Automated non-contact cleaning

<u>FIELD OF INVENTION</u>

0001The present invention generally concerns cleaning systems; and more particularly, representative and exemplary embodiments of the present invention generally relate to systems, devices and methods for automated non-contact cleaning of articles with sublimation agents.

<u>BACKGROUND OF INVENTION</u>

0002Hardware equipment and other articles often require cleaning during manufacture, prior to transportation or shipment, after use, and prior to cleanroom entry. The purpose of the cleaning process is to remove particulate matter and other contaminants present on the surface of the article in order to prevent contamination of other surfaces in the cleanroom environment.

0003Solvent wipe and gas blow-off techniques are examples of conventional cleaning processes. For example, a solvent wipe may include physical contact of a low-linting cloth or fiber wipe (<i>e.g.,</i> moistened with a solvent such as isopropyl alcohol). For items with complex surface geometries, compressed air or dry nitrogen may be flowed over the surface to blow off contaminants.

0004Both solvent wipe and gas blow-off techniques have disadvantages with respect to the removal of particulate contaminants. Representatively, since solvent wiping is a contact cleaning method, there is a high risk of damage to sensitive components or delicate surfaces. Gas blow-off techniques generally remove larger particles, but typically will not remove particles smaller than about 2 microns due to boundary layer effects. Additionally, both solvent wipe and gas blow-off are tedious and difficult for operators to perform effectively on large equipment surfaces.

0005An alternative, non-contact cleaning technique involves the use of carbon dioxide (CO₂) snow cleaning. In this method, liquid CO₂ is flowed under high pressure through a small orifice positioned to face the item to be cleaned. The resulting pressure differential forces the liquid CO₂ to transition from the liquid to the solid phase by operation of Joule-Thompson cooling.

0006The relationship between temperature, pressure and volume of a gas is generally described by the gas laws. When volume is increased, the gas laws do not uniquely determine what happens to the pressure and temperature of the gas. In general, when a gas expands adiabatically, the temperature may either decrease or increase, depending on the initial temperature and pressure. For a fixed pressure, a gas has a Joule-Thomson (Kelvin) inversion temperature, above which expansion causes the temperature to rise, and below which expansion causes cooling. For most gases, at atmospheric pressure this temperature is fairly high (above room temperature), and so gases may be cooled by expansion.

0007In accordance with this procedure, CO₂ snowflakes may be produced in the 5 micron range for aggressive cleaning as well as up to about 0.5 cm for the cleaning of delicate surfaces. Control of the size of the CO₂ snowflakes may be accomplished by varying the flow rate through the nozzle. As CO₂ snowflakes impinge on a surface, they transfer momentum to particulate matter. When the CO₂ snowflakes sublime, particulate contamination is generally carried away from the surface, thus cleaning the surface.

0008This form of cleaning is able to achieve a higher level of cleanliness than simply blowing a gas, such as dry air or nitrogen, over a surface. The carbon dioxide flakes are able to penetrate the boundary layer and efficiently remove sub-micron contaminants down to 0.1 microns in size. Since CO₂ snowflakes sublime upon impingement on a surface, substantially no residue is left on the surface after cleaning.

0009The benefits of the CO₂ snow cleaning technique are that it is a non-contact method, thereby reducing the risk of damage to sensitive surfaces. Additionally, CO₂ snow cleaning removes very small (e.g., sub-micron) contaminants. Moreover, CO₂ snow cleaning is appropriate for the removal of light hydrocarbons. For example, a thin layer of liquid CO₂, formed at the interfaces between the CO₂ snow particle and the surface, may act as a solvent by dissolving organic contaminants and lifting them away from the surface in the flow of CO₂ snow and vapor.

0010Conventional CO₂ snow cleaning equipment generally consists of hand-held spray gins with hose attachments to a CO₂ liquid source. The operator performing the cleaning must generally hold the spray gun and control the flow of CO₂ snow over the surface to be cleaned. For larger pieces of hardware, cleaning with a CO₂ snow gun may be difficult, since only a small surface area at a time may typically be cleaned. In these situations, cleaning with a single CO₂ snow gun may be time consuming, and it may be difficult to identify which surfaces have already been cleaned and which surfaces are yet to be cleaned.

