FASTENER BACK-OUT EROSION DEVICES AND SYSTEMS

RELATED APPLICATION

[0001] This application claims the full Paris Convention benefit of and priority to U.S. Provisional Patent Application Serial No. 61/308,799, filed February 26, 2010 the contents of which are incorporated by reference herein in their entirety, as if fully set forth herein.

BACKGROUND

[0002] 1. Field

[0003] This disclosure relates to electrical discharge machining (EDM).

[0004] 2. General Background

[0005] Single-use fasteners, such as a rivet or aerospace fastener where the fastener is formed during the assembly process, is common in many industries. In aerospace, the maintenance of air frames frequently requires removal of hundreds of fasteners in order to replace or repair structural members such as longerons, bulkheads, center barrels, and the like. Fasteners commonly include rivets or threaded fasteners which have been malleably distorted so they cannot be directly removed. Many of these fasteners are manufactured in titanium or other difficult to machine materials.

[0006] Traditional methods which have been utilized for many years to remove such fasteners is to machine away the head of the fastener with a drill which is manually positioned. The drill adds pressure to the region being drilled as well as heat. Additionally, when the fastener is of titanium or other difficult to machine materials, such drilling results in a significant consumption of drill bits. Traditional drilling of fasteners operation has a known risk of damage to the structure in which the fastener is engaged. Damage to surrounding structures may result from vibration, drill bit slips, or drilling too deep. If drill bit slippage damage occurs to the surrounding material, or if the hole should be cut too deep, an oversized fastener might be used during reassembly, or the entire component may need to be replaced. Measures to correct such undesirable damage may result in additional expense associated with the operation. [0007] Electric discharge machining, or EDM operates through the utilization of an electrical discharge to remove metal from the workpiece. In the EDM process, an electrode is brought into close proximity to the workpiece. High voltage is applied in pulses at high frequency. The process occurs in the presence of a dielectric fluid. This creates sparking at generally the closest position between the workpiece and the electrode. Particles are removed from the workpiece when sparking is quenched. The duration of the spark (on-time) and the recovery time (off-time) are controlled so that the workpiece and electrode temperatures are not raised to the temperature of bulk melting. Therefore, erosion is essentially limited to a vaporization process.

SUMMARY

[0008] In some exemplary implementations, a hand held edm device shape, guide, channel or recess forming a "key hole" is eroded into a fastener such that said key corresponds to the external shape of a removal tool. Said key hole may also be eroded through non-homogeneous conductive materials such as a titanium fastener with a broken steel drill bit lodged therein. In some instances said removal tool is sufficiently sturdy to be used to reverse out / rotate a stuck threaded fastener so that the fastener can be removed for disassembly from a surrounding structure. In some instances the hand-held edm device may be connected to a service module which need not be handheld but supplies the hand-held device at least one of power, flushing fluid, return pathways for spent flushing fluid, and power management to control the hand-held device. The hand held edm device may be brought to a workpiece and operated in such a manner as to remove a sufficient part of a fastener to permit the fastener to be removed from a frame or structure without damaging the structure of the frame.

[0009] According to some exemplary implementations, a method is disclosed, comprising: providing a voltage differential across a gap between an erosion electrode and a fastener threaded onto a workpiece, the gap containing a dielectric, whereby a dielectric breakdown across the gap causes the fastener to erode; advancing the erosion electrode of a given geometry along a path penetrating a portion of the fastener, whereby a reception drive is created in the fastener defined by the geometry of the erosion electrode and the path, wherein the geometry of the erosion electrode corresponds to a geometry of a removal tool, said path may be referred to as "an erosion pathway". The method may further comprise: inserting the removal tool into the reception drive; and rotating the fastener with the removal tool, whereby the fastener is unthreaded from the workpiece. Rotating the fastener with the removal tool may comprise: transferring torque from the removal tool to the fastener via the reception drive. The workpiece may be at least one of a frame and a collar. The path may be along a central axis of the fastener. The path may further penetrate debris other than the fastener. The debris may be a portion of a recovery device that remains in the fastener after an attempt to unthread the fastener. The reception drive may exceed the debris in at least one of depth and width. The fastener may contain a first drive in a damaged state. The reception drive may exceed the first drive in at least one of depth and width. The path may penetrate a head of the fastener. The path may penetrate a shank of the fastener. In some instances the geometry of the erosion electrode may increase surface area with legs, arms, folds, wall or the like as opposed to circular in cross section. The geometry of the removal tool corresponds to the geometry of the erosion pathway

[0010] According to some exemplary implementations, a method is disclosed, comprising: providing to a hand-held EDM device to a fastener with non-homogeneous other conductive material lodged therein; applying an erosion electrode of the hand-held EDM device; creating at least one of an erosion pathway and a reception drive in the fastener, wherein the fastener may be removed by use of the reception drive.

[0011] According to some exemplary implementations, a hand-held EDM device is disclosed, comprising: an erosion electrode of a given geometry, wherein the erosion electrode is configured to be advanced linearly along a path penetrating a head of a threaded fastener; a power supply configured to provide a voltage differential across a gap between an erosion electrode and a fastener; wherein the geometry of the erosion electrode and the erosion pathway it produces during and after erosion corresponds to a geometry of a removal tool configured to rotate the threaded fastener.

[0012] According to some exemplary implementations, a toolkit is disclosed, comprising: a hand-held EDM device, comprising: a first erosion electrode of a given geometry, wherein the erosion electrode is configured to be advanced linearly along a first path penetrating a head of a threaded fastener; a power supply configured to provide a voltage differential across a gap between an erosion electrode and a fastener; a removal tool; wherein the geometry of the erosion electrode corresponds to a geometry of a removal tool configured to rotate the threaded fastener. Each of the erosion electrode and the removal tool may form a polygon when viewed in cross section. The erosion electrode may further comprise a dielectric inlet configured to deliver a dielectric fluid to the gap between the erosion electrode and the fastener. A reception drive created by the erosion electrode may contain a pin corresponding to the location of the dielectric inlet of the erosion electrode. The removal tool may contain a space corresponding to the location of the pin of the reception drive. The removal tool may correspond to the shape of the erosion electrode in an eroded state. The handheld EDM device may further comprise: a second erosion electrode configured to be advanced linearly along a second path that is parallel to the first path. A reception drive eroded by the first erosion electrode and the second erosion electrode may be a singular recess within the fastener.

[0013] According to some exemplary implementations, a toolkit is disclosed, comprising: a hand-held EDM device, comprising: a first erosion electrode of a given geometry, wherein the erosion electrode is configured to be advanced linearly along a first path penetrating a head of a threaded fastener; a power supply configured to provide a voltage differential across a gap between an erosion electrode and a fastener; a removal tool; wherein the geometry of the erosion electrode and erosion pathway for a key hole or guide that corresponds to a geometry of a removal tool configured to rotate the threaded fastener. In some instances the erosion electrode and the removal tool form a geometry with a compound curve consisting of two or more arcs of different radii curving in the same direction and having a common tangent or transition curve at their point of junction. In some instances the erosion electrode and the removal tool form a geometry with at least a reverse curve portion that is an S-shaped curve. DRAWINGS

[0014] The above-mentioned features of the present disclosure will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements and in which:

[0015] Figure 1 shows a view of a workman applying a hand-held EDM device to a workpiece;

[0016] Figure 2 shows a front view of a hand-held EDM device;

[0017] Figure 3 shows a side view of a hand-held EDM device;

[0018] Figure 4A shows a sectional view of a hand-held EDM device, shown in association with a fastener receiving a pilot hole;

