Edge sensing arrangement

Abstract

The invention relates to an arrangement in connection with a wire guide roll of a paper machine. The arrangement comprises a wire guide roll which is arranged to guide a wire, if the wire is driven to the side from its normal track of travel. The wire guide roll is turned in the direction of travel of the wire by means of at least one actuator. The lateral position of the wire is observed by means of a guide flap monitoring the movement of the wire edge, from which guide flap the guidance information is transmitted to a control unit Which, for its part, controls said actuator. Furthermore, at least one sensor is arranged in connection with the guide flap to determine the position of the guide flap and to control the lateral exceedings of the wire.

That which is claimed:  
     
         1 . An arrangement in connection with a wire guide roll of a paper machine, which arrangement comprises a wire guide roll transverse to the direction of travel of a wire, the wire guide roll being arranged to be turned in the direction of travel of the wire by means of at least one actuator, and which arrangement comprises a guide flap arranged against the wire edge and adapted to observe the lateral position of the wire, and in which arrangement the wire guide roll is arranged to turn and guide the wire on the basis of information provided by the guide flap on the lateral position of the wire and which arrangement further comprises means that are arranged to inform a control system of the paper machine of the lateral position of the wire, wherein at least one sensor is arranged in connection with the guide flap and that the information on the lateral position of the wire is adapted to be transmitted from the sensor to the control system of the paper machine.  
     
     
         2 . An arrangement as claimed in  claim 1 , wherein the guide flap is arranged to the free end of an arm that is arranged pivotally, that the arm is arranged to pivot according to the lateral position of the wire and that the arrangement comprises at least one sensor arranged in connection with the arm, whereby the lateral movement of the guide flap and thereby that of the wire are arranged to be determined by means of said sensor.  
     
     
         3 . An arrangement as claimed in  claim 2 , wherein a first and a second sensor are arranged in the direction of movement of the arm to different sides of the arm at a distance from each other, this distance being arranged to determine the allowable lateral operating range of the wire.  
     
     
         4 . An arrangement as claimed in  claim 3 , wherein the relative position of the sensors is adjustable, whereby the size of the allowable operating range is also adjustable.  
     
     
         5 . An arrangement as claimed in any one of the preceding claims, wherein the sensors are limit switches.  
     
     
         6 . An arrangement as claimed in  claim 1 , wherein the sensor is arranged to measure the position of the guide flap and thereby transmit the measuring information on the lateral position of the wire to the control system of the paper machine.  
     
     
         7 . An arrangement as claimed in  claim 1 , wherein the guide flap is arranged in connection with the guide roll, into its immediate proximity, so that due to the nearby guide roll the wire edges are still firm at the guide flap.