Grinding tool for grinding buttons on a rock drill bit

A grinding cup for detachable connection to an output drive shaft of a grinding machine for grinding buttons on drill bits or cutters, the grinding cup comprising:

• a lower grinding section and an upper body section co-axial with the lower grinding section to form the grinding cup with a centrally disposed recess formed in the bottom surface of the lower grinding section, the upper body section having an upper base;
• a centrally disposed upright support section extending from a top surface of the upper base and sized and shaped to fit within a co-axial recess in a free end of the output drive shaft, the centrally disposed upright support section having a first support section extending from the top surface of the upper base and a co-axial drive component extending from the first support section;
• the first support section having a first cylindrical section with a circular cross-section extending from the top surface of the upper base and a stem extending from a top of the first cylindrical section;
• a plastic sleeve press-fitted around a first cylindrical section of the centrally disposed upright support section the plastic sleeve having an annular groove;
• the co-axial drive component comprising:
• a lower cam portion shaped and sized to fit within lobed grooves in a sidewall of the co-axial recess in the output drive shaft;
• and
• an upper portion coaxial with the lower cam portion and sized and shaped to fit within the co-axial recess in the output drive shaft;
• and
• retaining means positioned within the annular groove for detachably connecting the grinding cup to the output drive shaft of the grinding machine,
• wherein the upper portion of the coaxial drive component provides radial support for the grinding cup above the lower cam portion when positioned within the output drive shaft, and
• the retaining means provides radial support for the grinding cup below the lower cam portion when positioned within the output drive shaft.

A holder system for a grinding machine having a motor which drives an output drive shaft, comprising:

• a grinding cup comprising:
• a lower grinding section;
• an upper base coaxial with the lower grinding section;
• a centrally disposed upright support section extending from a top surface of the upper base and sized and shaped to fit within a co-axial recess in a free end of the output drive shaft, the centrally disposed upright support section having a first support section extending from the top surface of the upper base and a co-axial drive component extending from the first support section;
• the first support section having a first cylindrical section with a circular cross-section extending from the top surface of the upper base and a stem extends from a top of the first cylindrical section;
• the co-axial drive component connected to the stem and extending from an upper surface of the first cylindrical section of the first support section of the centrally disposed upright support section to a free end of the co-axial drive component, the coaxial drive component comprising:
• a lower cam portion having a non-circular, curved cross-section shaped and sized to fit within the co-axial recess in the output drive shaft;
• and
• an upper portion coaxial with and positioned above the lower cam portion and having a circular cross-section, the upper portion sized and shaped to fit within the co-axial recess in the output drive shaft;
• and
• retaining means for detachably connecting the grinding cup to the output drive shaft of the grinding machine, the retaining means positioned below along the centrally disposed upright support section below the lower cam portion;
• and
• a holder device for detachably connecting the grinding cup to the grinding machine comprising:
• a rotatable drive member having a free end adapted to extend axially away from the grinding machine, the rotatable drive member being provided with an axial recess at its free end with a coaxial passageway extending from the axial recess along a length of the rotatable drive member or part thereof and through which coolant fluid may be directed to the grinding cup supported thereon, the axial recess is adapted to receive the upright drive section on the grinding cup, the axial recess having a first support section extending from the free end of the rotatable drive member, and adjacent the first support section are a series of lobed grooves that are machined into an interior wall of the axial recess, the series of lobed grooves having a non-circular cross-section to match the cam portion on the upright drive section of the grinding cup, adjacent to the series of lobed grooves is a second support section in an upper portion of the axial recess.