typically introduces or further specifies a single additional element.
Exceptions (e.g., Markush Formulas): Multiple alternatives may sometimes be included in a single claim.
Antecedent Basis: A dependent claim that limits or modifies an existing element should depend on a claim that provides a clear antecedent for that element. A claim introducing a separate new element may depend on any appropriate preceding claim, including multiple claims.
Successive Addition: Additional elements are usually introduced step by step, often in order of their importance to the invention.

The discussion then proceeds to a schematic example of drafting a single dependency group of claims for an initial patent application intended to serve as the basis for a future PCT filing across multiple jurisdictions.

Example
Following a brainstorming session, the inventor and patent drafter conclude that:

A writing device is an appropriate designation for the claimed subject matter.
The prototype consists of a writing device having A11, B11, C1, D, E, and F, which will be described in the embodiments section.
Only A11, B11, and C1 (or broader versions thereof) are considered essential elements.
The remaining elements are ranked in importance as D > E > F. Element G, although not part of the prototype, is also of interest but is less important than F.
Two mutually exclusive alternatives, H1 and H2, are considered useful for addressing different market segments.
The closest prior art discloses a writing device having A11 and B11.
There is strong support for broadening A11 → A1 → A and B11 → B1 → B.
A skilled person would likely regard C1 as equivalent to C2, C3, and C4, justifying a Markush group containing these alternatives.

Based on these assumptions, the following independent claim can be drafted:

[Standard Format]

Claim 1. A writing device comprising:

element A;
element B; and
element C selected from the group consisting of C1, C2, C3 and C4.

Depending on the circumstances, an EPO examiner may require a two-part format. Considering that “a writing device having A11 and B11” belongs to the prior art, Claim 1 could be written as:

[Two-Part Format]

Claim 1. A writing device comprising: element A; and element B; characterized by further comprising element C selected from the group consisting of C1, C2, C3 and C4.

Regardless of the format used, before introducing dependent claims with additional elements, the drafter recommends adding fallback positions through dependent claims that progressively narrow the broader elements of Claim 1.

In this example, selected values are introduced in the order A > B > C, reflecting the relative importance of these elements and the available support for broadening them. The first dependent claims are therefore:

Claim 2. The writing device according to Claim 1, wherein element A is A1.

Claim 3. The writing device according to Claim 2, wherein element A1 is A11.

Up to this point, Claims 1-3 form a dependency chain with only singular dependency, which is recommended when introducing successive selected elements.

When later dependent claims introduce additional elements, particularly for EPO practice, it is recommended to use multiple dependent claims. Thus:

Claim 4. The writing device according to any one of Claims 1-3, wherein element B is B1.
Claim 5. The writing device according to Claim 4, wherein element B1 is B11.
Claim 6. The writing device according to any one of Claims 1-5, wherein element C is C1.

The remaining elements are then added according to their importance (D > E > F > G), with mutually exclusive alternatives H1 and H2 introduced last:

Claim 7. The writing device according to any one of Claims 1-6, further comprising element D.
Claim 8. The writing device according to any one of Claims 1-7, further comprising element E.
Claim 9. The writing device according to any one of Claims 1-8, further comprising element F.
Claim 10. The writing device according to any one of Claims 1-9, further comprising element G.
Claim 11. The writing device according to any one of Claims 1-10, further comprising element H1.
Claim 12. The writing device according to any one of Claims 1-10, further comprising element H2.

Although the claim set contains only 12 numbered claims below the EPO threshold of 15 claims that can be filed without an additional claim fee it effectively covers 844 actual claim combinations.

When drafting patent claims, the procedural requirements of different patent offices must also be considered. The example above is tailored for the EPO and other jurisdictions that permit multiple dependencies from multiple dependent claims.

USPTO Restriction: The USPTO does not permit multiple dependencies from multiple dependent claims.

