| 摘要 |
An electronic torque wrench has a digital read-out for indicating the actual torque applied by a drive head of the wrench and an electronically actuated warning mechanism for enabling a user to control the maximum torque applied at a terminal drive portion of the drive head of the wrench. The warning mechanism may for example be an electronic equivalent of a click mechanism. That threshold value is calculated in response to the target torque, to the applied torque as measured by a strain sensor, and to the rate of change of torque. The calculation is predictive including a means for extrapolating from the monitored rate of change to predict the threshold value. The threshold value may be a time value, a torque value or an angle value. It may initially be set to compensate for the average reaction time of a user, but successive iterations and successive calculations progressively refine that threshold to bring the final actual attained torque nearer to the target torque. |
