How Do I Read Patent Claims?
During the Protestant Reformation, Martin Luther supposedly met with the protestant leaders at Marburg to determine if they could reconcile their differences and unite into a single protestant church.
The stakes couldn’t have been higher!
They agreed on every point… except for one.
Martin interpreted the biblical phase “this is my body” to literally mean that the bread of communion became the flesh of Jesus Christ. However, the protestant leaders interpreted the phrase to be symbolic. To their way of thinking, it couldn’t be taken literally. There was no apparent physical change or scientific explanation for that statement. Taken in context, Jesus must have meant it symbolically.
The protestant leaders argued this point again and again.
Martin got so angry that he pulled out a knife and carved the phrase “this is my body” into the wood of the table. Every time the other side would try to argue this point, Martin would just angrily point to the words without further comment.
Martin would not budge. The Lutheran church was born.
Claim Fundamentalism
This story may seem like a strange one for a patent law blog, but it always comes to mind when I think about how patent attorneys interpret claims.
Patent attorneys are claim fundamentalists!
It does not matter what makes sense scientifically. It does not matter what the author meant. The only thing that matters are the words of the claim and how they are interpreted in the context of the patent.
In some countries, patent claims are interpreted for the gist or general idea of the invention. In the U.S., patent claims are interpreted very literally and narrowly to mean exactly what they say.
Patent litigators arguing claims look just like Martin Luther. They keep angrily pointing to the language of the claims.
What Are The Parts Of A Patent Claim?
There are three parts to patent claims: the preamble, the transitional phrase, and the body of the claim. For the purposes of explaining how claims should be read, I am going to draft claims for a peanut butter and jelly sandwich. This example may seem silly, but most people are familiar with this technology, and the legal principles are the same.
A square sandwich for satisfying hunger comprising:
a first piece of white bread and a second piece of white bread;
a peanut butter layer; and
a jelly layer,
wherein the peanut butter layer and the jelly layer are located between the first piece of white bread and the second piece of white bread.
The sandwich of claim 1, wherein a crust of the first and second pieces of white bread has been removed.
In claim 1, the preamble is “A square sandwich for satisfying hunger,” the transitional phrase is “comprising,” and the body of the claims is everything that comes after the transitional phrase.
Preamble
The preamble is the first part of the claim and indicates the context for the claim. In claim 1, the preamble is the phrase “A square sandwich for satisfying hunger.” In claim 2, the preamble is “The sandwich of claim 1.”
There are 3 things that should be learned from preambles:
- Product or Process
- Independent or Dependent
- Limiting or Not Limiting
Product or Process
The preamble indicates what is being claimed: a product or a method. The preamble is important because a product claim will not protect your method, and a method claim will not protect your product.
Claims 1 and 2 indicate that a sandwich is being claimed, so claims 1 and 2 are product claims. If you want a patent that excludes others from making, using, selling or importing your product, make sure that some of your claims are product claims.
Independent or Dependent
Preambles usually indicate if a claim is an independent claim or a dependent claim. An independent claim does not refer to any other claim. In contrast, a dependent claim contains a reference to another claim. For example, the preamble in claim 2 indicates that claim 2 depends on claim 1 by stating “of claim 1.”
Dependent claims can be thought of as a short hand that avoids reciting the bulk of an independent claim. For example, according to patent law, claim 2 would be read and interpreted as the following:
A square sandwich for satisfying hunger comprising:
a first piece of white bread and a second piece of white bread;
a peanut butter layer; and
a jelly layer to sweeten the taste of the sandwich,
wherein the peanut butter layer and the jelly layer are located between the first piece of white bread and the second pieces of white bread,
wherein a crust of the first and second pieces of white bread has been removed.
Claim 2 automatically contains all of the text of claim 1, so for all practical purposes, the text of claim 2 is simply added onto the text of claim 1. Dependent claims are required to limit the claim upon which they depend. Therefore, by legal requirement, independent claims are broader than the claims which depend from them.
