Abstract:
A debris trap for use in a gas valve fitting is provided. The debris trap comprises an elongated body extending about a first axis. The elongated body forms a passage therein extending along the first axis between an inlet formed in a first end of the elongated body and at least one outlet formed in the elongated body. The at least one outlet is formed in a side wall of the elongated body to provide fluid communication with the passage about a second axis perpendicular to the first axis.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to adjustable seat gas valves for use in appliances, and more particularly, to adjustable seat poppet gas valves for use in appliances. 
     BACKGROUND OF THE INVENTION 
     Many household appliances, particularly ranges, water heaters and dryers, burn natural gas or liquid petroleum (“LP”) (natural gas and LP will be hereinafter referred to generally as “gas”) to create heat energy. The appliances require a flow regulating valve to control the gas flow from a gas supply to a burner. One such flow regulating valve is a poppet valve. 
     A poppet valve has a seat that includes a gas passage and a sealing device such as a rubber poppet connected to an actuating arm. The poppet valve functions by selectively moving the rubber poppet toward or away from the seat by selectively actuating the arm connected to the rubber poppet. Particularly, the rubber poppet is moved away from the seat to increase the size of the flow passage or “open” the valve to increase the gas flow rate. The rubber poppet is moved toward the seat to decrease the size of the flow passage or to “close” the valve to decrease or terminate the gas flow rate. The amount of travel by the arm away from the seat determines the distance between the rubber poppet and the seat and the size of the flow passage that is created. To completely stop the gas flow, the rubber poppet is pressed against the seat to completely seal the gas flow passage. 
     Typically, the arm must be actuated to open the valve. To provide for fail safe operation, the arm is typically spring loaded such that it will automatically close when the arm is not being actuated. This configuration is preferred because if the action mechanism fails it is preferred to have the valve fail in the “closed” position. 
     The seat is typically a metallic material and the rubber poppet is typically a resilient material such as rubber, plastic or nylon that allows for good sealing contact with the metal seat. 
     The seat is typically threaded into a metal fitting that is attached to the body of the valve. By being threaded into the fitting, the valve may be adjusted by screwing the seat towards or away from the sealing disc of the poppet. This adjustable configuration is typically referred to as an adjustable seat valve. The metal fitting further includes threads for attaching the gas valve to a gas line having a corresponding fitting. 
     One problem with the current design of the adjustable seat valve is that when a metal fitting of the gas line is threaded to the metal fitting of the gas valve, the sliding contact between the two fittings forms tiny metal particulates and shavings. Further, when the seat is adjusted, the interaction between the seat and the tool used to adjust the seat may create metal particulates and shavings as well. 
     To prevent such particulates and shavings from falling into the valve, a wire mesh screen is typically employed above the sealing surface of the valve. Unfortunately, while such a screen is effective to block particles greater than 0.010″, particulates and shavings smaller than this are able to fall through the screen and the gas flow passage of the seat and land on the rubber poppet. Over time, this debris may prematurely deteriorate the sealing disc of the poppet thereby decreasing the seal that can be formed between the rubber poppet and the seat. Particulates from 0.001″ to 0.010″ are identified to cause such leaks. Unfortunately, providing increased filtering of such particulates would unacceptably reduce the BTU flow rate and pressure drop through the valve. 
     Therefore, a device that would prevent the metal particulate or shavings from falling through the gas flow passage and onto the rubber poppet to prevent deterioration of the seal without unacceptably reducing the BTU flow rate and the pressure drop through the valve would be desirable. The invention provides such a device. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect, the invention provides a debris trap for use in gas valve fittings. The debris trap comprises an elongated body extending about a first axis. The elongated body forming a passage therein extending along the first axis between an inlet formed in a first end of the elongated body and at least one outlet formed in the elongated body. The at least one outlet is formed in a side wall of the elongated body to provide fluid communication with the passage about a second axis perpendicular to the first axis. 
     In another aspect, the invention provides a debris trap for a gas valve. The debris trap comprises a fitting body defining a first passage therethrough having an inlet adapted to couple to the gas valve and an outlet adapted to mate with an external gas fitting. The debris trap further comprising an adjustable seat positioned at least partially within the fitting body at the inlet and an elongated body positioned at least partially within the fitting body at the outlet. The elongated body forms a second passage therein between a first end of the elongated body and at least one gas outlet formed in a side wall of the elongated body. The elongated body has a closed end distally positioned from the first end. The outer diameter of the elongated body and an inner diameter of the outlet of the fitting body form a debris trapping channel therebetween. 
