Electric discharge machining assembly

Abstract

An electrode guide assembly for an EDM process includes a guide tube having a first end and a second end, a fluid feed portion, a fluid return portion, and an electrode. The guide tube has a set of at least two supporting protrusions, with the protrusions projecting radially inwardly from an inner diametral surface of the guide tube. The electrode is slidably accommodated within the guide tube, with an outer diametral surface of the electrode abutting against the set of supporting protrusions. The first end of the guide tube is in fluid communication with the second end of the guide tube to thereby provide a fluid feed channel, and the second end of the guide tube is in fluid communication with the first end of the guide tube to thereby provide a fluid return channel.

Claims

1. An electrode guide assembly for an EDM process, the assembly comprising: a guide tube having a first end and a second end; and an electrode, the guide tube having a set of at least two supporting protrusions, the protrusions projecting radially inwardly from an inner diametral surface of the guide tube, the electrode being slidably accommodated within the guide tube, with an outer diametral surface of the electrode abutting against the set of supporting protrusions, the first end of the guide tube being in fluid communication with the second end of the guide tube to thereby define a fluid feed channel, the second end of the guide tube being in fluid communication with the first end of the guide tube to thereby define a fluid return channel.

2. The assembly as claimed in claim 1, further comprising a plurality of sets of supporting protrusions, and wherein the sets of supporting protrusions are spaced axially apart along the entire length of the guide tube.

3. The assembly as claimed in claim 2, wherein the spacing between axially adjacent sets of supporting protrusions is between 3L and 8L, where L is the axial length of the supporting protrusions.

4. The assembly as claimed in claim 2, wherein an axial length of each supporting protrusion is greater than an internal diameter of the guide tube.

5. The assembly as claimed in claim 1, wherein the fluid feed channel is internal to the electrode, and the fluid return channel is between the inner diametral surface of the guide tube and the outer diametral surface of the electrode.

6. The assembly as claimed in claim 1, wherein each set of supporting protrusions comprises N supporting protrusions, where N≥2, the N supporting protrusions defining N semi-annular cavities therebetween, one or more of the semi-annular cavities forming the fluid feed channel, and another one or more of the semi-annular cavities forming the return channel.

7. The assembly as claimed in claim 1, wherein each set of supporting protrusions defines an electrode support circumference, a cumulative circumferential length of the radially innermost surface of each supporting protrusion in a set being between 0.4 and 0.7 of the electrode support circumference.

8. The assembly as claimed in claim 1, further comprising an offset transfer portion, the offset transfer portion comprising a housing: the housing enclosing: an input electrode; a lateral transfer electrode; and an output electrode, wherein the lateral transfer electrode has a first end and an opposite second end, the first end being conductively connected to the input electrode, and the second end being conductively connected to the output electrode, a longitudinal axis of the input electrode being offset from a longitudinal axis of the output electrode, and wherein a length of the lateral transfer electrode defines an offset between the input electrode and the output electrode, and axial movement of the input electrode results in a corresponding axial movement of the output electrode.

9. An EDM fastener erosion device, the device comprising: a housing configured to be positioned on a surface of a workpiece and proximal to a fastener to be eroded; an electrode guide assembly according to claim 1, the erosion electrode positioned at least partially within the housing, the erosion electrode being movable relative to the housing along a longitudinal axis of the fastener, the housing being positioned at the second end of the guide tube; a ground electrode being conductively connected to the fastener; and a dielectric fluid supply being configured to deliver a dielectric fluid to a region between the erosion electrode and the fastener; wherein the electrode is slidably accommodated within the electrode guide assembly, the housing is positioned at the second end of the guide tube, the dielectric fluid supply is configured to provide a supply of a dielectric fluid along the guide tube from the first end to the second end and thence to a region between the erosion electrode and the fastener.

10. The EDM fastener removal device as claimed in claim 9, further comprising an electrode advance mechanism, the electrode advance mechanism being positioned at a first end of the electrode guide assembly, the electrode advance mechanism being configured to provide axial movement of the electrode within the guide tube.

