What Are The Five Patent Classes?

1. Processes and methods

These are steps for doing or making something.  They can be steps that change something physically or even manual steps, like how you type on a keyboard.  They cannot, however, consists of only mental steps.

There are primarily three categories of processes:

1. conventional

This is what you would traditionally consider a process, like a chemical reaction or steps to physically construct an item.

2. software

To be classified as a process or method, a software program must produce a tangible, utilitarian result, or affect some piece of hardware or another software.  The federal court in In re Bilski stated software processes must transform an article into a different thing or state, or it must be related to a specific machine or apparatus.

3. business

This includes methods of conducting business, such as software to calculate financial records.  It is also circumscribed by the decision in In re Bilski.

2. Machines

Machines are devices or things that interact and, as a result, accomplish something.  It’s related to processes but the focus here is on the actual machine, not the methods that the machine employees.  Machines can include traditional notions of what is a machine, such as a sewing machine. It also covers software depending on how you write the patent application.

3. articles of manufacture

This includes what results from manufacturing or what’s made by humans.  It’s an invention that accomplishes something without the interaction of moveable parts or objects with incidental moveable parts.  For example, knives, erasers or books are articles of manufacture.  Usually, naturally occurring things do not fit into this category but there are some exceptions, e.g. a novel, non-obvious use of a natural thing.  Also, there may be some overlap between articles of manufacture, and machines or compositions of matter.

4. compositions of matter

Chemicals or other material combinations that are produced as a result of chemicals are compositions of matter. This includes glues, plastics and gasoline.  Natural items are not considered compositions of matter but, for example, their derivative chemicals or extracts in purified form are.  

Compositions of matter often overlap with articles of manufacture.  However, compositions are primarily concerned with the chemical building blocks rather than the shape of the article.

5. improvements

Improvements are novel uses for an existing invention. Under this category, you may need a license from the original patent owner if the underlying invention is still patent protected.