Patent Publication Number: US-11390088-B2

Title: Printer fluid ports

Description:
BACKGROUND 
     Printers may employ a liquid printing agent to produce an image on a substrate (e.g., a piece of paper). To facilitate the use of such a liquid printing agent, printers may include multiple internal compartments and fluid paths for flowing or transporting the liquid printing agent (e.g., ink) throughout the printer and ultimately to the substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various examples will be described below referring to the following figures: 
         FIG. 1  is a schematic, partial cross-sectional view of a printer including a fluid handling system according to some examples; 
         FIG. 2  is a schematic, partial cross-sectional view of the fluid handling system of  FIG. 1 ; 
         FIG. 3  is a perspective view of a portion of the fluid port of the fluid handling system of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the fluid port of the fluid handling system of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of another fluid port for use within the fluid handling system of  FIG. 1  according to some examples; 
         FIGS. 6 and 7  are progressive enlarged, partial cross-sectional views of the fluid port of the fluid handling system of  FIG. 1  showing the valve member and barrier of the fluid port transitioning between an open and closed position; 
         FIG. 8  is a schematic, partial cross-sectional view of the fluid handling system of  FIG. 1  showing liquid printing agent flowing therethrough; and 
         FIGS. 9-11  are progressive enlarged, partial cross-sectional views of the fluid port of the fluid handling system of  FIG. 1 , with the valve member and barrier of the fluid port being cycled between the open and closed positions to dislodge gas disposed therein. 
     
    
    
     DETAILED DESCRIPTION 
     The following discussion is directed to various examples. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any example is meant to be descriptive of that example, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that example. 
     The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and the details of some elements may not be shown in interest of clarity and conciseness. 
     In the following discussion, and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. As used herein, the terms “about,” “approximately,” “substantially,” and the like mean plus or minus 20% of the stated value or direction. As used herein, the term “computing device” refers to any device (or collection of devices) that are to execute, store, and/or deliver machine readable instructions (such as, for example, software). Thus, the term “computing device” may include, for example, desktop computers, laptop computers, tablet computers, servers, smart phones, smart watches, personal data assistants, etc. 
     In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. 
     As previously described, printers may include multiple internal compartments and fluid paths for flowing or transporting a liquid printing agent (e.g., ink) throughout the printer and ultimately to the substrate (e.g., pieces of paper, a roll of paper, etc.). As the liquid printing agent flows through the compartments and fluid paths within the printer, air or other gases typically flow or migrate counter to the advancing printing agent in order to equalize the pressures within the printer. However, the counter migrating gases (e.g., air) can encounter resistance within the internal fluid paths such that so-called “gas-lock” or “air-lock” can occur, whereby a bubble (or multiple bubbles or a meniscus) of gas blocks the fluid flow path such that the flow of printing agent is stopped (or restricted). Accordingly, the examples disclosed herein provide for gas-liquid exchange fluid ports that allow the counter flow or movement of a liquid printing agent and gases (e.g., air). Thus, through use of the fluid ports described herein, the flow reliability of printing agent throughout a printer is enhanced. In the following description, counter-flowing gases (e.g., gases that flow counter to the liquid printing agent) within a printer are generically referred to as “air”; however, it should be appreciated that any gas may be disposed within the disclosed printers and fluid handling systems. Therefore, use of the term “air” in the following description should not be interpreted as limiting the other potential gases that may exist and flow within the disclosed printers and fluid handling systems during operations. 
     Referring now to  FIG. 1 , a printer  10  including a fluid handling system  100  and a printing mechanism  12  according to some examples is shown. During operations, printer  10  places a printing agent onto a substrate  20  via the printing mechanism  12  (e.g., according to machine readable instructions transmitted from a separate computing device) to form an image on the substrate  20 . In some examples, the printing agent is a liquid printing agent, such as, for example, liquid ink. Thus, in some examples, printer  10  may be an inkjet printer. In addition, in this example, substrate  20  is a piece of paper; however, in other examples substrate  20  may be a paper fed from a roll, or may be some other surface or object capable of receiving a printing agent thereon. Further, printing mechanism  12  may comprise any suitable mechanism or assembly for disposing printing agent onto substrate  20  (e.g., a print head, roller or combination thereof). During printing operations, printing mechanism  12  receives printing agent from fluid handling system  100  and deposits the printing agent onto the substrate  20 . Thus, fluid handling system  100  may operate to store and transport the liquid printing agent as desired within printer  10 . 
