Valve orifice insert

A valve orifice insert has a stepped-shaped wall including a first tubular section and a second tubular section having a smaller outer dimension than the first tubular section, and a lip structure protruding axially and including a planar valve seat surface. The first tubular section and the second tubular section being are joined by a step structure. At least one circumferential protrusion extends radially outward a predetermined distance from an outer surface of the first tubular section or an outer surface of the second tubular section to form an interference fit with the step-shaped opening when the valve orifice insert is fitted into the step-shaped opening.

BACKGROUND

Many conventional valves are operated by lowering or raising a diaphragm to close or open a valve orifice gap, respectively, to regulate the flow of fluid through the valve. In one type of conventional valve, the valve closes by making metal-to-metal contact between the diaphragm and the valve orifice. Even small misalignment in the surfaces making metal-to-metal contact can result in a poor seal and fluid leakage. Further as this type of valve ages, corrosion of the metal can make the metal-to-metal contact seal poorly and leak. Poor sealing and leakage degrade the quality of the manufacturing process in which the valve is being utilized.

In another type of conventional valve described in U.S. Pat. No. 8,733,397, a resin part is sandwiched between two metal parts by compressive forces, and the resin part is contacted by a diaphragm to seal the orifice. While this avoids metal-to-metal contact between the diagram and sealing surface of the resin part, the integrity of the seal between the resin part and surrounding metal parts is at risk of degrading over time, resulting in fluid leakage or entrapment. Further, the sealing surface of the resin part may become misaligned at the time of manufacture or during use, and this misalignment can make it difficult to control very low flow rates. A degradation in the quality of seal such can negatively affect manufacturing processes that demand highly precise fluid flow control and low contamination levels, especially in the field of semiconductor manufacturing. These technical challenges have thus far stood as barriers to further advancements in valve design.

SUMMARY

According to one aspect of the present disclosure, a valve orifice insert is provided that is sized to be fitted in a step-shaped opening in an orifice structure of a valve assembly. The valve orifice insert comprises a plastic tubular body having a stepped-shaped wall including a first tubular section and a second tubular section having a smaller outer dimension than the first tubular section, the first tubular section and the second tubular section being joined by a step structure; and at least one circumferential protrusion extending radially outward a predetermined distance from an outer surface of the first tubular section or an outer surface of the second tubular section to form an interference fit with the step-shaped opening when the valve orifice insert is fitted into the step-shaped opening.

DETAILED DESCRIPTION

In view of the above issues, referring toFIG.1, a valve orifice insert10is sized to be fitted in a step-shaped opening104in an orifice structure102of a valve assembly100according to a first example of the present disclosure. The valve orifice insert10comprises a plastic tubular body12having a stepped-shaped wall14including a first tubular section16and a second tubular section18having a smaller outer dimension than the first tubular section16. The first tubular section16and the second tubular section18are joined by a step structure22. A first circumferential protrusion20extends radially outward a first predetermined distance37afrom an outer surface34of the first tubular section16form an interference fit with the step-shaped opening104when the valve orifice insert10is fitted into the step-shaped opening104. A second circumferential protrusion24extends radially outward a second predetermined distance37bfrom an outer surface of the second tubular section18to form an interference fit with the step-shaped opening104when the valve orifice insert10is fitted into the step-shaped opening104. A first interference distance36aof the interference fit between the first circumferential protrusion20and the step-shaped opening104and a second interference distance36bof the interference fit between the second circumferential protrusion24and the step-shaped opening104may be 1/10000 to 1/100 of an inch, for example. It will be appreciated that the interference distance is the difference between the outer diameter of the first circumferential protrusion20and the inner diameter of the step-shaped opening104and also refers to the difference between the outer diameter of the second circumferential protrusion and the inner diameter of the stepped shaped opening.

It will be appreciated that the valve orifice insert10may be fabricated with different diameters of the first tubular section16and the second tubular section18to match orifice structures102with different orifice diameters.

The first tubular section16includes a lip structure26protruding axially from a first end28of the first tubular section16and includes a planar valve seat surface30formed at a distal end of the lip structure26. The first tubular section16also includes an axially protruding central structure48with a central opening50for a central flow passage40extending axially to fluidically couple with a transverse flow passage42extending in a transverse direction within the valve orifice insert10. A central planar valve seat surface49is formed at a distal end of the axially protruding central structure48.