Before entering the U.S. national phase from a PCT application drafted in EPO style, the claims must therefore be amended to comply with USPTO rules.

PCT Amendment Opportunity: The PCT system allows claims to be amended to meet national requirements.
Risk of Losing Fallback Positions: If the adaptation is performed by someone other than the original drafter, the carefully designed dependency structure may be simplified. For example, claims originally depending on “any one of Claims 1-x” may be rewritten to depend only on Claim 1.
The Claim 1 Pyramid Problem: Such simplification can create a dependency pyramid with Claim 1 at the top. This is generally undesirable because it weakens fallback positions. If Claim 1 is later found invalid for lack of novelty or inventive step, the entire claim structure may become vulnerable.

The next step is to examine a systematic method for converting claims drafted in the EPO two-part format into a dependency structure compliant with USPTO requirements while preserving the strategic benefits of the original claim set.

Example
Original Claims 1-3 are already suitable for USPTO practice because they contain only singular dependencies. However, original Claims 4 and 6-12 use multiple dependent claim format and must be adapted.

To convert these claims into USPTO-compliant singular dependencies, the practitioner typically prepares:

Dependency chains based on the broadest interpretation of the elements.
Dependency chains based on the most restrictive interpretation of the elements.
Intermediate claim variations, provided the overall claim count remains reasonable (ideally not exceeding 20 claims to avoid additional fees).

In this example, the first two approaches are sufficient to create a 20-claim USPTO-compliant set.

Step 1: Broad Dependency Chain

US-Claims 1-3: Correspond to EPO Claims 1-3 in standard format.
US-Claim 4: According to Claim 1, wherein element B is B1.
US-Claim 5: According to Claim 4, wherein element B is B11.
US-Claim 6: According to Claim 1, wherein element C is C1.
US-Claim 7: According to Claim 1, further comprising element D.
US-Claim 8: According to Claim 7, further comprising element E.
US-Claim 9: According to Claim 8, further comprising element F.
US-Claim 10: According to Claim 9, further comprising element G.
US-Claim 11: According to Claim 10, further comprising element H1.
US-Claim 12: According to Claim 10, further comprising element H2.

Step 2: Narrow Dependency Chain

US-Claim 13: According to Claim 3, wherein element B is B11.
US-Claim 14: According to Claim 13, wherein element C is C1.
US-Claim 15: According to Claim 14, further comprising element D.
US-Claim 16: According to Claim 15, further comprising element E.
US-Claim 17: According to Claim 16, further comprising element F.
US-Claim 18: According to Claim 17, further comprising element G.
US-Claim 19: According to Claim 18, further comprising element H1.
US-Claim 20: According to Claim 18, further comprising element H2.

The logic behind this structure is:

US-Claim 4 depends on the broadest claim (Claim 1) and introduces the broad selection B1, while US-Claim 13 depends on the narrowest of the initial claims (Claim 3) and introduces the most specific selection B11.
US-Claim 6 introduces C1 from the broadest claim, whereas US-Claim 14 introduces the same limitation from the narrower dependency path.
US-Claim 7 adds element D to the broadest claim, creating a broad branch from which US-Claims 8-12 extend.
US-Claim 15 also introduces D, but through the narrower path beginning with Claim 3 and continuing through Claims 13 and 14. Consequently, US-Claims 15-20 form a narrow branch.

As a result, the 20-claim USPTO set preserves both broad and narrow fallback positions while complying with USPTO restrictions on multiple dependencies. Considering U.S. amendment practice and the prohibition against adding new matter, the USPTO will generally allow amendments to claim scopes lying between the broadest claim (US-Claim 1) and the narrowest claims (US-Claims 19-20).

The Secretariat of WIPO assumes no liability or responsibility with regard to the transformation or translation of the original content.
World Intellectual Property Organization (WIPO) (2023). WIPO Patent Drafting Manual, Second edition. Geneva: WIPO. DOI: 10.34667/tind.44657