What is the purpose of utility patent drawings?
Drawings are an important component of the overall disclosure in a patent. Features shown in the patent figures provide support for the claims. Generally, you cannot claim a feature that is absent from the drawings.
How difficult is it to amend drawings?
There is not much flexibility to add new features to drawings once a patent application is filed. You can, of course, file a CIP application where the drawing changes would be considered new matter. An argument can be made that certain features were originally disclosed in the written specification, so adding such disclosed features to the drawings would not constitute new matter. It will be up to the examiner on whether such drawing amendments will be allowed.
Replacement drawings to clarify original figures are generally more acceptable. Perhaps certain original figures were fuzzy or otherwise unclear. It is also proper and advisable to replace any initially filed informal drawings with formal drawings.
Common drawing amendments also include inserting missing numerals or correcting mislabeled numerals.
How are utility drawings different from design drawings?
In a design patent, the figures are typically limited to a single embodiment. Design figures must meet strict drawing requirements and show the claimed design from certain views/angles (e.g., front, rear, top, bottom, left and right).
Utility patent drawings do not require any particular views. Utility patents commonly include drawings showing several embodiments, or examples of the invention. If a utility application involves a mechanical invention, it may help to show exploded and cross-sectional views to provide adequate disclosure of components and the internal parts of a device. Operative views that show a device in use in an intended environment may also be helpful.
Utility patents may also include block diagrams and flowcharts, especially when business methods and software are involved. Method diagrams may help to provide support for method claims, even when the overall nature of the invention is more directed to an apparatus.
Should you hire a professional patent illustrator or do the drawings yourself?
Do-it-yourself drawings might be fine if you’re filing a provisional patent application. In a nonprovisional patent application, I would recommend professional patent drawings if time permits. Illustrator fees are relatively low in comparison to patent attorney’s fees. Any potential cost savings in DIY drawings in a nonprovisional application may be exceeded by the time and expense of having to correct the drawings subsequently during prosecution. We generally recommend having a nonprovisional application prepared properly upfront to avoid delays and further expenses down the road.
For design patent applications, we always recommend using patent illustrators with substantial experience in drafting design patent drawings. Submitting proper design patent figures with the initial filing can save the applicant from a potential design Office Action which, in most design applications, involve objections to the drawings.