What is a single means claim and why is it problematic?

A single means claim is a claim that recites a means-plus-function limitation as the only limitation of the claim. These claims are problematic because they cover every conceivable means for achieving the stated result. The MPEP explains:

The long-recognized problem with a single means claim is that it covers every conceivable means for achieving the stated result, while the specification discloses at most only those means known to the inventor.

Single means claims are typically rejected under 35 U.S.C. 112(a) for lack of enablement, as they read on subject matter that is not enabled by the specification.

To learn more:

Topics: MPEP 2100 - Patentability, MPEP 2181 - Identifying And Interpreting A 35 U.S.C. 112(F) Or Pre - Aia 35 U.S.C. 112, Patent Law, Patent Procedure, Sixth Paragraph Limitation
Tags: 112(A), 112(F), claim drafting, Enablement, Single Means Claim