     Fluid handling system  100  includes a first compartment  110  and a second compartment  120  fluidly coupled to one another through a fluid port  150 . During operations, printing agent (not shown) is flowed or provided from first compartment  110  to second compartment  120  through fluid port  150 , and then from second compartment  120  to printing mechanism  12 . In this example, first compartment  110  is disposed vertically above second compartment  120 , and thus, printing agent flows from first compartment  110  to second compartment  120 , via fluid port  150 , under the force of gravity. It should be appreciated that other components, fluid compartments, and/or flow passages may be disposed upstream and downstream of fluid handling system  100  within printer  10 , such as between fluid handling system  100  and printing mechanism  12 . 
     Referring now to  FIG. 2 , first compartment  110  includes a wall or housing  112  that defines an inner chamber  113 . A filling port  114  extends into chamber  113  at a vertically upper side of compartment  110 . Port  114  includes a lid or cap  116  that is placed over port  114  to selectively close chamber  113 . In this example, cap  116  sealingly engages with port  114  so that fluids (e.g., air, printing agent, etc.) are prevented from entering and exiting chamber  113  within first compartment  110  via port  114  when cap  116  is closed. In some examples, printing agent is filled into first compartment  110  via port  114 , and thus, in these examples, port  114  is externally accessible from printer  10  (i.e., port  114  extends outside the outer housing of printer  10  or is accessible via an access door or cover on an outer housing of printer  10 ). 
     Second compartment  120  includes a wall or housing  122  that defines an inner chamber  123 . An exit port  124  extends into chamber  123  at a position proximate (or on) the vertically lower side of second compartment  120 . Exit port  124  is fluidly coupled (e.g., either directly or indirectly) to printing mechanism  12 , such that during a printing operation, printing agent is flowed or provided from second compartment  120  to printing mechanism  12  via exit port  124 . In addition, second compartment  120  also includes a vent port  126  extending into chamber  123 . In this example, vent port  126  is disposed at a position proximate (or on) a vertically upper end of second compartment  120 ; however, in other examples vent port  126  may be disposed equidistant between the vertically upper and lower ends of second compartment  120  or may be more proximate vertically lower end of compartment  120 . Vent port  126  is in fluid communication with the environment outside of printer  10  (e.g., the atmosphere), and therefore, the pressure of second compartment  120  is maintained at the pressure of the environment surrounding printer  10  (e.g., atmospheric pressure). 
     While both the first compartment  110  and second compartment  120  are shown to be vertically above (or partially above) printing mechanism  12 , it should be appreciated that the relative placement of fluid handling system  100  and printing mechanism  12  (specifically compartments  110 ,  120 ) may be greatly varied in other examples. For instance, one of the compartments  110 ,  120 , or both of the compartments  110 ,  120  may be placed vertically above, below, or even with printing mechanism  12 . Thus, the depicted arrangement of fluid handling system  100  relative to printing mechanism  12  (and substrate  20 ) in  FIG. 1  is merely schematic and is not meant to limit the relative positions of fluid handling system  100 , printing mechanism  12 , and substrate  20 . 
     Referring still to  FIG. 2 , fluid port  150  extends between the first compartment  110  and the second compartment  120 , and thus places chambers  113 ,  123  in fluid communication with one another. Fluid port  150  includes central axis  155 , a first or upper end  150   a , and a second or lower end  150   b  opposite upper end  150   a . As previously described in this example, first compartment  110  is disposed vertically above second compartment  120 . Thus, fluid port  150  and axis  155  extend substantially vertically through a lower side of first compartment  110  and an upper side of second compartment  120  (i.e., axis  155  extends substantially vertically). However, it should be appreciated that fluid port  150  (particularly axis  155 ) may not extend substantially vertically in other examples. Regardless, in the example of  FIG. 2 , upper end  150   a  of port  150  is disposed within chamber  113  of first compartment  110  while lower end  150   b  of fluid port  150  is disposed within chamber  123  of second compartment  120 . 
