Is it possible to add new content to a utility patent application?
It’s not an uncommon desire to add new matter to an already-filed patent application. Sometimes inventors think of new features after a utility patent application has already been filed. It’s also possible that broad concepts generally described in the original patent application need to be fleshed out in greater detail and supplemented with more specific examples.
How to add to a utility non-provisional patent application
Yes and no. While you cannot amend an existing patent application to add new subject matter, you can file a certain continuing patent application known as a Continuation-In-Part (CIP) to add the new content. A CIP application will maintain the earlier filing date of the patent filing (“priority date”) for all the subject matter disclosed in the earlier filing, and will receive a later priority date for the new matter added to the CIP.
For example, suppose a first utility non-provisional patent application disclosing features A and B is filed on January 1. While this “parent” application is still pending, a CIP is filed on March 1 that same year disclosing features A, B and C. Accordingly, features A and B in the CIP will maintain the earlier Jan. 1st priority date while feature C will be accorded a March 1st date.
What if new content merely clarifies the disclosure of a pending application?
In certain situations, the new content desired to be added does not introduce any new features, but simply clarifies what was already disclosed in the pending application. For example, suppose you filed a patent application that disclosed a fairly straightforward mechanical structure, such as a tube. You assumed that it was common sense that a tube had to be hollow, so you never explicitly used the term “hollow” to refer to the absence of material in a tube. You are then confronted with an Office Action where prior art is being applied that shows solid structures which the examiner is interpreting as tubes.
So, you now want to go back to your description and add negative” descriptions (i.e., what the structure is not) so that you can claim negative limitations in order to distinguish your apparatus from the prior art devices. In such circumstances, it may worthwhile to consider a straight continuation application which may add some clarifying language to the detailed description without adding new subject matter. This is a tricky issue that would warrant discussion with your patent practitioner.
Adding new content to a provisional patent application (PPA)
If the original application was a provisional patent application, new descriptions may be added in the non-provisional filed within 12 months of the provisional, but the same principle applies. Any new matter introduced in non-provisional application that is not supported by the provisional application will not get the benefit of the earlier provisional filing date. A provisional application, therefore, is only as valuable as whatever content is included in the filing.
You could also include additional details in a series of subsequent provisional applications filed within 12 months of the first provisional, and then consolidate all the details into a single non-provisional application filed within 1 year of the first provisional application. This would result in staggering priority dates for the new features introduced in each provisional.