What is the difference between combining and substituting equivalents in patent law?

In patent law, there is a distinction between combining equivalents and substituting equivalents, as outlined in MPEP 2144.06. The key differences are:

• Combining Equivalents: This involves using two or more components together, each known for the same purpose, to create a new composition or method for that same purpose. The In re Kerkhoven case exemplifies this principle.
• Substituting Equivalents: This involves replacing one component with another that is known to serve the same purpose in the prior art. The equivalency must be recognized in the prior art and cannot be based solely on the applicant’s disclosure.

While both principles fall under the broader concept of “Art Recognized Equivalence for the Same Purpose,” they are applied differently in obviousness determinations. Combining is about using multiple known components together, while substituting is about replacing one component with another known equivalent.

To learn more:

• Combining Equivalents
• Substituting Equivalents
• Obviousness
• Patent Examination
• Art Recognized Equivalence