[0019] Figure 4B shows a sectional view of a hand-held EDM device, shown in association with a fastener having a pilot hole;

[0020] Figure 5A shows a sectional view of a hand-held EDM device, shown during an erosion process and in association with a fastener to be removed;

[0021] Figure 5B shows a sectional view of a hand-held EDM device, shown after an erosion process in association with a fastener to be removed;

[0022] Figure 6A shows a sectional view of a hand-held EDM device, shown prior to an erosion process and in association with a fastener and collar to be separated;

[0023] Figure 6B shows a sectional view of a hand-held EDM device, shown during an erosion process and in association with a fastener and collar to be separated;

[0024] Figure 6C shows a sectional view of a hand-held EDM device, shown after an erosion process and in association with a fastener and collar to be separated;

[0025] Figure 7 shows a schematic electrical diagram of an plasma power system and components of a hand-held EDM device;

[0026] Figure 8 shows a schematic diagram of the dielectric supply and waste systems; [0027] Figure 9 shows a longitudinal section through a ground pin guide in a forward part of a hand-held EDM device;

[0028] Figure 10 shows components of a hand-held EDM device configured to dispense dielectric fluid;

[0029] Figure 1 1 A shows an erosion electrode near a protrusion;

[0030] Figure 1 1 B shows an erosion electrode eroding a protrusion;

[0031] Figure 1 1 C shows an eroded protrusion;

[0032] Figure 1 1 D shows a sectional view of an erosion electrode and axis of rotation;

[0033] Figure 12 shows a graph of measurements taken during an exemplary startup process of a hand-held EDM device;

[0034] Figure 13A shows a sectional view of an erosion electrode near a fastener;

[0035] Figure 13B shows a top view of a fastener;

[0036] Figure 14A shows a sectional view of an erosion electrode eroding a fastener;

[0037] Figure 14B shows a top view of a fastener;

[0038] Figure 15 shows a removal tool near a fastener;

[0039] Figure 16 shows a removal tool in a fastener;

[0040] Figure 17 shows a removal tool rotating a fastener;

[0041] Figures 8A-18C show perspective views of an erosion electrode;

[0042] Figures 19A-19C show perspective views of a fastener;

[0043] Figures 20A-20C show perspective views of a removal tool;

[0044] Figure 21 A shows a sectional view of a fastener with a first drive;

[0045] Figure 21 B shows a top view of a fastener with a first drive;

[0046] Figure 22A shows a sectional view of a fastener with a first drive;

[0047] Figure 22B shows a top view of a fastener with a first drive;

[0048] Figure 23A shows a sectional view of an erosion electrode eroding a fastener; [0049] Figure 23B shows a top view of a fastener;

[0050] Figure 24 shows a removal tool in a fastener;

[0051] Figure 25A shows a sectional view of a fastener with a first drive;

[0052] Figure 25B shows a top view of a fastener with a first drive;

[0053] Figure 26A shows a sectional view of a fastener with a first drive;

[0054] Figure 26B shows a top view of a fastener with a first drive;

[0055] Figure 27 shows a sectional view of a fastener with a first drive;

[0056] Figure 28 shows a sectional view of a recovery device in a fastener;

[0057] Figure 29A shows a sectional view of a fastener with debris;

[0058] Figure 29B shows a top view of a fastener with debris;

[0059] Figure 30A shows a sectional view of an erosion electrode eroding a fastener;

[0060] Figure 30B shows a top view of a fastener;

[0061] Figure 31 shows a sectional view of a fastener;

[0062] Figure 32 shows a sectional view of an erosion electrode eroding a fastener;

[0063] Figure 33 shows a removal tool in a fastener;

[0064] Figure 34 shows a removal tool rotating a fastener;

[0065] Figure 35A shows a perspective view of an erosion electrode;

[0066] Figure 35B shows a perspective view of a fastener;

[0067] Figure 35C shows a perspective view of a removal tool;

[0068] Figure 36A shows a perspective view of a pair of erosion electrodes;

[0069] Figure 36B shows a perspective view of a fastener;

[0070] Figure 36C shows a perspective view of a removal tool;

[0071] Figure 37 shows a sectional view of an erosion electrode near a fastener;

[0072] Figure 38 shows a sectional view of an erosion electrode eroding a fastener; [0073] Figure 39 shows a sectional view of a removal tool in a fastener; and

[0074] Figure 40 shows a sectional view of a removal tool in a fastener.

DETAILED DESCRIPTION

[0075] Figure 1 shows the hand-held device 10 being hand-held by a user. In this implementation the hand-held device 10 is part of a system which supplies power, control and dielectric fluid (which may also be a coolant) via the support unit 14. Flexible umbilical 16 interconnects the hand-held device 10 and the support unit 14 so that the hand-held device can be positioned as desired.

[0076] According to some exemplary implementations, a hand-held device 10 is shown in side elevational view in Figure 2. According to some exemplary implementations, a side view is shown in Figure 3.

[0077] As shown in the figures, a hand-held device 10 may be positioned to remove a fastener 18 which extends through one or more frames. As further shown in the figures, fastener 18 and fastener collar 24 secure one or more frames. As will be clear to those skilled in the art, any variety of fasteners and associated components may be the object upon which some exemplary implementations of the disclosed device and method may operate.

[0078] Figures 4A, 4B, 5A, 5B, 6A, 6B, and 6C shows a longitudinal section through a hand-held device 10 according to exemplary implementations. The principle structural reference part of the hand-held device 10 is the base 26. The base may be maneuvered by handle 28, which is secured thereto. The handle 28 may be configured to be held in the hand of the workman. Various configurations may be provided to provide hand-held operation of the device 10. According to some exemplary implementations, the handle 28 may carry a switch 30 to activate components of the hand-held device 10, as disclosed herein.

[0079] According to some exemplary implementations, mounted on a distal end of the base 26 is a hood 32. The hood 32 defines a workspace, within which erosion activity may occur. The hood 32 may be configured to seal against a portion of a workpiece, such as a frame, thereby enclosing the workspace such that the workspace includes access to at least a portion of a fastener 18, a collar 24, or another workpiece. The portion enclosed may be at least one of the shank of fastener 18, the head of fastener 18, and the collar 24. According to some exemplary implementations, as the hood 32 engages the workpiece, the hood 32 may be configured to enclose the workspace so as to substantially isolate it from the environment outside the workspace. Accordingly, substances within the workspace may be contained except through controlled inlets and outlets, as disclosed herein. For example, at least a portion of the hood 32 may be of a flexible or deformable material that adaptably interfaces with the surface 20 of the workpiece to create a seal at the interface. There may be provided a rigid structure for stabilizing the hand-held device 10 against a workpiece, such as at the surface 20, as shown in the figures. Channels may be provided for passage of dielectric fluid there through.

[0080] According to some exemplary implementations, hand-held device 10 may include a ground electrode 38 and erosion electrode 66. The erosion electrode 66 may be configured to controllably approach a portion of a workpiece to be eroded, such as a fastener 18 or a collar 24.

[0081] A variety of electrode shapes, geometries, and morphologies may be provided for the erosion electrode 66. Electrode morphologies may be selected according to desired usage (i.e. erosion results and application specific variables).

