| 摘要 |
PURPOSE:To perform operation even when a weight is slightly away from a gauge mark or even when the circumference is a little bit dark by inserting a light emission body and a power source into the weight, and emitting a light beam from the hole at the lower end of the weight and illuminating the gauge mark. CONSTITUTION:The weight 2 is reverse conic and a large-diameter hole 2d for storing the battery 6 and a small-diameter hole 2f for storing the light emission body 8 are formed at the center part; and a small-diameter (about 1mm.) hole 2g is further formed at its lower end while extending to the lower end surface of the weight 2. The upper end of yarn 1 is fitted to a body whose verticalness is to be detected, and when a lid 3 is clamped, a switch contact plate 4 is lowered to close an electric circuit, turning on the light emission body 8. Its light is emitted downward as a light beam from the small-diameter hole 2g. At this time, a tripod and the length of the yarn are only adjusted so that the beam strikes the gauge mark. Consequently, the weight need not be put as close to the gauge point as a conventional plumb, so damage to the tip need not be considered and the verticalness is detected by a single-time adjustment even if the circumference is a little bit dark. |