0011In another conventional application, CO₂ snow cleaning may be performed within a manual glove box. An operator must generally fit gloved hands into the glove box and manually orient the surface of the article to be cleaned with one hand while controlling the CO₂ snow gun with the other hand. The reduces the non-contact aspect of CO₂ snow cleaning, and is generally not effective for cleaning larger hardware articles and surfaces.

0012<patcit id="pcit0001" dnum="EP0764500A1"><text>EP0764 500 A1</text></patcit> describes a system and method for polishing metal surfaces, such as gold mirror surfaces, and the like, using CO₂ snow is disclosed. The system includes an enclosure for holding a component having a metal surface that is to be polished. A CO₂ jet spray system is provided for producing solid CO₂ gas snow and the cleaning chamber is purged through suitably configured air inlets and outlets.

<u>SUMMARY OF THE INVENTION</u>

0013The present invention provides an automated non-contact cleaning system and method as set out in claims 1 and 5, which basically include: a cleaning chamber configured to at least partially enclose the hardware article to be cleaned; a plurality of nozzles disposed on a rotatable curved arc manifold, and configured to spray a sublimating agent on the hardware article; an air inlet configured to purge the chamber with a gas; and an air outlet configured to exhaust the purge gas and sublimating agent from the chamber.

0014Advantages of the present invention will be set forth in the Detailed Description which follows and may be apparent from the Detailed Description or may be learned by practice of exemplary embodiments of the invention. Still other advantages of the invention may be realized by means of any of the instrumentalities, methods or combinations particularly pointed out in the claims.

<u>BRIEF DESCRIPTION OF THE DRAWINGS</u>

0015Representative elements, operational features, applications and/or advantages of the present invention reside <i>inter alia</i> in the details of construction and operation as more fully hereafter depicted, described and claimed - reference being made to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. Other elements, operational features, applications and/or advantages will become apparent in light of certain exemplary embodiments recited in the Detailed Description, wherein: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. <b>1</b></figref> representatively illustrates a non-contact cleaning chamber not forming part of the present invention;</li><li><figref idref="f0001">FIG. 2</figref> representatively illustrates an automated non-contact cleaning system also not forming part of the present invention;</li><li><figref idref="f0002">FIG. <b>3</b></figref> representatively illustrates a non-contact cleaning chamber which does not fall within the scope of the present invention;</li><li><figref idref="f0002">FIG. 4</figref> representatively illustrates another automated non-contact cleaning system which does also not form part of the present invention;</li><li><figref idref="f0003">FIG. <b>5</b></figref> representatively illustrates a non-contact cleaning chamber in accordance with one embodiment of the present invention; and</li><li><figref idref="f0003">FIG. <b>6</b></figref> representatively illustrates another automated non-contact cleaning system in accordance with another embodiment of the present invention.</li></ul>

0016Elements in the Figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the Figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Furthermore, the terms "first", "second", and the like herein, if any, are used <i>inter alia</i> for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. Moreover, the terms "front", "back", "top", "bottom", "over", "under", "forward", "aft", and the like in the Description and/or in the claims, if any, are generally employed for descriptive purposes and not necessarily for comprehensively describing exclusive relative position. Any of the preceding terms so used may be interchanged under appropriate circumstances such that various embodiments of the invention described herein, for example, may be capable of operation in other configurations and/or orientations than those explicitly illustrated or otherwise described.

<b>DETAILED DESCRIPTION</b> OF

<u>EXEMPLARY EMBODIMENTS</u>

0017The following representative descriptions of the present invention generally relate to exemplary embodiments and the inventors' conception of the best mode, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description is intended to provide convenient illustrations for implementing various embodiments of the invention.

0018An exemplary embodiment of the present invention comprises an automated chamber in which hardware articles to be cleaned may be placed inside a chamber with multiple nozzles providing a shower of CO₂ snow. Two representative designs include: a walk-in chamber for cleaning larger articles, and a smaller chamber for use as, for example, a cleanroom pass-through. Both representative designs provide an enclosure for containing the hardware article to be cleaned, the CO₂ snow, contaminants and purge gases. The cleaning process may be adapted to comprise a substantially automated process, thereby reducing the potential for human error and eliminating the need for an operator to guide the carbon dioxide snow nozzles.