     In yet another aspect, the invention provides a debris trap for use in gas valve fittings. The debris trap comprises an elongated body extending about a first axis. The elongated body forming a passage therein extending along the first axis between an inlet formed in a first end of the elongated body. A cap is formed at a second end of the elongated body. The elongated body further forms at least one outlet in a side wall of the elongated body to provide fluid communication with the passage. 
     Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
         FIG. 1  is a top view of an exemplary embodiment of a gas valve constructed in accordance with the teachings of the present invention; 
         FIG. 2  is a cross-sectional illustration of the gas valve of  FIG. 1  about line  2 - 2  better illustrating the gas valve outlet fitting constructed in accordance with the teachings of the present invention; 
         FIG. 3  is an enlarged partial illustration of the outlet fitting in  FIG. 2  in a closed position; 
         FIG. 4  is an enlarged partial illustration of the outlet fitting in  FIG. 2  in an open position; 
         FIG. 5  is a perspective illustration of a further embodiment of a debris trap in accordance with the present invention having an annular channel in a radially extending flange; 
         FIG. 6  is a cross-sectional illustration of the debris trap of  FIG. 5 ; 
         FIG. 7  is a perspective illustration of a further embodiment of a debris trap in accordance with the present invention having rectangular shaped apertures; 
         FIG. 8  is a cross-sectional illustration of the debris trap of  FIG. 7 ; 
         FIG. 9  is a cross-sectional illustration of a further embodiment of an adjustable seat constructed in accordance with the present invention wherein the debris trap is integrally formed with the adjustable seat; 
         FIG. 10  is a perspective illustration of the adjustable seat of the  FIG. 9 ; 
         FIG. 11  is a perspective illustration of a further embodiment of an adjustable seat constructed in accordance with the present invention wherein the debris trap is integrally formed with the adjustable seat; 
         FIG. 12  is a cross-sectional illustration of the adjustable seat of  FIG. 11 ; 
         FIG. 13  is a cross-sectional illustration of a further embodiment of a seat and a debris trap constructed in accordance with the present invention wherein the debris trap is press-fit connected to the seat; and 
         FIG. 14  is a perspective illustration of the debris trap in  FIG. 13  illustrating the ribs for improving the press fit connection between the debris trap and seat. 
     
    
    
     While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a gas valve  10  according to one embodiment of the present invention is disclosed. The gas valve  10  generally includes a valve body  12 , a lid or cover  14 , an inlet fitting  16 , an outlet fitting  18 , a secondary bypass outlet fitting  20 , a pair of electric terminals  22 ,  24  and a mounting bracket  26 . The inlet fitting  16  is the gas inlet from the gas supply line for the gas valve  10  and the outlet fittings  18 ,  20  are the gas outlets that may be connected to the appliance&#39;s burners, etc. for the gas valve  10 . 
     As shown in  FIG. 2 , the gas valve  10  defines a chamber  28  defined between the valve body  12  and the lid  14 . The lid  14  is sealingly attached to the valve body  12 , e.g., by rolled edges  30 ,  32  of the valve body  12 . A poppet valve assembly  40  is secured to the interior side  42  of the lid  14 . The poppet valve assembly  40  generally includes actuating means  44 , an extension arm  46 , and a poppet  48 . The actuating means  44  actuates the extension arm  46  to selectively move the poppet  48  upward (towards the lid  14 ) or downward (away from the lid  14 ) in the orientation illustrated in  FIG. 2 . 
     In this embodiment, the actuating means  44  includes a bimetallic strip  50 . Particularly, a portion of the extension arm  46  at a first end  51  includes the bimetallic strip  50  which is surrounded by a heating coil  52 . The heating coil  52 , which is connected to terminals  22 ,  24  ( FIG. 1 ), is used to selectively heat the bimetallic strip  50  to cause the bimetallic strip  50  to bend and thereby selectively actuate the poppet  48  to move it in a downward direction, as oriented in  FIG. 2 , and open the valve  10 , as shown in  FIG. 4 . When the bimetallic strip  50  cools, the bimetallic strip  50  straightens and actuates the poppet  48  in an upward direction to close the valve  10 . 
