Linear Compensator Tool for Drill Countersinking and Seal Groove Machining

• US 20100028097A1
• Filed: 07/31/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Luepke, Richard A.
• Granted Patent: US 8,585,332 B2
• Time in Patent Office: Days
• US Class Current: 408/180
• CPC Class Codes: B23B 31/083 axially
• CPC Class Codes: B23B 49/005 Attached to the drill
• CPC Class Codes: B23B 51/104 with stops
• CPC Class Codes: B23C 3/28 Grooving workpieces tread-cutting by milling B23G1/32
• CPC Class Codes: Y10T 408/03 Processes
• CPC Class Codes: Y10T 408/56245 including tool-guide [or bushing]
• CPC Class Codes: Y10T 408/5653 with means to bias Tool away from work
• CPC Class Codes: Y10T 408/8595 Pivotable tool-support
• CPC Class Codes: Y10T 408/8925 Depth-limiting member

Abstract

A drill countersinking and seal groove machining tool to accommodate an accurate drill countersinking and seal groove machining operation. The linear compensator tool applies sufficient force to react to the drilling or seal groove machining process, but not so much force as to distort the work piece being drilled or machined. The tool ensures that the reactant force does not exceed the machine force override allowances. Varying spring rates and/or air pressures on the linear compensator system will accommodate most applications. The tool absorbs over travel of the machining tool, in order to ensure that the surface to be machined is always in contact with the machining tool

Claims

1. A linear compensator tool for attachment to a machining apparatus having a rotatably driven spindle that can be advanced to a selected point in space comprising:

a compensator member with first and second ends, the first end having a coupling for mounting to the spindle for movement to the selected point in space;

a nose piece having a bore with an axis into which a machining tool is inserted and retained, the nose piece being mounted to the second end for axial movement of the compensator member relative to the nose piece between first and second positions;

a bias member mounted between first and second ends that urges the compensator member toward the first position; and

a stop member carried by the nose piece for contacting the surface of a workpiece, the stop member preventing further movement of the nose piece toward the workpiece, so that continued movement of the compensator member toward the point in space causes the compensator member to overcome the bias member and move from the first position toward the second position.

2. The linear compensator tool of claim 1 wherein the bias member is a spring.

3. The linear compensator tool of claim 1 wherein the bias member is a pressurized air chamber.

4. The linear compensator tool of claim 1 wherein the bias member is a pressurized fluid chamber.

5. The linear compensator tool of claim 1 wherein the compensator member further comprises:

an outer casing, connected to and axially extending from the coupling; and

an inner casing axially disposed within the outer casing and capable of limited axial movement.

6. The linear compensator tool of claim 1 wherein the compensator member further comprises:

an upper plate, connected to an axially extending from the coupling; and

a lower plate, connected to the upper plate by at least one linear bearing and capable of limited axial movement.

7. A linear compensator tool comprising:

a coupling for connecting the compensator tool to a machining apparatus having a rotatably driven spindle;

an outer casing, connected to and axially extending from the coupling;

an inner casing axially disposed within the outer casing and capable of limited axial movement;

a bias member located between the inner casing and outer casing for controlling the axial movement of the inner casing within the outer casing;

a nose piece connected to and axially extending from the inner casing;

a shaft capable of rotation extending from spindle through the outer casing, the inner casing, and into the nose piece; and

a machining tool connected to the shaft and extending axially from the nose piece.

8. The linear compensator tool of claim 7 further comprising:

a pressure port located on and extending through the outer casing for pressurizing an annulus between the inner casing and the outer casing; and

a downward facing shoulder on the interior surface of the outer casing, and a flange section on the exterior surface of the inner casing, for limiting the axial movement of the inner casing within the outer casing.

9. A method of machining a workpiece with a machining apparatus comprising:

(a) mounting a nose piece with a stop member to a compensator member with first and second ends, the compensator member being capable of movement relative to the nosepiece between first and second positions;

(b) mounting the compensator member to a spindle of the machining apparatus;

(c) inserting a machining tool into the nose piece;

(d) urging the tool holder to the first position;

(e) rotating the tool and moving the tool into the workpiece;

(f) engaging the stop member with the surface of the workpiece;

then

(g) continuing movement of the compensator member toward the workpiece while the nose piece is prevented by the stop member from further movement;

thereby causing the compensator member to move from the first position toward the second position.

10. The method according to claim 9 wherein step (d) further comprises:

urging the tool holder to the first position by placing a spring between the first and second ends of the compensator member.

11. The method according to claim 9 wherein step (d) further comprises:

urging the tool holder to the first position by introducing air between the first and second ends of the compensator member.

12. The method according to claim 9 wherein step (d) further comprises:

urging the tool holder to the first position by introducing fluid between the first and second ends of the compensator member.