Device and procedure for the regulation of the contact pressure of a winding bobbin

Abstract

Device and process for the regulation of thread winding onto a bobbin by applying a desired contact pressure P c of the operating bobbin, providing the bobbin-holder arm with a counterweighing counterthrust P p , on the basis of a pre-established trend of the value of P c in relation to the advance length of the bobbin, indicating the weight of the bobbin in relation to the ratio between the length reached and indicating the rising a angle of the bobbin-holder arm, calculating the weight component due to the bobbin and said arm and applying a counterthrust P p equal to the difference between said component and the pre-established value of the contact pressure P c referred to the length reached.

1 . A process for the regulation of the winding of the thread onto a bobbin to obtain bobbins having the desired form and density, by the application of a desired contact pressure P c  of the bobbin ( 10 ) being processed, by applying a counterthrust P p  to the bobbin-holder arm ( 11 ) provided by the counterweighing device ( 44 ), on the basis of a pre-established trend of the value of P c  in relation to the advance degree of the bobbin, characterized in that said pre-established trend of the contact pressure value P c  is calculated with respect to the advance length of the bobbin and that during the formation of the bobbin, the device indicates the weight of the bobbin in formation P r  on the basis of the measurement of its length reached, it measures the rising angle (α) of the bobbin-holder arm and, for each indication of the angle (α) and length reached of the bobbin in formation, it calculates the total weight component (P r +P ba ) which is resting on the driving cylinder ( 16 ), applying a counterthrust P p  each time, calculated as the difference between said weight. component and the pre-established contact pressure value, according to the formula P p =(P r +P ba )−P c  referring to the length reached.  
   
   
       2 . The process for regulating the winding of the thread onto a bobbin according to  claim 1 , characterized in that the length reached by the bobbin in formation is detected on the basis of the number of progressive revs effected by the driving cylinder ( 16 ) starting from the beginning of the bobbin ( 10 ).  
   
   
       3 . The process for regulating the winding of the thread onto a bobbin according to  claim 1 , characterized in that the value of the rising angle (α) of the bobbin-holder arm ( 11 ) is measured directly on said arm each time.  
   
   
       4 . The process for regulating the winding of the thread onto a bobbin according to  claim 1 , characterized in that the value of the rising angle (α) of the bobbin-holder arm ( 11 ) is calculated on the basis of the length measured and corresponding to the volume of the bobbin reached, the geometry of the system and the winding density of the bobbin being known.  
   
   
       5 . The process for regulating the winding of the thread onto a bobbin according to  claim 1 , characterized in that the value of the rising angle (α) of the bobbin-holder arm ( 11 ) is both detected directly on said arm and calculated on the basis of the length reached, each time, subsequently comparing the two values and in that, when said values differ significantly, the control unit ( 48 ) of the winding unit increases or reduces the thread tension to increase or decrease the density of the bobbin ρ to the desired value, processing and sending the relative command signal to the thread-tensioner.  
   
   
       6 . The process for regulating the winding of the thread onto a bobbin according to  claim 1 , characterized in that in the restarting phase of the bobbin, the value of P c  is increased, reducing the counterthrust P p  of the counterweighing device ( 44 ), with respect to the regime regulation value for the length reached.  
   
   
       7 . The process for regulating the winding of the thread onto a bobbin according to  claim 6 , characterized in that the reduction value of the counterthrust value P p  is within the range of 20% -60%, and preferably from 25% to 35%.  
   
   
       8 . A device for regulating the thread winding onto a bobbin to obtain bobbins having the desired form and density, by the application of a desired contact pressure P c  of the bobbin ( 10 ) being processed, comprising a counterweighing device ( 44 ) applied to the bobbin-holder arm ( 11 ) to provide a counterthrust P p , on the basis of a pre-established trend of the value of P c  in relation to the advance degree of the bobbin, characterized in that said pre-established contact pressure value P c  is calculated with respect to the advance length of the bobbin and in that the device comprises measuring means ( 42 ) of the length reached for determining the weight of the bobbin in formation P r , means ( 34 ) for determining the rising angle (α) of the bobbin-holder arm ( 11 ) and means, at each detection of the α angle and length reached by the bobbin in formation, for calculating the total weight component (P r +P ba ) which is resting on the driving cylinder ( 16 ) without counterthrusts, each time applying a counterthrust P p  with a counterweighing device ( 44 ) calculated as the difference between said weight component and the pre-established value of the contact pressure, with the formula P p =(P r +P ba )−P c  referring to the length reached.  
   
   
       9 . The device for the regulation of the thread winding according to  claim 8 , characterized in that the measuring means of the length reached consist of a rev-counter devices of the progressive number of revs of the driving cylinder ( 16 ) from the beginning of the bobbin.  
   
   
       10 . The device for the regulation of the thread winding according to  claim 8 , characterized in that the counterweighing device consists of a simple-effect piston ( 44 ) fed by an electrovalve ( 46 ) which determines the pressure of the service fluid to be supplied to the piston ( 44 ).  
   
   
       11 . The device for the regulation of the thread winding according to  claim 8 , characterized in that the determination of the rising angle (α) of the bobbin-holder arm ( 11 ) is effected by the control unit ( 48 ) of the bobbin-winding station by calculation on the basis of the length measured.