| 摘要 |
PURPOSE:To perform the selection and changing of springs smoothly, when the single coil spring is selected among a plurality of coil springs having different spring constants and measuring operation is performed, by disengaging the engagement of a pan receiving fitting and all the coils. CONSTITUTION:By the rotation of a selecting shaft 16, the peripheral part of the selecting cam 19 compresses the side part of the coil spring 13 and the lower end part of the spring 13 is disengaged from an engaging groove 8 of the pan receiving fitting 2, and the spring 13 is evacuated. Since the selecting cam 18 is separated from the coil spring 12, and the lower end part of the spring 12 is engaged with the engaging groove 8, the displacement of the pan receiving fitting is transmitted to the coil spring 12 for measuring the specified weight. When the selecting shaft 16 is rotated by 90 deg., the cams 18 and 19 are separated from the springs 12 and 13 a locking cam 17 pushes up a pan 1 through a locking piece 22 at the same time, and the lower end parts of the coil springs 12 and 13 are disengaged from the engaging groove 8. When the rotary shaft is further rotated by 90 deg., the fitting 2 is lowered, the spring 12 is evacuated, and the spring 13 is used for the measuring operation. Therefore, the selection and changing of the springs 12 and 13 are performed smoothly. |
