Patent ID: 8857532

Claim:
A control device for a power wrench arranged to prevent negligence of at least one unacceptably tightened screw joint on an assembled object, the power wrench comprising at least one operation parameter indicating unit, and the control device comprising: a position sensing system configured to continuously indicate an actual multi-dimensional position of the power wrench during tightening of the at least one screw joint on the object to be assembled; and a control unit configured to compare obtained operation parameter values indicated by said at least one operation parameter indicating unit at each tightening operation with predetermined operation parameter limit values, and to issue an OK or an NOK signal indicating whether or not a tightening result of each screw joint is acceptable depending on whether or not said limit values are passed for each screw joint; wherein said control unit is configured to lock operation of the power wrench to an object position for which an NOK indicated screw joint tightening result has been indicated, and to enable the power wrench for tightening operations on other objects than the object position for which said NOK indicated screw joint tightening result has been indicated only when said NOK indication is removed.