This is the fourth post in my “How To Protect An Idea: A Guide For Scientists, Engineers, Inventors, And Business Leaders To Understand Patent Claims” series. If you read my second post, then you know that only the claims section of issued patents can be used to sue your competitors for patent infringement. If you read the third post, then you have a few tips for reading patent claims.
The post discusses three special types of claim that are very common.
What is a Markush 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, wherein the jelly layer contains a plant material selected from the group consisting of a grape, a strawberry, a raspberry, a blackberry, and a cherry,
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.
A peanut butter and jelly sandwich containing grape jelly would likely infringe this claim because a grape is one of the plant materials listed.
Markush groups are not open ended. If you can think of any possibility that is not listed, then that possibility would not literally infringe the claim.
For example, here in Houston, jalapeno jelly is popular. Since jalapenos are a plant material that is not specifically listed, a sandwich containing jalapeno jelly would not infringe claim 3.
Also, Markush groups can be interpreted to not cover mixtures of their possibilities, unless the claim indicates otherwise. For example, a sandwich that contains a mixture of grape and strawberry jelly might not infringe claim 3. But if claim 3 were to recite “a plant material selected from the group consisting of a grape, a strawberry, a raspberry, a blackberry, and a cherry, or a mixture thereof”, then the mixture would literally infringe the claim.
The Markush format works well when there are a limited number of discrete, technical possibilities. For this reason, Markush groups are very common in the chemical and biotechnology areas, where the science limits the possible variations.
Review Strategy: Can you think of a technical variation not recited in the Markush group?
If so, then the claim will not cover that technical variation.
What Is A Means-Plus-Function Claim?
A means-plus-function claim is a claim that contains a special phrase. The classic means-plus-function phrase is “means (of or for doing something).” For example, a means-plus-function claim might recite a “means for providing power” or a “means of projecting an image.”
The means-plus-function format is used in situations where there are many possibilities for providing power, and it is understood that it does not particularly matter which one is used.
However, this claim format is in decline, because means-plus-function claims are currently interpreted by courts as only including the possibilities recited in the specification. For example, if a claim recites “means for providing power” and the specification indicates that “means for providing power” includes a battery and a power cord,” then the claim would be interpreted to only cover those two possibilities.
Review Strategy: If you see the means-plus-function language in your claims, read the part of the specification that supports that language. Make sure that the specification mentions all of the possible variations that you want to cover.
What Is A Product-By-Process Claim?
A product-by-process claim is any claim that contains a description of a product or component in terms of how it was made. For example, Claim 1 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,
wherein the white bread was baked in a wood oven.
Best practices for describing a product are to describe the characteristics or composition of the product or component. These are measurable characteristics of the thing itself. In contrast, describing even one component in terms of how that component was made converts the product claim into a product-by-process claim.
Product-by-process claims were originally developed at a time when it was difficult to chemically analyze what a molecule or material was made out of, but you could accurately and reproducibly explain how to make it. Product-by-process claims are strongest when there is only one way of making the product so that possession of the product is practically proof of infringement.
There are two important points to understand about product-by-process claims. First, they are much weaker than regular product claims during examination by the USPTO. Specifically, the Examiner will assume that the product or component is identical to those in the prior art unless you can establish to the Examiner’s satisfaction that the recited process would be expected to provide a product having different characteristics.
You read that correctly.
A product-by-process claim will require you to prove to an Examiner that the white bread will have different physical characteristics because it was baked in a wood oven as opposed to a brick oven. If you adopt this strategy, bring your lunch.
Second, product-by-process claims are difficult to enforce because you have to detect and prove that the product was made using the recited method. For example, you would have to prove that the sandwich was made using white bread baked in a wood oven.
Review Strategy: Look for words in your product claim that discuss how the product or a component was made. Ask your patent attorney if it is possible to redraft the claim in terms of the physical characteristics or composition of the product that you want to claim.
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 “How Can A Product Claim Protect My Product?” Click here for the next post.