Utility patent drawings are the figures filed with a utility application at the United States Patent and Trademark Office (USPTO) to show the invention that its claims define. The rules set no fixed number of figures: the drawing must contain as many views as necessary to show the invention, including every feature specified in the claims.
In practice, the claims decide the figure set: a mechanical device usually needs a perspective view, sectional or detail views, and a separate view for each alternative form. A method claim is usually shown as a flowchart and a system claim as a block diagram. The drafting side is described on the utility patent drawings service page.
What utility patent drawings must show
Under section 113 of the patent statute (35 U.S.C. 113), the applicant furnishes a drawing where it is necessary for understanding the subject matter. The Code of Federal Regulations (CFR), at 37 CFR 1.81(b), adds that drawings may include flow sheets for processes and diagrammatic views.
The content rule is 37 CFR 1.83(a). The drawing in a nonprovisional application must show every feature of the invention specified in the claims. Conventional features whose detail is not essential to understanding the invention should appear as a graphical symbol or a labelled box.
The views allowed in utility patent drawings
37 CFR 1.84(h) names plan, elevation, section and perspective views, and allows detail views on a larger scale. It also covers 4 special cases:
- exploded views, with the separated parts embraced by a bracket;
- partial views of a large machine, with a smaller view of the whole;
- sectional views, marked on the source view by a broken line with arrows, with cut surfaces hatched;
- a moved position, shown in broken lines or, if crowded, in a separate view.
Modified forms of construction must be shown in separate views. A second claimed form therefore normally has its own figure, even when it differs from the first in one part only.
Choosing views by type of claim
The subject of the claims points to the usual figures, and many applications combine several rows.
| Claimed subject | Usual figures |
|---|---|
| Mechanical device | Perspective view, elevations, sectional view |
| Assembly of parts | Exploded view, plus an assembled view |
| Part that moves | Second position in broken lines, or a second view |
| Method or process | Flowchart with one box per step |
| System or software | Block diagram with labelled boxes |
| Improvement on an old machine | Improved part alone, plus the connecting old structure |
Planning utility patent drawings from the claims
A practical way to settle the figure set is a claim-to-figure map, prepared before any sheet is drawn. It lists each claim element beside the figure and reference numeral that will show it.
- Each claim, including the dependent claims, is broken into its elements.
- Each element is assigned to at least one figure and a reference numeral.
- A figure is added for each claimed form described in the specification.
- One view of the whole invention is chosen for the front page.
- The map is checked against the brief description of the drawings.
An element with no figure beside it is the gap an examiner would raise under 37 CFR 1.83(a). Drawings planned this way are covered on the patent drawing and illustration support page.
Figure numbering and the front page view
Views are numbered in consecutive Arabic numerals starting with 1, independent of the sheet numbers. Each number is preceded by the abbreviation FIG., and view numbers must be larger than the reference characters. Partial views that form one complete view share a number followed by a capital letter, such as FIG. 3A and FIG. 3B.
An application with a single view does not number it. The applicant may also suggest, by figure number, one view for the front page of the publication and the patent.
Where utility patent drawings fall short
Common gaps in a filed figure set are:
- a feature from a dependent claim appears in no figure;
- a claimed alternative form is described but not drawn;
- a sectional view has no section line on its source view;
- the brief description lists a figure that does not exist.
Several of these arise when drawings are prepared from sketches without reference to the claims. The resulting objection is covered in the guide to responding to a drawing objection, and sheet and margin rules in the patent drawing rules checklist.
Utility patent drawings for US filings
Our utility patent drawings service prepares formal figures for US utility applications, and you can contact us to discuss one.
This guide is general information and is not legal advice.
Frequently Asked Questions
How many figures does a utility patent application need?
There is no fixed number. 37 CFR 1.84(h) requires as many views as necessary to show the invention, and 37 CFR 1.83(a) requires every claimed feature to be shown. A simple hand tool may need only a few figures, while a system with several embodiments can need many more.
Is a drawing required for a method claim?
A drawing is required wherever it is necessary to understand the invention, under 35 U.S.C. 113. Method claims are usually illustrated with a flowchart, which 37 CFR 1.81(b) treats as a flow sheet for a process. The examiner can require a drawing when the subject matter admits of illustration.
Can photographs be used in utility patent drawings?
Only in limited cases. Under 37 CFR 1.84(b)(1), photographs are not ordinarily permitted. The USPTO accepts them where they are the only practicable medium for illustrating the invention, such as electrophoresis gels or histological sections. Colour photographs must meet both these conditions and the colour drawing conditions in 37 CFR 1.84(a)(2).
Can a figure be added after a utility application is filed?
Only if it shows nothing beyond the original disclosure. Under 37 CFR 1.81(d), later drawings cannot cure an inadequate specification, and 35 U.S.C. 132 bars new matter in amendments. A new embodiment therefore cannot be added to a pending application by amendment.
What is the difference between a sectional view and a detail view?
A sectional view shows the object as if cut along a plane marked by a broken line on another view, with cut surfaces hatched. A detail view shows part of an element on a larger scale. An enlarged view and its source view are labelled as separate views.
Filed under