The space between the lip structure26and the central structure48forms a recessed cavity38which has a first side opening52for a first side flow passage44and a second side opening54for a second side flow passage46. The first side flow passage44and the second side flow passage46extend axially within the valve orifice insert10. The orifice structure102may include a first outlet112aand a second outlet112bopening to a first orifice flow passage116aand a second orifice flow passage116bof the orifice structure102, respectively, which fluidically communicate with the space in the recessed cavity38.

In cross-sectional views,FIG.1shows the valve orifice insert10being inserted into the step-shaped opening104of the orifice structure102such that after insertion, at least the first circumferential protrusion20extends radially outward a first predetermined distance37afrom an outer surface of the first tubular section16, and the second circumferential protrusion24extends radially outward a second predetermined distance37bfrom an outer surface of the second tubular section18to form an interference fit with the tapered surface106of the step-shaped opening104. As the interference fit between the second circumferential protrusion24and the tapered surface106occurs at an angle relative to the axial direction of the insertion, the interference fit is enhanced by both axial compressive forces in an axial vector V1and radial compressive forces in a radial vector V2that act on the tapered surface106. In particular, forces in the axial direction indicated by vector V1promote the secure retention of insert in the step-shaped opening104. The insertion of the valve orifice insert is stopped at a predetermined depth by the step structure22. After insertion, the first tubular section16rests on the stepped surface110of the step-shaped opening104, and the planar valve seat surface30formed at a distal end of the lip structure26is coplanar with an upper surface120of the orifice structure102and the central planar valve seat surface49formed at the distal end of the axially protruding central structure48.

The first circumferential protrusion20is shaped as a ridge extending radially outward from the outer surface of the first tubular section16, formed adjacent the first end28of the plastic tubular body12. The interference fit compresses the first circumferential protrusion20the first predetermined distance37aagainst a side wall108of the step-shaped opening104, thereby effecting a seal, so that fluid within the valve orifice insert10does not leak out and become entrapped in the spaces between the valve orifice insert10and the orifice structure102. The second circumferential protrusion24has a lobe shape, and extends radially outward from the outer surface of the second tubular section18, formed adjacent a second end32of the plastic tubular body12opposite the first end28of the plastic tubular body12.

The step-shaped opening104has a tapered surface106which tapers away from a second end32of the valve orifice insert10fitted into the step-shaped opening104, and at least the second circumferential protrusion24contacts at least a portion of the tapered surface106. The tapered surface106faces away from a surface of the step structure22. As the valve orifice insert10is inserted into the step-shaped opening104, the second circumferential protrusion24compresses and slides down towards the tapered surface106. When the second circumferential protrusion24reaches the tapered surface106, the second circumferential protrusion24springs out and contacts the tapered surface106, thereby producing a seal and locking action. In other words, the interference fit compresses the second circumferential protrusion24the second predetermined distance37bagainst the tapered surface106, thereby effecting a seal and forming a locking mechanism to secure the valve orifice insert10within the step-shaped opening104, so that fluid within the valve orifice insert10does not leak out and become entrapped in the spaces between the valve orifice insert10and the orifice structure102.

The valve orifice insert10comprises an engineered-type plastic. The engineered-type plastic may be selected from the group consisting of polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), and polychlorotrifluoroethylene (PCTFE). The engineered-type plastic is preferably PEEK plastic due to its compressibility, resilience, and flexibility.

Referring toFIG.2, the valve orifice insert10according to the first example of the present disclosure is illustrated in a perspective view of the first end28of the valve orifice insert10and the distal end of the lip structure26of the first tubular section16. The outer surface of the first tubular section16is cylindrical or conical. In this view, the recessed cavity38forms a ring around the central structure48and the central opening50. The lip structure26forms a protruded ring surrounding the recessed cavity38. The first side opening52and the second side opening54flank the central opening50within the recessed cavity38.

Referring toFIG.3, the valve orifice insert10according to the first example of the present disclosure is illustrated in a perspective view of the second end32of the valve orifice insert10showing a first inlet56to the first side flow passage44and a second inlet58to the second side flow passage46as viewed on a distal surface60of the second tubular section18. The transverse flow passage42extending radially within the second tubular section18is shown on the side wall62of the second tubular section18. In this view, the transverse flow passage42runs perpendicularly to the first side flow passage44and the second side flow passage46. The outer surface of the second tubular section18is also cylindrical or conical. The outer surfaces of the first tubular section16and the second tubular section18are concentric to each other.

