Legal Definitions - statutory double-patenting rejection

A statutory double-patenting rejection occurs when the United States Patent and Trademark Office (USPTO) refuses to grant a patent application because the invention described and claimed in that application is either the same invention as, or an obvious variation of, an invention already patented by the same applicant or assignee. This rule is based on specific patent laws (statutes) and is designed to prevent an inventor from obtaining multiple patents for essentially the same invention, which would unfairly extend the period of exclusive rights granted by a single patent. It ensures that each patent protects a distinct and non-obvious invention.

• Example 1: Identical Invention Claims

  Imagine a medical device company successfully patents a novel surgical tool designed for minimally invasive procedures. A year later, the same company files a new patent application that describes and claims *exactly the same design, components, and method of operation* for that identical surgical tool. The claims in the second application are indistinguishable from those already granted in the first patent.

  The USPTO would issue a statutory double-patenting rejection for the second application. Since the claims are identical to an invention already patented by the same entity, allowing a second patent would improperly extend the period of exclusive rights for that specific surgical tool beyond what the law intends for a single invention.

• Example 2: Obvious Variation of a Patented Invention

  Consider an inventor who obtains a patent for a unique type of drone propeller blade made from a specific carbon fiber composite, which significantly reduces noise. A few months later, the same inventor files a second patent application for a drone propeller blade that uses *the exact same shape and carbon fiber composite*, but with a slightly different surface texture that an expert in the field would consider a minor, obvious aesthetic modification, offering no new functional benefit.

  The USPTO would likely issue a statutory double-patenting rejection. While there's a minor difference, the core inventive concept (the shape and material combination for noise reduction) is already patented. The surface texture change is an obvious variation that does not represent a sufficiently distinct new invention to warrant a separate patent, and granting one would unfairly extend the protection for the original inventive concept.

• Example 3: Claiming the Same Component in a New System

  A technology company patents a groundbreaking new battery cell design that offers superior energy density and lifespan. Later, the same company develops a new electric vehicle and files a patent application for the vehicle, with some of its claims specifically covering the *incorporation and use of that exact same patented battery cell design* within the vehicle's power system.

  The USPTO could issue a statutory double-patenting rejection for the claims in the second application that specifically cover the battery cell design itself. Even though the overall electric vehicle is a new product, the specific battery cell design being claimed is already protected by the first patent. Allowing a second patent for the same battery cell design, even within a new context, would grant an unwarranted extension of the exclusive rights to that specific battery technology.