Abstract:
A diaphragm for use in a gas meter that includes an expansion section having a series of convolutions. During repeated use of the diaphragm, the expansion section flexes to allow the center section of the diaphragm and the attached diaphragm disk to move between a retracted position and extended position. The convolutions formed in the expansion section include a series of curved peaks and curved troughs joined by web sections. The multiple convolutions in the expansion section allows for more consistent and repeatable movement and volume displacement of the diaphragm between the extended and retracted positions. The action of the convolutions also contributes to extended life by eliminating wrinkling of the diaphragm material.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present disclosure generally relates to a diaphragm-type gas meter for determining the usage of a gas product. More specifically, the present invention relates to an improved diaphragm for use in a diaphragm-type gas meter to provide more consistent metering and extended diaphragm life. 
         [0002]    Positive displacement gas meters have long been used to determine the amount of gas usage by a consumer. Particularly, where gas flow rates are relatively low, such as at the gas inlets of homes and small buildings, diaphragm meters are used to measure gas consumption. Diaphragm meters are connected to a supply pipe that delivers pressurized gas from an external source. An outlet pipe runs from the diaphragm gas meter to the inside of the house or building to supply the metered gas to the building. 
         [0003]    When a gas burning device, such as a stove or furnace, is activated, gas begins to flow into the enclosed housing of the meter. Diaphragm meters measure the amount of gas consumed in the following manner. Initially, a valve in the diaphragm meter is in a first position in which gas flows into the enclosed housing on one side of the diaphragm enclosed within the diaphragm meter. As the first side of the diaphragm expands outward due to the pressure of the gas flowing into the enclosed housing, gas on the opposite side of the diaphragm is forced out of the diaphragm meter to the outlet pipe. As the diaphragm moves due to the pressure of gas from the supply, the diaphragm rotates the flag axle with an arm attached to one end. The arm forces the metering components within the meter to move, which rotates dials to indicate the amount of gas usage. The flag axle also has a crankshaft attached to an arm that moves internal valving within the diaphragm meter. Movement of the valving uncovers another passage that exposes the opposite side of the diaphragm to the pressurized gas. Thus, as gas is continually used by the consumer, the diaphragms reciprocate between two different positions, where each movement causes a dial within the meter to rotate to indicate gas consumption. 
         [0004]    As the above description indicates, the diaphragms within the diaphragm-type gas meter continuously reciprocate between extended and retracted positions. This movement of each the diaphragm must be consistent to provide a repeatable volume displacement for an accurate reading by the gas meter. Further, since gas meters are typically left in the field for numerous years, the diaphragm must be durable over the life period of the gas meter. 
       SUMMARY OF THE INVENTION 
       [0005]    The present disclosure generally relates to a diaphragm assembly for use in a gas meter. More specifically, the present invention relates to a diaphragm for use in a gas meter that includes a series of spaced convolutions that allow the diaphragm to more accurately displace a constant volume between a retracted position and an extended position. 
         [0006]    The diaphragm of the present disclosure includes a generally circular center section although oval and squared configurations are also possible. The center section receives a diaphragm disk having an attachment bracket that receives a flag rod of the metering assembly. As the diaphragm moves between a retracted position and an extended position, the diaphragm disk rotates the flag rod, thereby resulting in metering of the gas being consumed by the metered facility. 
         [0007]    The diaphragm further includes an expansion section that extends around the center section. The expansion section is attached to an attachment section that allows the diaphragm to be secured to a diaphragm pan. Preferably, the center section, the expansion section and the attachment section are formed from a single material. However, it is contemplated that the diaphragm could be formed from multiple materials, as desired. 
         [0008]    The expansion section of the diaphragm includes a series of spaced convolutions that allow the diaphragm to flex from the retracted position and move to the extended position. Preferably, each of the convolutions are spaced from each other in concentric rings within the expansion section, 
         [0009]    Each of the convolutions includes a curved peak joined to a corresponding curved trough by a connecting web. As the diaphragm moves from the retracted position to the extended position, each of the curved peaks and curved troughs flex to allow the diaphragm to move to the extended position. 
         [0010]    Since the expansion section includes a series of convolutions formed in concentric rings, the expansion section allows the diaphragm to flex outward in a more controlled and known manner. Further, the curved convolutions of the expansion section increase the durability of the diaphragm over repeated movements between the extended and retracted positions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The drawings illustrate the best mode presently contemplated of carrying out the invention. In the drawings: 
           [0012]      FIG. 1  is a front perspective view of a diaphragm-type gas meter utilizing the convoluted diagram of the present disclosure; 
           [0013]      FIG. 2  is a section view of the diaphragm assembly, including the convoluted diaphragm and support pan shown in  FIG. 1 ; 
           [0014]      FIG. 3  is a magnified view taken along line  3 - 3  of  FIG. 2 ; 
           [0015]      FIG. 4  is a section view similar to  FIG. 2  showing the convoluted diaphragm in its extended condition; and 
           [0016]      FIG. 5  is a section view similar to  FIG. 2  showing the convoluted diaphragm in its retracted condition. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]      FIG. 1  is a front perspective view of a gas meter  10  constructed in accordance with the present disclosure. The gas meter  10  is a generally conventional residential diaphragm-type gas meter including a diaphragm assemblies  12  constructed in accordance with the present disclosure. As an example, the residential gas meter  10  shown in  FIG. 1  could be the Sensus Metering Systems Model R-275 residential gas meter. Various other residential gas meters  10  could be utilized while operating within the scope of the present disclosure. 