     As best shown in  FIG. 3  (with the poppet  48  in the closed position) and  FIG. 4  (with the poppet  48  in the open position), the poppet  48  is attached to a second end  53  of the extension arm  46  and interacts with an adjustable seat  54  connected to and partially located in the outlet fitting  18 . The poppet  48  is generally made from any rubber, plastic, nylon or other material that is impervious to gas and forms good sealing contact with metal or plastic. The adjustable seat  54  is generally made from any plastic or metal that is impervious to and immune to gas. The interaction between the adjustable seat  54  and the poppet  48  controls the flow of gas through the gas valve  10 . 
     Particularly, a top surface  56  of the poppet  48  interacts with a bottom surface  58  of an annular shoulder portion  60  of the adjustable seat  54 . The top surface  56  of the poppet  48  is pressed vertically upward against the bottom surface  58  of the annular shoulder portion  60  to create a seal and prevent gas from flowing through passage  62  in the adjustable seat  54 . As is illustrated in  FIG. 3 , the rubber poppet  48  deforms to some extent as it is pressed against the adjustable seat  54 . In this condition, the valve  10  is in a “closed” position. To move the valve to an “open” position, the rubber poppet  48  is moved vertically downward (in the orientation of  FIGS. 3 and 4 ) and away from the adjustable seat  54 , as illustrated by arrow  170  in  FIG. 4 . This condition allows gas to flow through the passage  62  of the adjustable seat  54  and the outlet fitting  18 , as illustrated by arrows  172 . 
     Referring again to  FIG. 3 , the adjustable seat  54  includes threads  68  that cooperate with threads  70  of the outlet fitting  18  to threadedly and adjustably connect the adjustable seat  54  to and at least partially within the outlet fitting  18 . The adjustable seat  54  and outlet fitting  18  are positioned coaxial along central axis  72 . The adjustable seat  54  may be selectively adjusted by axially positioning the adjustable seat  54  within the outlet fitting  18 , thereby calibrating the gas valve  10 , as will be more fully explained below. The adjustable seat  54  further includes an annular groove  78  that carries an o-ring  80  which interacts with an inner surface  81  of the outlet fitting  18  to seal the adjustable seat  54  within the outlet fitting  18 . 
     The adjustable seat  54  requires structure for a tool (not shown) to thread the adjustable seat  54  within the outlet fitting  18 . In an embodiment of the present invention, the interior surfaces  76  of a top portion of the passage  62  define a hexagonally shaped passage. Thus, a tool having a hexagonal shape can be inserted into the hexagonally shaped passage to engage the adjustable seat  54  to enable calibration thereof. 
     Referring to  FIG. 4 , if the gas valve  10  is allowing too much gas to flow through the gas valve  10  when the valve  10  is opened, the gap between the adjustable seat  54  and the top surface  56  of the rubber poppet  48  is too large. Thus, the gas valve must be calibrated by threading the adjustable seat  54  axially/vertically downward towards the top surface  56  of the rubber poppet  48  to reduce the gap between the top surface  56  of the rubber poppet  48  and the adjustable seat  54 . This will restrict the flow of gas through the gas valve  10  to a desired setting. Likewise, if an insufficient amount of gas is flowing through the gas valve  10  when in the open position, the valve can be calibrated in the opposite manner by selectively threading the adjustable seat  54  axially/vertically upward and away from the top surface  56  of the rubber poppet  48  to increase the gap therebetween. 
     In an embodiment of the present invention as illustrated in  FIGS. 3 and 4 , a debris trap  82  is located within the outlet fitting  18 . The debris trap  82  is preferably positioned vertically above the adjustable seat  54  as well as coaxial with the adjustable seat  54  and outlet fitting  18 . In an embodiment, the debris trap  82  is generally cylindrical in shape and defines a passage  83  therein. However, it is contemplated that the debris trap  82  could take any shape such that it may be secured within the outlet fitting  18  and it does not require a round cross-section. Furthermore, the debris trap may be manufactured from any plastic, nylon, rubber, metal or other material that is appropriate in a gas environment. 