Referring toFIG.4, a perspective view is shown of the orifice structure102of the valve assembly100showing the stepped surface110of the step-shaped opening104and the upper surface120of the orifice structure102. The upper surface120forms an annular surface around the edge of the orifice structure102. The first orifice flow passage116aand the second orifice flow passage116bare two of a plurality of orifice flow passages116a-j. Likewise, the first outlet112aand the second outlet112bare two of a plurality of outlets112a-j. A first transverse outlet114aand a second transverse outlet114bprovided on a side wall118of the orifice structure102and configured to communicate with the transverse flow passage42when the valve orifice insert10is fully inserted into the orifice structure102.

Referring toFIG.5, a perspective view is shown of the orifice structure102of the valve assembly100showing the tapered surface106of the step-shaped opening104and a bottom surface122of the orifice structure102. The tapered surface106forms an annular surface around the step-shaped opening104. The first outlet112ais show in the view ofFIG.5.

Referring toFIG.6, a perspective view is shown of the valve orifice insert10fully inserted into the step-shaped opening104of the orifice structure102of the valve assembly100so that the planar valve seat surface30formed at a distal end of the lip structure26is coplanar with an upper surface120of the orifice structure102. It will be appreciated that, in the process of manufacturing the valve assembly100with the valve orifice insert10fully inserted, the lip structure26of the tubular plastic valve insert10and the upper surface120of the orifice structure102of the valve assembly100are concurrently lapped with a planar lapping tool so as to form a valve sealing surface30on the lip structure26and a central planar valve seat surface49on the central structure48that are coplanar with the upper surface120of the orifice structure102of the valve assembly100. The coplanarity of the planar valve seat surface30and the central planar valve seat surface49with the surface of the orifice structure102allows for fine control of the flow of fluid through the orifice structure102at a relatively small commanded flow rate.

Referring toFIG.7, a perspective view is shown of the valve orifice insert10fully inserted into the step-shaped opening104of the orifice structure102of the valve assembly100so that the second circumferential protrusion24springs out and contacts the tapered surface106, thereby producing a seal and locking action. A first inlet56to the first side flow passage44and a second inlet58to the second side flow passage46are on the distal surface60of the second tubular section18.

Referring toFIG.8, a sectional view is shown of a fluid flow controller130incorporating the valve orifice insert10and the valve assembly100of the first example according to one example of the present disclosure. The fluid flow controller130comprises a flow path126and a valve assembly100provided in the flow path126to control the flow of fluid along the flow path126. The valve orifice insert10and the valve assembly100depicted inFIG.8are substantially similar to the examples ofFIGS.1-7. The valve assembly100includes a first outlet112a, a second outlet112b, an actuator136, and a diaphragm132coupled to the actuator136. An orifice structure102of the valve assembly100has a valve orifice insert10positioned in a step-shaped opening104of the valve assembly100. The actuator136is configured to move the diaphragm132under command of a controller138operatively coupled to the actuator136to cause the diaphragm132to selectively contact or separate from a planar valve seat surface30by a distance to stop or allow the flow of fluid through the orifice structure102at a commanded flow rate, which may be in a range of sub sccm from 0.05 to 1 sccm, for example.

For example, when the diaphragm132is in a closed position contacting the planar valve seat surface30, the fluid reaching the outer surface of the first tubular section16from the first side flow passage44and the second side flow passage46is trapped within the recessed cavity38. However, as the diaphragm132lifts away from the planar valve seat surface30, the fluid trapped within the recessed cavity38starts flowing into the first orifice flow passage116a, the second orifice flow passage116b, and enter through the central opening50of the axially protruding central structure48into the central flow passage40. Because the central planar valve seat surface49of the central structure48, the planar valve seat surface30of the lip structure26, and the upper surface120of the orifice structure102are all coplanar to each other, the flow of fluid from the recessed cavity38into the orifice flow passages116a,116band the central flow passage40can be finely regulated by the actuator136operatively coupled to the diaphragm132.

