Abstract:
Potential leakage points are avoided, mishandling or loss of loose, unattached parts minimized and installation in tight places facilitated by a meter bar of elongated cast metal structure having a central bar, an outlet conduit section and an inlet conduit section, both integral with the meter bar. The inlet and outlet sections may include integral tail pieces and an upstream end of the inlet section includes an elongated, downwardly curved conduit to eliminate the need for the use of elbows, pipes or nipples, etc.

Description:
FIELD OF THE INVENTION 
     This invention relates to a meter bar, and more particularly, to a meter bar assembly that is adapted to be connected into a fluid handling system, such as a gas distribution system, for mounting a fluid flow measuring meter in the system. 
     BACKGROUND OF THE INVENTION 
     Meter bars are common in various types of fluid distribution systems, most notably, natural gas and other manufactured gas distribution systems. In the usual case, the bar is disposed generally horizontally and supports a meter which meters the flow of the fluid through the system. In the usual case, the meter bar will have an inlet end and an outlet end and both have conduits internal to the bar itself. At the inlet end, one port for the conduit will be connected to the fluid supply and the other connected to the inlet side of the meter. At the outlet end of the bar, the outlet of the meter will be connected to one of the ports and the other port at the outlet end will be connected to the system that distributes the fluid to a point of use, typically within a structure or the like. 
     While conventional meter bars work well for their intended purpose, they are not without their points of potential weaknesses. With reference to  FIG. 1 , which illustrates a conventional prior art construction, a typical meter bar includes a central section  10  which is adapted to be disposed horizontally to mount a meter. At one end of the central section  10  is an inlet section  12  while at the opposite end of the central section, is an outlet section, generally designated  14 . The inlet section includes an internal conduit  16  which curves approximately 90° within the inlet section  12  from a first, internally threaded port  18  to a second, internally threaded port  20 . The port  18  is intended to be connected to a supply of the fluid whose flow is to be measured while the port  20  includes a so-called tailpiece  22  which is threaded into the port  20 , and which in turn includes a nut  24  and a gasket  26  by which the inlet side of a meter, such as a gas meter, can be mounted to the bar. 
     The outlet section also includes a 90° conduit  28  terminating in threaded ports  30  and  32 . The threaded port  30  is adapted to be connected to the part of the distribution system that distributes the fluid to points of use while the threaded port  32  receives a second tailpiece  22  including a nut  24  and a gasket  26  for mounting the outlet side of the meter (not shown). 
     Those familiar with gas distribution systems will recognize that not infrequently, supply pipes are vertically oriented and thus require an elbow and a section of pipe or nipple to extend between the elbow and the port  18 . As a consequence, several potential points of leakage are present. There are two potential points of leakage at the elbow, one on the upstream end and one on the downstream end. There is a further potential point of leakage where the pipe or nipple interfaces with the port  18 . 
     Furthermore, the use of tailpieces such as the tailpieces  22  which must be threaded into the ports  20  and  32  create additional potential leakage points at those ports as well. 
     Needless to say, when a combustible material such as natural gas or other manufactured gas is being metered, leakage creates a hazard, particularly if the meter bar with the meter mounted thereon is located indoors or within a structure that minimizes the possibility of dissipation of any small leakage to the ambient. 
     Furthermore, in some situations, connections to the upstream side of the inlet conduit  16  or the downstream side of the outlet conduit  28  may be made difficult by spacial limitations. Consequently, there is also a need in meter bars for an adaptor or connector for connecting the same into a fluid distribution system in confined spaces and in a reliable way. 
     The present invention is directed to solving one or more of the above problems. 
     SUMMARY OF THE INVENTION 
     It is the principal object of the invention to provide a new and improved meter bar for mounting flow measuring meters. More particularly, it is an object of the invention to provide a meter bar assembly that significantly reduces potential leak points in installations using the same, minimizes the number of loose, unattached parts required for a given assembly, thereby reducing the possibility that one or more parts will become lost or otherwise mishandled during the installation process and which may be installed with relative ease even at locations where there are severe spacial constraints. 
