Method and device for notching tubes and the tube thus obtained

Abstract

The invention relates to a method of notching a tube. The inventive method is characterised in that it comprises the to-and-fro movement of at least one pressure roller. During said movement, the aforementioned roller applies pressure locally to the wall of the tube ( 1 ) and plastically deforms same. The movement of the pressure roller is produced by a combination of at least two other movements, namely: a first essentially rectilinear to-and-fro movement, during which the roller rolls against the wall of the tube ( 1 ); and a second forward movement, the resultant of which is essentially perpendicular to the direction of the first movement. In this way, the tube ( 1 ) is plastically deformed in at least two movements of the pressure roller.

1 . Process for notching a tube, comprising a back and forth motion of at least one pressing roller, movement during which this roller locally presses and plastically deforms the tube wall, and where the movement of the pressing roller consists of a combination of at least two displacements, namely: 
 a first motion, largely rectilinear, back and forth, during which the roller rolls against the tube wall;    a second motion, called a forward motion, whose result is largely perpendicular to the direction of the first motion, the plastic deformation of the tube thus being obtained in at least two passes of the pressing roller.    
   
   
       2 . Notching process according to  claim 1 , further comprising an inspection stage where a selected parameter is chosen from the group consisting of: the force of the pressing roller on the tube, the position of the roller during its contact with the tube.  
   
   
       3 . Machine for the implementation of the process according to  claim 1  comprising a means of temporarily holding at least one tube in a predetermined position, and a means of motorized drive of the pressure rollers following their first motion.  
   
   
       4 . Machine according to  claim 3 , comprising a means to cause the second motion, known as the forward motion, of the pressing roller, in a controlled manner, these means comprising a means chosen from the group consisting of springs, activators such as jacks.  
   
   
       5 . Machine according to  claim 3 , comprising a motorized roller-mount trolley, the trolley being driven back and forth following said first motion and being mounted mobile in rotation around an axle that is largely perpendicular to the direction of this first motion.  
   
   
       6 . Machine according to  claim 3 , comprising three pressure rollers of diameters that are largely identical, and whose rotational axes are largely aligned according to the direction of the first back and forth motion.  
   
   
       7 . Machine according to claims  3 , comprising a means of servo-system for the pressure roller displacement, as a function of at least one parameter selected from among the group consisting of: the force of the pressure roller on the tube, the position of the roller upon contact with the tube.  
   
   
       8 . Machine according to  claim 7 , wherein the servo-system is of the electro-hydraulic type.  
   
   
       9 . Tube obtained by the implementation of the process according to  claim 1 , wherein the tube for a headrest support.