What is a Patent Claim? How to Quickly Interpret the Meaning of a Claim

Posted by Christopher Proskey on Friday, October 23, 2015

As we say in the industry, “The Name of the Game is the Claim!”

Claims are by far the most important part of a patent application.  They are the numbered paragraphs at the end of a patent.  The claims define “scope” of the patent.  Just like a property line defines a piece of property, claims define what is patented.  Anything that is within the claims is patented, anything that is outside of the claims, is not patented.

There are two types of claims, “Independent” claims and “Dependent” claims.  Without paying additional fees, in the U.S. an applicant is allowed up to 20 claims with up to 3 of those claims being independent. 

Independent claims are exactly that, they are independent. Meaning that they stand on their own. Independent claims are the broadest claims in the patent application and therefore they are by-far the most important claims. Claim 1 is always an independent claim. 

In contrast, dependent claims depend on at least one other claim, and sometimes more than one claim.  Dependent claims are distinguished from independent claims because their preamble always states which claim they depend upon. 

EXAMPLE: Set of claims from U.S. Patent No. 7,134,814 “Adjustable Pocket Drilling Fixture”, which is a patent I was involved with in litigation.  This patent has 12 claims which begin at the bottom of column 7.  As can be seen, claims 1, 5 7 and 8 are independent, whereas, claims 2-4, 6 and 9-12 are dependent.  

Independent claims 1, 5, 7 and 8 have been circled.  These claims are easily identified as being independent because they begin with “An adjustable pocket drilling fixture, comprising…”

In contrast, the dependent claims 2-4, 6 and 9-12 state the claim from which they depend.  For instance, claim 2 states “The adjustable pocket drilling fixture of claim 1 further comprising…”  As such, claim 2 clearly depends from claim 1. 

To infringe a patent you must meet each-and-every limitation of the claims, either literally – which means that the claim limitation is literally met, or by what is known as “the doctrine of equivalents” – which means that while the limitation is not literally met, an equivalent is present. 

A dependent claim cannot be infringed unless the independent claim from which it depends is also infringed. 

One process to quickly determine whether a patent is infringed is to first identify all of the independent claims, and then to determine whether all of the elements within the independent claims have been met.  If even a single element is missing, then the claim is not infringed.  In the claims above, each of the elements of the independent claims have been underlined.  For instance claim 1 includes the following elements:

  • Base
  • Base Face
  • Workpiece
  • Clamp Body
  • First Clamping Face
  • Clamping Structure
  • Clamp Actuator
  • Guide Carrier
  • Second Clamping Face
  • At Least One Drill Guide

To understand what a claim means, the claim must be read “in light of the specification”.  That is, to determine what these elements within the claim mean, the specification or body of the patent application must be reviewed.  Upon review of the specification each of the elements in claim 1 relate to a reference numeral as follows:

  • Base – reference numeral 62
  • Base Face – reference numeral 90
  • Workpiece – reference numeral 10/74
  • Clamp Body – reference numeral 68
  • First Clamping Face – reference numeral 72
  • Clamping Structure – reference numeral 86/84/88
  • Clamp Actuator – reference numeral 84
  • Guide Carrier – reference numeral 98
  • Second Clamping Face – reference numeral 106
  • At Least One Drill Guide – reference numeral 100, 102, 104

These reference numerals are then shown in Fig. 7 of the patent application.