The controller138includes a processor140and memory142that is operatively coupled to the processor140. The processor140sends driving signals to the actuator136to move the diaphragm132to selectively contact or separate from the planar valve seat surface30and the central planar valve seat surface49. When the diaphragm132contacts the planar valve seat surface30and the central planar valve seat surface49to form a seal, the upper surface120of the orifice structure102aligns with a mounting structure134supporting the diaphragm132. In this example, the processor140and the memory142are physically integrated into the controller138. Alternatively, the processor140and/or the memory142may be included in a separate physical computing device configured to communicate with the actuator136via wired and/or wireless signals. The functions of the processor140and the memory142may, in some examples, be distributed between a plurality of communicatively coupled computing devices, which may include one or more client computing devices and/or one or more server computing devices.

The valve orifice insert10includes plastic tubular body12having an outer surface34. A first circumferential protrusion20extends radially outward from the outer surface34of the first tubular section16to form an interference fit with a side wall108of the step-shaped opening104, and a second circumferential protrusion24forms an interference fit with a tapered surface106of the orifice structure102, thereby effecting a seal, so that fluid within the valve orifice insert10does not leak out and become entrapped in the spaces between the outer surface34of the plastic tubular body12and the orifice structure102. The lip structure26includes the planar valve seat surface30formed at a distal end of the lip structure26that is coplanar with the central planar valve seat surface49of the central structure48and an upper surface120of the orifice structure102that supports a mounting structure134of the diaphragm132. The coplanarity of the planar valve seat surface30with the central planar valve seat surface49of the central structure48and the upper surface120of the orifice structure102allows for fine control of the flow of fluid through the orifice structure102at a relatively small commanded flow rate, which may be as small as 0.05 to 1 sccm, for example.

With reference now toFIG.9, a valve orifice insert210according to a second example of the present disclosure is illustrated. As the configuration of the valve orifice insert210of the second example is substantially similar to the configuration of the valve orifice insert10of the first example, the detailed description thereof is abbreviated here for the sake of brevity. It is to be noted that like parts are designated by like reference numerals throughout the detailed description and the accompanying drawings.

FIG.9shows the valve orifice insert210being inserted into the step-shaped opening104of the orifice structure102such that after insertion, at least the first circumferential protrusion220extends radially outward a first predetermined distance237afrom an outer surface234of the first tubular section216to form an interference fit with a side wall108of the step-shaped opening104, and the second circumferential protrusion224extends radially outward a second predetermined distance237bfrom an outer surface of the second tubular section218to form an interference fit with the tapered surface106of the step-shaped opening104. A first interference distance236aof the interference fit between the first circumferential protrusion220and the step-shaped opening104and a second interference distance236bof the interference fit between the second circumferential protrusion224and the step-shaped opening104may be 1/10000 to 1/100 of an inch, for example. As discussed above, interference distance refers to the difference in the outer and inner diameters of the valve orifice insert and the step-shaped orifice, prior to insertion.

The first tubular section216includes an alignment structure226protruding axially from a first end228of the first tubular section216and includes an alignment surface230formed at a distal end of the alignment structure226and a central planar valve seat surface249formed at a distal end of the central structure248. After insertion, the first tubular section216rests on the stepped surface110of the step-shaped opening104, and the alignment surface230formed at the distal end of the alignment structure226and the central planar valve seat surface249formed at the distal end of the central structure248are coplanar with an upper surface120of the orifice structure102.

A central structure248axially protrudes from the center of the first tubular section216. A central opening250is provided at the center of the central structure248for a central flow passage240extending radially within the valve orifice insert210. In the second example, the central flow passage240is narrower than the central flow passage40of the valve orifice insert10of the first example. Unlike the first example, the valve orifice insert210of the second example lacks side flow passages that flow parallel to the central flow passage240.

With reference now toFIG.10, the valve orifice insert210according to the second example of the present disclosure is illustrated in a perspective view showing the first end228of the valve orifice insert210and the distal end of the alignment structure226of the first tubular section216. In the second example, the alignment structure226comprises four separate alignment structures226a-dprotruding from the surface of the first end228of the first tubular section216, each separate alignment structure226a-dforming an alignment surface230at a distal end of each separate alignment structure226a-d. However, it will be appreciated that the number of alignment structures226a-dis not particularly limited to four, and may number two, three, or more than four in alternative embodiments. The space between the separate alignment structures226a-dand the central structure248forms a recessed cavity238, which has no side openings in the second example. It will be appreciated that, when the valve orifice insert210is inserted into the orifice structure102of the valve assembly100, the upper surface120of the orifice structure102will be coplanar with the alignment surface230at the distal end of each separate alignment structure226a-dand the central planar valve seat surface249at the distal end of the central structure248.

