On Mon, 20 Nov 2017 20:30:39 +0000, N_Cook wrote:

A sort of slip clutch in a gear train that transmits torque until ther
is a jam. Then at a preset back-torque a "ratchet" mechanism engages
making a clicking noise as the drive side turns relatively freely to
protect a motor etc and alerts a user to a problem.
"Ball detent overload release" is one name for this type of clutch.
Eric