Multistation grinding machine

A multi-station grinding machine comprising

• a machine bed;
• a worktable mounted on said machine bed to rotate thereon about a principal axis, said worktable comprising a plurality of workpiece holding means mounted thereon at equal angular intervals around said axis and uniformly spaced therefrom, each holding means defining parallel to said principal axis a support axis for a workpiece to be held therein;
• a loading/unloading station and a plurality of work stations positioned around said bed, said stations being distributed about said principal axis at angular spacings corresponding to the angular intervals between said holding means, and each work station including precision grinding means operative to effect material removal from a workpiece;
• table index means operative between said table and said bed to effect angular indexing of said table about said principal axis through a series of registered positions in each of which one holding means has its support axis in precise register with said loading/unloading station and others of said holding means have their support axes in precise register with respective ones of said work stations, indexing of said table being effective to bring a workpiece successively into register with each of said work stations;
• said table index means comprising a power drive means coupled to said table and operative to effect rotary drive thereof, and a rotary encoder associated with a peripheral region of said table and adapted to generate signals providing a precise measurement of angular movements of said table, control means connected to receive said signals and operative to regulate said power drive means to terminate angular movement of said table each time it reaches one of said registered positions;
• brake means selectively operable to lock said table when in a registered position and to release said table for rotation between registered positions;
• workpiece index means at each said work station engageable with a said holding means when the table is in a registered position to drive that holding means and effect predetermined incremental indexing rotation of a workpiece held therein to present preselected portions of the workpiece for engagement by the associated machining means;
• and
• coupling means for forming a rigid rotary drive connection between each indexing means and a holding means, said coupling means being engageable when the table is in a registered position and being selectively disengageable to permit rotation of the table between registered positions.