0019In the walk-in chamber design, a door may be opened and the hardware article transported into the chamber. The chamber may be located in an anteroom of a cleanroom so that hardware articles entering the cleanroom may be cleaned with CO₂ snow and then transferred to the cleanroom via a door on the opposite (e.g., cleanroom) side of the chamber. Fixturing of the hardware article may be provided in order to prevent the article from moving during the cleaning process. Additionally, hardware articles that are sensitive to electrostatic discharge (ESD) may be grounded via a grounding strap.

0020Once the hardware article is secured, the doors of the chamber may be closed and the cleaning process may commence. The chamber may be initially purged with dry air, nitrogen, and/or the like, which passes through a dehumidifier to remove or otherwise reduce moisture and then a high efficiency particulate air (HEPA) filter to remove or otherwise reduce particulate contaminants before the sublimation agent is introduced to the chamber. This generally ensures that moisture will not condense on the hardware article during the cleaning process. Once the chamber is sufficiently purged, the sublimating agent may then be introduced. For example, liquid CO₂ may generally be delivered from a storage source to the nozzle manifold. The liquid CO₂ will generally undergo a phase change to the solid state at the orifice of each nozzle. The hardware article to be cleaned may then be sprayed with the CO₂ snow. The hardware article may also be rotated on a rotary table or may remain stationary while the CO₂ manifold arm rotates around the hardware article to ensure thorough cleaning.

0021The CO₂ snow cleaning process should generally take only a few minutes to sufficiently cover the hardware article. Once cleaning is complete, the liquid CO₂ supply valve may be closed and the CO₂ snow shower stops. The HEPA filtered dry air or nitrogen may then be introduced to the chamber again to purge CO₂ and contaminants out of the chamber. CO₂ and exhaust gases will generally flow down through the grated floor of the chamber and may then be vented to a safe location. The cleaned hardware article may thereafter safely enter the cleanroom environment.

0022Smaller objects are typically admitted to a cleanroom environment via a pass-through. The pass-through may be fixed in the wall of a cleanroom and generally be configured with a door on the cleanroom side and a door on the opposite side to the non-cleanroom environment. A representative pass-through chamber design, in accordance with exemplary aspects of the present invention, generally allows for easy cleaning of the hardware article before entering the cleanroom. The door to the pass-through on the non-cleanroom side may be opened and the hardware article to be cleaned may be placed on, for example, a grate rack. Fixturing of the hardware article may be performed in order to prevent the hardware article from moving during the cleaning process. Articles that are sensitive to ESD may be grounded via a grounding strap. Once the door is closed, the chamber environment may be purged with HEPA filtered dry air or nitrogen, as generally described <i>vide supra.</i> Multiple nozzles present in the pass-through may be configured to spray the hardware article with CO₂ snow, so that substantially all sides of the hardware article are cleaned. After the CO₂ snow cleaning process is complete, the pass-through chamber may be flushed with HEPA filtered dry air or nitrogen, and the gases may then be exhausted to a safe location. The pass-through door on the cleanroom side may then be opened to withdraw the hardware article and admit it to the cleanroom.

0023Representatively disclosed designs may be suitably adapted to clean hardware articles with CO₂ snow at intermediate points during manufacturing processes as well, and as a final cleaning step for hardware to be packaged for transport or final shipment. For example, hardware articles in a cleanroom environment that become contaminated with particles may be placed in the pass-through to undergo a CO₂ snow cleaning without removing the hardware from the cleanroom environment.

0024As representatively depicted in <figref idref="f0001">Fig. <b>1</b></figref><b>,</b> chamber <b>130</b> may comprise a cleanroom pass-through. Chamber <b>130</b> generally has doors on each side (<i>e.g</i>., front access door <b>120</b> and rear access door <b>140)</b> of the pass-through. A plurality of CO₂ snow nozzles <b>100</b> may be disposed within chamber <b>130;</b> the number and locations of which may at least partially be determined by the size and shape of the chamber as well as the type and configuration of hardware articles to be cleaned. Grate floor <b>110</b> may be used with nozzles underneath in order to clean the bottom side of the hardware article. In an exemplary embodiment, grate floor <b>110</b> may be removable to allow for maintenance and cleaning.

0025A non-contact cleaning system utilizing the chamber <b>130</b> generally depicted in <figref idref="f0001">Fig. <b>1</b></figref>, is representatively illustrated in <figref idref="f0001">Fig. <b>2</b></figref><b>.</b> Chamber <b>130</b> may comprise an enclosure of arbitrary size and/or shape. The enclosure may be constructed of rigid materials, such as polycarbonate and/or the like, or of a rigid frame covered with a film such as polyethylene. Utilization of an at least partially transparent material in the construction of the enclosure will generally aide the observation of the cleaning process, but is not a required feature or element of the present invention.

