Deburr tool

Abstract

A deburr tool has a flexible drive shaft and an expandable burr removal head. The expandable burr removal head is selectively collapsible and expandable. While collapsed, the burr removal head can navigate through the lumen of a non-straight tube, including across the abrupt right angle turn from an inlet tube section to an outlet tube section in an aircraft Piccolo tube. When expanded, the burr removal head engages the inner wall of the tube. The flexible drive shaft operatively connects the burr removal head to a prime move such that the prime mover drives rotation of the burr removal head while expanded. The rotating, expanded burr removal head removes burrs from inside the tube.

What is claimed is: 
     
         1 . A deburr tool comprising:
 a flexible drive shaft having an axis of rotation and a proximal end portion and a distal end portion spaced apart along the axis of rotation, the proximal end portion of the flexible drive shaft configured to couple to a prime mover such that the prime mover can drive rotation of the flexible drive shaft about the axis of rotation; and   an expandable burr removal head comprising a burr removal element, the expandable burr removal head being selectively adjustable between a collapsed configuration in which the burr removal element is radially spaced apart from the axis of rotation by a first radial dimension and an expanded configuration in which the burr removal element is radially spaced apart from the axis of rotation by a second radial dimension greater than the first radial dimension, the expandable burr removal head being operatively coupled to the distal end portion of the flexible drive shaft such that the burr removal element rotates with the flexible drive shaft about the axis of rotation.   
     
     
         2 . The deburr tool of  claim 1 , wherein the expandable burr removal head further comprises a resilient member yieldably biasing the burr removal head toward the collapsed configuration. 
     
     
         3 . The deburr tool of  claim 1 , wherein the expandable burr removal head is passable through a lumen of a 2 inch-diameter pipe in the collapsed configuration. 
     
     
         4 . The deburr tool of  claim 3 , wherein the deburr head is passable through an abrupt right angle turn from one 2-inch diameter pipe segment to another 2-inch diameter pipe segment. 
     
     
         5 . The deburr tool of  claim 1 , wherein the flexible drive shaft has a contiguous flexible length of at least 6 feet, the flexible drive shaft being flexible along essentially the entire contiguous flexible length. 
     
     
         6 . The deburr tool of  claim 1 , wherein the flexible drive shaft comprises a flexible drive coil and a flexible sheath encasing a length of the flexible drive coil. 
     
     
         7 . The deburr tool of  claim 6 , wherein the flexible sheath is movable in relation to the flexile drive coil between a retracted position and an extended position. 
     
     
         8 . The deburr tool of  claim 7 , wherein the flexible sheath is operatively coupled to the expandable burr removal head such that the flexible sheath adjusts the expandable burr removal head from the collapsed configuration to the expanded configuration as the flexible sheath moves from the retracted position to the extended position. 
     
     
         9 . The deburr tool of  claim 8 , wherein the expandable burr removal head comprises:
 a hub fastened to the drive coil for rotation with the drive coil about the axis of rotation;   a plurality of hone arms, each hone arm having a proximal end portion and a distal end portion, each hone arm having a first pivot point between the proximal end portion and the distal end portion and a second pivot point at the distal end portion thereof, each hone arm being pivotably connected to the hub at the respective first pivot point;   a plurality of hone stones, the burr removal element being one of the plurality of hone stones, each of the plurality of hone stones being pivotably connected to a respective one of the hone arms at the second pivot point thereof;   a cone member having an interior and an exterior, the cone member being movable in relation to the drive coil along the axis of rotation between a first position and a second position, the cone member being operatively connected to the flexible sheath such that the flexible sheath drives movement of the cone member from the first position toward the second position as the flexible sheath moves from the retracted position to the extended position, the interior of the cone member bearing against the proximal end portions of the hone arms such that the cone member causes the hone arms to pivot about the first pivot points in an outward rotational direction to adjust the burr removal head from the collapsed configuration to the expanded configuration as the cone member moves from the first position to the second position; and   a spring configured to be loaded between the flexible sheath and the cone member when the flexible sheath is in the extended position such that the spring yieldably biases the cone member toward the second portion.   
     
     
         10 . The deburr tool of  claim 9 , wherein the expandable burr removal head further comprises an elastic band disposed around the plurality of hone arms such that the elastic band yieldably biases the plurality of hone arms inward direction about the first pivot points. 
     
     
         11 . The deburr tool of  claim 9 , wherein each hone stone has an entire length less than 1 inch. 
     
     
         12 . The deburr tool of  claim 9 , wherein the expandable burr removal head further comprises a nose cone configured to interfere with pivoting movement of each of the hone stones about the respective second point to an inverted orientation in which the hone stone would face inward. 
     
     
         13 . The deburr tool of  claim 8 , wherein each home arm has an effective length extending from the respective first pivot point to the respective second pivot point and wherein the effective length of each hone arm is less than 1.1 inches. 
     
     
         14 . The deburr tool of  claim 1 , wherein in the collapsed configuration, the expandable burr removal head has collapsed effective diameter, and in the expanded configuration, the expandable burr removal head has an expanded effective diameter greater than the collapsed effective diameter. 
     
     
         15 . The deburr tool of  claim 14 , wherein the expanded effective diameter is at least 0.75 inches greater than the collapsed effective diameter. 
     
     
         16 . The deburr tool of  claim 14 , wherein the collapsed effective diameter is in an inclusive range of from 1 inch to 1.5 inches. 
     
     
         17 . The deburr tool of  claim 14 , wherein the expanded effective diameter ED 2  is in an inclusive range of from 2.25 inches to 2.75 inches. 
     
     
         18 . A method of deburring a Piccolo tube installed in a preassembled aircraft engine, the method comprising:
 inserting a deburr tool through an inlet neck of the Piccolo tube until an expandable burr removal head of the deburr tool is located inside an outlet section of the Piccolo tube;   expanding the expandable burr removal head inside the outlet section of the Piccolo tube; and   driving a flexible drive shaft of the deburr tool in rotation to rotate the expanded expandable burr removal head inside the outlet section of the Piccolo tube.   
     
     
         19 . The method of  claim 18 , further comprising inserting a redirection guide into the inlet neck before inserting the deburr tool, wherein said inserting the causes the expandable head to slide along the redirection guide whereby the redirection guide routes the deburr tool through an abrupt right angle turn from the inlet neck to the outlet section. 
     
     
         20 . The method of  claim 18 , wherein said expanding comprises moving a flexible sheath of the flexible drive shaft in relation to the flexile drive coil of the flexible drive shaft from a retracted position to an extended position and wherein the method further comprises, after said driving, moving the flexible sheath from the extended position to the retracted position whereby an elastic band collapses the expandable burr head inside the outlet section of the Piccolo tube.