Diverging Definitions: Is A Range Exclusive Or Inclusive Of The Endpoints?

A patent drafter has many choices when deciding how to word a phrase that recites a range of values in an application and claims. For example, "between X and Y," "range of X to Y," "from X to Y," and "up to Y," are just some of the ways that a range of values could be described. While seemingly simple, these phrases may have a significant impact on claim scope and patentability. For example, when a patent claim indicates a range as being "between X and Y," does that include X and Y, or exclude X and Y?

The Federal Circuit in Athletic Alternatives Inc., v. Prince Manufacturing, Inc., 73 F.3d 1537 (Fed. Cir. 1996), wrestled with this issue and identified two definitions of "between" that result in the endpoint inclusive versus endpoint exclusive debate: "in the space that separates; in the midst of; or surrounded by" and "from one to the other." "In the space that separates" would not include the endpoints, whereas "from one to the other" would include the