11. The EDM device as claimed in claim 9, wherein the housing comprises one or more alignment portions, and the or each alignment portion of the housing is configured to locate against the fastener, to secure the housing proximal to the fastener.

12. The EDM device as claimed in claim 9, wherein the fastener extends from the workpiece, the workpiece comprises one or more alignment features, the housing comprises one or more alignment portions, and the or each alignment portion of the housing is configured to locate against a corresponding alignment feature of the workpiece, to secure the housing proximal to the fastener.

13. The EDM device as claimed in claim 9, wherein the housing is configured to enclose a working volume when positioned against the workpiece, the fastener extends from the workpiece into the working volume, the erosion electrode moves within the working volume, and the dielectric fluid is delivered into the working volume.

14. A method of electro-discharge machining a fastener, the fastener being located in a workpiece, the method comprising the steps of: providing an EDM device comprising a housing, an electrode guide assembly according to claim 1, and a ground electrode, the housing being positioned at the second end of the guide tube; positioning the housing on a surface of the workpiece and proximal to the fastener; positioning the ground electrode in conductive connection with the fastener; delivering a dielectric fluid along the guide tube from the first end to the second end, and thence to the housing in a region between the erosion electrode and the fastener; moving the erosion electrode towards the fastener along a longitudinal axis of the fastener; and generating an electrical potential in the erosion electrode sufficient to cause a breakdown in a gap between the erosion electrode and the fastener, to thereby cause a portion of the fastener to be eroded, the eroded portion being suspended in the dielectric fluid.

Description

DESCRIPTION OF THE DRAWINGS

(1) There now follows a description of an embodiment of the disclosure, by way of non-limiting example, with reference being made to the accompanying drawings in which:

(2) FIG. 1 shows a schematic perspective view of an electrode guide assembly according to a first embodiment of the disclosure;

(3) FIG. 2 shows a schematic sectional view of an electrode guide assembly according to a second embodiment of the disclosure;

(4) FIG. 3 shows a schematic perspective view of an electrode guide assembly according to a third embodiment of the disclosure;

(5) FIG. 4 shows a schematic sectional view of the guide tube of the embodiment of FIG. 3;

(6) FIG. 5 shows a schematic perspective view of an electrode guide assembly according to a fourth embodiment of the disclosure;

(7) FIG. 6 shows a schematic sectional view of the guide tube of FIG. 5 illustrating the geometric relationship between guide tube diameter and electrode travel;

(8) FIG. 7 shows a schematic perspective view of an offset transfer portion according to a fifth embodiment of the disclosure;

(9) FIG. 8 shows a schematic part-sectional view of the offset transfer portion of FIG. 7 in a first, retracted position;

(10) FIG. 9 shows a schematic part-sectional view of the offset transfer portion of FIG. 7 in a second, extended position;

(11) FIG. 10 shows a schematic, part-sectional view of a universal joint according to a sixth embodiment of the disclosure;

(12) FIG. 11 shows a schematic, perspective view of the cross of the universal joint of FIG. 10;

(13) FIG. 12 shows a schematic view of an EDM fastener erosion device according to a seventh embodiment of the disclosure; and

(14) FIG. 13 shows a schematic, sectional view of an EDM dielectric fluid flow control valve according to a eighth embodiment of the disclosure.

(15) It is noted that the drawings may not be to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.

DETAILED DESCRIPTION

(16) Referring to FIG. 1, an electrode guide assembly for an EDM process according to a first embodiment of the disclosure is designated generally by the reference numeral 100.

(17) The electrode guide assembly 100 comprises a guide tube 110 and an electrode 150. The guide tube 110 has a first proximal end 112 and an opposite second distal end 114. The guide tube 110 has an inner diametral surface 118 having an internal diameter 116. The guide tube 110 has a length 120.