     An exemplary embodiment of the invention achieves one or more of the above objects in a meter bar that includes an elongated cast metal structure including a generally central bar section, an outlet conduit section integral with the central section at one end thereof and including an integral outlet conduit terminating at its ends in two spaced ports, one of the ports including a tailpiece for connection to the outlet side of a fluid meter, an inlet conduit section integral with the central section at another end thereof opposite the central section one end and including an integral inlet conduit terminating at its ends in two spaced ports, one of the inlet conduit ports being parallel to the one outlet port and spaced therefrom and including a tailpiece for connection to the inlet side of a fluid meter. 
     In a preferred embodiment, the other of the inlet ports is located at an end of an elongated, curved section of the inlet conduit to open in the same direction as the one inlet port. 
     In a preferred embodiment, the tailpieces are integral with the inlet, outlet and central sections forming part of a single casting. 
     In a preferred embodiment, the central section is generally horizontal and the inlet and outlet port tailpieces and the other inlet port open downwardly. 
     In one embodiment of the invention, the curved section of the inlet port has an arc length, about 90°, or about 180° from the inlet port tailpiece. 
     Others of the above objects are accomplished by a meter bar that includes an elongated structure having a generally central bar section, an outlet section at one end of the central section and including an internal conduit having first and second ports at ends thereof, and an inlet section at an opposite end of the central section and having an internal conduit terminating in first and second ports at the ends thereof. The second ports are aligned and are adapted to be connected to a meter for measuring the flow of fluid through the conduits. An adaptor is mounted about at least one of the first ports, the one first port being surrounded by two, axially spaced, radially outward opening grooves with an O-ring seal in one of the grooves and a retaining ring partially received in the other groove and extending radially outward thereof. The adaptor includes an internal bore telescopically receiving the one first port and a radially inward opening groove partially receiving the retaining ring. At least one of the other groove and the radially inwardly opening groove are axially elongated to allow the adaptor to shift axially relative to the retaining ring and thus telescope on the port. 
     In a preferred embodiment, both the other groove and the radially inward opening groove are axially elongated. 
     A highly preferred embodiment contemplates that there be an additional radially outward opening groove on the port which is axially spaced from the other groove on a side thereof remote from the one groove and which is sized to wholly contain the retaining ring. A cam surface is located on an end of the adaptor about an end of the bore for camming the retaining ring into the additional groove when the adaptor is first located about the first port and a retaining ring retaining shoulder is located adjacent the cam surface to define a side wall of the radially inward opening groove for capturing the retaining ring therein. 
     Other objects and advantages will become apparent from the following specification taken in connection with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view of a meter bar made according to the prior art; 
         FIG. 2  is a sectional view of one embodiment of a meter bar made according to the invention; 
         FIG. 3  is a fragmentary, sectional view of a modified embodiment of a meter bar made according to the invention; 
         FIG. 4  is a fragmentary, sectional view of still another embodiment of a meter bar made according to the invention; 
         FIG. 5  is a fragmentary, sectional view of part of a tailpiece connection made according to the invention as an alternative embodiment thereof; 
         FIG. 6  is a fragmentary, sectional view of a swivel adaptor mounted on the meter bar; and 
         FIG. 7  is a fragmentary, sectional view of a telescoping swivel adaptor mounted on the meter bar. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention herein disclosed is primarily intended for use in natural gas distribution systems, it may be used in other fluid distribution systems wherein flow of the fluid being distributed is to be monitored by a meter, and no limitation to gas systems is intended except insofar as stated in the appended claims. 