With reference now toFIG.11, the valve orifice insert210according to the second example of the present disclosure is illustrated in a perspective view showing the second end232of the valve orifice insert210showing an opening to the central flow passage240on a distal surface260of the second tubular section218. Unlike the first example, the distal surface260of the valve orifice insert210of the second example has no side openings to side flow passages.

Referring toFIG.12, a valve orifice insert310according to a third example of the present disclosure is illustrated. As the configuration of the valve orifice insert310of the third example is substantially similar to the configuration of the valve orifice insert210of the second example, the detailed description thereof is abbreviated here for the sake of brevity. It is to be noted that like parts are designated by like reference numerals throughout the detailed description and the accompanying drawings.

FIG.12shows the valve orifice insert310being inserted into the step-shaped opening104of the orifice structure102such that after insertion, at least the first circumferential protrusion320extends radially outward a first predetermined distance337afrom an outer surface of the first tubular section316, and the second circumferential protrusion324extends radially outward a second predetermined distance337bfrom an outer surface of the second tubular section318to form an interference fit with the tapered surface106of the step-shaped opening104.

The first tubular section316includes a lip structure326protruding axially from a first end328of the first tubular section316and includes a planar valve seat surface330formed at a distal end of the lip structure326. After insertion, the first tubular section316rests on the stepped surface110of the step-shaped opening104, and the planar valve seat surface330formed at a distal end of the lip structure326is coplanar with an upper surface120of the orifice structure102.

Unlike the first example, the valve orifice insert310of the third example lacks a central structure or side flow passages. Instead, the space encircled by the lip structure326forms a recessed cavity338which opens into the central flow passage340extending axially within the valve orifice insert310, forming an inner surface of the first tubular section316and an inner surface of the second tubular section318which are cylindrical or conical and are concentric.

With reference now toFIG.13, the valve orifice insert310according to the third example of the present disclosure is illustrated in a perspective view showing the first end328of the valve orifice insert310and the distal end of the lip structure326of the first tubular section316. In the third example, the lip structure326forms a protruded ring surrounding the recessed cavity338. A ring-shaped planar valve seat surface330is formed at a distal end of the lip structure326.

With reference now toFIG.14, the valve orifice insert310according to the third example of the present disclosure is illustrated in a perspective view showing the second end332of the valve orifice insert310. Unlike the first example, the distal surface360of the valve orifice insert310of the third example has no side openings to side flow passages. Instead, the space encircled by the second circumferential protrusion324forms one opening to the central flow passage340.

Referring toFIG.15, a cross-sectional view is shown of the valve orifice insert310of the third example fully inserted into a step-shaped opening404of an orifice structure402of a valve assembly400, where the orifice structure402is a valve block. At least the first circumferential protrusion320extends radially outward a first predetermined distance337afrom an outer surface334of the first tubular section316to form an interference fit with a side wall408of the step-shaped opening404, and the second circumferential protrusion324extends radially outward a second predetermined distance337bfrom an outer surface of the second tubular section318to form an interference fit with the tapered surface406of the step-shaped opening404. A first interference distance336aof the interference fit between the first circumferential protrusion320and the side wall408and a second interference distance336bof the interference fit between the second circumferential protrusion324and the tapered surface406may be 1/10000 to 1/100 of an inch, for example. As discussed above, interference distance refers to the difference in the outer and inner diameters of the valve orifice insert and the step-shaped orifice, prior to insertion.

In this example, the orifice structure402includes a first orifice flow passage416and a second orifice flow passage418which fluidically communicate with the central flow passage340. After insertion, the first tubular section316rests on the stepped surface410of the step-shaped opening404, and the planar valve seat surface330formed at a distal end of the lip structure326is coplanar with an upper surface420of the orifice structure402.

Referring toFIG.16, a method500is described for manufacturing a valve assembly. The following description of the method500is provided with reference to the software and hardware components described above and shown inFIGS.1-15. It will be appreciated that the method500also may be performed in other contexts using other suitable hardware and software components.