     Referring now to  FIGS. 2 and 3 , fluid port  150  includes a radially inner surface  154  extending between ends  150   a ,  150   b , and a radially outer surface  153  also extending between ends  150   a ,  150   b . Radially inner surface  154  may be referred to herein as inner wall  154  and radially outer surface  153  may be referred to herein as outer wall  153 . Inner wall  154  defines an internal passage or throughbore  151  extending between ends  150   a ,  150   b . Ends  150   a ,  150   b  are both open, thereby allowing fluid communication between throughbore  151  and chambers  113 ,  123 , via ends  150   a ,  150   b , respectively. 
     A recess  157  extends axially from lower end  150   b  of fluid port  150  that also extends radially between inner wall  154  and outer wall  153  (recess  157  is best shown in  FIG. 3 ). Accordingly, recess  157  represents an arcuate hole or aperture that is in fluid port  150  within chamber  123  of second compartment  120 , and throughbore  151  is in fluid communication with chamber  123  of second compartment  120  via lower end  150   b  and recess  157  (see  FIGS. 2 and 3 ). 
     As best shown in  FIG. 2 , in this example, both inner wall  154  and outer wall  153  taper radially outward or away from central axis  155  when moving from lower end  150   b  to upper end  150   a  (i.e., when moving from second compartment  120  to first compartment  110 ). In this example, both inner wall  154  and outer wall  153  are tapered relative to central axis  155  at an angle θ, that may be a positive angle (i.e., greater than 0°). In some examples, the angle θ is greater than or equal to about 1°, and in other examples, the angle θ ranges from about 1° to about 10°. In some examples, the angle θ equals approximately 2°. In some examples, inner wall  154  is tapered along angle θ, while outer wall  153  extends substantially axially between ends  150   a ,  150   b . In still other examples, inner wall  154  and outer wall  153  are tapered at different angles. 
     Referring still to  FIGS. 2 and 3 , a barrier  160  is disposed within throughbore  151  of fluid port  150 . In this example, barrier  160  extends axially within throughbore  151  to thereby separate throughbore  151  into a first channel  156  and a second channel  158 . Channels  156 ,  158  each extend axially between open ends  150   a ,  150   b  of fluid port  150 , and thus define independent flow paths for fluids (e.g., printing agent, air, etc.) through port  150  between chambers  113 ,  123  of compartments  110 ,  120 , respectively. Open upper end  150   a  of fluid port  150  defines an entrance (which may be an inlet or outlet depending on the direction of fluid flow) into each channel  156 ,  158  within chamber  113  of first compartment  110 . Lower end  150   b  of fluid port  150  defines another entrance into channel  158  (which again may be an inlet or an outlet depending on the direction of fluid flow) within chamber  123  of second compartment  120 . Further, both lower end  150   b  of fluid port  150  and recess  157  define an entrance into channel  156  within chamber  123  of second compartment  120  (which may be an inlet or outlet depending on the direction of fluid flow). 
     Referring now to  FIGS. 4 and 5 , barrier  160  may comprise a number of different forms or shapes within fluid port  150  in various examples. Referring specifically to  FIG. 4 , in this example, barrier  160  is rectangular in cross-section and extends substantially radially across throughbore  151 . In other examples, the shape of barrier  160  may be different than that shown in  FIG. 4 . For example, referring to  FIG. 5 , in some examples barrier  160  may have a chevron-type cross-section. In still other examples, barrier  160  may have a curved cross-section. Without being limited to this or any other theory, the shape of barrier  160  affects the relative cross-sectional division of throughbore  151  between channels  156 ,  158 . Thus, the size, shape, cross-section, etc., of barrier  160  may be altered to provide the desired division of this cross-sectional area between channels  156 ,  158 . In addition, the materials making up barrier  160  as well as the rest of fluid port  150  (and even compartments  110 ,  120 ) may be selected (in combination with the other physical parameters discussed above) to achieve a maximum flow rate (e.g., through port  150 ) and/or reliability during operations. 
