PURPOSE: To obtain a low cost by constituting a device providing at least two distance sensors to be arranged approaching a vibrator further with the distance from it different from each other and generating an alarm when amplitude by both the sensors is not between the first and second predetermined values.
CONSTITUTION: A one part 21 in a side of a driving part 3, opposed facing to one part 20 in a side of a trough 2, is formed bending, and the one part 21 fixes one proximity sensor 24 to a high part 21a of this part 21 and the other sensor 27 to a low part 21b. The one part 20 in the side of the trough 2 forms a distance of its detected surface 20a from these sensors 24, 27 respectively to b1, b2, and a device is constituted such that when the distance between the parts 20, 21 decreases by the first predetermined value or more from this condition, the sensor 24 is turned on, and when the distance decreases by the second predetermined value, larger than the first predetermined value, or more, also the sensor 27 is turned on. That is, in the amplitude within the predetermined value, the sensor 24 is turned on and the sensor 27 is turned off. When the amplitude exceeds the upper limit, also the sensor 27 is turned on, while when the amplitude decreases from the lower limit, the sensor 24 is turned off, and in both cases, an alarm is generated.
KATO YOSHIO
SUZUKI YOSHITSUGU
KOBAYASHI NAOKI
| JPS6120826A | 1986-01-29 | |||
| JPS6227215A | 1987-02-05 | |||
| JP54179675B |