0026Clean air (and/or an inert gas; such as nitrogen, argon, krypton, <i>etc.</i>) may be introduced to chamber <b>130</b> through diffuser <b>250</b> and HEPA filter <b>260</b> in the ceiling or upper wall of the chamber. Dehumidifier <b>240</b> may be optionally included in the system to dry the incoming air in order to eliminate or otherwise reduce condensation of moisture on the hardware article <b>230</b> prior to and during the cleaning process. Air may be exhausted through a duct disposed, for example, near the floor of chamber <b>130</b> or under grate false floor <b>110.</b> Blower <b>270</b> may be suitably configured inline with the air intake or exhaust to provide air handling. In the case of a CO₂ snow chamber system, the exhaust may be ducted to a safe location to eliminate or otherwise reduce the possibility of ambient carbon dioxide concentrations accumulating to dangerous levels. In addition to carbon dioxide, various other sublimating agents, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed in order to achieve a substantially similar result.

0027Hardware article <b>230</b> may be optionally configured with fixture standoffs <b>210</b> (<i>e.g.</i>, support elements) in order to suitably orient hardware article <b>230</b> with respect to nozzles <b>100</b> as well as to substantially immobilized hardware article <b>230</b> during the cleaning process. Accordingly, It will be appreciated that hardware fixturing may be employed in order to render the cleaning process more effective and/or to prevent damage to the article <b>230</b> being cleaned.

0028Controlled introduction of liquid sublimation agent (e.g., CO₂) may be accomplished via valve <b>200.</b> Valve <b>200</b> may be actuated via manual, mechanical and/or electronic control(s). The system may be optionally configured with safety interlocks in order to prevent, for example, activation of CO₂ snow production while doors <b>120, 140</b> to chamber <b>130</b> are open.

0029Chamber <b>130</b> may comprise a substantially permanent installation, may be semi-permanent (such as in the case of a folding structure), or may be suitably configured as a mobile assembly with, for example: wheels; skids; hoist rings; and/or the like. It will be appreciated that various other structural features and/or elements, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed to produce a substantially similar result.

0030As representatively illustrated in <figref idref="f0002">Fig. <b>3</b></figref><b>,</b> chamber <b>330</b> may comprise a rotary table design. Chamber <b>330</b> generally may be configured with doors on each side (<i>e.g</i>., front access door <b>320</b> and rear access door <b>340)</b> of the enclosure in order to facilitate the transference of hardware articles from one room to another after cleaning. It will be appreciated, however, that more doors may be added as needed.

0031A plurality of CO₂ snow nozzles <b>300</b> may be disposed within chamber <b>330;</b> the number and locations of which may at least partially be determined by the size and shape of the chamber as well as the type and configuration of hardware articles to be cleaned. Chamber <b>330</b> may also be configured with a motorized rotary turn-table <b>310,</b> which may be actuated in order to rotate hardware article <b>230</b> during cleaning. As hardware article <b>230</b> is rotated, substantially every surface of article <b>230</b> may be exposed to the sublimating agent introduced through nozzles <b>300</b> in order to affect non-contact cleaning of hardware article <b>230.</b>

0032A non-contact cleaning system utilizing the chamber <b>330</b> generally depicted in <figref idref="f0002">Fig. <b>3</b></figref><b>,</b> is representatively illustrated in <figref idref="f0002">Fig. 4</figref>. Chamber <b>330</b> may comprise an enclosure of arbitrary size and/or shape. The enclosure may be constructed of rigid materials, such as polycarbonate and/or the like, or of a rigid frame covered with a film such as polyethylene. Utilization of an at least partially transparent material in the construction of the enclosure will generally aide the observation of the cleaning process, but is not a required feature or essential element of the present invention.