         [0018]    The gas meter  10  includes a meter housing  14 . The meter housing  14  includes a pair of diaphragm chambers  16  separated by a center web  18 . Each of the diaphragm chambers  16  receives one of the diaphragm assemblies  12 . In the embodiment shown in  FIG. 1 , only a single diaphragm assembly  12  is shown. However, it should be understood that a corresponding second diaphragm assembly is utilized with the gas meter  10  shown in  FIG. 1 . 
         [0019]    As shown in  FIG. 1 , the diaphragm assembly  12  is part of a larger measuring module  20  that includes the diaphragm assembly  12  and the metering assembly  22 . The metering assembly  22  includes a series of valves that direct the supply of gas into the pair of diaphragm chambers  16  to reciprocally move the diaphragm  24  of the diaphragm assembly  12 . As illustrated in  FIG. 1 , a diaphragm disk  26  is attached to the front surface of the diaphragm  24 . The diaphragm disk is a rigid element positioned along the front surface of the diaphragm  24 . The diaphragm disk  26  includes an attachment bracket  28  that includes a top flange  30  and a bottom flange  32 . The attachment bracket  28  receives the lower end  34  of a flag rod  36 . The flag rod  36  includes a lower bend  38  and an upper bend  40 . 
         [0020]    The upper end of the flag rod  36  extends through a top plate  42  and is joined to one end  44  of a meter linkage  46 . A second end  48  of the meter linkage is connected to a corresponding flag rod (not shown) for the second diaphragm assembly. 
         [0021]    As is well known in the industry, as the diaphragm  24  of the diaphragm assembly  12  reciprocates between an extended position and a retracted position, the movement of the flag rod  36  causes the meter linkage  46  to both open and close valves within the metering assembly  22  and operate a measurement dial for the meter. The configuration of the metering module  20  shown in  FIG. 1  is a conventional module, the details of which are well known and thus will not be described in the present disclosure. 
         [0022]    Referring now to  FIG. 2 , thereshown is a detailed cross-section view of the diaphragm assembly  12  constructed in accordance with the present disclosure. As illustrated in  FIG. 2 , the diaphragm assembly includes the diaphragm disk  26  mounted to an outer surface  50  of the diaphragm  24  and a diaphragm disk  51  mounted to an inner surface  84  of the diaphragm  24 . Specifically, the diaphragm disk  26  is secured to the diaphragm disk  51  by a pair of connectors that pass through the generally planar center section  52  of the diaphragm  24 . In this manner, the diaphragm disks  26 ,  51  sandwich the center section  52  therebetween, as illustrated in  FIG. 2 . The attachment bracket  28  is secured to the diaphragm disk  26  and receives the first end  34  of the flag rod  36 . 
         [0023]    As illustrated in  FIG. 2 , the diaphragm  24  extends across and is supported by a diaphragm pan assembly  54 . The pan assembly  54  includes a ported outer wall  56  that extends between a closed back end  58  and an open front end  60 . The open front end  60  receives the diaphragm  24 , as is clearly illustrated. 
         [0024]    The outer wall  56  defines the open front end by a curved outer edge surface  62 , as best shown in  FIG. 3 . The outer wall  56  further includes an extending support flange  64  that extends from the outer wall  56  to define a receiving groove  66 . The receiving groove  66  extends along the entire outer surface of the pan assembly  54 . 
         [0025]    Referring back to  FIG. 2 , the diaphragm  24  further includes an expansion section  68  and an attachment section  70 . Specifically, the expansion section  68  is joined to the generally planar center section  52  and allows the diaphragm  24  to reciprocate between the retracted position shown in  FIG. 2  and the extended position shown in  FIG. 5 . The details of the expansion section  68  will be described in greater detail below. 
         [0026]    The expansion section  68  is positioned between the center section  52  and the attachment section  70 , as is shown in  FIG. 2 . The attachment device  72  provides retention of the diaphragm  24  such that the diaphragm  24  can be securely attached to the pan assembly  54 . 
         [0027]    Referring now to  FIG. 3 , the attachment section  70  extends over the outer edge surface  62  of the outer wall  56  and extends through the receiving groove  66  and over the outer surface of the support finger  64 . As illustrated in  FIG. 3 , a resilient clamping ring  72  extends around the outer circumference of the pan assembly  54  to securely hold the diaphragm  24  in place. In the embodiment shown in  FIG. 3 , the outermost edge of the diaphragm  24  includes an expanded retaining bead  74 . The retaining bead  74  prevents the outer end of the diaphragm from passing by the clamping ring  72  during repeated use of the diaphragm. Specifically, the retaining bead  74  contacts the clamping ring  72  to prevent the outer end of the diaphragm from becoming disengaged from the diaphragm pan assembly  54 . 