Limiting or Not Limiting
The text of the preamble may or may not limit a claim. For example, the phrase “A square sandwich for satisfying hunger” may be completely ignored by USPTO Examiners and U.S. Courts. A second interpretation might be to limit the invention to only those sandwiches that are square shaped. A third interpretation might be to limit the possible ingredients of the sandwich to edible ingredients because the preamble indicates that the sandwich is for satisfying hunger.
The rules for deciding whether a preamble is limiting or not are complex. To make sure that words limit the invention, don’t put them in the preamble, put them in the body of the claim.
Transitional Phrases
Transitional phrases are terms or phrases that indicate whether the claimed invention can contain additional components or steps.
The transitional phrases “comprises,” “comprising,” “includes,” and “contains” indicate that a competing product or method must have the components or steps recited in the body of the claim to infringe the claim. However, the invention could also contain other components not recited in the body of the claim. These transitional phrases create “open-ended claims.”
Strategy: When using open-ended transitional phrases, you only want to recite those components or steps that are absolutely necessary to infringe the claim.
A square sandwich for satisfying hunger comprising:
a first piece of white bread and a second piece of white bread;
a peanut butter layer; and
a jelly layer to sweeten the taste of the sandwich,
wherein the peanut butter layer and the jelly layer are located between the first piece of white bread and the second piece of white bread.
Elvis Presley supposedly loved adding banana slices and honey to sandwiches. Suppose he made a sandwich with two square pieces of white bread and a filling of peanut butter, jelly, banana slices, and honey.
Could this sandwich infringe claim 1?
Yes, because claim 1 uses the phrase “comprising.” Therefore, the invention of claim 1 can include components that are not mentioned in the claims, such as banana slices and honey.
Suppose Elvis made a sandwich with two square pieces of white bread and a filling of peanut butter, banana slices, and honey, but no jelly.
Could this sandwich infringe claim 1?
No, because claim 1 recites that the claim must include a “jelly layer.”
In contrast, the transitional phrases “consisting of,” “consists of,” “is,” or similar phrases indicate that the invention is closed-ended and can only have the components or steps recited in the body of the claim.
If claim 1 were changed to recite “consisting of” instead of “comprising,” would a sandwich containing banana slices still infringe?
No, because banana slices are not a component recited by the body of the claim.
For this reason, closed transitional phrases are best avoided because they usually allow competitors to add one thing that is not recited in your claim to avoid infringing your claim.
The Body
The body of the claim is the part of the claim after the transitional phrase. The body of the claim may be thought of as a list of components, characteristics, or steps that a product or method must contain in order to literally infringe the claims.
However, watch out for phrases and words that are predictive or aspirational. For example, in the phrase “a jelly layer to sweeten the taste of the sandwich,” an Examiner at the U.S. Patent and Trademark Office (“USPTO”) would probably ignore the phrase “to sweeten the taste of the sandwich” because that phrase does not characterize the component (jelly), it merely discusses what the component is intended to do.
Also, remember that remember that patent attorneys are claims fundamentalists. The claim recites that the first piece of bread must be white bread and the second pieces of bread must be white bread. Therefore, a sandwich that contains one piece of white bread and one piece of whole-grain bread would not literally infringe the claim.
The importance of the body of the claim and claim fundamentalism will be discussed in later posts.
Summary
You can only rely on claims to protect the invention that is literally written in the body of your claims, so you must thoroughly understand your technology, and every word of your claim must be carefully chosen.
If you are not sure if your claim would cover a technical variation of your invention, ask your patent attorney.
The next post in my “How To Protect An Idea: A Guide For Scientists, Engineers, Inventors, And Business Leaders To Understand Patent Claims” series will cover “What is a Markush Claim? What is a Means-Plus-Function Claim? What is a Product-By-Process Claim?” Click here for the next post.