JPS5790363A - Method of detecting remaining quantity of wire wound around bobbin or drum - Google Patents

Abstract

PURPOSE: To accurately detect the remaining quantity of wire around a bobbin or drum, by providing two photoelectric tubes at a smaller distance from each other than the width of the bobbin or drum so that the tubes are juxtaposed in parallel with the axis of the bobbin or drum and by using a logical circuit to judge whether or not outputs based on light reflected from the bobbin or drum are overlapped with each other.

CONSTITUTION: Two photoelectric tubes 1, 2 are provided at a fixed distance from each other so that the tubes are juxtaposed in parallel with the axis of a bobbin 3. When there is a wire around the whole peripheral surface of the bobbin 3 as shown in Fig. (A), the photoelectric tubes 1, 2 which receive reflected light during the movement of the bobbin in the direction of the arrow generate outputs as shown in Fig. (a) where regions pH1, pH2 show the time of the output generation by the photoelectric tubes 1, 2 respectively and a hatched region shows the time of the simultaneously output generation by both the tubes. When a half quantity of the wire remains, the hatched region becomes as shown in Fig. (b). When the remainng quantity of the wire is as shown in Fig. (D), the hatched region disappears. It is judged through digital processing in a logical circuit whether the simultaneous output generation is performed or not. A remaining quantity detection signal is produced to stop the machine.

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