     The debris trap  82  includes an annular flange  84  at a bottom end  86  and a cap  88  at a second end  90 . The cap  88  prevents contaminates from falling vertically downward through the passage  62  of the adjustable seat  54 . To allow gas to flow through the debris trap  82 , because the second end  90  of the debris trap  82  and the passage  83  it defines is closed by the cap  88  to axial flow of gas, a plurality of apertures  92  located generally at the second end  90  extend horizontally through a sidewall  94  of the debris trap  82 . In an embodiment, these apertures are oval in shape. However, it is contemplated that these apertures could take any shape that that allows gas to flow therethrough (see  FIGS. 5 and 7 ). Furthermore, the apertures  92  are axially spaced above the annular flange  84  a sufficient distance to define an annular debris catching channel  96  between an outer surface  98  of the sidewall  94  and an inner surface  100  of the outlet fitting  18  and above the annular flange  84 . 
     The annular flange  84  at the bottom end  86  of the debris trap  82  secures the debris trap  82  within the outlet fitting  18 . In one embodiment, the outer diameter of the annular flange  84  is approximately equal to or slightly larger than the inner diameter of the outlet fitting  18  wherein the debris trap  82  is positioned. In this embodiment, the debris trap  82  is secured within the outlet fitting  18  by a friction fit whereby the interior of the outlet fitting  18  resiliently compresses the flange  84 . Alternatively, the outer surface of the debris trap  82  could be threadedly connected to the outlet fitting  18 . In a further alternative embodiment, the debris trap  82  could be secured within the main outlet fitting  18  using a sealant or adhesive. 
     A further embodiment of the present invention does not require a flange on the debris trap. In this embodiment, the debris catching channel  96  would still be formed between an outer surface  98  of the sidewall  94  and an inner surface  100  of the outlet fitting  18 , but the bottom of the debris catching channel would be a radially inward projecting shoulder defined by the outlet fitting  18 . The embodiment that does not include a flange may be mounted within the outlet fitting by any of the means explained previously such as, but without limitation, by adhesive, threading, friction fit and the like. 
     In the illustrated embodiment of  FIG. 3 , the main outlet fitting  18  includes an internally threaded portion  106  at a top end  108  defining a female portion of a coupling (not shown). A male threaded portion of an orifice, a threaded tube or a locking collar for a double folded tube can be threaded into the threaded portion  106  to connect the gas valve  10  to a burner or orifice (not shown). The main outlet fitting  18  typically has an outer periphery  110  (see also  FIG. 1 ) that is hexagonal in shape. This allows a wrench to be secured to the outlet fitting  18  when tightening the tubing, orifice, or the like to the outlet fitting  18 . One of skill in the art will appreciate that the outer periphery  110  is also not limited in shape. 
     Alternative embodiments of debris traps according to the present invention are illustrated in  FIGS. 5-8 . The debris trap  120  illustrated in  FIGS. 5 and 6  is similar to the previously disclosed embodiment. However, the annular flange  122  in this embodiment includes an annular groove  124  defined in the annular flange  122 . This groove  124  further facilitates trapping debris as will be discussed more fully below. 
     In another embodiment of the debris trap  128 , illustrated in  FIGS. 7 and 8 , the debris trap  128  is also similar to the previously disclosed embodiments. However, this debris trap  128  includes rectangular shaped apertures  130  defined in the cylindrical side wall  132  of the debris trap  128 . 
     A further embodiment of an adjustable seat  138  constructed in accordance with the teachings of the present invention is illustrated in  FIGS. 9 and 10 . In this embodiment the adjustable seat  138  incorporates the debris trap  82  and adjustable seat  54  of the previous embodiments into a unitary body. As best illustrated in  FIG. 9 , the adjustable seat  138  does not terminate axially at threads  140 . Instead, the adjustable seat includes an upper portion  142  that extends axially beyond and vertically above the threads  140  that connect the adjustable seat  138  to the main outlet fitting  144 . In this embodiment, the upper portion  142  and the adjustable seat  138  are cylindrical. However, it will be appreciated by one of skill in the art that the adjustable seat  138  and upper portion  142  may take other shapes and profiles. Particularly, the adjustable seat and upper portion will be configured to be inserted into the outlet fitting  144 . 