     Referring back again to  FIG. 2 , barrier  160  has a first or upper end  160   a , and a second or lower end  160   b  opposite upper end  160   a . Upper end  160   a  is coupled to a valve member  170  that may selectively, sealingly engage with a valve seat  152  defined at upper end  150   a  of fluid port  150 . Valve member  170  is coupled to a lever assembly  172 . As will be described in more detail below, valve member  170  is movable within chamber  113  of first compartment  110  by actuation or manipulation of lever assembly  172 . Thus, actuation of valve member  170  via lever assembly  172  provides for selective fluid communication between chambers  113 ,  123  of compartments  110 ,  120 , respectively, via channels  156 ,  158  of fluid port  150  during operations. In addition, as will also be described in more detail below, actuation of valve member  170  within chamber  113  also causes axial actuation of barrier  160  within throughbore  151 . 
     Referring now to  FIGS. 6 and 7 , in this example, barrier  160  and valve member  170  are axially transitionable or actuatable via actuation or manipulation of lever assembly  172  between a first position shown in  FIG. 6  and a second position shown in  FIG. 7 . In the first position of  FIG. 6 , valve member  170  is engaged (e.g., sealingly engaged) with valve seat  152 , and lower end  160   b  of barrier  160  is disposed within throughbore  151  proximate to or aligned with lower end  150   b  of fluid port  150 . In the second position of  FIG. 7 , valve member  170  is disengaged from and axially separated from valve seat  152  and barrier  160  is axially shifted or translated upward from the first position (see  FIG. 6 ). Thus, lower end  160   b  of barrier  160  is more proximate lower end  150   b  of fluid port  150  when barrier  160  is in the first position of  FIG. 6  than when barrier  160  is in the second position of  FIG. 7 . 
     As previously described, when valve member  170  and barrier  160  are in the first position ( FIG. 6 ), valve member  170  may be sealingly engaged with valve seat  152 , and when valve member  170  and barrier  160  are in the second position ( FIG. 7 ), valve member  170  is axially spaced from valve seat  152 . Accordingly, when valve member  170  and barrier  160  are in the first position of  FIG. 6 , fluid communication is prevented (or restricted) from flowing between throughbore  151  (and thus channels  156 ,  158 ) and chamber  113  via upper end  150   a  of fluid port  150 , and when valve member  170  and barrier  160  are in the second position of  FIG. 7 , fluid communication is established between throughbore  151  (and thus channels  156 ,  158 ) and chamber  113  via upper end  150   a  of fluid port  150 . Thus, the first position of  FIG. 6  may be referred to herein as a “closed” position, and the second position of  FIG. 7  may be referred to herein as an “open” position. 
     Lever assembly  172  may be actuated via any suitable method to transition valve member  170  and barrier  160  between the open and closed positions of  FIGS. 7 and 6 , respectively. For instance, in some implementations, lever assembly  172  may be actuated directly by a user engaging with a distal end of lever assembly  172  that extends outside of an outer housing of printer  10  (see e.g.,  FIG. 1 ). In other implementations, the actuation of lever assembly  172 , and thus valve member  170  and barrier  160  is tied or coupled (e.g., mechanically, electrically) to the opening and closing of cap  116  on port  114 . In these implementations, a user may open cap  116  to refill first compartment  110 , and the opening of cap  116  may cause (e.g., again via mechanical linkage and/or electrical actuation) lever assembly  172  to actuate valve member  170  and barrier  160  to the closed position of  FIG. 6 , thereby preventing the flow of printing agent from the first compartment  110  to the second compartment  120 . Conversely, in these examples when the cap  116  is again closed (e.g., such as at the completion of filing chamber  113  of first compartment  110 ), the lever assembly  172  is actuated (via the mechanical linkage or electronic actuation previously described above) to transition valve member  170  and barrier  160  to the open position of  FIG. 7  and once again establish fluid communication between compartments  110 ,  120  via fluid port  150 . 
