US Patent 8438956 Torque indicating driver

In one embodiment, a torque-indicating driver includes a handle configured to receive applied torque. One or more flat springs are coupled via a housing to the handle at their proximate ends. The one or more flat springs are configured to angularly deflect elastically in response to the applied torque. A hub is coupled to a distal end of the one or more flat springs, the hub having a torsion rod extending therefrom. The torsion rod is configured to apply torque to a load. An outer sleeve at least partially covers the housing. One or more plungers are affixed to the housing and configured to engage one or more holes or depressions disposed at predetermined locations in the outer sleeve. Engagement with the holes or depressions creates auditory and tactile feedback perceivable by a user of the torque-indicating driver to indicate when a particular torque level is reached.