     As illustrated, the upper portion  142  has a smaller outside diameter than the inside diameter of an axially corresponding portion of the main outlet fitting  144 . In this embodiment, rather than having a separate debris trap component to define a debris trapping channel, an annular debris trapping channel  146  is defined between an inner surface  148  of the main outlet fitting  144  and an outer surface  150  of the upper portion  142 . It will be appreciated from the foregoing that in an embodiment the debris trap and outlet fitting may be formed from an unitary body. 
     Like the debris trap in the previous embodiments, the adjustable seat  138  of the present embodiment includes a passage  152  through which the gas flows. Further, the passage  152  is capped at the end by a cap  154  that prevents gas from exiting the adjustable seat  138  in an axial direction. However, in this embodiment the cap  154  includes the means for a tool (not shown) to engage the adjustable seat  138  to calibrate the adjustable seat  138  as explained previously. In the embodiment of  FIGS. 9 and 10 , the cap  154  includes a cavity  156  having a hexagonal interior shape such that a hexagonally shaped tool, such as an allen wrench or the like, may engage the adjustable seat  138  for calibration. It is contemplated that the means for engaging the tool could be any shape. A further embodiment of an adjustable seat  157 , shown in  FIGS. 11 and 12 , includes a slot  159  for receipt of a flat bladed screwdriver or the like. However, as just stated, this slot could be of different configurations, e.g., crossed to accommodate a Phillips head screwdriver, etc. 
     Returning to  FIG. 9 , the passage  152  includes a cap  154  on the end of the cylindrical portion  142  that prevents gas from exiting the adjustable seat  138  in an axial direction, a plurality of apertures  158  extend through the side wall  160  of the cylindrical portion  142  to allow gas to exit the adjustable seat  138  by flowing radially outward through the sidewall  160 . Again, it is contemplated that the apertures  158  may be any shape sufficient to allow gas to flow therethrough. 
     The adjustable seat  138  of the present invention may also include a screen  164  adapted to prevent larger particles and contaminate from falling through the adjustable seat  138  and onto the poppet  48 . It is preferable that the screen  164  is substantially conical in shape such that the particulate it traps falls to the edges of the screen  164  to minimize or reduce the blockage thereof. 
     In an embodiment, as illustrated in  FIG. 9 , the outlet fitting  144  is a male fitting such that it is externally threaded rather than internally threaded as in the previous embodiments. The fitting  144  threadedly couples with a female fitting  166 . 
       FIG. 13  illustrates another embodiment of an adjustable seat and debris trap in accordance with the present invention. In this embodiment, the debris trap  180  and seat  182  are separate components. In one embodiment, the debris trap  180  is press fit secured to the seat  182 . Specifically, a male coupling portion  184  of the debris trap  180  is press-fit into a corresponding female coupling portion  186  of the seat  182 . To increase the press-fit connection between the debris trap  180  and the seat  1   82 , the outer surface  1   87  of an embodiment of the male coupling portion  184  of the debris trap  180  includes a plurality of ribs  188  (see  FIG. 14 ). These ribs  188  deflect and/or compress when the male coupling portion  184  is pressed into the female coupling portion  186  to increase the connection therebetween. Furthermore, these ribs  188  may be positioned on the inside of the female coupling portion  186 . To assist insertion, the male and female coupling portions  184  and  186  may be chamfered. It will be appreciated that the debris trap  180  may be secured to the seat  182  in numerous ways including snap fit, threading and the like. The invention is not, therefore, limited to only a press fit connection between the debris trap  180  and the seat  182 . 
     Returning to  FIG. 13 , at an end opposite the male coupling portion  184 , the debris trap  180  includes a cavity  190  for an adjustment tool (not shown) to engage while adjusting the gas valve  10 . The cavity  190  may take any shape sufficient for engagement by the tool, as explained and illustrated previously. The debris trap  180  includes an externally threaded portion  192  for threadedly securing the debris trap  180  within the main outlet fitting  193 . The threaded portion  192  further functions to allow for adjustment and calibration of the gas valve  10 , as explained previously. A plurality of apertures  194  extend through a side wall  196  of the debris trap  180  and allow gas to pass through the debris trap  180 . 
