Textiles: weaving – Weft manipulation – Weaving with stationary weft supply
Patent
1984-08-08
1986-06-17
Jaudon, Henry S.
Textiles: weaving
Weft manipulation
Weaving with stationary weft supply
242 4701, 139452, D03D 4736
Patent
active
045950393
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a method and apparatus for controlling a plurality of relay nozzles in a jet weaving machine.
BACKGROUND OF THE INVENTION
The present invention relates to a method and device for controlling a plurality of relay nozzles in a jet weaving machine. Such relay nozzles are sequentially actuated, i.e. opened, for supporting the insertion of the weft yarn into the shed of the weaving machine, from the insertion side of the machine and up to the arrival end of the shed on the other side of the machine. The actuation of the relay nozlzes is carried out by sequentially opening electro-magnetic or solenoid valves associated with the nozzles. In some known types of weaving machines the relay nozzles are kept open from the moment when they are opened up to the moment when the weft yarn reaches the arrival end of the shed, at which latter moment all relay nozzles are closed simultaneously. In other types of machines the relay nozzles are sequentially closed a predetermined moment of time after they have been opened. The present invention is applicable to both these different kinds of relay nozzle control.
A known method of the above-mentioned kind is for example disclosed in German Offenlegungsschrift No. 28 36 206. There, the relay nozzles are actuated in synchronism with the rotation of the main shaft of the weaving machine. For carrying out this known method, the electro-magnetic or solenoid valves associated with the relay nozzles are connected to and thus receive actuation signals from a rotary sensor in the form of a code disc co-acting with an optical detector, said code disc being fixed on the main shaft.
This known method works in an optimal way only if there is a perfect synchronism between the weft insertion process and the rotation of the main shaft of the weaving machine. However, such a synchronism cannot always be maintained, since on one hand the main shaft rotation is a relatively non-varying parameter in this connection, whereas on the other hand the weft yarn insertion curve as a function of time can vary a great deal in dependence on e.g. the pressure of the utilized compressed medium, preferably air, and also from yarn to yarn having different friction coefficient, thickness and structure. This means with the known method that the control of the nozzles must be carried out with sufficient compensation for the variations in synchronism between the weft insertion process and the main shaft rotation, preferably by providing relatively generous time tolerances for the sequential opening (and closing, if any) of the series of nozzles. As a consequence hereof the nozzles will consume much more pressure medium (air) than would be necessary for the support of weft insertion as such, which altogether means higher production costs for the woven fabric.
The object of the present invention is primarily to provide a method and a device by which the above-mentioned drawbacks have been eliminated.
SUMMARY OF THE INVENTION
This is achieved in accordance with the invention by the solenoid valves for the relay nozzles being controlled on the basis of calculated information representing the momentary actual position of the leading end of the weft yarn during its path in the shed of the weaving machine.
By this method the necessary opening time intervals can always, irrespective of varying compressed medium pressure, wearing of the nozzles and valves, and utilized yarn quality, be kept at a minimum, which means considerable savings in compressed medium consumption and corresponding reduction of production costs.
An apparatus for carrying out this new method is based on Applicant's own earlier international patent application No. PCT/EP 83/00254 and has a yarn storing, feeding and measuring device for the weft yarn to be supplied into the shed of the weaving machine, said device comprising a stationary storing drum onto which an intermediate yarn store is wound by a winding-on member and from which the yarn is withdrawn spiralling around the withdrawal end o
REFERENCES:
patent: 3776480 (1973-12-01), Lawson
patent: 3853153 (1974-12-01), VanDuynhoven et al.
patent: 4020877 (1977-05-01), Spisiak
patent: 4445546 (1984-05-01), Hintsch
patent: 4458726 (1984-07-01), Wenig
Aktiebolaget IRO
Jaudon Henry S.
LandOfFree
Method and device for controlling a plurality of relay nozzles i 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 device for controlling a plurality of relay nozzles i, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for controlling a plurality of relay nozzles i will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2268322