Textiles: knitting – Feeding – Positive
Patent
1999-03-08
2000-10-03
Falik, Andy
Textiles: knitting
Feeding
Positive
139452, 250205, 2423648, B65H 5122
Patent
active
061256633
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for monitoring scanning conditions during the control of a yarn feeding device including a sensor device oriented towards a scanning zone defined on a yarn storing surface. The sensor device senses motion or the presence or absence of an object in the scanning zone, and a control circuit processes an output signal of the sensor device to control a drive motor for replenishing the yarn storing surface with yarn.
BACKGROUND OF THE INVENTION
Such a method is disclosed in U.S. Pat. No. 4,865,085 (corresponding to EP-0 199 059 BI). In this method, the sensor device operates with a receiver which monitors the axial movement of yarn windings on a stationary storing drum, and a second receiver monitors the quality of the light transmission. An output signal of the second receiver is compared with a threshold value in order to provide an additional useful signal which serves to increase the light intensity for both receivers when the light transmission has deteriorated. Also, an alarm signal for an operator can be generated indicating the necessity for cleaning of the light transmission path by removing contaminants which disturb or block the light transmission.
In a method disclosed in U.S. Pat. No. 4,963,757, a light source feeds two receivers, one of which scans a yarn and the other scans only the light transmission quality in order to maintain the relation between the output signals of both receivers substantially constant, and to compensate for a deterioration of the light transmission quality.
According to a method disclosed in U.S. Pat. No. 3,907,440, phase-offset light pulses for one receiver are generated by means of two pulsed light sources, and a yarn is scanned only with the light pulses of one of the light sources. The output signals originating from the light pulses not used for yarn scanning are compared with a nominal signal value in order to maintain a predetermined relation between both signals and to compensate for disturbing influences.
GB-A-22 27 092 discloses an optoelectronic sensor which consists of a light source and a receiver. The sensor is checked in a bank-note receiving and discharging device as to the instantaneous scanning characteristics before the sensor takes part in the checking of a bank note. In a test routine, a state, as may later be found in testing a bank note, is simulated by darkening the light source at the control side, as compared with the normal light intensity of the light source. The level of resulting output signals of the receiver is compared with a threshold value level calculated by the control device from those output signals of the receiver that are obtained without and with the darkening action. If the level of the darkened output signal is below the threshold value level, an alarm will be initiated.
According to another method known from WO95/16628 and used for controlling the drive motor of a yarn feeding device for a knitting machine, the yarn feeding device includes a rotatably driveable storing drum defining a storing surface and a stationary sensor device. Circumferentially offset surface areas of the storing surface are simultaneously optoelectronically scanned in the scanning zone by means of a plurality of sensors. In case where yarn is present in the scanning zone, the sensors simultaneously output identical output signals. In contrast, when yarn is absent from the scanning zone, the sensors simultaneously generate different output signals. By discrimination between the output signals, control signals are derived, and the drive motor is driven as long as the scanning zone is free from yarn, until yarn reaches the scanning zone again. When replenishing the yarn store, i.e., in the driven state of the drive motor, a speed signal for the control circuit is derived from the output signal of a sensor. A predetermined quality of the light transmission is required for the operation of the sensor device. Contaminants and lint, which unavoidably occur when processing yarns, de
REFERENCES:
patent: 3907440 (1975-09-01), Eichenberger et al.
patent: 4769532 (1988-09-01), Kawakami
patent: 4865085 (1989-09-01), Ghiardo
patent: 4963757 (1990-10-01), Liefde et al.
patent: 5377922 (1995-01-01), Frediksson et al.
patent: 5613528 (1997-03-01), Zenoni et al.
patent: 5694979 (1997-12-01), Toda
patent: 5765399 (1998-06-01), Huss et al.
Falik Andy
Memminger-Iro GmbH
LandOfFree
Method and apparatus for monitoring scanning conditions during c does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for monitoring scanning conditions during c, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for monitoring scanning conditions during c will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-184714