         [0028]    Referring back to  FIG. 3 , the expansion section  68  of the diaphragm  24  will be more specifically described. As illustrated in  FIG. 3 , the expansion section includes a plurality of convolutions  76   a ,  76   b . The expansion sections  76   a ,  76   b  are formed concentrically, as can best be seen in  FIG. 1 . Although a pair of convolutions is shown in  FIGS. 1 and 3 , it should be understood that a different number of convolutions of varying magnitude, could be utilized while operating within the scope of the present disclosure. 
         [0029]    Referring back to  FIG. 3 , each of the convolutions includes a curved peak  78  and a curved trough  80  that are each joined by a connecting web  82 . Specifically, the curved trough  80  of one convolution is joined to the curved peak  78  of the next convolution by a connecting web  82 . 
         [0030]    As illustrated in  FIGS. 2 and 3 , the entire diaphragm  24  is formed from a continuous section of material. The material can be formed from woven or loose reinforced or non-reinforced material. Preferably, the entire diaphragm is formed or pressed in a simple two-piece mold utilizing the construction material. 
         [0031]    Although the entire diaphragm is preferably constructed as a unitary structure, the diaphragm can have different thicknesses to maintain the rigidity of the diaphragm while allowing each of the convolutions  76   a ,  76   b  to roll and flex consistently during the movement between the retracted and extended position. 
         [0032]    Referring now to  FIG. 3 , in one embodiment of the disclosure, the diaphragm has varying thicknesses across the expansion section  68 . In the embodiment illustrated, the thickness of each curved peak, represented by A, is approximately 0.018 inches. Likewise, the thickness of the material in each of the curved troughs  80 , represented by thickness B, is also 0.018 inches. However, in the embodiment shown in  FIG. 3 , the thickness of each connecting web  82 , shown by C has a reduced thickness of approximately 0.015 inches. The increase in the thickness of the material in the curved peaks  78  and the curved troughs  80  allows the diaphragm to maintain its curved configuration during repeated use. Likewise, the relatively decreased thickness of the material in the connecting webs  82  allows the expansion section to more easily move between the retracted position shown in  FIG. 5  and the extended position shown in  FIG. 4 . In the embodiment illustrated in  FIG. 3 , the center section  50  has a thickness D of approximately 0.014 inches, which is less than both the thickness of the connecting webs  82 , the curved peaks  78  and the curved troughs  80 . Further, in the embodiment shown, the entire attachment section  70  has the greater thickness of the curved trough  80  and curved peaks  78  to provide a more durable web for the attachment section  70 . 
         [0033]    As discussed above,  FIG. 2  illustrates the diaphragm  24  in its neutral position. In the retracted position,  FIG. 5 , gas pressure on the outer surface  50  of the diaphragm exceeds the gas pressure on the inner surface  84 . However, when the gas pressure on the inner surface  84  increases, as shown in  FIG. 4 , the entire diaphragm  24  flexes outward to the extended position shown in  FIG. 4 . As can be seen in  FIG. 4 , when the diaphragm  24  moves to the extended position, the curved troughs  80  and the curved peaks  78  straighten out to allow the center section  52  and the attached diaphragm disk  26  to move upward by the extension distance E shown in  FIG. 4 . This movement of the diaphragm disk  26  rotates the flag rod  36 , which results in rotation of the measurement dials in the meter assembly. 
         [0034]    As described previously, the curved peaks  78  and the curved troughs  80  have an expanded thickness relative to the connecting web  82  such that the curved peaks  78  and the curved troughs  80  maintain their curvature upon the return movement of the diaphragm  24  to the retracted position shown in  FIG. 5 . Additionally, the multiple convolutions in the expansion section  68 , as best shown in  FIG. 3 , provide for increased consistency of movement and eliminate wrinkling and distortion in the diaphragm during the multiple and repeated movements of the diaphragm between the neutral position of  FIG. 2 , the extended position of  FIG. 4 , and the retracted position of  FIG. 5 . 
         [0035]      FIGS. 1-4  illustrate only one of the two diaphragm assemblies  12  utilized with the gas meter  10  shown in  FIG. 1 . A second diaphragm assembly not shown in the drawing figures has an identical configuration to the diaphragm assembly  12  shown in  FIG. 1 . The combination of the pair of diaphragm assemblies  12  provides the driving arrangement for the metering assembly  22  of the gas meter  10 . 
         [0036]    In the embodiment shown in  FIGS. 1-5 , the diaphragm  24  includes a series of equally spaced convolutions  76  that allow the diaphragm to move between the retracted and extended positions. It is contemplated that either a larger or smaller number of convolutions with varying magnitudes could be utilized while operating within the scope of the present disclosure. Further, it is contemplated that the convolutions could be spaced unevenly from each other while also operating within the scope of the present disclosure.