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.

Claims

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 ED2 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.

Description

DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a perspective of an inlet assembly of an aircraft engine nacelle, wherein exterior panels of the nacelle are shown transparent to reveal internal components including a Piccolo tube;

[0009] FIG. 2 is a perspective of the Piccolo tube;

[0010] FIG. 3 is a fragmentary perspective of a deburr tool;

[0011] FIG. 4 is an exploded fragmentary perspective of the deburr tool;

[0012] FIG. 5 is a fragmentary perspective of the deburr tool in a collapsed configuration;

[0013] FIG. 6 is an elevation of the deburr tool in the collapsed configuration;

[0014] FIG. 7 is a cross section taken in the plane of line 7-7 of FIG. 6;

[0015] FIG. 8 is a fragmentary perspective of the deburr tool in an expanded configuration;

[0016] FIG. 9 is another fragmentary perspective of the deburr tool in the expanded configuration;

[0017] FIG. 10 is an elevation of the deburr tool in the expanded configuration;

[0018] FIG. 11 is a cross section taken in the plane of line 11-11 of FIG. 10;

[0019] FIG. 12 is a fragmentary perspective of a portion of the deburr tool including a collar;

[0020] FIG. 13 is an exploded perspective of the collar;

[0021] FIG. 14 is a perspective of a guide for guiding the deburr tool into the outlet section of a Piccolo tube from an inlet neck thereof;

[0022] FIG. 15 is a fragmentary perspective of the Piccolo tube with a collapsed deburr tool inside being guided along the guide toward a right angle turn from the inlet neck to the outlet section; and

[0023] FIG. 16 is a fragmentary perspective of the Piccolo tube with the expanded deburr tool removing burrs from the outlet section.

[0024] Corresponding parts are given corresponding reference numbers throughout the drawings.

DETAILED DESCRIPTION

[0025] The inventor believes that a better tool is needed to remove burrs from the interior of a non-straight tube such as a Piccolo tube 12. As explained more fully below, this disclosure generally pertains to a tool that is capable of deburring a Piccolo tube in situ in a pre-assembled aircraft engine assembly. Those skilled in the art will also recognize that the tool disclosed herein could be useful for deburring the interior of other non-straight tubes. As explained more fully below, the tool is able to collapse to fit through the right angle turn from the inlet neck 18 to the outlet section 14 of the Piccolo tube 12 and then the tool can be selectively expanded inside the outlet section to properly engage the inner wall of the outlet section for removing internal burrs.

[0026] Referring to FIGS. 3-11, an exemplary embodiment of a deburr tool in accordance with the present disclosure is generally indicated at reference number 110. The deburr tool 110 broadly comprises a flexible drive shaft 112 and an expandable burr removal head 114. The flexible drive shaft 112 is sufficiently flexible and of sufficient length (i) to allow the expandable burr removal head 114 to be inserted through the inlet neck 18 of a 2 inch diameter Piccolo tube, (ii) for the expandable burr removal head 114 to subsequently make the right angle turn from the inlet neck 18 into the outlet section 14, and (iii) after making the turn, to pass through the lumen of the outlet section along at least about half the circumference of the outlet section (which allows the tool 110 to cover the entire circumference of the outlet section 14 by making the turn from inlet neck to outlet section in both directions). The expandable burr removal head 114 is broadly configured to adjust between a collapsed configuration (FIGS. 5-7) and an expanded configuration (FIGS. 8-11). In the collapsed configuration, the burr removal head 114 has a relatively small collapsed effective diameter ED1 (FIG. 6) for traveling through the lumen of the Piccolo tube 12, particularly, for making the right angle turn from the inlet neck 18 to the outlet section 14 of the Piccolo tube. In the expanded configuration, the burr removal head 114 has a greater expanded effective diameter ED2 (FIG. 10), such that the burr removal head is configured to press outward against the inner wall of the Piccolo tube 12. The flexible drive shaft 112 is configured to be coupled to a drill (broadly, a prime mover) so that the flexible drive shaft drives rotation of the expanded burr removal head 114 inside the Piccolo tube 12, whereby the burr removal head removes burrs from the inside of the outlet section 14 as it moves along the circumference of the Piccolo tube.