[0082] According to other exemplary implementations, aspects of which are shown in Figures 5A, 5B, 6A, 6B, and 6C, the erosion electrode 66 may be a hollow tubular structure. In some instances aspects of one exemplary implementation may fit properly into another exemplary implementation. The hollow tubular structure of an erosion electrode 66 may be symmetrical about an axis and configured to travel longitudinally along the axis, thereby eroding a ring-shaped portion of the workpiece. This shape is useful for separating the head flange of a fastener 18 from the shank of the fastener 18 (as shown in Figures 5A and 5B) or for eroding the interface 22 between the shank of a fastener 18 and a collar 24 (as shown in Figures 6A, 6B, and 6C). Where erosion of the frame is not desired, such erosion may be minimized or avoided by providing a hollow tubular erosion electrode 66 having an outer diameter that is about equal to or less than the outer diameter of the shank of the fastener 18 or the inner diameter of the hole of the frame.

[0083] According to some exemplary implementations, an erosion electrode 66 having a hollow tubular structure may be further configured to rotate about its axis of symmetry as it advances longitudinally along the axis. The rotation of the hollow tubular structure helps reduce issues associated with uneven wear of the erosion electrode 66 at its distal end. An uneven electrode results in correspondingly uneven workpiece erosion. This corresponding erosion causes the uneven portions of the erosion electrode 66 to remain uneven, because the gap distance between the erosion electrode 66 and the workpiece (the spark gap) at each point is equal. When the device is applied to the next fastener, the uneven erosion electrode 66 will be attenuated since the "high" portions of the erosion electrode 66 will contact first, but will not be completely eliminated for multiple cycles. A rotating electrode will recover sooner than a non-rotating electrode. As the hollow tubular structure is rotated as it advances, the orientation of the uneven surface of the erosion electrode 66 is altered with respect to the correspondingly uneven workpiece. The changing relative orientation causes portions of the erosion electrode 66 that may have disproportionately greater extension to be moved into other locations of which may result in increased erosion activity, whereby the continued wear of the erosion electrode 66 is in some circumstances at least partially self-correcting in terms of providing an even erosion electrode 66 and an evenly eroded workpiece.

[0084] According to some exemplary implementations, the erosion electrode 66 may be moved by translational motion and rotational motion. According to some exemplary implementations, the translational motion of the erosion electrode 66 may simultaneously create rotational motion, for example, a lead screw may be rotated to advance the erosion electrode 66 and simultaneously rotate it about an axis. According to some exemplary implementations, translational and rotational motion of the erosion electrode 66 may be applied independently, such that rotation and translation may be simultaneously or separately provided.

[0085] According to some exemplary implementations, an erosion electrode 66 may be a solid pin configured to penetrate a fastener 18 as shown in Figures 4A and 4B. This shape is useful for providing a pilot hole in the fastener 18 for subsequent mechanical drilling. Such pilot holes help control operation of a mechanical drill by providing a non-slip location. This shape electrode is also useful for eroding a central portion of a head of the fastener 18 to allow removal of the flange from the shank (not shown). The pilot hole may be of any shape and cross-section (for example square or triangular) and may be used to extract a threaded fastener where a previous rotating method has been damaged or otherwise rendered ineffective.

[0086] According to some exemplary implementations, an erosion electrode 66 may include a plurality of pointed electrode tips (not shown). The electrodes tips may be distributed equidistant from an axis and configured to rotate about the axis as they advance longitudinally along the axis. The resulting erosion of the workpiece is ring- shaped, similar to that resulting from the operation of a hollow tubular structure. According to some exemplary implementations, separate plasma control systems 86 may be provided for each of the plurality of pointed electrode tips. Structure such as brushes may be provided to allow each of the pointed electrode tips to be charged by the corresponding plasma control systems 86 as it rotates about the axis. A plurality of power sources reduce the cycle time by enabling multiple simultaneous material erosion locations.

[0087] According to some exemplary implementations, an erosion electrode 66 may be configured to erode and reduce a nub, burr, raised portion, or protrusion 36, such as an end of a fastener threaded through a frame 21 and extending from a surface 20, as shown in Figure 11 A. An erosion electrode 66 may be configured to target the protrusion 36 to bring it closer to even with the surface 20 from which it extends, as shown in Figure 1 1C. For example, the erosion electrode 66 may have a substantially flat tip facing the surface 20 from which the protrusion 36 extends, as shown in Figure 1 1 A. As the erosion electrode 66 advances toward the workpiece, the protrusion 36 is eroded, as shown in Figures 1 1 B and 11 C. Further, a ground electrode 38 may be provided to complete a circuit across the spark gap between the erosion electrode 66 and the protrusion 36. The ground electrode 38 may be in contact with a portion of the protrusion 36 (not shown) or another portion of the workpiece that is in electrical conduction with the protrusion 36, such as a frame 21. [0088] According to some exemplary implementations, an erosion electrode 66 approaching an uneven workpiece, such as a protrusion 36, may tend to experience its own erosion. In such a situation, the portion of the erosion electrode 66 that is eroded corresponds to the portion at which plasma events are occurring, which is generally the portion closest to the workpiece. In the case of eroding a protrusion 36, the wear on the erosion electrode 66 would be uneven, rendering the erosion electrode 66 unable to evenly reduce the protrusion 36 level with the surface 20 from which it extends because the tip of the erosion electrode 66 facing the workpiece surface 20 would no longer be flat. To reduce uneven wear on the erosion electrode 66, the position of the erosion electrode 66 relative to the protrusion 36 may be altered during the process such that the locations of plasma events are distributed across the erosion electrode 66. For example, the erosion electrode 66 may be rotated as it advances toward the protrusion. According to some exemplary implementations, the erosion electrode 66 may be rotated about an axis that passes through a portion of the protrusion 36 but does not pass through the center of the erosion electrode 66, as shown in Figures 11 A, 1 1 B, 1 1 C, and 1 1 D. The result is that any given exposed portion of the protrusion 36 is acted upon by different portions of the erosion electrode 66 during rotation of the erosion electrode 66. For example, a right side of the erosion electrode 66 is shown aligned with the center of the protrusion 36 in Figure 1 A, and a left side of the erosion electrode 66 is shown aligned with the center of the protrusion 36 in Figure 1 B. According to some exemplary implementations, other types of rotation may be applied or combined to distribute wear on the erosion electrode 66, such as rotation about a central axis of the erosion electrode 66.

[0089] According to some exemplary implementations, the erosion electrode 66 may be provided with a dielectric inlet 54 provided by one or multiple a channels within and extending along the erosion electrode 66, as shown in Figures 1 1 A, 1 1 B, 1 1 C, and 1 1 D. Such a configuration allows dielectric fluid to be provided directly to the location of plasma events in the spark gap. A dielectric outlet 34 may be provided in fluid communication with the workspace.

[0090] According to some exemplary implementations, configurations shown in Figures 1 1 A, 1 1 B, 11C, and 11 D and disclosed herein may be used to erode beyond the outer surface 20 of a workpiece (not shown). In such instances a countersink, recess, well, or divot will result.

[0091] According to some exemplary implementations, components may be provided to effectuate the advancement and retraction of erosion electrode 66 relative to the base 26 or the workpiece. According to some exemplary implementations, a motor 60 may be provided to affect the position of the erosion electrode 66 relative to the base 26 or the workpiece. For example, the motor 60 may be a linear motor or any motor adapted to effect linear motion. For example, a stepper motor may be used for the motor 60. When the hand-held device 10 is provided to a workpiece, the position of the erosion electrode 66 relative to the base 26 may correspond to the position of the erosion electrode 66 to the workpiece.