(18) The guide tube 110 has a set of at least two supporting protrusions 160. In the present arrangement the guide tube 110 has a set of three supporting protrusions 160. Each of the supporting protrusions 160 projects radially inwardly from the inner diametral surface 118. The radially innermost surface of the supporting protrusions 160 defines an electrode support circumference 166. The three supporting protrusions 160 define three semi-annular cavities 170 circumferentially therebetween. This can be seen in the section on plane ‘A’ of FIG. 1 where the arrangement of supporting protrusions 160 is a circumferential array of alternating supporting protrusions 160 and semi-annular cavities 170.

(19) In an alternative arrangement as shown in FIG. 2, the guide tube 110A has two supporting protrusions 160A, each projecting radially inwardly from the inner diametral surface 118A of the guide tube 110A. The radially innermost surface of the supporting protrusions 160A defines an electrode support circumference 166A. The two supporting protrusions 160A define two semi-annular cavities 170A circumferentially therebetween. The electrode 150 is slidably accommodated within the guide tube 110A with an outer diametral surface 152 of the electrode 150 slidably abutting against the pair of supporting protrusions 160A.

(20) The guide tube 110 of the present arrangement is formed from a thermoplastic material. However in alternative arrangements, the guide tube may be alternatively formed, for example from thermo-setting polymeric materials, or fibre reinforced composite material, or by additive layer manufacturing techniques.

(21) The set of three supporting protrusions 160 extends continuously along the entire axial length 120 of the guide tube 110.

(22) The electrode 150 is slidably accommodated within the guide tube 110 with an outer diametral surface 152 of the electrode 150 slidably abutting against the set of supporting protrusions 160. In other words, the outer diameter 154 of the electrode 150 is sized to be slightly smaller than the electrode support circumference 166 such that the electrode 150 can readily slide within the guide tube 110 as shown by axial movement 156.

(23) The electrode 150 is formed from copper or a copper alloy. In the present arrangement the electrode 150 has an outer diameter 154 of approximately 5 mm. However in other arrangements, this diameter may be in a range between approximately 2 mm and 12 mm or larger.

(24) In the present arrangement the electrode 150 is hollow and the central cavity within the electrode 150 forms a fluid feed channel 140 extending along the axial length 120 of the guide tube 110 in a direction from the first end 112 to the second end 114. Furthermore, in the present arrangement the semi-annular cavities 170 form a fluid return channel 140 extending along the axial length 120 of the guide tube 110 in a direction from the second end 114 to the first end 112.

(25) In an alternative arrangement (not shown) the electrode 150 may be a solid electrode. In this arrangement at least one of the semi-annular cavities 170 defined a fluid feed channel 130, and a further at least one of the semi-annular cavities 170 defined a fluid return channel 140.

(26) Referring to FIGS. 3 and 4, an electrode guide assembly according to a third embodiment of the disclosure is designated generally by the reference numeral 200. Features of the electrode guide assembly 200 which correspond to those of electrode guide assembly 100 have been given corresponding reference numerals for ease of reference.

(27) The electrode guide assembly 200 comprises a guide tube 210 and an electrode 150. The guide tube 210 has a first proximal end 212 and an opposite second distal end 214. The guide tube 210 has an inner diametral surface 218 with an internal diameter 216 and an axial length 220.

(28) In this arrangement the guide tube 210 also has a set of three supporting protrusions 260. As with the first embodiment described above, each of the supporting protrusions 260 projects radially inwardly from the inner diametral surface 218. The radially innermost surface of the supporting protrusions 260 defines an electrode support circumference 266, and the three supporting protrusions 160 define three semi-annular cavities 270 circumferentially therebetween.

(29) However in the third embodiment of the guide assembly 200, there are a plurality of sets of supporting protrusions 160. Each set of supporting protrusions 160 is spaced along the axial length 220 of the guide tube 210. As shown in FIG. 4, each set of supporting protrusions 260 has an axial length 264. Furthermore the sets of supporting protrusions 260 are regularly spaced along the axial length 220 of the guide tube 210 by an axial spacing 262. In an alternative arrangement the sets of supporting protrusions 260 may not all be equally spaced along the axial length 220 of the guide tube 210.