[0027] In one or more embodiments, the expanded effective diameter ED2 is at least 0.75 inches (1.9 cm) greater than the collapsed effective diameter ED1. In certain embodiments, the collapsed effective diameter ED1 is in an inclusive range of from 1 inch (2.5 cm) to 1.5 inches (3.8 cm). The expanded effective diameter ED2 can be in an inclusive range of from 2.25 inches (5.7 cm) to 2.75 inches (7.0 cm).

[0028] The flexible drive shaft 112 has an axis of rotation RA (FIGS. 3, 7) 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 112 is configured to couple to a drill (not shown) such that the drill can drive rotation of the flexible drive shaft about the axis of rotation RA. The flexible drive shaft 112 has a contiguous flexible length of at least 6 feet (e.g., at least 7 feet or at least 8 feet). The flexible drive shaft is flexible along essentially the entire contiguous flexible length, with the exception of very short sections (less than 5% of the overall length) where short rigid components such as an adjustment collar 120 (FIGS. 12-13) or an end-to-end coupler (not shown) for joining two flex shafts together are located.

[0029] The flexible drive shaft 112 comprises a flexible drive coil 116 and a flexible sheath 118 encasing a length of the flexible drive coil. The flexible sheath 118 is movable (axially) in relation to the flexile drive coil 116 between a retracted position (FIG. 7) and an extended position (FIG. 11). As explained more fully below, the flexible sheath 118 is operatively coupled to the expandable burr removal head 114 such that the flexible sheath can adjust the expandable burr removal head from the collapsed configuration to the expanded configuration as the flexible sheath moves from the retracted position to the protracted position.

[0030] Referring to FIGS. 12-13, the adjustment collar 120 is configured to facilitate manual adjustment of the flexible sheath 118 from the retracted position to the extended position and for locking the sheath in place in each position. The collar 120 broadly comprises a collar body 122, a sheath coupling 124, a coil bearing 126, and a set screw 128. The sheath coupling 124 couples the collar body 122 to a proximal end portion of the flexible sheath 118 so that the flexible sheath moves axially with the collar body in relation to the flexible coil 116. In the illustrated embodiment, the proximal end portion of the flexible sheath 118 is formed with key slots 130 that mate with internal keys 132 in the collar body 122. These keying features 130, 132 link the flexible shaft and collar 120 together for conjoint rotation about the axis of rotation RA. The coil bearing 126 fits over the coil 116 and provides a bearing surface for the collar 120 as it moves axially along the coil to extend and retract the flexible sheath 118. The coil bearing 126 also defines a threaded opening 134 for threadably coupling to the set screw 128. The set screw is configured to be threaded into the opening 134 to tighten against the flexible coil 116, whereby the set screw 128 locks the collar 120 (and thus the flexible sheath 118) in an axial position (e.g., retracted or extended) relative to the coil. The tightened set screw 128 also links the collar 120 (and thus the flexible sheath 118) to the flexible coil 116 for conjoint rotation with the flexible coil. To adjust the axial position of the collar 120 and flexible sheath 118, the set screw 128 is loosened.

[0031] Referring again to FIGS. 3-11, the expandable burr removal head 114 broadly comprises a burr removal element (e.g., a hone stone 140). In the illustrated embodiment, the burr removal head 114 comprises three burr removal elements (hone stones 140) spaced apart circumferentially about the axis of rotation RA. More particularly, the burr removal head 114 comprises three hone stones 140, similar to the hone stones used in brake cylinder hones for automotive repair. In comparison with the hone stones used in a brake cylinder hone, the hone stones 140 are notably shorter in length. Each hone stone has an entire length L1 (FIG. 11) less than 1 inch (2.5 cm). In addition, the edges and corners of the hone stones 140 are rounded to minimize scarring and gouging inside the Piccolo tube 12. The hone stones 140 have mildly abrasive outer surfaces that are configured to lightly abrade the inner wall of the Piccolo tube 12 as the burr removal head 114 rotates while expanded. This allows the hone stones 140 to remove burrs from the interior of the Piccolo tube 12 without damaging the Piccolo tube. In the collapsed configuration (FIGS. 5-7), the hone stones 140 are radially spaced apart from the axis of rotation RA by a first radial dimension RD1 (FIG. 6; e.g. one-half of ED1), and in the expanded configuration, the hone stones 140 are radially spaced apart from the axis of rotation by a second radial dimension RD2 (FIG. 10; e.g., one-half of ED2) greater than the first radial dimension. The effective diameters ED1, ED2 are equal to the diameter of a circle formed when a point along the outer surface of one of the hone stones is rotated 360 about the axis of rotation