     Referring now to  FIGS. 2 and 8 , during operations, liquid printing agent  180  is placed within chamber  113  of first compartment  110  via filling port  114 . Thereafter, cap  116  is closed and valve member  170  and barrier  160  are actuated via lever assembly  172  to the open position (see e.g.,  FIG. 7 ), such that the printing agent  180  begins to flow from chamber  113 , through channels  156 ,  158  of fluid port  150 , and into chamber  123  of second compartment  120 . As a result, the liquid level  121  of printing agent  180  within chamber  123  of second compartment  120  begins to rise and air  174  that is present within chamber  123  (e.g., air that is communicated into chamber  123  via vent port  126 ) is allowed to flow or bubble through channel  156 , via recess  157  and into chamber  113  of first compartment  110 . The air  174  entering chamber  113  from channel  156  collects at the upper end of chamber  113 , thereby displacing printing agent  180  as it is drained into chamber  123  of second compartment  120 . 
     Because cap  116  is closed, and fluids are therefore prevented from entering chamber  113  via port  114 , the flow of printing agent  180  out of chamber  113  via port  150  reduces the air pressure within chamber  113  relative to the air pressure within chamber  123  (which is in communication with the outer environment or atmosphere via port  126  as previously described above). However, without being limited to this or any other theory, because the entrance (or exit) into channel  156  is vertically higher than the entrance (or exit) into channel  158  within chamber  123 , a difference in head pressure for the liquid printing agent  180  is formed within port  150  between channels  156 ,  158  that encourages the flow of printing agent  180  into chamber  123  via channel  158 , and the counter flow of air into chamber  113  via channel  156 . Thus, fluid port  150  serves as an air-liquid exchange port between the chambers  113 ,  123  that vents air displaced from second compartment  120  by the liquid printing agent  180  entering chamber  123  via fluid port  150  (specifically channel  158 ), thereby ensuring a reliable flow of liquid printing agent  180  between chambers  113 ,  123  during operations. Accordingly, first channel  156  may be referred to herein as an air channel and second channel  158  may be referred to herein as a liquid channel. 
     In some examples, the fluid flow rates between chambers  113 ,  123  may be relatively slow. As a result, rather than a continuous stream of bubbles  174  emitting from channel  156 , a meniscus  176  may form within channel  156  proximate upper end  150   a  of port  150 . Accordingly, as printing agent  180  slowly flows (e.g., seeps) through channel  158  into chamber  123 , the meniscus  176  periodically erupts or bursts into a group of air bubbles  174  that migrate upward within chamber  113 . 
     While air  174  is typically encouraged to flow through channel  156  into chamber  113  of first compartment  110  due to, for example, the relatively larger (and vertically higher) opening or inlet into channel  156  provided by recess  157  as previously described, it should be appreciated that liquid printing agent  180  and air  174  may periodically flow through either channel  156 ,  158  during operations, based on a variety of factors. Specifically, in some examples, air  174  may also migrate or flow into chamber  113  through liquid channel  158  and printing agent  180  may flow into chamber  123  through air channel  156  during operations. 
     Referring still to  FIGS. 2 and 8 , the flow of printing agent  180  between chambers  113 ,  123  via fluid port  150  may continue until liquid level  121  within chamber  123  reaches an upper limit. For example, in some implementations, the upper limit for liquid level  121  may be located at the upper end of recess  157 . 
     However, the design of fluid handling system  100  may be altered in other examples to change the location of the upper limit of liquid level  121  within chamber  123 . 
     Referring now to  FIGS. 9-11 , during operations as the liquid printing agent  180  flows through fluid port  150  between chambers  113 ,  123 , air may become lodged within channel  156  and/or channel  158  (see e.g., the meniscus  176  of air disposed within channel  156  in  FIG. 9 ). In some cases, the air (or other gases) lodged within channel  156  may prevent or restrict the continued flow of liquid printing agent  180  through fluid port  150 , such that flow through fluid port  150  may be come air-locked. According to some examples disclosed herein, a user may actuate barrier  160  and valve member  170  between the open position and closed position (see e.g.,  FIGS. 7 and 6 , respectively) to encourage the flow of air from channel  156  and/or channel  158 . 
