Device for feeding a yarn to a textile machine having a yarn-cutting device

Abstract

A device for feeding a yarn to a textile machine includes a housing with which a rotary member is associated to cooperate with the yarn unwinding from a package and directed, on leaving the device, to the machine where it is processed. Correct feed of the yarn is monitored by a feed controller associated with the housing in accordance with at least one measured parameter related to the rotary member or to an intrinsic characteristic of the yarn such as its tension or its feed velocity. A yarn cutting member is provided. This is connected to and controlled by the controller on the basis of the measured parameter of the yarn. The cutting member is activated by the controller to cut the yarn whenever the parameter monitored by the controller has a value exceeding a predetermined required value.

1 . A device for feeding a yarn to a textile machine operating on the basis of measuring any characteristic of the yarn, which is directly measured or indirectly measured.
 said device comprising a housing with which a rotary member is associated to cooperate with the yarn unwinding from a package and directed, on leaving the device, to said machine where the yarn is processed,   feed control means associated with said housing, said feed control means for monitoring correct feed of the yarn in accordance with at least one measured parameter related to an intrinsic characteristic of the yarn,   a yarn cutting connected to and controlled by said control means on the basis of the measured parameter of the yarn, said control means for activating said yarn cutting member to cut the yarn whenever the measured parameter monitored by said control means presents a value exceeding a predetermined required value,   wherein the control means comprises a control unit connected to a storage memory unit for memorizing said predetermined required value with which to compare said measured parameter monitored by said control means.   
     
     
         2 . A device as claimed in  claim 1 , wherein the control means is connected to a tension sensor associated with the device housing, said sensor enabling said control means to measure the tension of the yarn leaving the device, this tension defining said monitored parameter. 
     
     
         3 . A device as claimed in  claim 1 , wherein the control means is connected to an electric motor or actuator for the rotary member and measures a characteristic parameter of that actuator, said parameter being a parameter monitored for the activation or non-activation of the yarn cutting member. 
     
     
         4 . A device as claimed in  claim 3 , wherein said characteristic parameter is the motor torque. 
     
     
         5 . A device as claimed in  claim 4 , wherein said characteristic parameter is measured via the current absorbed by the motor. 
     
     
         6 . A device as claimed in  claim 1 , wherein the control means is connected to a velocity sensor operationally associated with the rotary member, said control means measuring in this manner the quantity of yarn fed to the textile machine, this quantity defining the parameter which is monitored for the activation or non-activation of the cutting member. 
     
     
         7 . A device as claimed in  claim 1 , wherein the monitored parameter is the number of turns of the yarn formed on the rotary member. 
     
     
         8 . (canceled) 
     
     
         9 . A device as claimed in  claim 1 , wherein said predetermined required value is alternatively a constant value, a programmable value, this programmable value for a fixed time during operation of the textile machine or a programmable time, or a value variable on the basis of the processing stage of the textile machine. 
     
     
         10 . A device as claimed in  claim 1 , wherein the cutting member is alternatively fixed to the housing of the feeding device or is separate from this feeding device. 
     
     
         11 . A device as claimed in  claim 1 , wherein the correct feed of the yarn is monitored by the feed control means associated with said housing in accordance with said at least one measured parameter related to said intrinsic characteristic of the yarn which comprises a directly measured characteristic selected from yarn tension or yarn velocity. 
     
     
         12 . A device as claimed in  claim 1 , wherein the correct feed of the yarn is monitored by the feed control means associated with said housing in accordance with said at least one measured parameter related to said intrinsic characteristic of the yarn which comprises an indirectly measured characteristic selected from yarn quantity wound on a storage member or an electrical consumption of said storage member. 
     
     
         13 . A device as claimed in  claim 1 , wherein the correct feed of the yarn is monitored by feed control means associated with said housing in accordance with said at least one measured parameter related to said intrinsic characteristic of the yarn selected from the group consisting of yarn tension or yarn feed velocity. 
     
     
         14 . A device as claimed in  claim 1 , wherein the control unit comprises a microprocessor connected to said storage memory unit in which said predetermined required value with which to compare said monitored parameter is memorized.