Grinder attachment for precision grinding machines

A grinder attachment for precision grinding with an existing grinding machine having an external housing and a driven shaft rotatable about a grinder machine axis at a predetermined rotational speed when energized, the attachment comprising a driving pulley wheel having a first diameter attachable on the driven shaft for rotation therewith about the machine axis;

• an attachment housing;
• attachment means for rigidly attaching said attachment housing to the external housing of the grinding machine to substantially prevent any movements of said attachment housing in the three dimensional space relative to the external housing of the grinding machine;
• a spindle rotatably mounted on said attachment housing;
• a driven pulley wheel fixedly mounted on said spindle to rotate with said spindle;
• a grinding abrasive element mounted on said spindle at a grinding station for rotation therewith;
• coupling means for mechanically coupling said pulleys to cause rotation of said driven pulley when the driving pulley is rotated by the grinding machine, said attachment housing including a portion that selectively clamps a first portion of the grinding machine external housing eliminating at least two degrees of freedom of movement within a plane normal to the grinding machine axis, said attachment means comprising a member that rigidly secures said attachment housing to a second portion of the grinding machine external housing against at least a third degree of movement along a direction substantially parallel to the grinding machine axis and said pulley wheels having different diameters, whereby actuation of the grinding machine causes said abrasive elements to only rotate relative to the external housing at a selected speed different from said predetermined rotational speed for precision grinding at the grinding station.