(30) This can be seen in the section on plane ‘A’ of FIG. 3, and also in FIG. 4, where the arrangement of supporting protrusions 260 is a circumferential array of alternating supporting protrusions 260 and semi-annular cavities 270. The section at plane ‘A’ in this arrangement corresponds to a mid-point (i.e. L/2, where L is the length of the guide tube 110) along the guide tube 100.

(31) Returning to FIG. 3, the sections on planes ‘B’ and ‘C’ correspond to positions along the axial length 220 of the guide tube 210 where there are no supporting protrusions 260. These positions correspond to the L/3 and 2L/3 (where L is the length of the guide tube 110) points along the length 110 of the guide tube 100.

(32) As with the embodiment of FIG. 1, the electrode 150 is slidably accommodated within the guide tube 210 with an outer diametral surface 152 of the electrode 150 slidably abutting against each of the sets of supporting protrusions 260 along the length of the guide tube 210. In other words, the outer diameter 154 of the electrode 150 is sized to be slightly smaller than the electrode support circumference 266 such that the electrode 150 can readily slide within the guide tube 210 as shown by axial movement 156.

(33) In the present arrangement the electrode 150 is hollow and the central cavity within the electrode 150 forms a fluid feed channel 140 extending along the axial length 220 of the guide tube 210 in a direction from the first end 212 to the second end 214. Likewise as previously described in the present arrangement, the semi-annular cavities 270 form a fluid return channel 240 extending along the axial length 220 of the guide tube 210 in a direction from the second end 214 to the first end 212.

(34) In an alternative arrangement (not shown) the electrode 150 may be a solid electrode, with at least one of the semi-annular cavities 270 defining a fluid feed channel 230, and a further at least one of the semi-annular cavities 270 defining a fluid return channel 240.

(35) Referring to FIG. 5, an electrode guide assembly according to a fourth embodiment of the disclosure is designated generally by the reference numeral 300. Features of the electrode guide assembly 300 which correspond to those of electrode guide assembly 100 have been given corresponding reference numerals for ease of reference.

(36) The electrode guide assembly 300 includes all of the features of the electrode guide assembly 200 described above and shown in FIGS. 3 and 4 with the additional feature of an angled guide tube 310.

(37) In this arrangement, the guide tube 310 has a bend or kink along the length 320 of the guide tube 310. The bend has an included angle 380. This means that the guide tube 310 can be positioned in configurations in which the second end of the guide tube 310 is in a region that is physically inaccessible to a user or extremely difficult to access by the user.

(38) In all other aspects, the electrode guide assembly 300 corresponds to the electrode guide assembly 200 described in detail above. In other words, the electrode guide assembly 300 comprises a plurality of sets of supporting protrusions 360 that are spaced along a length 320 of the guide tube 310. Furthermore the electrode 150 is slidably positioned within the guide tube 310 and slidably abuts against the radially innermost surfaces of each set of supporting protrusions 360.

(39) FIG. 6 shows the angled portion of the guide tube 310 of the fourth embodiment of the disclosure. In particular FIG. 6 illustrates the trigonometrical relationship between the internal diameter 316 (shown as ‘ID’ in FIG. 6) and the travel ‘L’ of the electrode 150. This relationship is described by the following equation.

(40) $X=\left(\left(\frac{A}{2}\right)\times \sin \left(90-\left(\frac{B}{2}\right)\right)\right)+\left(C\times \left(\frac{\sin \left(90-\left(\frac{B}{2}\right)\right)}{\tan \left(90-\left(\frac{B}{2}\right)\right)}\right)\right)$

(41) The above equation can be simplified as shown below.