[0092] According to some exemplary implementations, a ground electrode 38 may be configured to contact at least a portion of the workpiece that is electrically conductive with another portion of the workpiece that is eroded by the erosion electrode 66. For example, where portions of the head, flange, or shank of fastener 18 are to be eroded, the ground electrode 38 may be configured to contact a portion of the fastener 8, such that a dielectric breakdown between the erosion electrode 66 and the fastener 18 may be achieved.

[0093] According to some exemplary implementations, a ground electrode 38 may be any conductive structure configured to complete an electrical circuit when placed in electrical conduction with an erosion electrode 66. For example, a ground electrode 38 may act as a "floating ground." A ground electrode 38 may have an applied charge that is in contrast to the charge applied to the erosion electrode 66, whether or not the ground electrode 38 provides a zero voltage reference point. Alternatively, a ground electrode 38 may be connected to "Earth ground," such that any charge from the erosion electrode 66 is drawn to the ground electrode 38.

[0094] According to some exemplary implementations, a ground electrode 38 may be disposed central to and concentric with a tubular erosion electrode 66, as shown in Figures 5A, 5B, 6A, 6B, and 6C. According to some exemplary implementations, a ground electrode 38 may be a hollow tubular structure having an erosion electrode 66 disposed therein, as shown in Figures 4A and 4B.

[0095] Where conduction of electricity through the frames is not desired or required, electrical conductivity through the frames may be avoided by maintaining the ground electrode 38 in contact with the workpiece that is being eroded. For example, electrical charge may travel through from the erosion electrode 66 through the dielectric fluid to the fastener 18. From there, it may travel directly to the ground electrode 38 rather than through the frame. Coatings provided on the fastener 18, the collar 24, or the frames and other factors at the interfaces between these components may further inhibit inter- component conductivity. Thereby, electrical activity in the frame or other undesired portions may be avoided, as well as other associated collateral issues.

[0096] According to some exemplary implementations, and as shown in Figures 5A, 5B, 6A, 6B, and 6C, the ground electrode 38 may be disposed concentrically within a hollow tubular structure of an erosion electrode 66 and configured to contact a central portion of the fastener 18 concentric with the erosion activity effectuated by the erosion electrode 66.

[0097] According to some exemplary implementations, to maintain this concentricity, a guide structure 70 may be provided, as shown in Figure 9. A guide tube 72 is provided and is of an insulating material to serve as a buffer between the ground electrode 38 and the erosion electrode 66. Insulating bearings 80 may be provided within openings 76 along the guide tube 72. The bearings 80 maintain an insulating separation between the ground electrode 38. and the erosion electrode 66 and facilitate relative longitudinal motion between the ground electrode 38 and the erosion electrode 66. This configuration may be provided so as to maintain fluid communication for the dielectric fluid flow across the guide structure 70.

[0098] According to some exemplary implementations, a dielectric inlet 54 and dielectric outlet 34 are provided in fluid communication with the workspace defined by the hood 32. According to some exemplary implementations, dielectric fluid may be provided to the workspace or the gap between the erosion electrode 66 and the workpiece by a variety of structures and methods. For example, the dielectric inlet 54 may provide targeted, high-velocity flow of the dielectric fluid directed to the spark gap between the erosion electrode 66 and the workpiece.

[0099] According to some exemplary implementations, a dielectric inlet 54 is configured to provide a dielectric fluid to the gap between the erosion electrode 66 and the workpiece. According to some exemplary implementations, the dielectric inlet 54 may provide dielectric fluid along at least a portion of the erosion electrode 66 such that the dielectric fluid is delivered directly to the location of plasma events occurring at the end of the erosion electrode 66. For example, where the erosion electrode 66 is a hollow tubular structure, the dielectric inlet 54 may provide the dielectric fluid within the hollow tubular structure, such that the dielectric fluid is drawn through the spark gap to reach a dielectric outlet 34 located outside the hollow tubular structure. Where the erosion electrode 66 is disposed within a hollow tubular structure, the dielectric inlet 54 may likewise provide the dielectric fluid within the hollow tubular structure to the spark gap. Those of ordinary skill in the art will recognize that the coolant fluid may in some instances be the dielectric fluid. In other cases, a dielectric fluid and a coolant fluid may be provided in sequence. For example, a coolant fluid may be provided after an erosion process has been completed.

[00100] According to some exemplary implementations, a dielectric outlet 34 may be provided and configured to evacuate the dielectric fluid and other debris from the workspace. The dielectric outlet 34 may evacuate the dielectric fluid and other debris through a directed channel of flow, such as where the spark gap is disposed between the dielectric inlet 54 and the dielectric outlet 34. According to some exemplary implementations, the dielectric outlet 34 may evacuate the dielectric fluid generally from the workspace defined by the hood 32, wherein turbulence within the workspace provides opportunities for the dielectric fluid and other debris to be removed through the dielectric outlet 34.

[00101] According to some exemplary implementations, the flow of dielectric fluid may be facilitated by at least one of an inlet pump 92 connected to the dielectric inlet 54 and a drain pump 84 connected to the dielectric outlet 34, as shown in Figure 8. The inlet pump 92 may increase the velocity with which the dielectric fluid travels through the spark gap by applying a high pressure to the dielectric inlet 54. The drain pump 84 may further increase the velocity with which the dielectric fluid travels through the spark gap by applying a low pressure to the dielectric outlet 34. According to some exemplary implementations, the combination of an inlet pump 92 and a drain pump 84 provide high speed flushing of the spark gap, resulting in faster evacuation of debris that may otherwise adversely affect the performance of the erosion electrode 66. For example, pressure provided by the inlet pump 92 in the range of up to about 80 PSI provides improved erosion performance. Pressure below 80 PSI were shown to increase the time required to achieved erosion targets (cycle time). For example, a pressure of 60 PSI approximately doubled cycle times for some workpiece materials. Pressure may be provided up to levels that allow a seal with the workpiece to be maintained under operator forces/pressures such that the dielectric fluid is substantially contained within the workspace enclosed by a hood 32 while a user operates the hand-held device 10.

[00102] According to some exemplary implementations, the dielectric fluid provides the channel through which plasma events occur. For example, a sufficient voltage difference across the spark gap between the erosion electrode 66 and the workpiece may cause breakdown of the dielectric fluid and electrical conduction through the plasma that is formed thereby. The dielectric fluid may be of de-ionized water, oil, or other appropriate substances that are generally non-conductive.

[00103] According to some exemplary implementations, the dielectric outlet 34 may evacuate debris removed from the workpiece during operation of the hand-held device 10. The presence of debris between the erosion electrode 66 and the workpiece may adversely affect the operation of the hand-held device 10 by altering the nature of the materials in the gap. Because the workpiece debris may be generally conductive material, its presence in the dielectric fluid may alter the environment of the fluid as a dielectric. Large enough debris may provide a conductive bridge across the gap that prevents breakdown of the dielectric fluid and plasma formation. Thus, the dielectric fluid may be provided with high flow rate to facilitate flushing of the debris.

[00104] According to some exemplary implementations, the dielectric fluid may provide cooling for the components involved in the operation of hand-held device 10. For example, the high energy states of plasma events occurring in the gap between the erosion electrode 66 and the workpiece may tend to heat the electrodes and/or workpiece. However, the cooling effect provided by the dielectric fluid may maintain the electrodes and/or workpiece at a temperature that improves safety and efficiency to the user. For example, after operation of the hand-held device 10, the electrodes and/or workpiece may be immediately operated upon by a user without the danger of residual high temperatures in the workpiece.