[0032] In the illustrated embodiment, the expandable burr removal head 114 is adjusted between the retracted and expanded configurations by a mechanism similar to that of a brake cylinder hone. Thus, the expandable burr removal head 114 comprises a hub 142 (FIGS. 4, 7) fastened to the drive coil for rotation with the drive coil about the axis of rotation RA, a plurality of hone arms 144 pivotably connecting the hub to the hone stones 140, a cone member 145 movable in relation to the drive coil between a first position (FIGS. 5-7) and a second position (FIGS. 8-11) to adjust the expandable burr removal head 114 between the retracted configuration and the expanded configuration, and a spring 146 configured to be loaded between the flexible sheath 118 and the cone member when the flexible sheath is in the extended position.

[0033] The hub 142 comprises an annular central portion 150 centered on the axis of rotation RA and three hone arm spokes 152 extending radially outward from the annular central portion 150. The annular central portion 150 includes one or more threaded openings 154 configured to threadably couple to set screws 156 that affix the hub 142 to the flexible drive coil 116. Pins 157 couple the hone arm spokes 152 to the hone arms 144 such that the hone arms can pivot in relation to the hub.

[0034] Each hone arm 144 has a proximal end portion and a distal end portion. A first pivot point 1441 is located between the proximal end portion and the distal end portion and a second pivot 1442 point is located at the distal end portion thereof. A pin 157 pivotably connects each hone arm 144 to the hub 142 at the respective first pivot point 1441, and a pin-shaped fastener 1401 pivotably couples each hone stone 140 a respective hone arm at the second pivot point 1442. In the illustrated embodiment, each pin-shaped fastener 1401 comprises a screw fastened in place with a nut 1402. Each home arm 144 has an effective length L2 (FIG. 11) extending from the respective first pivot point 1441 to the respective second pivot point 1442, and the effective length L2 of each hone arm is less than 1.1 inches (2.8 cm). This is considerably less than the corresponding distance in a brake cylinder hone and is one parameter that contributes to low profile so that the expandable burr removal head 114 can traverse the lumen of a 2 inch (5.1 cm) diameter Piccolo tube. Near the proximal end portion of each hone arm 114, the outer surface of the hone harm has a convexly curved shape that is configured for camming engagement with the cone member 145.

[0035] The cone member 145 has an interior (conical) surface (see FIGS. 7 and 11) and an exterior (conical) surface. The spring 146 comprises a compression spring (e.g., a cone-shaped compression spring) with a proximal end portion operatively coupled to the flexible sheath 118 and a distal end portion engaging the exterior of the cone member 145. When the flexible sheath 118 moves distally from the retracted position to the extended position, it moves the spring 146 distally, which in turn moves the cone member 145 distally from the first position to the second position. For example, a bearing 1181 on the distal end portion of the flexible sheath engages the proximal end portion of the spring 146 and thereby moves the spring and the cone member 145 distally. Hence, the cone member 145 is operatively connected to the flexible sheath 118 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 145 bears against the outer convex camming surfaces of the proximal end portions of the hone arms 144 as the cone member 145 moves distally from the first position to the second position. As the cone member 145 moves distally from the first position to the second position, the interior of the cone member 145 pivots the hone arms 144 about the first pivot points 1441 in an outward rotational direction to adjust the burr removal head from the collapsed configuration to the expanded configuration.

[0036] When this occurs, the spring 146 is loaded between the flexible sheath 118 and the cone member 145 such that the spring yieldably biases the cone member distally toward the second position. As the hone stones 140 come into contact with the inner wall of the Piccolo tube 12, the spring 146 can yield to allow the cone member 145 to move proximally in relation to the flexible drive shaft 112. This yielding ensures the hone stones 140 engage the inner wall of the Piccolo tube 12 with the proper amount of force and allows for some retraction of the expandable burr removal head 114 from the fully expanded position when it encounters restrictive geometry or other obstacles inside the Piccolo tube.

