Grinding machine workhead fitted with a dressing tool

A grinding machine workhead fitted with a dressing tool, said grinding machine comprising:

• (a) a chuck (30;
• 31) for rotatably supporting a workpiece (32;
• 33);
• (b) a tool slide (6;
• 11) for rotatably supporting a grinding tool (9;
• 14);
• (c) means (2, 4;
• 3, 5) for effecting relative axial displacement between the tool slide and the chuck to move the grinding tool into and out of a workpiece engagement location, and to attendantly feed the grinding tool in an axial direction;
• (d) means (6, 7;
• 11, 12) for effecting relative transverse movement between the tool slide and the chuck to engage the grinding tool with the workpiece, and for attendantly transversely feeding the grinding tool;
• and
• (e) a dressing tool (36a, 37a) mounted in association with the chuck for co-rotation therewith;
• wherein
• (f) the chuck (30;
• 31) has an outwardly projecting auxiliary member (34;
• 35) which carries at an axial distance externally of the workpiece (32;
• 33) and concentric with the geometric axis thereof an annular dressing tool (36) (37) having an inner diameter larger than an outer diameter of the workpiece, said dressing tool including an annular holder having an inner dressing lining (36a, 37a) of diamond material or the like, such that the grinding tool (9, 14) passes through the dressing tool when brought into engagement with the workpiece, and the auxiliary member includes means (40, 42;
• 41, 43) for adjusting the relative concentricity between the dressing tool and the workpiece.