[00105] According to some exemplary implementations, the dielectric inlet 54 and the dielectric outlet 34 may be parts of a closed loop system that recycles dielectric fluid and isolates workpiece debris, as shown in Figure 8. For example, the dielectric inlet 54 may deliver the dielectric fluid from a dielectric supply tank 56 to the workspace; the dielectric fluid and debris may be evacuated from the workspace through the dielectric outlet 34 to a debris extraction zone, where the debris may be separated from the dielectric fluid; and the dielectric fluid is returned to the dielectric inlet 54. If de-ionized water is used as a dielectric fluid, the system may include a subsystem that reestablishes the de-ionized character of the dielectric fluid.

[00106] According to some exemplary implementations, the debris separation zone may be within the hand-held device 10 or outside the hand-held device 10 to provide a more compact hand-held portion. For example, the dielectric inlet 54 and the dielectric outlet 34 may connect to the umbilical 16 to provide fluid communication to and from the support unit 14, where the debris separation zone may be located. The debris separation zone may include a filter, sediment deposition portion, or other features to separate the debris from the dielectric fluid. For example, in a sediment deposition, the debris-laden dielectric fluid may be provided to a tank with low flow rate, giving the debris— having higher density than the dielectric fluid— an opportunity to collect at the bottom of the tank. The dielectric fluid may be taken from the portion above the collected debris and recycled to the dielectric inlet 54.

[00107] According to some exemplary implementations, the flow of dielectric fluid to the workspace may be controlled so as to occur when an appropriate seal is formed at the interface of the hood 32 and the workpiece. For example, the flow of dielectric fluid may be activated by the switch 30 operated by a user or other events that correspond to a time when the hand-held device 10 is prepared to flow the dielectric fluid.

[00108] According to some exemplary implementations, the application of the ground electrode 38 against the workpiece may enable the flow of dielectric fluid. For example, the ground electrode 38 may be mounted to a ground tube 40 in fluid connection with the workspace. The ground tube 40 may be slideably disposed within a valve block 42, as shown in Figure 10. In an unactuated position, the ground tube 40 rests against valve ball 48, which is resiliently held against the valve block 42 by valve compression spring 52, thereby restricting flow of the dielectric fluid from the dielectric inlet 54. When the ground electrode 38 is pressed against the workpiece, the ground electrode 38 and the ground tube 40 cause the valve ball 48 to slide away from the valve block 42, thereby permitting flow from the dielectric inlet 54 to the workspace. Accordingly, when the ground electrode 38 is removed from the workpiece, the spring 52 causes the valve ball 48 to restrict flow of the dielectric fluid. Further, the configuration may automatically limit flow of the dielectric fluid if the portion of the workpiece contacted by the ground electrode 38 is removed, such as if a shank of a fastener were to slip out of the workspace. Thus, flow of the dielectric fluid may be automated based on the status of the ground electrode 38.

[00109] According to some exemplary implementations, devices and methods for providing visual observation of the workspace during operation of the hand-held device 10 are disclosed. According to some exemplary implementations, an image sensor 94 is provided at or near the workspace enclosed by the hood 32. For example, the image sensor may include a charge-coupled device (CCD), a complementary metal-oxide- semiconductor (CMOS), another active-pixel sensor, or another device configured to capture images such as digital images. The image sensor 94 is configured capture an image or series of images corresponding to the interface between the hand-held device 10 and the workpiece. For example, the image sensor 94 may capture images of a fastener 18 including a projected point of contact with at least one of the ground electrode 38 and the erosion electrode 66. The image sensor 94 may be connected to an aiming display 96 configured to provide a display of the image captured by the image sensor 94. For example, a portion of the aiming display may be known to correspond to a location at which the ground electrode 38 or the erosion electrode 66 would contact the workpiece. Accordingly, a user may properly position and orient components of the hand-held device 10 relative to the workpiece based on the visualization provided by the image sensor 94 and aiming display 96.

[00110] According to some exemplary implementations, a power supply 86 may provide electrical power to the hand-held device 10 during operation. The power supply 86 may be located within the support unit 14 in connection with the hand-held device 10, or the power supply 86 may be located onboard the hand-held device 10. The power supply 86 may provide power for operation of the motor 60, the image sensor 94, the aiming display 96, the inlet pump 92, the drain pump 84, the erosion electrode 66, or any other components operable with electrical power.

[00111] According to some exemplary implementations, methods of operating a handheld device 10 and removing fasteners 18 are disclosed herein. In use, a user brings the hand-held device 10 to a workpiece. The workpiece may include at least one of a fastener 18, a collar 24, and a protrusion. For example, the hand-held device may be brought to the head of a fastener 18, the shank of a fastener 18, or a collar 24.

[00112] The relationships between the dielectric pressure (near the end of the electrode) ("v"), the size of the spark gap ("d"), and the erosion power ("p") across time during an exemplary implementation of a startup process are represented in the chart of Figure 12.

[00113] According to some exemplary implementations, the user engages the hood 32 onto a portion of the workpiece to create and maintain a seal enclosing a workspace. The drain pump 84 may cause a negative or relatively lower pressure to be created in the workspace to facilitate engagement of the hood 32 onto the workpiece. The negative or relatively lower pressure may also facilitate introduction of the dielectric fluid from the dielectric inlet 54. This operation is demonstrated starting at point 1 in Figure 12.

[00114] According to some exemplary implementations, the hand-held device 10 is centered onto the workpiece. The centering may correspond to the location of the erosion electrode 66 or the ground electrode 38 relative to the workpiece to be eroded. For example, location of the hand-held device may determine the targeted path that the erosion electrode 66 will travel. A user may use the view captured by the image sensor 94 and shown on the aiming display 96 to position the hand-held device 10 relative to the workpiece.

[00115] According to some exemplary implementations, the erosion electrode 66 is brought into contact with the portion of the workpiece to be eroded; the ground electrode 38 is brought into contact with a portion of the workpiece that is in electrical conduction with the portion to be eroded (see point 2 in Figure 12). The hand-held device 10 then verifies that a closed circuit is provided by the pathway through the workpiece from the erosion electrode 66 to the ground electrode 38 (see point 3 in Figure 12). This step verifies that the workpiece is conductive from the portion to be eroded to the portion contacted by the ground electrode 38. This step also verifies that the ground electrode 38 is in contact with the workpiece. Other methods are contemplated to verify that the ground electrode 38 is in contact with the workpiece, such as a detectable limit on the advancement of the ground electrode 38 as it contacts the workpiece, or actuating sensors at the interface between the device and the workpiece.

[00116] According to some exemplary implementations, the position of the erosion electrode 66 while it is in contact with the workpiece may be recorded and utilized as a calibration position from which the depth of cutting may be calculated. For example, the difference between (1) the position of the erosion electrode while contacting the workpiece during a calibration step and (2) the position at any given time during an erosion process may indicate the approximate depth of cutting at that given time.

[00117] According to some exemplary implementations, the erosion electrode 66 is retracted a distance from the workpiece after contacting the workpiece (see point 4 of Figure 12). The distance of retraction may be at least about the distance anticipated for a plasma event to occur in a spark gap.

[00118] According to some exemplary implementations, flow of dielectric fluid is commenced into and out of the sealed and enclosed workspace, particularly through the spark gap. The dielectric fluid may be provided as a result of pressure provided from inlet pump 92. For example, pressure provided may result in a controllable flow rate. The flow may be initiated according to a variety of events, as disclosed herein. For example, flow may be automatically initiated by the provision of the ground electrode 38 to the workpiece, as disclosed herein. Flow may be initiated following verification that the proper conditions for plasma events are provided, as disclosed herein.