     In particular, as shown in  FIG. 9 , a meniscus  176  of air is lodged within channel  156  and is blocking further air flow through channel  156  from chamber  123  into chamber  113  so that the flow rate of liquid printing agent  180  through channel  158  from chamber  113  to chamber  123  may be restricted (or ceased entirely). In this example, meniscus  176  is lodged within channel  156  below upper end  150   a  of fluid port  150 . Accordingly, as shown in  FIG. 10 , a user (or a computing device) may actuate lever assembly  172  so that valve member  170  and barrier  160  are actuated from the open position (see  FIGS. 9-10 ) to the closed position (see  FIG. 10 ), and then from the closed position back to the open position (see  FIGS. 10-11 ). The axial movement of barrier  160  within fluid port  150 , as valve member  170  and barrier  160  are transitioned or cycled between the open and closed positions as shown in  FIGS. 9-11 , causes barrier  160  to shear meniscus  176 , which thereby encourages upward progress of the air through channel  156  and into chamber  113  of first compartment  110 . Thereafter, normal air-liquid exchange through channels  156 ,  158  of fluid port  150  may resume so that liquid printing agent  180  progresses from chamber  113  to chamber  123  as previously described above. 
     In some examples, the cycling or movement of valve member  170  and barrier  160  may be altered while still achieving the same shearing function discussed above. For example, in some implementations, valve member  170  and barrier  160  may be further axially translated upward from the open position shown in  FIG. 9  (rather than first translating the valve member  170  and barrier  160  to the closed position first as shown in  FIGS. 9-10 ). This additional axially upward movement of valve member  170  and barrier  160  results in the same shearing action discussed above so that meniscus  176  is encouraged to progress upward through channel  156  into chamber  113  in substantially the same manner as previously described. 
     Referring again to  FIGS. 2 and 8 , in addition to the axial movement of barrier  160 , the tapered inner wall  154  of fluid port  150  may also provide additional flow assurance for air through channel  156  (and/or channel  158 ) during operations. In particular, because inner wall  154  tapers radially outward from axis  155  when moving axially from lower end  150   b  toward upper end  150   a  of fluid port  150 , the cross-sectional area of channels  156 ,  158  become progressively larger when moving axially from lower end  150   b  toward upper end  150   a  (i.e., when moving from second compartment  120  toward first compartment  110 ). 
     Accordingly, for a bubble or meniscus that fills the entire channel  156  and/or channel  158  (e.g., such as meniscus  176  shown in  FIG. 9 ), continued progression of the air axially upward toward upper end  150   a  of fluid port  150  results in progressively more space for the meniscus  176 . Without being limited to this or any other theory, this progressively increasing space may also cause a progressive reduction in any distortion (e.g., axial elongation) of the bubble or meniscus so that the overall surface area thereof decreases during axial progression upward toward upper end  150   a . The reduced fluid pressure associated with decreasing depth of the air may also contribute to the progressively reduced surface area of the bubble or meniscus during axially upward progression as well. The progressive reduction in surface area further reduces contact between the air, inner wall  154 , and barrier  160  so that less and less resistance is applied to the air as it continues axially upward flow into chamber  113 . As a result, the overall progression of the air (e.g., bubbles, a meniscus, etc.) toward chamber  113  of first compartment  110  is encouraged and facilitated by the shape of fluid port  150  (particularly the tapered inner wall  154 ). 
     The examples disclosed herein have provided gas-liquid exchange fluid ports (e.g., fluid port  150 ) that allow the free counter flow or movement of liquid printing agent and gases (e.g., air). Thus, through use of the fluid ports described herein, the flow reliability of printing agent throughout a printer is enhanced so that printing agent (e.g., liquid printing agent) is reliably flowed through the printer to the printing mechanism (e.g., printing mechanism  12 ) during printing operations. 
     While the examples specifically depicted herein include a valve member  170  within chamber  113  of first compartment  110 , it should be appreciated that other examples may place valve member  170  (or a similar valve member) within chamber  123  of second compartment  120 . During operations, the actuation of valve member  170  within port provides substantially the same functionality discussed above, except that the actuation of valve member  170  occurs within chamber  123  rather than chamber  113 . 
     While various examples have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The examples described herein are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the examples described herein. The scope of the claims that follow shall include all equivalents of the subject matter of the claims.