[Patent Talk] Building a Patent Portfolio Through Divisional Applications

In a previous column, I mentioned that large global companies use divisional applications to build sizable patent portfolios around their core patents. This column looks specifically at how a divisional application strategy can be used.

First, a divisional application can be considered when, after examination, a notice of preliminary rejection is issued but multiple claims are found allowable. Suppose, for example, that independent claim 1 consists of elements 'a+b+c', and dependent claims 2 and 3 each refer to claim 1, with claim 2 adding element d and claim 3 adding element e. If the notice of preliminary rejection rejects independent claim 1 but indicates that dependent claims 2 and 3 are both allowable, the parent application can be amended to incorporate dependent claim 2 into claim 1, and a separate divisional application can be filed for dependent claim 3. In this way, the invention consisting of 'a+b+c+d' is protected in the parent application, and the invention consisting of 'a+b+c+e' is protected in the divisional application.

Second, a divisional application can be considered when an independent claim allowed after examination includes an element that is not essential. For example, if allowed independent claim 1 consists of elements 'a+b+c+d+e', with element e being the core technical feature, and element c is not essential so that a third party could omit it and still practice the invention, the invention consisting of 'a+b+d+e' can be filed separately as a divisional application.

Third, a divisional application can be considered when you wish to obtain rights for another embodiment included in the specification as filed. For example, if the technical feature lies in a 'cushioning member' and the specification includes two or more embodiments with different specific design structures, the embodiments not claimed in the parent application can be protected through a separate divisional application.

Fourth, a divisional application can be considered when the scope of an independent claim allowed after examination is too broad. In the case of a pioneering patent applicable to many technical fields...