| 摘要 |
PROBLEM TO BE SOLVED: To realize a quick and accurate sighting by tracing a line to be measured while a measuring device body is placed at position on the line to be measured by using a sighting mechanism and a caster mechanism of the measuring device. SOLUTION: A caster box 9 which follows and moves while a device body 1 is pressed down to a cross mark of a line to be measured, is rotated by a torque produced by a contact pressure of a rotary disc 7, an offset (f) of a caster and a tracing force, and the rotary disc 7 follows the direction of movement of the device body 1. Since the rotary disc 7 is provided with slits corresponding to its outer circumference, an electric pulse signal which corresponds to the rotation length and is emitted from a transmission type photo interruptor 8 is sent to a computing function board 5 from any position of a caster through a slip ring 10 or even during rotation. The electric signal is calculated in a circuit on the computing function board 5 according to a pre-indicated menu by using a constant input button 4b, and it becomes a target value and indicated on a digital indication plate 3.
|