(42) $X=\left(\left(\frac{A}{2}\right)\times \sin \left(90-\left(\frac{B}{2}\right)\right)\right)+\left(C\times \left(\cos \left(90-\left(\frac{B}{2}\right)\right)\right)\right)$

(43) Referring to FIGS. 7 to 9, an electrode guide assembly according to a fifth embodiment of the disclosure includes an offset transfer portion 400.

(44) The offset transfer portion 400 comprises a housing 410, an input electrode 420, a lateral transfer electrode 430, and an output electrode 440. The input electrode 420 has a longitudinal axis 422 and the input electrode 420 is capable of axial movement 424 along the longitudinal axis 422. Likewise, the output electrode 440 has a longitudinal axis 442 and the output electrode 440 is capable of axial movement 444 along the longitudinal axis 442.

(45) The lateral transfer electrode 430 has a first end 432 and an opposite second end 434. The lateral transfer electrode 430 has a length 436. The first end 432 of the lateral transfer electrode 430 is conductively connected to the input electrode 420, and the second end 434 of the lateral transfer electrode 430. An axial movement 424 of the input electrode 420 therefore results in a corresponding axial movement 444 of the output electrode 440. FIG. 8 shows the offset transfer portion 400 in a first position in which the output electrode 440 is in a retracted position, while FIG. 9 shows the offset transfer portion 400 in a second position in which the output electrode 440 is in an extended position.

(46) The longitudinal axis 422 of the input electrode 420 is axially offset from the longitudinal axis 442 of the output electrode 440 by an offset distance 450 corresponding to the length 436 of the lateral transfer electrode 430.

(47) The offset transfer portion 400 may be incorporated into the electrode guide assembly 100:200:300 of any of the above-described embodiments. When included along the length of the corresponding guide tube 110:210:310 the offset transfer portion 400 allows the electrode 150 to ‘step over’ or laterally bypass some obstruction while still providing EDM access to a fastener or other feature at a location corresponding t the second distal end 114:214:314 of the guide tube 110:210:310.

(48) FIGS. 10 and 11 relate to an electrode guide assembly according to a sixth embodiment of the disclosure including a universal joint 500.

(49) The universal joint 500 comprises a first yoke 510, a second yoke 520 and a cross 530. The first yoke 510 is rotationally offset from the second yoke 520 by a quarter turn. The cross 530 connects to the first yoke 510 by a pair of first yoke pivots 512, and connects to the second yoke by a pair of second yoke pivots 522. The cross 530 further comprises a hole 532 extending therethrough.

(50) In use, the universal joint 500 might be incorporated at some point along the length 120 of the guide tube 110:210:310. The electrode 150 is slidable accommodated within the hole 532.

(51) A flexible gaiter 540 extends from the first yoke 510 to the second yoke 520, and fluidly encloses the space between the first yoke 510 and the second yoke 520.

(52) The operation of the universal joint 500 follows that of a conventional mechanical universal joint and consequently will not be discussed further here.

(53) In one arrangement, the electrode 150 may take the form of a flexible conducting tube in which a wire braided outer sleeve encloses a flexible tube. The electrode 150 may be moved axially by the action of the EDM process whilst still allowing the movement of fluid along the tube.

(54) Referring to FIG. 12, an EDM fastener erosion device according to a seventh embodiment of the disclosure is designated generally by the reference numeral 600.

(55) Features of the EDM fastener erosion device 600 which correspond to those of electrode guide assembly 100 have been given corresponding reference numerals for ease of reference.

(56) The EDM erosion device 600 comprises a housing 610, an erosion electrode 150, a ground electrode 630 and a dielectric fluid supply 640. The housing 610 can be positioned on a surface 622 of a workpiece 620, and proximal to a fastener 624 that is to be eroded.

(57) The erosion electrode 150 is positioned at least partially within the housing 610. The erosion electrode 150 is movable relative to the housing 610 along the longitudinal axis of the fastener 624.

(58) The ground electrode 630 is conductively connected to the fastener 624. The ground electrode 630 completes an electrical connection back to the erosion electrode 150.