[0037] In the illustrated embodiment, the expandable burr removal head 114 further comprises a nose cone 160 coupled to the hub 142. The nose cone 160 comprises a tapered distal section extending distally from the hub 142. The tapered distal section of the nose cone 160 is configured to provide clearance for some pivoting of the hone stones 140 when the burr removal head 114 is expanded. But the tapered distal section of the nose cone 160 will also interfere with pivoting movement to a fully inverted orientation in which the abrasive surface of the hone stone would face inward. If the hone stones 140 were to fully invert during use, it may restrict removal of the deburr tool 110 from the Piccolo tube 12.

[0038] Unlike a brake cylinder hone, the illustrated burr removal head 114 further comprises a resilient member 170 for yieldably biasing the burr removal head toward the collapsed configuration. More particularly, the illustrated resilient member 170 is an elastic band disposed around the plurality of hone arms 144 such that the elastic band yieldably biases the plurality of hone arms inward about the first pivot points 1441. In the illustrated embodiment, the elastic band 170 is threaded through openings in the inner proximal end portions of the hone stones 140. The elastic band 170 is thought to provide particular advantage for using the deburr tool 110 inside a non-straight tube because it forces the burr removal head 112 toward the collapsed configuration when the flexible sheath 118 is retracted. Without the elastic band 170 the burr removal head 114 would have a tendency to remain expanded even after the sheath 118 is retracted, which would make it difficult to withdraw the tool from a Piccolo tube (or other non-straight tube) after deburring.

[0039] An exemplary method of using the deburr tool 110 for deburring a Piccolo tube 12 will now be briefly described. Referring to FIG. 14, in some embodiments, the method begins with a technician inserting a redirection guide 210 into the inlet neck 18 of the Piccolo tube. The redirection guide 210 defines a smoothly curved guide surface 212 along which the expandable head 114 of the deburr tool 110 can slide as it makes a right angle turn from the inlet neck 18 to the outlet section 14 of the Piccolo tube 12.

[0040] As shown in FIG. 15, with the expandable head 114 collapsed, the technician inserts the deburr tool 110 through the inlet neck 18 of the Piccolo tube 12 (head first). The expandable head 114 slides along the guide surface 212 and makes the right angle turn from the inlet neck 18 to the outlet section 14 of the Piccolo tube 12. At this time, the technician may remove the redirection guide 210 from the inlet neck 18 of the Piccolo tube 12.

[0041] As shown in FIG. 16, the technician then uses the collar 120 (not visible in FIG. 16) to extend the flexible sheath 118, which expands the expandable burr removal head 114 (as explained above) inside the outlet section 14 of the Piccolo tube 12. The technician tightens the set screw 128 of collar 120 to secure the expandable burr removal head 114 in the expanded configuration, then uses a drill to rotate the expanded expandable burr removal head 114 inside the outlet section of the Piccolo tube. The technician moves the tool axially so that the rotating burr removal head 114 travels along half the circumference of the outlet section 14 and removes the burrs from that segment of the outlet section.

[0042] Subsequently, the expandable burr removal head 114 can be collapsed (by loosening the set screw 128 and retracting the flexible sheath 118) and removed from the Piccolo tube 12. The guide 210 can then be reinserted so that the surface 212 turns toward the other half-circumference of the Piccolo tube, and the steps for using the deburr tool 110 can be repeated for the other half of the outlet section.

[0043] Accordingly, it can be seen that the deburr tool 100 is able to remove burrs from the interior of a non-straight tube such as a Piccolo tube 12 in situ, e.g., in a pre-assembled aircraft engine assembly. The tool 100 provides an expandable burr removal head 114 that is biased toward a collapsed configuration, but which can be selectively expanded from a remote location outside of the Piccolo tube 12. Thus, the expandable burr removal head 114 can navigate the right angle turn from the inlet neck 18 to the outlet section 14 of the Piccolo tube while collapsed. Then the head 114 can be expanded inside the outlet section 14 and rotate while expanded for removing internal burrs. Finally, the head 114 can collapse while still located within the outlet section so that it can be withdrawn from the Piccolo tube in the collapsed configuration without getting hung up as it navigates backward from the outlet section to the neck.

[0044] When introducing elements of the present disclosure or the preferred embodiment(s) thereof, the articles a, an, the and said are intended to mean that there are one or more of the elements. The terms comprising, including and having are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0045] In view of the above, it will be seen that the several objects of the disclosure are achieved and other advantageous results attained.

[0046] As various changes could be made in the above products and methods without departing from the scope of the disclosure, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.