0033Clean air (and/or an inert gas; such as nitrogen, argon, krypton, <i>etc.</i>) may be introduced to chamber <b>330</b> through diffuser <b>480</b> and HEPA filter <b>470</b> in the ceiling or upper wall of chamber <b>330.</b> Dehumidifier <b>490</b> may be optionally included in the system to dry the incoming air in order to eliminate or otherwise reduce condensation on hardware article <b>230</b> prior to and during the cleaning process. Air may be exhausted through a duct disposed, for example, near the floor of chamber <b>330</b> or under grate false floor <b>430.</b> Blower <b>460</b> may be suitably configured inline with the air intake or exhaust to provide air handling. In the case of a CO₂ snow chamber system, the exhaust may be ducted to a safe location to eliminate or otherwise reduce the possibility of ambient carbon dioxide concentrations accumulating to dangerous levels. In addition to carbon dioxide, various other sublimating agents, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed in order to achieve a substantially similar result. For example, krypton may also be used as a sublimating agent.

0034Nozzle manifold <b>300</b> may comprise a curved arc of individual nozzles <b>410</b> oriented with respect to hardware article <b>230</b> so as to deliver sublimating agent to substantially every surface of the article to be cleaned. Nozzle manifold <b>300</b> may be supported by a manifold support <b>420</b> in order to substantially fix the disposition of nozzle manifold <b>300</b> with respect to the hardware article <b>230</b> to be cleaned.

0035False floor <b>430</b> may be of a grate-type material suitably configured to facilitate substantially unobstructed airflow within chamber <b>330.</b> False floor <b>430</b> may also comprise ramps which may be used to transport hardware articles <b>230</b> into and out of chamber <b>330</b>. False floor <b>430</b> may also be removable in order to facilitate maintenance and cleaning.

0036Hardware article <b>230</b> may be optionally configured with fixture standoffs <b>450</b> (<i>e.g</i>., support elements) in order to suitably orient hardware article <b>230</b> with respect to nozzles <b>300</b> as well as to substantially immobilized hardware article <b>230</b> during the cleaning process. Accordingly, it will be appreciated that hardware fixturing may be employed in order to render the cleaning process more effective and/or to prevent damage to the article <b>230</b> being cleaned.

0037Controlled introduction of liquid sublimation agent(s) (<i>e.g</i>., CO₂, krypton, <i>etc</i>.) may be accomplished via valve <b>400.</b> Valve <b>400</b> may be actuated via manual, mechanical and/or electronic control(s). The system may be optionally configured with safety interlocks in order to prevent, for example, activation of CO₂ snow production while doors <b>320, 340</b> to chamber <b>330</b> are open.

0038Chamber <b>330</b> may comprise a substantially permanent installation, may be semi-permanent (such as in the case of a folding structure), or may be suitably configured as a mobile assembly with, for example: wheels; skids; hoist rings; and/or the like. It will be appreciated that various other structural features and/or elements, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed to produce a substantially similar result.

0039As representatively illustrated in <figref idref="f0003">Fig. <b>5</b></figref><b>,</b> chamber <b>530</b> comprises a rotary manifold articulation mechanism <b>550</b> suitably configured to allow nozzle manifold <b>500</b> to be rotated about a region of chamber <b>530.</b> Chamber <b>530</b> generally may be configured with doors on each side (e.g., front access door <b>520</b> and rear access door <b>540)</b> of the enclosure in order to facilitate the transference of hardware from one room to another after cleaning. It will be appreciated, however, that more doors may be added as needed.

0040A plurality of CO₂ snow nozzles are disposed on a curved arc manifold <b>500</b> within chamber <b>530;</b> the number and locations of which may at least partially be determined by the size and shape of the chamber as well as the type and configuration of hardware articles to be cleaned. As rotary manifold articulation mechanism <b>550</b> is rotated, substantially every surface of article <b>230</b> may be consequently exposed to the sublimating agent introduced through nozzles <b>500</b> in order to affect non-contact cleaning of hardware article <b>230.</b>

0041A non-contact cleaning system utilizing the chamber <b>530</b> generally depicted in <figref idref="f0003">Fig. <b>5</b></figref><b>,</b> in accordance with another exemplary embodiment of the present invention, is representatively illustrated in <figref idref="f0003">Fig. <b>6</b></figref><b>.</b> Chamber <b>530</b> may comprise an enclosure of arbitrary size and/or shape. The enclosure may be constructed of rigid materials, such as polycarbonate and/or the like, or of a rigid frame covered with a film such as polyethylene. Utilization of an at least partially transparent material in the construction of the enclosure will generally aide the observation of the cleaning process, but is not a required feature or essential element of the present invention.

