Yarn feeding device and method for yarn feeding

Abstract

A yarn feeding device B of a weaving machine W comprising at least two yarn feeding appliances F 1 , F 2 delivering the same yarn quality in a weft mixing process. Each yarn feeding appliance comprises a variable speed control system C, a sensor arrangement 6 which supplies control signals for the size of the stored yarn supply, and t least one fault sensor Z 1 , Z 2 , by which means a fault signal X indicating a change in the weft mixing condition, e.g. a yarn break in the upstream from the stored yarn supply, can be emitted. A fault signal transmission link Q 1 , Q 2 is provided extending from each yarn feeding appliance to the speed control system C of each other yarn feeding appliance, and an over-regulating routine 6 is provided in each speed control system C, said routine enabling the speed to be increased before the change in the weft mixing condition, by means off the fault signal X, independently from the control signals of the sensor arrangement 6.

1 . Yarn feeding device of a weaving machine, comprising at least one group consisting of at least two yarn feeding appliances feeding the same yarn quality in a weft mixing process, each yarn feeding appliance including a variable speed control for a winding element, a sensor arrangement for the size of a yarn supply package on a storage body, which sensor arrangement delivers control signals and is connected to the speed control, and at least one disturbance sensor for outputting a disturbance signal indicating a change of the condition of the weft mixing process, wherein a real time disturbance signal transmission link is provided which extends from each yarn feeding appliance of the group to at least one further yarn feeding appliance of the group, and wherein an overruling routine is provided in each speed control by which overruling routine the speed of the winding element is increased in advance to the change of the condition of the weft mixing process by consideration of the disturbance signal independent from control signals originating from the sensor arrangement.  
   
   
       2 . Yarn feeding device as in  claim 1 , wherein the yarn feeding appliances of the group are equal high duty yarn feeding appliances having powerful drive motors and a large separation on the storage body, particularly for projectile weaving machines or rapier weaving machines having large weaving widths.  
   
   
       3 . Yarn feeding device as in  claim 1 , wherein the disturbance sensor of the yarn feeding appliances of the group are connected to a common interface, that the common interface is connected by a combination element with a weaving machine control device, and wherein each signal transmission link branches off upstream of the combination element to the speed control of at least the one further yarn feeding appliance of the group.  
   
   
       4 . Yarn feeding device as in  claim 1  wherein the overruling routine is installed by software into the speed control.  
   
   
       5 . Yarn feeding device as in  claim 3 , wherein at least the combination element is an opto-coupler.  
   
   
       6 . Yarn feeding device as in  claim 1 , wherein a controlled yarn selector is provided at the weaving machine which releases only a respective yarn channel corresponding to the respective condition of the weft mixing process, and wherein the yarn channel of a disturbed yarn feeding appliance is blocked by the yarn selector either by means of the disturbance signal or via the control device of the weaving machine, respectively.  
   
   
       7 . Yarn feeding device as in  claim 1 , wherein the group includes more than two yarn feeding appliances, and wherein the disturbance signal of one yarn feeding appliance is transmitted to the speed control of only one further yarn feeding appliance or to the speed controls of all further yarn feeding appliances of the group, respectively.  
   
   
       8 . Method for feeding yarn into a weaving machine according to which method equal yarn qualities are fed in a weft mixing process by at least two yarn feeding appliances of at least one group, such that for the formation of a yarn supply package size on a storage body sufficiently large to cover the consumption the speed of each yarn feeding appliance is variably speed controlled under consideration of control signals derived from the yarn supply package size and such that a disturbance signal is generated in case of a change of the condition of the weft mixing process caused by a disturbance, wherein the disturbance signal of one yarn feeding appliance is transmitted in real time to a variable speed control of at least one further yarn feeding appliance of the group, and wherein the speed of the further yarn feeding appliance is raised by a speed increase increment at most to a predetermined maximum speed (Vmax) to preparatorily enlarge the yarn supply package size for the upcoming change of the condition of the weft mixing process.