(59) The dielectric fluid supply 640 delivers a flow of a dielectric fluid 642 to a delivery region 628, which is the region between the erosion electrode 150 and the fastener 624.

(60) In operation, the motion of the erosion electrode 150 relative to the fastener 624 is that of a conventional electro-discharge machining operation. An electric voltage in the form of a high frequency pulsed waveform is applied between the erosion electrode 150 and the fastener 624. The erosion electrode 150 is positioned against the fastener 624 with a small gap therebetween, which causes a spark to form in the gap. The details of this EDM operation are well known and will not be described further herein.

(61) To fully realise the potential for confined space long range hand held EDM erosion of fasteners 624 there is a requirement for an operator to see the position of the electrode 150 and thence to be able to guide it to the fastener 624 to be eroded. By incorporating a camera (not shown) into the second end of the guide tube 110:210:310, an operator is provided with real-time location information about the location and orientation of the electrode 150. This in turn allows the operator to manipulate the electrode guide assembly so as to align the erosion electrode 150 with the fasteners axis so as to erode the fastener.

(62) Referring to FIG. 13, an electrode guide assembly according to a eighth embodiment of the disclosure includes an EDM dielectric fluid flow control valve 700.

(63) The EDM dielectric fluid flow control valve 700 comprises a housing 720 having a spool valve 730 and a spring 740. The spool valve 730 has a first end 732 and an opposite second end 734.

(64) The spool valve 730 and the spring are accommodated within the housing 720. The spool valve 730 is biased in a closed position 736 by the spring 740. The housing 720 has a signal flow inlet port 722. The first end 732 of the spool valve 730 is adapted to receive a signal flow 714 of a dielectric fluid 710 from the signal flow inlet port 722. The signal flow 714 acts on the first end 732 of the spool valve 730 to thereby cause movement of the spool valve 730 from the closed position 736 to an open position 738.

(65) With the spool valve 730 in the open position, the dielectric fluid 710 can flow from the main flow inlet port 726 to the main flow outlet port 728.

(66) The EDM erosion process relies for its efficient operation on a pressure of dielectric fluid 710 in the region 628 between the erosion electrode 150 and the fastener 624. A conventional hand-held EDM tool will require time to raise the pressure of the dielectric fluid 710 following initiation of erosion by an operator but before erosion can begin.

(67) The dielectric fluid flow control valve 700 of the present embodiment is intended to be positioned at the second end 114:214:314 of the guide tube 110:210:310. This positioning enables a working pressure of the dielectric fluid 710 to be maintained along the length of the guide tube 110:210:310 and means that when the operator initiates the EDM process the delay while the pressure of the dielectric fluid is raised can be significantly reduced over the conventional prior art arrangements.

(68) In one or more examples, the operations described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the operations may be stored on or transmitted over, as one or more instructions or code, a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol. In this manner, computer-readable media generally may correspond to (1) tangible computer-readable storage media, which is non-transitory or (2) a communication medium such as a signal or carrier wave. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure. A computer program product may include a computer-readable medium.

(69) By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are instead directed to non-transient, tangible storage media. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

(70) Instructions may be executed by one or more processors, such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and/or software modules. Also, the techniques could be fully implemented in one or more circuits or logic elements.

(71) The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a processor, an integrated circuit (IC) or a set of ICs (e.g., a chip set). Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a hardware unit or provided by a collection of interoperative hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware.

(72) The invention includes methods that may be performed using the subject devices. The methods may comprise the act of providing such a suitable device. Such provision may be performed by the end user. In other words, the “providing” act merely requires the end user obtain, access, approach, position, set-up, activate, power-up or otherwise

(73) act to provide the requisite device in the subject method. Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as in the recited order of events.

(74) In addition, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention.

(75) Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

(76) While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Moreover, in determining extent of protection, due account shall be taken of any element which is equivalent to an element specified in the claims. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

(77) Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set.

(78) To aid the Patent Office and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke 35 U.S.C. 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.