Legal Definitions - closed-ended claim

A closed-ended claim is a type of patent claim that limits its scope to a specific list of elements. This list is typically introduced by the phrase "consisting of." This means that any product or process that includes elements not on the list would not be covered by the patent.

• A patent claim for a new type of car engine that includes the elements "piston, crankshaft, and fuel injection system" would be a closed-ended claim.
• On the other hand, a patent claim for a car engine that includes the elements "piston, crankshaft, fuel injection system, or any other similar component" would not be a closed-ended claim because it allows for additional elements not on the list.

These examples illustrate how a closed-ended claim can limit the scope of a patent to only the specific elements listed, making it easier for competitors to design around the patent by using similar but not identical elements.