| 摘要 |
A torque wrench having a reaction bar and an arm extending laterally in the same direction from a work engaging head. The arm is flexed in response to torque applied to the head through the bar and cooperable members on the bar and arm respectively engage as a consequence of that flexing. The member on the bar is a pivoted lever which responds to the aforementioned engagement to swing towards a signal generating position at which it causes a switch to operate to close a circuit contained within a handle part of the bar. The circuit includes audible and visible signal means and those means are energized while the circuit remains closed. The switch is normally urged towards a circuit closed position but is prevented from reaching that position by a blocking member, and the aforementioned pivoted lever renders that blocking member inoperative when the pivoted lever is swung into its signal generating position. Thus, the signals continue to be generated until the pivoted lever is moved back from the signal generating position. Lost motion means functions to allow some relative movement between the pivoted lever and blocking member.
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