     Turning first to  FIG. 2 , a first embodiment of a meter bar made according to the invention will be described. As in the prior art, the same includes a central bar section, generally designated  10 , which typically will have a cross section much like an I-beam. At one end, specifically the right end as shown in  FIG. 2 , an outlet section, generally designated  14 , is located while at the left hand and as shown in  FIG. 2 , the central section  10  terminates at an inlet section  12 . The inlet section  12  includes an inlet conduit  16  which, at one end  40 , includes an integral tailpiece  42 . At its other end, the inlet conduit  16  includes an elongated, curved section  44  which terminates in a downwardly opening, male threaded port  46 . The presence of the curved section  44 , which has an arcuate extent of approximately 90°, allows the meter bar assembly to be connected into a vertical supply line with the central section  10  horizontal while eliminating any need for an elbow and pipe or nipple as in the prior art. The total arcuate extent of the conduit  16  from the integral tailpiece  42  to the port  46  is approximately 180°. 
     In the embodiment shown in  FIG. 2 , the outlet section  14  includes an internal conduit  28  which terminates in a horizontally directed, male port  48  for connection to the distribution system to which the fluid whose flow is being monitored is directed. Oppositely, the outlet conduit  28  terminates in an integral tailpiece  42  which is identical to that previously described in connection with the inlet conduit  16 . 
     The components thus far described are integral in a sense that they constitute one piece, as opposed to a plurality of separate pieces joined together by bonding mechanical connections, etc. A preferred embodiment of the invention contemplates that the components thus far described be formed of a one piece metal casting. 
     As the two tailpieces  42  on both the inlet and outlet sides of the meter bar are identical, only that on the inlet conduit  16  will be described in detail. 
     The port  40  includes an axially directed shoulder  50  surrounded by a flat  52  which receives a flat gasket seal  54  which may be of conventional construction. Just above the gasket seal  54 , the integral tailpiece includes a radially outwardly opening groove  56  which extends about the entire tailpiece. A resilient retaining ring  58  may be slipped over the end of the tailpiece  42  to partially reside within the groove  56 . It will be readily appreciated from  FIG. 2  that even when the ring  58  is seated against the bottom of the groove  56 , it protrudes radially from the groove  56  a certain distance. 
     A nut  60  includes an internal thread  62  for connection to the appropriate port on the fluid meter. Opposite of the internal thread  62 , the same includes a radially inwardly directed, peripheral shoulder  64  whose inner diameter is less than the outer diameter of the retaining ring  58  when the same is nested in the groove  56 . Thus, when the nut  60  is turned, it is retained on the integral tailpiece  42  by the retaining ring  58  and will tighten the seal  54  against both of the flat face  52  of the tailpiece  42  and a mating sealing surface on the meter. 
     It will be observed that the distance between the central section  10  of the meter bar and the groove  56  is such that the nut  60  can be moved to the position shown at the outlet conduit  14  in  FIG. 2  to allow installation of the retaining ring  58 . 
     The described structure has a number of advantages over the prior art. As alluded to previously, potential leak points on the upstream side of the inlet conduit  16  are greatly reduced. Furthermore, leak points where the tailpieces  42  are joined to the respective inlet and outlet ends  12  and  14  are eliminated entirely through the use of integral tailpieces  42  made according to the invention. Additionally, the unique use of the retaining ring construction assures positive retention of the nut  60  whether loose or tight on its associated tailpiece  42 , eliminating the need to handle unattached loose parts as well as the possibility of mishandling or losing the same. 
     The invention may be employed in styles of meter bars other than that shown in  FIG. 2 . For example, in  FIG. 3 , the meter bar may be identical to that illustrated in  FIG. 2  except that, in lieu of the horizontally directed male thread outlet port  48 , a vertically directed, male threaded outlet port  70  may be employed. All other components may be the same. 
     Still another possibility is shown in  FIG. 4 . In this case, the elongated curved section  44  is done away with and the inlet conduit  16 , and its upstream side, terminates in an externally threaded male connector  72  that is horizontally directed. This form of the invention retains the advantage of eliminating leak points in the prior art where separate tailpieces must be threaded into ports for the inlet and outlet conduits  16  and  28 . 
       FIG. 5  shows an alternative structure for connection to the meter. In this case, the tailpiece  42  terminates in a flat face  74  having an axially opening, peripheral groove  76 . An O-ring  78  is located in the groove  76  in lieu of the flat seal  54  used in the previously described embodiments. 