At step502, a step-shaped opening is formed in an orifice structure of the valve assembly. At step504, a valve orifice insert is formed from a plastic material to have a tubular body having a stepped-shaped wall including a first tubular section and a second tubular section having a smaller outer dimension than the first tubular section, the first tubular section and the second tubular section being joined by a step structure. At step506, the valve orifice insert is inserted into the step-shaped opening, such that after insertion at least one circumferential protrusion extending radially outward a predetermined distance from an outer surface of the first tubular section or an outer surface of the second tubular section to form an interference fit with the step-shaped opening. The insertion of the valve orifice insert may be stopped at a predetermined depth by the step structure.

At step508, a lip structure of the tubular plastic valve insert and a surface at the orifice structure of the valve assembly are concurrently lapped with a planar lapping tool so as to form a valve sealing surface on the lip structure that is coplanar with the surface at the orifice structure of the valve assembly. The lip structure protrudes axially from a first end of the first tubular section. The lip structure includes a planar valve seat surface formed at a distal end of the lip structure.

The above-described systems and methods may be used to enhance sealing between the orifice and the valve diaphragm, allow the control valve to control to lower flow rates, and extend the effective stroke of the valve by requiring less force to make a seal. As opposed to conventional designs which use a compressive force for sealing with a resin part sandwiched between two metal parts, the present disclosure uses a diametrical interference fit for sealing, resulting in a simpler design with fewer parts. Compared to fits involving a resin part sandwiched between two metal parts, the interference fit also reduces leakage and entrapment of fluids between the valve orifice insert and the orifice structure, which may result in corrosion of the orifice structure and contamination of the fluids flowing within the flow passages of fluid control systems. The compressibility, flexibility, and resilience of the plastic material of the valve orifice insert enhances the interference fit and ensures longevity. The synergistic effect of the two different interference fits ensures that the valve orifice insert resists displacement from the orifice structure more robustly compared to valve designs involving a resin part sandwiched between two metal parts. The coplanarity of the planar valve seat surface with the surface of the orifice structure allows for fine control of the flow of fluid through the orifice structure at a relatively small commanded flow rate. The present disclosure may be applied in many valve designs which regulate fluid flow.

FIG.17schematically shows a non-limiting embodiment of a computing system600that can enact one or more of the processes described above. Computing system600is shown in simplified form. Computing system600may embody the controller138described above and illustrated inFIG.8. Computing system600may take the form of one or more personal computers, server computers, network computing devices, mobile computing devices, mobile communication devices (e.g., smart phone), and/or other computing devices, and custom circuit board assemblies.

Computing system600includes a logic processor602volatile memory604, and a non-volatile storage device606. Computing system600may optionally include a display subsystem608, input subsystem610, communication subsystem612, and/or other components not shown inFIG.8.

Non-volatile storage device606includes one or more physical devices configured to hold instructions executable by the logic processors to implement the methods and processes described herein. When such methods and processes are implemented, the state of non-volatile storage device606may be transformed—e.g., to hold different data.

Volatile memory604may include physical devices that include random access memory. Volatile memory604is typically utilized by logic processor602to temporarily store information during processing of software instructions. It will be appreciated that volatile memory604typically does not continue to store instructions when power is cut to the volatile memory604.

When included, display subsystem608may be used to present a visual representation of data held by non-volatile storage device606. The visual representation may take the form of a graphical user interface (GUI). As the herein described methods and processes change the data held by the non-volatile storage device, and thus transform the state of the non-volatile storage device, the state of display subsystem608may likewise be transformed to visually represent changes in the underlying data. Display subsystem608may include one or more display devices utilizing virtually any type of technology. Such display devices may be combined with logic processor602, volatile memory604, and/or non-volatile storage device606in a shared enclosure, or such display devices may be peripheral display devices.

When included, input subsystem610may comprise or interface with one or more user-input devices such as a keyboard, mouse, or touch screen.

The subject disclosure includes all novel and non-obvious combinations and subcombinations of the various features and techniques disclosed herein. The various features and techniques disclosed herein are not necessarily required of all examples of the subject disclosure. Furthermore, the various features and techniques disclosed herein may define patentable subject matter apart from the disclosed examples and may find utility in other implementations not expressly disclosed herein.

It will be appreciated that “and/or” as used herein refers to the logical disjunction operation, and thus A and/or B has the following truth table.

To the extent that terms “includes,” “including,” “has,” “contains,” and variants thereof are used herein, such terms are intended to be inclusive in a manner similar to the term “comprises” as an open transition word without precluding any additional or other elements.