How are “equivalents” interpreted in means-plus-function claims?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-29 10 Rules 5 Related FAQs This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice. The interpretation of “equivalents” in means-plus-function claims can vary depending on how the element is described in the supporting specification. According to MPEP 2184 : “Generally, an ‘equivalent’ is interpreted as embracing more than the specific elements described in the specification for performing the specified function, but less than any element that performs the function specified in the claim.” The scope of equivalents can range from broad to narrow: If the disclosure is broad, it may encompass any structure, material, or act that performs the claimed function. If the specification describes the invention only in the context of a specific structure, material, or act, the scope of equivalents may be constricted to virtually only the disclosed embodiments. Related Rules from the Manual of Patent Examining Procedure 10 rules Collapse Specification Describes More Than Specific Elements But Less Than Function Performing Element MPEP 2184 Equivalence Scope Varies Depending on Specification Description MPEP 2184 Scope of Equivalents Dependent on Specification Description MPEP 2184 Factors for Proving Nonequivalence of Prior Art Element MPEP 2184 Permitted Claims Must Be Read Broadly When Disclosure Is Comprehensive MPEP 2184 Required Equivalents May Constrict Claim Scope to Disclosed Embodiments MPEP 2184 Permitted Means-Plus-Function Claim Element Interpretation MPEP 2184 Applicant Must Prove Non-Equivalence After Prima Facie Case MPEP 2184 Claim Must Be Read Broadly When Disclosure Is Comprehensive MPEP 2184 Claim May Include All Structures Performing Function MPEP 2184 Prohibited Other Related FAQs 5 FAQs Collapse Are mere allegations of nonequivalence sufficient to overcome a prima...