Textiles: weaving – Weft manipulation – Weaving with stationary weft supply
Patent
1984-08-08
1985-09-17
Jaudon, Henry S.
Textiles: weaving
Weft manipulation
Weaving with stationary weft supply
242 4701, D03D 4736
Patent
active
045414629
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a weft yarn storing, feeding and measuring device, preferably for jet weaving machines, in accordance with the generic clause of claim 1.
DE-OS No. 31 23 760 (which corresponds to U.S. Pat. No. 4,407,336) discloses a yarn storing, feeding and measuring device for jet weaving machines having a stationary storage drum onto which an intermediate yarn store is wound by a winding-on device and from which the yarn is withdrawn spiralling around the withdrawal end of the storage drum, yarn sensing means being arranged such that the yarn is passing its detection area during withdrawal from the drum, said yarn sensing means producing pulse signals, each pulse signal indicating that the yarn passes a detection area of the yarn sensing means, a plurality of yarn stopping devices being arranged at angular intervals around the storage drum, said yarn stopping devices consisting of yarn stopping elements and actuator means moving said stopping elements into and out of the path of the yarn being withdrawn, and an actuator control device adjustable to desired weft yarn lengths to be withdrawn, said control device being responsive to said pulse signals in such a way that an actuating signal is transmitted to a yarn stopping device the angular position of which corresponds to the position rendered by the yarn when said desired yarn length has been withdrawn. The yarn sensing means consists of a plurality of yarn sensors, each of these sensors being associated with a yarn stopping device. Hence, the number of yarn sensors required for such a device corresponds to the number of yarn stopping devices. Yarn storing, feeding and measuring devices of this kind not only serve to intermediately store the weft yarn on a storage drum, but also serve to supply the jet weaving machine with a weft yarn length of a desired value. For the latter purpose, this known device carries out the following steps in order to obtain the desired yarn length for each weft yarn insertion into the shed of the weaving machine:
After releasing or de-actuating the yarn stopping device actuated at the end of a previous yarn withdrawal cycle, the yarn is withdrawn spiralling around the withdrawal end of the storage drum. Thereby, the yarn subsequently passes the detection area of each of the several yarn sensors being arranged at the withdrawal end of the storage drum in a spaced, angular relationship with respect to each other. Each yarn sensor generates a pulse signal indicating that the yarn passes its detection area, these pulse signals being fed to the control device. Hence, the control device receives a number of pulse signals, this number corresponding to the number of yarn sensors being passed by the yarn during the withdrawal from the storage drum. By counting these pulse signals received from the yarn sensors, the control device generates a count value corresponding to the actual position of the withdrawal point of the yarn with respect to the yarn sensors. The count value corresponds to the length of yarn having been withdrawn from the storage drum. When the count value corresponds to the desired yarn length to be withdrawn, the control device actuates the stopping device being located with respect to the angular movement of the withdrawal point of the yarn behind the yarn sensor which generated the last pulse signal. Thereby, the withdrawal of the yarn is stopped so that the desired yarn length is obtained. This known yarn storing, feeding and measuring device is costly and complicated due to the great number of yarn sensors required to achieve a sufficiently great number of different yarn lengths, or in other words to achieve a sufficiently great accuracy in the desired weft yarn length. A further drawback is caused by the fact that yarn sensors are also sensitive in operation, since they usually comprise optical elements which can be covered by lintor be disturbed by irrelevant light rays. If one of the several yarn sensors is e.g. covered by lint, it will no longer generate pulse signals when the yarn passes it
REFERENCES:
patent: 3776480 (1973-12-01), Lawson
patent: 3853153 (1974-12-01), Van Duynhoven
patent: 4407336 (1983-10-01), Steiner
patent: 4415008 (1983-11-01), Keller et al.
Aktiebolaget IRO
Jaudon Henry S.
Shongut S.
LandOfFree
Weft yarn storing, feeding and measuring device, preferably for does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Weft yarn storing, feeding and measuring device, preferably for , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Weft yarn storing, feeding and measuring device, preferably for will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-365498