     Turning now to  FIG. 6 , a swivel adaptor that may be used to connect the meter bar into the system is illustrated. The swivel adaptor allows the meter bar to be assembled or disassembled to rigid piping where spacial constraints do not allow the bar to be swung around to be tightened to mating parts or where traditional union ends are not available. In  FIG. 6 , one form of swivel adaptor is generally designated  80  and includes a male threaded end  82  for connection to rigid piping at one end and an enlarged bore  84  opening to the other end. The bore  84  is received on an unthreaded end  86  of the inlet conduit  16  of the inlet section  12 . 
     That is, the swivel adaptor  80  is located on the port at the upstream end of the inlet conduit  16  in the illustration shown in  FIG. 6 . Such a port includes a radially outwardly opening groove  88  for receiving an O-ring seal at a location closest to an end  90  of the inlet section  12 . A second groove  92  which is also a radially outwardly opening is located above the groove  88  and is sized so as to be capable of wholly receiving and containing a resilient retaining ring  94 . The bore  84  also includes a radially inwardly opening groove  96  which is sized to only partially receive a retaining ring  94 , that is to say, when the retaining ring  94  enters the groove  96  as far as possible, a part of the retaining ring  94  projects inwardly to be received in the groove  92 . 
     Just above the groove  96  in the swivel adaptor  80 , the bore  84  opens in a beveled cam surface  98 . 
     To assemble the swivel adaptor to the meter bar, the resilient retaining ring  94  is located in groove  92  with the O-ring seal already in place. The swivel adaptor  80  is fitted over the end  90  until the cam surface  98  contacts the retaining ring  94 . At this point, the diameter of the retaining  94  will be reduced by the camming force provided by the surface  98  to cam the retaining ring  94  fully into the groove  92  allowing continued axial movement of the swivel adaptor  80  until the groove  96  aligns with the groove  92 . At this point, the retaining ring is no longer restrained by the inner diameter of the swivel adaptor  80  and snaps into the groove  96  to hold the swivel adaptor  80  on the end  90 . Thus, a connection to a supply line can be made without any need for moving the meter bar in the process, allowing ready, reliable connections to be made in tight areas. Again, the need for handling loose parts that are unassembled from the meter bar is eliminated in this construction. 
       FIG. 7  illustrates a telescoping swivel adaptor that also telescopes while maintaining a seal. The telescoping swivel adaptor is generally designated  100  and includes an internal bore  102  of approximately the same diameter as the end  90  of the inlet section  12  of the meter bar  10 . The end  90  includes a radially outwardly opening groove  104  for receipt of an O-ring  106 , a second groove  108 , and a third or additional groove  110  which is sized to completely receive a retaining ring  112 . The groove  96  in the swivel adaptor corresponding to that shown in the swivel adaptor in  FIG. 6  is axially elongated as is the groove  108 . 
     Assembly is as with the embodiment of  FIG. 6 , making use of a cam surface  98  on a swivel adaptor  100  and a shoulder  112  defining a side of the groove  110  adjacent the cam surface  98 . It will be appreciated that not only will the swivel adaptor  100  be rotatable complete an installation in a small area with fixed pipes, but the same is also axially extendable because, due to the elongation of the grooves  96  and  108 , the swivel adaptor  100  may be telescoped onto and partially off of the end  90  of the inlet end  12  while maintaining a seal. Thus, a meter bar fitted with swivel adaptors shown in  FIGS. 6 and 7  is readily installed in areas where the meter bar cannot be pivoted and where plumbing is fixed and spacial constraints exist. Further, the swivel adaptors of both embodiments shown eliminate unattached loose parts and the attendant problems. 
     It will therefore be appreciated that a meter bar made according to this invention including all of the facets described herein eliminate the difficulties encountered in the use of unattached loose parts, minimize points of potential leakage and eliminate them altogether in the case of the tailpieces  42 . Further, ease of installation in tight places is considerably enhanced.