Lapping Head for Machining Workpieces of Hard Stone Materials

Abstract

A lapping head ( 10 ) for machining a workpiece of hard stone materials comprises a body ( 12 ) rotatable about a vertical axis (Y) and having tools ( 20 a,b,c,d,e,f ) mounted thereon in such a way that each tool can swing about an axis arranged radially with respect to said vertical axis (Y). The tools ( 20 a,b,c,d,e,f ) are subdivided into at least two groups of tools ( 20 a,c,e and 20 b,d,f ) positioned at different distances from the vertical axis (Y). In each group the tools are equidistant from the vertical axis (Y) and arranged in a circumferentially equidistant manner.

1 . Lapping head ( 10 ) for machining a workpiece of hard stone materials comprising a body ( 12 ) rotating about a vertical axis (Y) on which tools ( 20   a,b,c,d,e,f ) are mounted, each tool ( 20   a,b,c,d,e,f ) oscillating about an axis arranged radially with respect to said vertical axis (Y) and said tools ( 20   a,b,c,d,e,f ) being circumferentially equidistant from each other, characterized in that said tools ( 20   a,b,c,d,e,f ) are subdivided into at least two groups of tools, each group being positioned at a distance from said vertical axis (Y) different from the distance of each other group, the tools in each group being equidistant from said vertical axis and arranged in a circumferentially equidistant manner with respect to each other.  
   
   
       2 . Lapping head according to  claim 1 , characterized in that said tools ( 20   a,b,c,d,e,f ) are six in number, circumferentially equidistant from each other, so as to form an angle of 60° relative to each other, said six tools ( 20   a,b,c,d,e,f ) being subdivided into two groups ( 20   a,c,d  and  20   b,d,f ) of three tools each, the tools in each group being circumferentially equidistant from each other so as to form an angle of 120° relative to each other.  
   
   
       3 . Lapping head according to  claim 2 , characterized in that all of the tools in said two groups of tools ( 20   a,c,d  and  20   b,d,f ) are of the same radial length.  
   
   
       4 . Lapping head according to  claim 2 , characterized in that the tools in each group are of the same length and the length of the tools in one group ( 20   a,c,d ) is different from the length of tools in the other group ( 20   b,d,f ).  
   
   
       5 . Lapping head according to  claim 2 , characterized in that the distance of the tools ( 20   a,c,e ) in the group positioned at a greater distance from said vertical axis (Y) is such that the abrasive action by the tools of this group overlaps, in a circular zone of predefined amplitude, the portion of the workpiece subject to the abrasive action of the tools ( 20   b,d,f ) in the group positioned at a smaller distance from said axis (Y).  
   
   
       6 . Lapping head according to  claim 2 , characterized in that the distance of the tools ( 20   a,c,e ) in the group positioned at a greater distance from said vertical axis (Y) is such that the abrasive action of the tools in this group does not overlap, but is adjacent to the abrasive action of the tools ( 20   b,d,f ) in the group positioned at a smaller distance from said axis.  
   
   
       7 . Lapping head according to  claim 1 , characterized in that said tools are nine in number, circumferentially equidistant from each other so as to form an angle of 40° relative to each other, said nine tools being subdivided into three groups of three tools, the tools in each group being circumferentially equidistant from each other so as to form an angle of 120° relative to each other.  
   
   
       8 . Lapping head according to  claim 1 , characterized in that said tools are nine in number, circumferentially equidistant from each other so as to form an angle of 40° relative to each other, and are subdivided into two groups, namely: a first group of three tools circumferentially equidistant from each other so as to form an angle of 120° relative to each other and arranged at a smaller distance from said vertical axis (Y) and a second group of six tools arranged in pairs circumferentially equidistant from each other so as to form an angle of 120° relative to each other and arranged at a greater distance from the vertical axis Y.