Work table orientation apparatus and method

A method of precisely calibrating the position of a spindle with respect to a work table, said spindle and said work table forming a portion of a drilling apparatus, said drilling apparatus including a control device which calculates an expected relative position of said spindle and said work table based upon predetermined information regarding the relative position of said spindle and said work table and the controlled movement of said spindle relative to said worktable, comprising the steps of:

• positioning said spindle in a first position with respect to said work table;
• empirically determining the position of said first position with respect to said work table in a first direction;
• empirically determining the position of said first position with respect to said work table in a second direction;
• comparing said expected relative position of said spindle and said work table at said first position with the empirically determined relative position of said spindle relative said work table in said first direction and said second direction so as to ascertain a correction factor;
• positioning said spindle in a second position with respect to said work table;
• empirically determining the position of said second position with respect to said work table in a third direction;
• and,
• comparing said expected relative position of said spindle and said work table at said second position with the empirically determined relative position of said spindle relative to said work table in said third direction so as to ascertain a correction factor.

A method of precisely calibrating the position of a spindle of a drilling apparatus with respect to a work table, said spindle and said work table forming a portion of a drilling apparatus, said drilling apparatus including a control device which calculates an expected relative position of said spindle and said work table based upon predetermined information regarding the relative position of said spindle and said work table and the controlled movement of said spindle relative to said worktable, said work table including a first positioning clamp to secure a workpiece to said table, comprising the steps of:

• inserting a member into said first clamp;
• closing said first clamp to secure said member against movement in a first direction;
• positioning a first sensor having a first position indicator such that said first position indicator indicates the position of said member in said first direction with respect to said first sensor;
• securing said first sensor against movement in said first direction with respect to the clamped position of said member;
• releasing said first clamp sufficiently to permit removal of said member from said first clamp;
• removing said member from said first clamp;
• positioning said spindle in said first direction in a calibration position which is the expected position of said clamped position of said member in said first clamp in said first direction as determined by said control device;
• and,
• positioning said work table in said first direction such that said first position indicator indicates that the calibration position of said spindle in said first direction is the same as said clamped position of said member in said first clamp in said first direction.

A calibration device, comprising:

• a body defining an aperture and an opening spaced from said aperture;
• a first differential pressure transducer measuring the position of an object in said aperture in a first direction;
• a second differential pressure transducer measuring the position of an object in said aperture in a second direction different than said first direction;
• and,
• a third differential pressure transducer measuring the position of an object in said opening in said first direction.

A drilling machine, comprising:

• a spindle movable at least in a vertical direction, a drill tool removably mounted in said spindle, said spindle being adapted to cause rotation of said drill tool to effect drilling, said work table including a first positioning clamp and a second positioning clamp to secure a workpiece to said table;
• a worktable positioned beneath said spindle, said worktable adapted to have a workpiece mounted thereon, said worktable being movable in at least one direction in a horizontal plane so as to position said workpiece at desired locations beneath said spindle;
• a control device which controls operation of said drilling machine, said control device calculating an expected relative position of said spindle and said worktable based upon predetermined information regarding the relative position of said spindle and said worktable;
• and,
• a calibration device adapted to be secured to said work table over said first positioning clamp, comprising:
• a body defining an aperture and an opening spaced from said aperture;
• a first differential pressure transducer measuring the position of an object in said aperture in a first direction;
• a second differential pressure transducer measuring the position of an object in said aperture in a second direction different than said first direction;
• and,
• a third differential pressure transducer measuring the position of an object in said opening in said first direction.

A calibration device, comprising:

• a body defining:
• an aperture;
• a first air supply chamber having an inlet port for communicating with a source of pressurized air and a first outlet port and a second outlet port;
• a first measurement channel communicating with said first air supply chamber outlet, said first port having a pressure transducer port and a escape port communicating with said aperture;
• a second measurement channel communicating with said first air supply chamber second outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• a second air supply chamber having an inlet port for communicating with a source of pressurized air and a first outlet port and a second outlet port;
• a third measurement channel communicating with said second air supply chamber first outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• and,
• a fourth measurement channel communicating with said second air supply chamber second outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• a first pressure transducer communicating with said first measurement channel and said third measurement channel;
• a first position indicator capable of indicating whether the pressure in said first and third measurement channels are equal;
• a second pressure transducer communicating with said second measurement channel and said fourth measurement channel;
• and,
• a second position indicator capable of indicating whether the pressure in said second and fourth measurement channels are equal.

A drilling machine, comprising:

• a spindle movable at least in a vertical direction, a drill tool removably mounted in said spindle, said spindle being adapted to cause rotation of said drill tool to effect drilling, said work table including a first positioning clamp and a second positioning clamp to secure a workpiece to said table;
• a worktable positioned beneath said spindle, said worktable adapted to have a workpiece mounted thereon, said worktable being movable in at least one direction in a horizontal plane so as to position said workpiece at desired locations beneath said spindle;
• a control device which controls operation said drilling machine, said control device calculating an expected relative position of said spindle and said worktable based upon predetermined information regarding the relative position of said spindle and said worktable;
• and,
• a calibration device adapted to be secured to said work table over said first positioning clamp, comprising:
• a body defining:
• an aperture;
• a first air supply chamber having an inlet port for communicating with a source of pressurized air and a first outlet port and a second outlet port;
• a first measurement channel communicating with said first air supply chamber outlet, said first port having a pressure transducer port and a escape port communicating with said aperture;
• a second measurement channel communicating with said first air supply chamber second outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• a second air supply chamber having an inlet port for communicating with a source of pressurized air and a first outlet port and a second outlet port;
• a third measurement channel communicating with said second air supply chamber first outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• and,
• a fourth measurement channel communicating with said second air supply chamber second outlet port having a pressure transducer port and a escape jet communicating with said aperture;
• a first pressure transducer communicating with said first measurement channel and said third measurement channel;
• a first position indicator capable of indicating whether the pressure in said first and third measurement channels are equal;
• a second pressure transducer communicating with said second measurement channel and said fourth measurement channel;
• and,
• a second position indicator capable of indicating whether the pressure in said second and fourth measurement channels are equal.