Textiles: knitting – Feeding – Positive
Patent
1996-08-16
1998-06-16
Falik, Andy
Textiles: knitting
Feeding
Positive
139452, B65H 5122, D03D 4736, D04B 1548
Patent
active
057653992
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention refers to a thread storage and feed device and a method for detecting a yarn storage in the yarn storage and feed device.
BACKGROUND OF THE RELATED ART
A thread storage and feed device for knitting machines known from U.S. Pat. No. 4,180,215 is provided with a storage body which is rotatably driven and which has a concave contour line. The storage body has a light-transmitting wall and different circumferential sections, e.g. longitudinal grooves or longitudinal slots so as to define small contact surfaces for the thread windings. Inside the storage body, a light-generating transmitter and a reflected-light receiver are arranged. Outside of the storage surface, a mirror is provided which reflects the light of the transmitter in the scanning zone to the receiver as long as no thread windings are located in said scanning zone. The axial transition between reflection and shading, which takes place in the axial direction, is detected so as to control the rotary drive means of the storage body. The reflection or absorption behavior of the thread windings influences the discrimination of the sensor signals. White, shiny thread windings of one thread quality will reflect the light like the mirror; whereas extremely thin thread windings of another thread quality will not sufficiently shade off reflected light. In these cases, the signal difference between the sensor signals will decrease, and this will have the effect that the sensitivity with which the sensor responds will have to be raised, whereupon the interfering influence of extraneous light, contaminations or of a decreasing optical transparency of the wall of the storage body will become stronger.
Similar problems arise with other optoelectronic sensors used for scanning thread supply boundaries by comparing the reflection behaviour of the thread windings with the reflection behaviour of the storage surface.
In thread storage and feed devices for knitting machines known from DE-C2 22 16 55 and GB-C-1 168 905, movements of the boundary of the thread supply are determined by a sensing element defining an inclined advance element and a sensor for actuating a switch in response to the degree of inclination. These functions mutually influence one another. In operation, these devices show a hysteresis resulting in an inaccurate operating behaviour. Furthermore, these devices react sensitively when the tension of the thread supplied changes.
It is the object of the present invention to provide a simple method to be used universally on various types of thread storage and feed devices. A further object is to provide a structurally simple thread storage and feed device by means of which it is possible to scan the movements of the boundary of the thread supply free from any susceptibility to trouble and, to a large extent, independently of the thread quality and the properties of the thread material.
SUMMARY OF THE INVENTION
According to the method of the invention, the respective control signal is either derived from the appearance or disappearance of the simultaneous nonidentical storage surface signals, or the control signals are derived from the discrimination between the simultaneous nonidentical storage surface signals and the thread signals which are identical among themselves, the very clear difference between the identicalness and the nonidenticalness being evaluated in any case. Even if the thread signals are similar to one of the nonidentical simultaneous storage surface signals, a control signal can be derived in a reliable manner. The quality of the scanning result is high because the scanning is carried out not only "axially" but simultaneously also in the circumferential direction. Any interfering influence of the thread quality is eliminated. The method is adapted to be used for rotatable storage bodies as well as for stationary storage bodies, and it is equally advantageous for thread storage and feed devices for weaving machines as well as for knitting machines.
In the thread storage and feed devic
REFERENCES:
patent: 4180215 (1979-12-01), Nurk
patent: 4325520 (1982-04-01), Hintsch
patent: 4687149 (1987-08-01), Riva
patent: 4715411 (1987-12-01), Van Bogaert et al.
patent: 4850400 (1989-07-01), Gorris
patent: 5211347 (1993-05-01), Riva
patent: 5377922 (1995-01-01), Fredriksson et al.
patent: 5590547 (1997-01-01), Conzelmann
Huss Rolf
Jacobsson Kurt Arne Gunnar
Tholander Lars Helge Gottfrid
Weber Friedrich
Falik Andy
Iro AB
Memminger-Iro GmbH
LandOfFree
Method and apparatus for detecting a thread supply boundary on a 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 detecting a thread supply boundary on a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for detecting a thread supply boundary on a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1714516