[00119J According to some exemplary implementations, the erosion electrode 66 is advanced along an axis toward the workpiece. A voltage difference across the erosion electrode 66 and the workpiece is established (see point 5 of Figure 12). The spark gap is narrowed until the dielectric fluid breaks down and a plasma is formed across the spark gap. The flow of dielectric fluid may be constricted as the spark gap narrows (see point 6 of Figure 12). The resultant plasma event causes erosion of the workpiece near the erosion electrode 66 (see point 7 of Figure 12).

[00120] According to some exemplary implementations, the flow and pressure of dielectric fluid is stabilized at a positive value, to prevent in ingress of air into the workspace (see point 7 of Figure 12).

[00121] According to some exemplary implementations, the erosion electrode 66 is recharged and advanced to create a series of plasma events, thereby eroding the workpiece until the desired cut shape is achieved. According to some exemplary implementations, the advancement of the erosion electrode 66 may be determined by its position relative to the base 26. For example, the motor 60 may advance the erosion electrode 66 relative to the base 26. The advancement may be constant, preprogrammed, or manually controlled. According to some exemplary implementations, maintenance of the gap between the erosion electrode 66 and the workpiece may be maintained to avoid shorting, facilitate dielectric breakdown, generate plasma events, and remove material from the workpiece. As needed, the erosion electrode 66 may also be retracted from the workpiece to maintain an appropriate spark gap size between the erosion electrode 66 and the workpiece. For example, if the erosion electrode 66 contacts the workpiece and shorts the electrical circuit, then the erosion electrode 66 may be retracted. [00122] According to some exemplary implementations, operation of the hand-held device 10 as shown in Figure 4A may provide a pilot hole as shown in Figure 4B.

[00123] According to some exemplary implementations, operation of the hand-held device 10 as shown in Figure 5A may facilitate separation of a flange of a fastener 18 from a shank of a fastener 18, as shown in Figure 5B by eroding the shape of a recess 23.

[00124] According to some exemplary implementations, operation of the hand-held device 10 as shown in Figures 6A and 6B may facilitate separation of a shank of a fastener 18 from a collar 24 at the interface 22, as shown in Figure 6C.

[00125] According to some exemplary implementations, operation of the hand-held device 10 as shown in Figures 1 1A and 1 1 B may result in reduced exposure of a protrusion, as shown in Figure 11 C

[00126] According to some exemplary implementations, the hand-held device 10 may deactivate some components based on the conditions sensed. For example, the lack of dielectric fluid flow may be sensed and cause the system to stop until remedied.

[00127] According to some exemplary implementations, the hand-held device 10 may deactivate some components when a programmed process is completed. When the operation is complete, the user stops actuation of the switch 30 and removes the device 10 from the proximity of the workpiece. According to some exemplary implementations, deactivation of switch 30 may cause systems and components that are not yet deactivated to become deactivated. According to some exemplary implementations, removal permits the ground tube 40 to move forward and causes the valve ball 48 to prohibit flow from the dielectric inlet 54.

[00128] According to some exemplary implementations, devices and methods for effecting removal of threaded fasteners are disclosed. As shown in figure 13A and 13B, fastener 18 may be threaded onto a workpiece, such as frame 21 or collar 24 (not shown). Rotation of fastener 18 may provide fixation onto or release from the accompanying workpiece. Devices and methods for effecting rotation of fastener 18 may be provided as disclosed herein. Fastener 18 may be any one of fastener, including round head, flat head, fillister, truss head, hex head, pan head, oval head, etc.

[00129] According to some exemplary implementations, as shown in Figure 14A, erosion electrode 66 may be provided to a portion of fastener 18 (e.g., head of fastener 18) and longitudinally advanced along a path, as disclosed herein. The path may penetrate at least a portion of fastener 18. For example, the path may be along a central axis of fastener 8. Erosion electrode 66 may erode reception drive 140 into a portion of fastener 18. As shown in Figure 14B, reception drive 140 may remain after operation of erosion electrode 66.

[00130] According to some exemplary implementations, components of an EDM system may be provided to facilitate creation of reception drive 140, such as ground electrode 38 (not shown) and dielectric inlet 54 (not shown).

[00131] According to some exemplary implementations, as shown in Figures 15 and 16, removal tool 150 may be provided to reception drive 140 of fastener 18. Removal tool 150 may have a geometry that corresponds to that of reception drive 140, such that rotation of removal tool 150 results in rotation of fastener 18. As shown in Figure 17, rotation of fastener 18 may result in removal of fastener 18 from the workpiece (e.g., frame 21 ) onto which it is threaded.

[00132] According to some exemplary implementations, each of erosion electrode 66, reception drive 140, and removal tool 150 may have a given geometry, shape, or morphology. As shown in Figures 18A, 18B, and 18C, three exemplary geometries are shown as examples for erosion electrode 66 (square, triangle, and TORX®, respectively). As shown in Figures 19A, 19B, and 19C, three fasteners 18 are shown, each with reception drive 140 having a geometry that corresponds with a given electrode 66. As shown in Figures 20A, 20B, and 20C, three removal tools 150 are shown, each having a geometry that corresponds with a given reception drive 140.

[00133] Various geometries may be provided for each of erosion electrode 66, reception drive 140, and removal tool 150. For example, each may form, in cross- section, a polygon (triangle, square, pentagon, hexagon, etc.), a star-shape (pentagram, hexagram, septagram, octagram, etc.). By further example, each of erosion electrode 66 and reception drive 140 may correspond to commercially available drive systems, including any commercially available removal tool 150, including slotted (flat or straight), Phillips ("crosshead"), Pozidriv® (supadriv), square head, Robertson (square socket), hex head, hex socket (Allen), TORX®, tri-wing, torq-set, spanner head (snake-eye), triple square, polydrive, one-way, spline drive, double hex, Bristol configurations, etc. Reception drive 140 may be configured to correspond to removal tool 150, such that torque applied to rotation tool 150 while inserted into reception drive 140 may be transferred to fastener 18.

[00134] According to some exemplary implementations, erosion electrode 66 may have a recessed geometry configured to erode at least an outer portion of fastener 18. During an erosion process, erosion electrode may erode a portion of fastener 18 while avoiding or limiting erosion within the recessed portion of erosion electrode 66. For example, erosion electrode 66 may be configured to erode fastener 18 to take the shape of a square head (four-sided head used for torque driving with a wrench or socket tool), hex head (similar to a square head except with six sides), or another shaped recess providing reception drive 140 with interfacing capability on an outer portion of fastener 18. Accordingly, removal tool 150 may be provided with capability to interface on an outer portion of fastener 18. For example, removal tool 150 may be a wrench, socket tool, box end wrench, or another tool, including common and commercially available tools. By further example, removal tool 150 may be any tool having geometry that generally complements that of erosion electrode 66, as disclosed herein.

[00135] According to some exemplary implementations, erosion electrode 66, reception drive 140, and removal tool 150 may not have a uniform shape along a longitudinal axis thereof. For example, erosion electrode 66, reception drive 140, and removal tool 50 may provide a tiered shape, such as that of a "french recess" (BNAE NFL22-070). A plurality of erosion electrodes 66 may be used in sequence or simultaneously to provided a given reception drive 140. According to some exemplary implementations, reception drive 140 may or may not be configured to cause removal tool 150 to cam out of reception drive 140 with sufficiently high torque. [00136] According to some exemplary implementations, fastener 18 may be provided with first drive 100. Examples of first drive 100 include slotted (flat or straight), Phillips ("crosshead"), Pozidriv® (supadriv), square head, Robertson (square socket), hex head, hex socket (alien), TORX®, tri-wing, torq-set, spanner head (snake-eye), triple square, polydrive, one-way, spline drive, double hex, bristol, etc. Generally, first drive 100 may be a drive configuration provided with fastener 18 and the configuration by which fastener 18 is installed.

