| 摘要 |
PURPOSE:To enhance measuring accuracy by preventing slackening, by tensioning a steel wire to be tensioned by tension applied prior to cutting. CONSTITUTION:By the screw 14 at the end of a movable rod 7 and the female screw 21 in the direction opposite to the male screw of a steel wire pulling knob 6a, the movable rod 7a is retractively moved relatively to the advance of the steel wire pulling knob 6a to impart tensioning force to the steel wire 9. With the advance movement of the steel wire pulling knob 6a, the collar 12 contacted with said knob 6a compresses a spring 20 to move to the same direction. As a result, the pin 13 provided to the collar 12 allows an indicator 17 to revolve to a direction increasing the numerical value of graduations. When the steel wire 9 is cut before long, the collar 12 having received the repulsive force of the compressed spring is retractively moved to the left direction. However, because the indicator 17 revolved once is stopped while indicates the tensioning force numerical value when the steel wire was cut, said numerical value is read. |