0042Clean air (and/or an inert gas; such as nitrogen, argon, krypton, <i>etc.</i>) may be introduced to chamber <b>530</b> through diffuser <b>680</b> and HEPA filter <b>670</b> in the ceiling or upper wall of chamber <b>530.</b> Dehumidifier <b>690</b> may be optionally included in the system to dry the incoming air in order to eliminate or otherwise reduce condensation on hardware article <b>230</b> prior to and during the cleaning process. Air may be exhausted through a duct disposed, for example, near the floor of chamber <b>530</b> or under grate false floor <b>630.</b> Blower <b>660</b> may be suitably configured inline with the air intake or exhaust to provide air handling. In the case of a CO₂ snow chamber system, the exhaust may be ducted to a safe location to eliminate or otherwise reduce the possibility of ambient carbon dioxide concentrations accumulating to dangerous levels. In addition to carbon dioxide, various other sublimating agents, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed in order to achieve a substantiatly similar result. For example, krypton may also be used as a sublimating agent.

0043Nozzle manifold <b>500</b> may comprise a curved arc of individual nozzles <b>610</b> oriented with respect to hardware article <b>230</b> so as to deliver sublimating agent to substantially every surface of the article to be cleaned upon rotation of nozzle manifold <b>500.</b> Nozzle manifold <b>500</b> may be supported by an articulated manifold support mechanism <b>550</b> suitably adapted to permit nozzle manifold <b>500</b> to be rotated about the hardware article <b>230</b> to be cleaned.

0044False floor <b>630</b> may be of a grate-type material suitably configured to facilitate substantially unobstructed airflow within chamber <b>530.</b> False floor <b>630</b> may also comprise ramps which may be used to transport hardware articles <b>230</b> into and out of chamber <b>530.</b> False floor <b>630</b> may be removable in order to facilitate maintenance and cleaning.

0045Hardware article <b>230</b> may be optionally configured with fixture standoffs <b>650</b> (<i>e.g.,</i> support elements) in order to suitably orient hardware article <b>230</b> with respect to nozzles <b>500</b> as well as to substantially immobilized hardware article <b>230</b> during the cleaning process. Accordingly, it will be appreciated that hardware fixturing may be employed in order to render the cleaning process more effective and/or to prevent damage to the article <b>230</b> being cleaned.

0046Controlled introduction of liquid sublimation agent(s) (<i>e.g.,</i> CO₂, krypton, <i>etc.</i>) may be accomplished via valve <b>600.</b> Valve <b>600</b> may be actuated via manual, mechanical and/or electronic control(s). The system may be optionally configured with safety interlocks in order to prevent, for example, activation of CO₂ snow production while doors <b>520, 540</b> to chamber <b>530</b> are open.

0047Chamber <b>530</b> may comprise a substantially permanent installation, may be semi-permanent (such as in the case of a folding structure), or may be suitably configured as a mobile assembly with, for example: wheels; skids; hoist rings; and/or the like. It will be appreciated that various other structural features and/or elements, whether now known or otherwise hereafter described in the art, may be alternatively, conjunctively or sequentially employed to produce a substantially similar result. The same modifications are to be understood as falling within the scope of the present invention.

0048In the foregoing specification, the invention has been described with reference to specific exemplary embodiments; however, it will be appreciated that various modifications and changes may be made without departing from the scope of the present invention as set forth in the claims below. The specification and Figures are to be regarded in an illustrative manner, rather than a restrictive one. Accordingly, the scope of the invention should be determined by the claims appended hereto rather than by merely the examples described above.

0049For example, the steps recited in any method or process claims may be executed in any order and are not limited to the specific order presented in the claims. Additionally, the components and/or elements recited in any apparatus claims may be assembled or otherwise operationally configured in a variety of permutations to produce substantially the same result as the present invention and are accordingly not limited to the specific configuration recited in the claims.

0050Benefits, other advantages and solutions to problems have been described above with regard to particular embodiments; however, any benefit, advantage, solution to problem or any element that may cause any particular benefit, advantage or solution to occur or to become more pronounced are not to be construed as critical, required or essential features or components of any or all the claims.

0051As used herein, the terms "comprising", "having", "including" or any variation thereof, are intended to reference a non-exclusive inclusion, such that a process, method, article, composition or apparatus that comprises a list of elements does not include only those elements recited, but may also include other elements not expressly listed or inherent to such process, method, article, composition or apparatus.