     Similar to the embodiment illustrated in  FIGS. 9-12 , an annular debris trapping channel  198  is defined between an inner surface  200  of the main outlet fitting  193  and an outer surface  202  of the debris trap  180 . This annular debris trapping channel  198  is axially positioned between the plurality of apertures  194  and the threaded portion  192 . 
     The seat  182  of this embodiment functions similarly to the adjustable seat  54  in the embodiments illustrated in  FIGS. 2-4  and explained previously. However, to threadedly adjust and calibrate the gas valve  10  by adjusting the seat  1   82  relative to the rubber poppet  48 , the debris trap  180 , to which the seat  182  is secured, must be threadedly adjusted relative to the main outlet fitting  193 . An o-ring  204  creates a seal between the seat  182  and the main outlet fitting  193 . 
     This embodiment is beneficial because the structurally more complex and more difficult component to manufacture, the debris trap  180 , may be manufactured from a more moldable material such as nylon or plastic. Furthermore, the structurally less complex component that none-the-less requires high, if not higher, tolerances, the seat  182 , may be manufactured from another material, such as a metal, e.g. aluminum. 
     In operation, the gas valve  10  ( FIGS. 1 and 2 ) regulates and controls the volume and flow of gas supplied to an appliance. Particularly, the gas valve  10  uses a poppet valve assembly  40  having a poppet  48  that cooperates with an adjustable seat  54  to control the flow of gas through the gas valve  10 . The extension arm  46  of the poppet valve  40  is actuated by passing electrical current through the heating coils  52  surrounding a bimetallic strip  50  which incorporates two metals that expand at different rates when heated that is attached to the extension arm  46 . As the bimetallic strip  50  increases in temperature, the two different types of metal in the bimetallic strip  50  expand at different rates thereby causing it to bend. In this embodiment, as the bimetallic strip  50  is heated, the bimetallic strip  50  bends such that the second end  53  of the extension arm  46  and the poppet  48  attached to the second end  53  are moved in a downward direction indicated by arrow  170 , see  FIG. 4 , and away from the annular shoulder portion  60  of the adjustable seat  54  to open the valve  10  and allow the flow of gas therethrough. 
     As the rubber poppet  48  goes from a seated or closed position (see  FIG. 3 ) wherein the poppet  48  and particularly the top surface  56  of the rubber poppet  48  is in full sealing contact with the bottom surface  58  of the annular shoulder portion  60  of the adjustable seat  54  to an unseated or open position (see  FIG. 4 ) wherein the rubber poppet  48  does not contact the adjustable seat  54 , gas previously trapped within the body  12  of the gas valve is permitted to flow through the adjustable seat  54 , particularly the passage  62  of the adjustable seat  54 , and out of the outlet fitting  18 . This flow of gas from within the gas valve  10  through the adjustable seat  54  and the outlet fitting  18  is illustrated by arrows  172 . 
     When a hose, tube, locking collar, or the like is threadedly attached and secured to the main outlet fitting  18  via the threaded portion  106  at the top of the outlet fitting  18 , contaminates such as small metal particulate, shavings, filings and the like are formed as discussed above. These contaminates fall vertically downward and into the outlet fitting  18 . Previously, these contaminates would fall all the way through the fitting and land on the poppet  48 . However, in the present invention, the contaminates fall (indicated by arrows  176  into the outlet fitting  18  and are trapped by the debris trap  82 . Particularly, the contaminates fall and hit the cap  88  of the debris trap  82 . These contaminates are either stopped on the cap  88  or fall into the annular debris trapping channel  96  defined between a portion of an inner surface  100  of the outlet fitting  18  and a portion of the outer surface  98  of the debris trap  82 . Thus, by adding the debris trap  82  to the valve, the contaminates are prevented from falling axially through the adjustable seat  54  and do not fall onto the poppet  48 . 
     It will be appreciated, that in alternative embodiments of the adjustable seat, namely the embodiments corresponding to  FIGS. 9-12 , contaminates created by the interaction of the adjustable seats  138 ,  157  and a tool during calibration of the adjustable seats  138 ,  157  are similarly prevented from falling onto the rubber poppet  48 . 
     All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.