Writing Patent Claims

Claims exclusively define the scope of what a patent protects

A nonprovisional application for a utility patent must make at least one "independent" claim, Independent claims are the most general statement of what is claimed as the invention in the patent application.  Generally, you can expect to encounter objections if you file an patent application with a number of independent claims that are completely unrelated, but many inventions are effectively combinations of more than one unique new element, and so up to five independent claims are allowed (a small additional fee applies for each independent claim above three).  Also, sometimes it will make defensive sense for two different independent claims to address the same invention using different approaches, or to additionally claim the method by which the invention solves a given problem.

Claims protect the invention according to an "all elements rule". Your patent only restricts others from making products that contain every element of at least one of your claims.  If your patent claims an invention comprising one or more wheels, one or more motors, one or more pork chops, and a ukulele, anyone on the planet can make and sell something with wheels, motors, and pork chops, and there is nothing you can do about it.  Every element you add to a claim restricts or narrows its protection.

Claims are constructed as a multi-layer defense gainst those who might seek to dispute or discredit them.  A patent therefore will include, in addition to its independent claims, a series of “dependent” claims, which reference the independent claims (or other dependent claims) to:

• Provide a slightly narrower, backup claim, in case the independent claim is ultimately defeated in litigation.
• Introduce additional novel features that you specifically want to protect when used in conjunction with the independent claim.
• Combine two claims so that the composite is specifically covered.

Dependent claims cannot contradict or arbitrarily modify a parent claim, but can only add additional elements or further constraints to its elements.  Clearly then, dependent claims are always more narrow than their parent claims.

The Essential Inventor's Guide contains an extensive discussion of claims structure, do's-and-don'ts, and strategy, sufficient to instill you with the know-how to produce correct, comprehensive, and defendable claims.  Nevertheless, because mistakes are costly, it is highly advisable that you have your claims reviewed by a qualified attourney before filing your application.  By applying the lessons you'll learn in The Essential Inventor's Guide, the cost of having your application professionally reviewed will be less than 1/10th of the cost of having an attourney draft the application from scratch (the larger the application, the more the savings), and you should find the finished document to be substantially close to your original draft.  Indeed, you will find it vital to understand the basics of how to write claims even when working with a professional, as it is up to you to check the attourney's work.  A competent attourney will draft correct and prosecutable claims; but, due to a lack of full comprehension of the invention, all too often will inadvertently leave something out that is only realized by the inventor later. Everyone needs to have someone check their work, and you can't perform that role unless you at least know enough about claims writing to ask the right questions.