Claim Drafting (Part 3) - Anatomy of a Method Claim. Episode 11
- Adam Diament
- Mar 15
- 4 min read
Introduction to Method Claims
In the last episode, I went through the parts of a device or apparatus claim, which are claims to inventions that are usually physical structures. In this episode, I’m going to go through the other main type of claim: a method claim.
A method claim is a claim for a new and non-obvious way of doing something. There are actually a couple of types of method claims:
A method for accomplishing a new goal – For example, I’ve talked a lot about the 3-in-1 avocado slicer device. A method claim might be “a method of pitting and slicing avocados.”
A method of making your new device – If you developed a new kind of manufacturing method that allowed you to make this new avocado slicer, that new method might be patentable.
A product-by-process claim – In this type of claim, you are actually claiming the end product, but only if that end product is made in a certain way. The example I’m going to go over later in this episode is a new method of making guacamole and actually claiming not just the method but the guacamole itself when it’s made in a specific way.
Basics of Method Claims
Before I go into specific examples of method claims that have been allowed, I first want to go over the basics. If I were to tell you to describe to someone how to fry an egg, how would you do it?
You might say:
Grab an egg from an egg carton.
Crack the egg on a hard surface.
Pull the eggshell apart over a heated pan.
Let the egg lay on the pan for two minutes.
Place a spatula under the egg.
Lift the spatula with the egg away from the pan.
Remove the egg from the spatula and place it on a plate.
That describes the basic steps of making a fried egg. But now we need to put it into patent language using the structure of a method claim.
Structure of a Method Claim
Just like device claims, method claims have three main parts:
Preamble – A brief introduction to what the method is for.
Transition Word – Almost always, this will be “comprising.”
Limitations – The individual steps of the method.
1. Preamble
The preamble for our frying egg example might be:
“A method of frying an egg”
“A method of cooking an egg”
“A method of preparing a food product”
The details aren’t that important, but it must start with “a method of” or “a method for” followed by what the method accomplishes. Instead of method, you can sometimes use the word process—both are acceptable.
2. Transition Word
The transition word will almost always be “comprising” and not “consisting of.” You should write:
“Comprising” or “comprising the steps of:”
Then, insert a colon (:) before listing the steps.
3. Limitations (Steps)
Each step must start with a gerund (a word ending in -ing). For example, instead of:
“Grab an egg” → You must write “Grabbing an egg.”
“Crack the egg on a hard surface” → You must write “Cracking the egg on a hard surface.”
Each step ends with a semicolon (;), not a period, because a claim must be one sentence.
Important Considerations When Drafting Method Claims
Proper Antecedent Basis: The first time you introduce an element, you must use “a” or “an”. The next time you reference it, you must use “the.”
Example: “Grabbing an egg” → “Cracking the egg.”
Avoid unnecessary steps: If a step is not essential to your new method, leave it out. If you include too many details, competitors may be able to avoid infringement by modifying just one step.
Example: If you say “Frying the egg for five minutes,” someone could fry it for four minutes and claim they aren’t infringing your method.
Be careful with specific materials or tools:
If you say “Grabbing an egg from an egg carton,” but someone grabs the egg from a bowl instead of a carton, they might not infringe your method.
Example of a Patented Method Claim
Here’s a real patent example: U.S. Patent No. 5,871,794 for a “Stabilized Guacamole and Method for Making Same.”The problem it solves? Guacamole spoils quickly and turns brown if not eaten immediately. This inventor developed a composition that prevents spoilage.
Claim 10: Method of Making Guacamole
Preamble and Transition Word:“A process for preparing a stabilized guacamole that can be stored at room temperature without spoilage, comprising the steps of:”
Limitations:
Removing the skin and pit of an avocado to obtain avocado flesh;
Removing the husk, seeds, and outer skin from a tomatillo to obtain tomatillo pulp;
Mixing the avocado flesh and tomatillo pulp;
Heating the mixture to about 85°C for about 10 minutes.
This patent was granted, though we could debate whether it should have been, but that’s not the focus here. Instead, I wanted to illustrate how method claims are structured.
Product-by-Process Claims
Another important type of method claim is a product-by-process claim, where you are not just claiming the method but also the end product when made using that method.
Claim 17: Product-by-Process
“A stabilized guacamole preparation that can be stored at room temperature without spoilage, made by the process of:”
Then, it repeats the same method steps from Claim 10.
Why is this important?
If a small manufacturer makes guacamole using this process and sells it to a large retailer, the retailer may not be infringing the method claim (because they are not making the guacamole).
But if you also have a product-by-process claim, you can sue the retailer for selling the guacamole made with your patented process.
Conclusion
Writing strong method claims ensures your patent protection is as broad as possible. By carefully structuring your claims, you can stop not only manufacturers but also distributors and sellers from infringing on your invention.
If you want help drafting your patent application and claims, I offer those services through my practice at Diament Patent Law. You can contact me at patentingforinventors.com.
I’m Adam Diament, and until next time, keep on inventing!
