Systems and methods for calibrating a tool

Abstract

A calibration system includes a housing, a drive shaft within the housing, a load application apparatus operatively connected to the drive shaft to apply a force to the drive shaft, and a plurality of housing transducers operatively connected to the drive shaft to measure at least one of an in-line torque or a prevailing torque of the drive shaft. A method for calibrating a tool includes generating at least one of a pass or fail output from a processing unit based on whether a variance between a prevailing torque from a tool transducer and a prevailing torque from an external tool is within a predetermined variance threshold. A method for measuring prevailing torque in a tool includes determining whether a prevailing torque value is within a predetermined prevailing torque range and adjusting a shut-off threshold torque based on the prevailing torque.

What is claimed is: 
     
         1 . A calibration system comprising:
 a housing;   a drive shaft within the housing extending to a connection point on a wall of the housing;   a load application apparatus operatively connected to the drive shaft to apply a force to the drive shaft; and   a plurality of housing transducers operatively connected to the drive shaft to measure at least one of an in-line torque or a prevailing torque of the drive shaft.   
     
     
         2 . The calibration system as recited in  claim 1 , further comprising a processing unit operatively connected to at least one of the plurality of housing transducers to provide a pass/fail output based on a comparison between the prevailing torque measurement from at least one of the housing transducers and a prevailing torque measurement from an external tool. 
     
     
         3 . The calibration system as recited in  claim 1 , a selectively removable tool operatively connected to the connection point on the wall of the housing to apply a torque to the drive shaft. 
     
     
         4 . The calibration system as recited in  claim 3 , wherein the selectively removable tool includes a tool transducer to determine at least one of an in-line torque and a prevailing torque being applied to the drive shaft by the selectively removable tool. 
     
     
         5 . The calibration system as recited in  claim 4 , wherein the tool transducer is operatively connected to a processing unit operatively connected to at least one of the plurality of housing transducers, wherein the processing unit provides a pass/fail output based on a comparison between the prevailing torque measurement from at least one of the plurality of housing transducers and the prevailing torque measurement from the tool transducer.