[00137] For example, as shown in Figures 21A and 21 B, fastener 18 may be provided with a Phillips-type first drive 100. As shown in Figures 21 A and 21 B, first drive 100 may be in a natural state, in which it is undamaged, unspoiled, or otherwise substantially as created at the time of fabrication.

[00138] According to some exemplary implementations, fastener 18 and first drive 100 may be operated upon by a corresponding first tool. As those having skill in the relevant art will recognize, torque applied to a threaded fastener may result in damage to first drive 100 rather than the desired rotation of fastener 18. This is often true where fastener 18 is tightly fixed relative to another structure, such as frame 21 or collar 24, such that high amounts of torque are required before rotation of fastener 18 is achieved. As shown in Figures 22A and 22B, such damage may alter the condition of first drive 100, placing it in a damaged state, in which its ability to transfer torque from a first tool to fastener 18 is substantially limited. In a damaged state, first drive 100 will generally fail to "grip" its corresponding first tool.

[00139] According to some exemplary implementations, as shown in Figure 23A, erosion electrode 66 may be provided to fastener 18 having first drive 100 in a damaged state. For example, erosion electrode 66 may be provided at or near the location of first drive 100. Erosion electrode 66 may erode at least a portion of fastener 18, optionally including portions of first drive 100, whereby reception drive 140 is created.

[00140] According to some exemplary implementations, reception drive 140 may exceed first drive 100 (having either a natural state or a damaged state) in at least one dimension. For example, reception drive 140 may exceed first drive 100 in depth, as shown in Figure 23A. As used herein, depth of reception drive 140 or first drive 100 1

refers to measurements of length taken from a common point, such as a top of fastener 18 or an entry point of erosion electrode 66 or removal tool 150. By further example, reception drive 140 may exceed first drive 100 in width, as shown in Figure 24. As used herein, width of reception drive 140 or first drive 100 refers to measurements of length taken in any direction along a plane orthogonal to the longitudinal axis of fastener 18, erosion electrode 66, or removal tool 150.

[00141] According to some exemplary implementations, as shown in Figure 24, removal tool 150 may be provided to reception drive 140. As a torque is applied to removal tool 150, reception drive 140 may transfer the torque to fastener 18, whereby fastener 18 is rotated.

[00142] According to some exemplary implementations, as shown in Figures 25A and 25B, fastener 18 may be provided with first drive 100 of a slotted-type configuration. As with a Phillips-type configuration, a slotted-type first drive 100 may have a natural state (as shown in Figures 25A and 25B) and a damaged state (as shown in Figures 26A and 26B). Damage may occur by operation of a first tool on first drive 100. As with other configurations, and as shown in Figures 23A, 23B, and 24, operation of erosion electrode 66 and removal tool 150 may facilitate rotation of fastener 18 despite damage to first drive 100. According to some exemplary implementations, other types of first drives 100 may each have a natural state and damaged state, whereby operation of erosion electrode 66 and removal tool 150 may facilitate rotation of fastener 18 despite damage to first drive 100.

[00143] According to some exemplary implementations, devices and methods of the present disclosure may be employed to remove fastener 18 despite failure of remedial or interventional devices and methods. A variety of recovery devices 120 and other components are commercially available, which include Easy Out®, Grabit®, Eazypower®, bolt extractors, screw extractors, bolt removers, stud extractors, stud removers, etc. As shown in Figures 27 and 28, certain recovery devices 120 utilize left- hand threads or other mechanisms to penetrate fastener 18. Such action under certain circumstances may provide an interface between recovery device 120 and fastener 18 to facilitate rotation of threaded fastener 18 for removal thereof. Many recovery devices 120 are designed and manufactured with hardened material, which may make them tough but brittle. Often such recovery devices 120 will be a conductive material which is dissimilar in composition, hardness, and conduction as compared to fastener 18. Due to the forces applied to recovery device 120, debris 130 may separate from recovery device 120 during use thereof, as shown in Figures 29A and 29B, compounding the issues associated with removing fastener 18. Yet other issues may arise during use of recovery device 120. For example, some recovery devices 120 require prior drilling of a preparatory hole. If the preparatory hole is too large, the mechanical force applied by drilling or use of recovery device 120 may expand the remaining portions of fastener 18, causing it to seize onto frame 21 or collar 24. If the preparatory hole is the proper size but off-center, the same result may occur. If the preparatory hole is the proper size and on-center but at an angle other than axially aligned with fastener 18, the drilling may adversely impact the threaded portions of fastener 18 or frame 21 or collar 24. The awkward location of certain fasteners 18 may further complicate these issues. In some cases, solutions to these issues involve destroying the fastener 18 by using a drill bit a little larger than the fastener 18 and using a tap and die set to rethread the hole for insertion of a larger screw that fits the new hole.

[00144] As indicated in Figure 30A, erosion electrode 66 may be provided to fastener 18 having first drive 100 in a damaged state and debris 130. Erosion electrode 66 may erode at least a portion of fastener 18, optionally including portions of first drive 100 or debris 130, whereby reception drive 140 is created.

[00145] According to some exemplary implementations, reception drive 140 may exceed first drive 100 (having either a natural state or a damaged state) or debris 130 in at least one dimension. For example, reception drive 140 may exceed first drive 100 or debris 130 in depth, as shown in Figure 30A. By further example, reception drive 140 may exceed first drive 100 or debris 130 in width, as shown in Figure 30B.

[00146] According to some exemplary implementations, devices and methods of the present disclosure may be employed at various portions of fastener 18. As shown in Figure 31 , fastener 18 may extend through a frame and have at least an exposed portion of the shank thereof (i.e., at an end opposite the head of fastener 18). As shown in Figure 32, erosion electrode 66 may be provided to fastener 18 at an end opposite the head thereof (e.g., at a shank of fastener 18), whereby by reception drive 140 is created. As shown in Figure 33, removal tool 150 may be provided to reception drive 140, and a torque applied thereto. As shown in Figure 34, this may result in removal of fastener 18.

[00147] According to some exemplary implementations, geometries of erosion electrode 66 may provide additional functionality. For example, as shown in Figure 35A, erosion electrode 66 may be provided with dielectric inlet 54. Accordingly, during an erosion process, erosion electrode 66 may form reception drive 140 having a "pin" that corresponds to dielectric inlet 54, as shown in Figure 35B. Dielectric inlet 54 may provide at least one dielectric fluid to a workspace during an erosion process, as further disclosed herein. According to some exemplary implementations, as shown in Figure 35C, removal tool 150 may have a geometry that accommodates the form of reception drive 140, including a pin thereof. For example, as shown in Figure 35C, a space may be provided on removal tool 150 to receive a pin of reception drive 140.

[00148] According to some exemplary implementations, reception drive 140 may correspond to a security drive that is known and commercially available. Many screw drives— including Phillips, torx, and hex socket— have tamper-resistant security drive variants. These typically have a pin protruding in the center of the screw head, necessitating a special tool for extraction. In some variants, the pin is placed slightly off-center, requiring a correspondingly shaped bit. Erosion electrode 66 may be configured to created such a security drive shape for reception drive 140, such that removal tool 150 may be one of a variety of commercially available devices.

