Perfected Grinding Machine and Grinding Method

Abstract

A grinding machine for operative cylinders, of the type comprising a piece-holder head and a tailstock center between which an operative cylinder is positioned for being ground, includes a moving system associated with both the piece-holder head and the tailstock center to allow them to be moved along a common movement direction. A further object of the present invention relates to a grinding method.

The invention claimed is: 
     
         1 . A grinding machine for operative cylinders comprising:
 a piece-holder head;   a tailstock center, the piece-holder head and the tailstock center being disposed to have a cylinder positioned to be ground positioned therebetween; and   a moving system associated with both the piece-holder head and the tailstock centre to allow them to be moved along a common movement direction.   
     
     
         2 . The grinding machine according to  claim 1 , further comprising one or more lunettes or contrast devices for the cylinder, suitable for at least supporting said cylinder being processed or to contrast grinding forces, said machine being equipped with a moving system associated with said lunettes to allow said lunettes to move along said common movement direction. 
     
     
         3 . The grinding machine according to  claim 1 , wherein said moving system comprises an endless screw associated with a base of the grinding machine, said endless screw being having a rotation axis along a parallel direction to said common movement direction and having two portions with a discordant helicoidal threading. 
     
     
         4 . The grinding machine according to  claim 3 , wherein said moving system further comprises, for each of the two portions having the discordant helicoidal threading of the screw, an internally threaded sleeve engaged on said screw and a coupling/decoupling system of one or more of said piece-holder head, said tailstock, or said lunettes with said internally threaded sleeve. 
     
     
         5 . The grinding machine according to  claim 4 , wherein said coupling/decoupling system comprises two arms with a fulcrum along a body thereof, each arm having an engagement end with said internally threaded sleeve and an opposite free end coupled with an actuator. 
     
     
         6 . The grinding machine according to  claim 5 , wherein said actuator is a linear actuator coupled with said free ends of said two arms, and wherein said engagement end of each arm is equipped with a jaw for coupling with an external cylindrical surface of said sleeve. 
     
     
         7 . The grinding machine according to  claim 5 , wherein said two arms have a fulcrum along their bodies at least at one of said piece-holder head, said tailstock, or said lunettes. 
     
     
         8 . The grinding machine according to  claim 7 , wherein said piece-holder head, said tailstock and said lunettes are each coupled with a corresponding coupling/decoupling system, a corresponding number of threaded sleeves being engaged on said screw, each of which is configured to be respectively coupled with each coupling/decoupling system. 
     
     
         9 . A positioning method for operative cylinders, for example of rolling-mills or paper-mills, on a grinding machine, the method comprising the following steps:
 positioning a transversal, longitudinal center-line plane of a cylinder in correspondence with a reference point situated between a movable piece-holder head and a tailstock center of said machine; and   moving said piece-holder head and said tailstock center in the direction of said cylinder until there is a reciprocal coupling for one or more of entraining or supporting the cylinder.   
     
     
         10 . A grinding machine according to  claim 1 , wherein the grinding machine is configured to perform a method according to  claim 9 . 
     
     
         11 . The grinding machine according to  claim 6 , wherein said jaw has linings.