Importance of an Independent Patent Claim

One more more independent claims are required for by the USPTO.

Under the U.S. Patent Office's Manual of Patent Examining Procedure (MPEP), a patent specification must have at least one "claim particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention or discovery." This claim is the independent claim. Just as real property is described in terms of metes and bounds, the parameters of an invention are described in claim language. Without an independent claim, the patent application could not be allowed.

Definitions

According to the glossary of the United States Patent and Trademark Office, an independent claim is one "that does not refer back to or depend on another claim." It is distinguished from a dependent claim, which "refers back to (depends on) and further limits a preceding dependent or independent claim. A dependent claim shall include every limitation of the claim from which it depends." In brief, an independent claim can stand on its own.

Parts of the Claim

The independent claim must begin with a preamble identifying the invention. It must also have a transitional phrase, and a list of the absolute essential elements of the invention.

For example, an independent claim describing a toaster might read:

An apparatus for the toasting of food, wherein said apparatus includes
a heating element that can be coupled to a power source; and
a means for holding said food.

In this example, the words "An apparatus for the toasting of food" is the preamble. The phrase "wherein said apparatus includes" is a transitional phrase. The heating element and the means for holding the food are the elements of the invention.

Types of Claims

There are several different types of independent claims commonly found in utility patents. The preamble will invariably cite "an apparatus," "a method" or "a composition." The claim that follows would be called "an apparatus claim," "a method claim" or "a composition claim."

Frequently, patent applications will include two independent claims. The first independent claim will be an apparatus claim. The second independent claim will describe a method for using that apparatus.

If the invention is a mixture of substances, the independent claim will describe the composition

Drafting technique

The language used in independent claims often seems impenetrable because common words are replaced by more general terms. For example, a button might be described as "a fastening means." The use of broad language to describe very specific features ultimately benefits the inventor because his invention is not narrowly construed.

Many experienced patent attorneys include independent claims that are very broad, and others that are more narrow. In this way, the client's interest is protected if the broad claim is not allowed.

Warning

Claim drafting is not for amateurs. Experience, skill and exposure to thousands of other claims all make an enormous difference. Having an attorney draft your claims or review the claims you have drafted is a good investment.

However, even if you use the services of a patent attorney or agent, learning the difference between independent and dependent claims can be very helpful. By framing the invention in terms of independent claims, you learn to think differently about your invention.

References

• USPTO: Manual of Patent Examining Procedure (MPEP): 608.01
• USPTO: Glossary