[00149] According to some exemplary implementations, erosion electrode 66 may be configured to remove the security feature of a security drive by eroding only the pin thereof, leaving a reception drive 140 that is readily operable with a generally available removal tool 150. In such cases, resultant reception drive 140 may be defined by more than just the geometry of erosion electrode 66.

[00150] According to some exemplary implementations, a plurality of erosion electrodes 66a and 66b may be provided. For example, as shown in Figure 36A, erosion electrodes 66a and 66b may be provided in close proximity. By further example, erosion electrodes 66a and 66b may be provided adjacent to each other and in contact with each other (not shown). Each of erosion electrodes 66a and 66b may travel along first and second paths, respectively. The first and second paths may be parallel to each other. Accordingly, during an erosion process, erosion electrode 66 may form reception drive 140 having a form resulting from the advancement of erosion electrodes 66a and 66b. Depending on the relative position of erosion electrodes 66a and 66b, reception drive 140 may have two channels (not shown) or, as shown in Figure 36B, reception drive 140 may be a single channel, wherein both of erosion electrodes 66a and 66b erode portions of fastener 18 passing between erosion electrodes 66a and 66b. The erosion being a compound curve consisting of two or more arcs similar, or different radii curving in the same direction and having a common tangent or transition curve at their point of junction, and a reverse curve portion that is an S-shaped curve.. This may occur where erosion electrodes 66a and 66b are sufficiently close, even when not in contact with each other. According to some exemplary implementations, as shown in Figure 36C, removal tool 150 may have a geometry that accommodates the form of reception drive 140. According to some exemplary implementations, reception drive 140 and removal tool 150 may generally form, in cross-section, a shape of a lemniscate, toric section of a toroid, a compound curve consisting of two or more arcs, similar or of different radii curving in the same direction and having a common tangent or transition curve at their point of junction, and a reverse curve portion that is an S-shaped curve.

[00151] According to some exemplary implementations, the shape and geometry of erosion electrode 66 may be altered during an erosion process. The rate at which an erosion process degrades erosion electrode 66 depends on the rate of the process, polarity of electrodes, material of erosion electrode 66, inter alia. The shape of erosion electrode 66 may directly or indirectly affect the resultant reception drive 140. As shown in Figure 37, erosion electrode 66 may begin an erosion process in a natural state (e.g., with a substantially flat end). As shown in Figure 38, erosion electrode 66 may achieve an eroded state with erosion occurring particularly at or near the edges and corners thereof. Accordingly, reception drive 140 may have a complementary shape. [00152] According to some exemplary implementations, as shown in Figure 39, reception drive 140 and removal tool 150 may be configured to ensure that at least a portion of removal tool 150 interfaces directly with at least a portion of reception drive 140. According to some exemplary implementations, as shown in Figure 40, removal tool 150 may provide a geometry that at least closely approximates the geometry of erosion electrode 66 in an eroded state, providing enhanced interfacing with reception drive 140. For example, erosion electrode 66 may have a natural state prior to an erosion process and an eroded state at or toward the conclusion of an erosion process, wherein the geometry of removal tool 150 may correspond to the geometry of erosion electrode 66 in the eroded state.

[00153] According to some exemplary implementations, where erosion is known or predictable, removal tool 150 may be provided to accommodate the resultant reception drive 140 created by erosion electrode 66 achieving an eroded state. According to some exemplary implementations, an eroded state of erosion electrode 66 may be defined, at least in part, by a longitudinal taper extending from an end thereof. For example, the longitudinal length of a tapered section caused by erosion may be approximately 5 times the diameter of an erosion electrode. According to some exemplary implementations, removal tool 150 may have more rounded edges than erosion electrode 66 in a natural state to accommodate for predictable rounding of the edges during an erosion process.

[00154] According to some exemplary implementations, the effect of erosion upon erosion electrode 66 may be mitigated by providing erosion electrode in a natural state structure that is resistant to erosion. For example, protruding edges of erosion electrode 66 may erode faster than substantially flat surfaces thereof. Accordingly, erosion electrode 66 may be provided with limited protruding edges or more rounded edges in a natural state.

[00155] According to some exemplary implementations, disclosed herein is a toolkit that includes devices and components of the present disclosure. For example, a toolkit may include hand-held device 10 having at least one erosion electrode 66 and removal tool 150 for use after operation of hand-held device 10 upon fastener 18. [00156] According to some exemplary implementations, the components of devices disclosed herein may be provided in any combination to accomplish desired functionality. Likewise, operations of methods disclosed may be provided in any sequence or combination to achieve results as disclosed herein.

[00157] While the method and agent have been described in terms of what are presently considered to be the most practical and preferred exemplary implementations, it is to be understood that the disclosure need not be limited to the disclosed exemplary implementations. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures. The present disclosure includes any and all exemplary implementations of the following claims.

[00158] It should also be understood that a variety of changes may be made without departing from the essence of the disclosure. Such changes are also implicitly included in the description. They still fall within the scope of this disclosure. It should be understood that this disclosure is intended to yield a patent covering numerous aspects of the disclosure both independently and as an overall system and in both method and apparatus modes.

[00159] Further, each of the various elements of the disclosure and claims may also be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an exemplary implementation of any apparatus implementation, a method or process implementation, or even merely a variation of any element of these.

[00160] Particularly, it should be understood that as the disclosure relates to elements of the disclosure, the words for each element may be expressed by equivalent apparatus terms or method terms - even if only the function or result is the same.

[00161] Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this disclosure is entitled. [00162] It should be understood that all actions may be expressed as a means for taking that action or as an element which causes that action.

[00163] Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates.

[00164] Any patents, publications, or other references mentioned in this application for patent are hereby incorporated by reference. In addition, as to each term used it should be understood that unless its utilization in this application is inconsistent with such interpretation, common dictionary definitions should be understood as incorporated for each term and all definitions, alternative terms, and synonyms such as contained in at least one of a standard technical dictionary recognized by artisans and the Random House Webster's Unabridged Dictionary, latest edition are hereby incorporated by reference.

[00165] Finally, all referenced listed in the Information Disclosure Statement or other information statement filed with the application are hereby appended and hereby incorporated by reference; however, as to each of the above, to the extent that such information or statements incorporated by reference might be considered inconsistent with the patenting of this/these disclosure(s), such statements are expressly not to be considered as made by the applicant(s).

[00166] In this regard it should be understood that for practical reasons and so as to avoid adding potentially hundreds of claims, the applicant has presented claims with initial dependencies only.

[00167] Support should be understood to exist to the degree required under new matter laws -- including but not limited to United States Patent Law 35 USC 132 or other such laws - to permit the addition of any of the various dependencies or other elements presented under one independent claim or concept as dependencies or elements under any other independent claim or concept.

[00168] To the extent that insubstantial substitutes are made, to the extent that the applicant did not in fact draft any claim so as to literally encompass any particular exemplary implementation, and to the extent otherwise applicable, the applicant should not be understood to have in any way intended to or actually relinquished such coverage as the applicant simply may not have been able to anticipate all eventualities; one skilled in the art, should not be reasonably expected to have drafted a claim that would have literally encompassed such alternative exemplary implementations.

[00169] Further, the use of the transitional phrase "comprising" is used to maintain the "open-end" claims herein, according to traditional claim interpretation. Thus, unless the context requires otherwise, it should be understood that the term "compromise" or variations such as "comprises" or "comprising", are intended to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.

[00170] Such terms should be interpreted in their most expansive forms so as to afford the applicant the broadest coverage legally permissible.