Symmetrical ultrasound gas flow meter housing and related multi-configuration gas flow meter assembly

[0002] The present invention relates to ultrasonic gas flow meters and, more particularly, to an ultrasonic gas flow meter housing which facilitates interconnection with other gas flow meter components to provide a multi-configuration system.

[0003] Ultrasonic gas flow meters are generally well known. Such meters commonly utilize a technique in which the difference between the time of travel of an ultrasonic wave upstream in a flowing gas and the time of travel of an ultrasonic wave downstream in the flowing gas is used to determined the flow rate of the gas. However, other techniques are also known and used.

[0004] Accumulation of liquids in the housings of ultrasonic gas flow meters can occur with sufficient frequency and in sufficient quantity to interfere with accurate gas flow measurement. In such instances the excessive liquid presents a service and maintenance problem for the gas utilities which maintain such meters, and therefore acts as a potential deterrent to successful widespread introduction and use of ultrasonic gas flow meters. The standard attachment position for residential size gas meters is with the inlet and outlet piping connections positioned on the top of the meter case or housing. In this position, the meter housing can become an accumulator for any liquids that are being transported by the flowing gas. In such ultrasonic gas flow meters if the liquid enters the area through which ultrasonic signals pass, the gas flow volume will tend to be measured inaccurately.

[0005] Thus, in certain applications there is a need for positioning the inlet and outlet piping connections on the bottom of the meter housing in order to permit the connections to effectively act as drains for any liquids that may enter the meter. However, this housing configuration presents a problem in many areas where the majority of gas meter installation sites still include downwardly extending inlet and outlet piping positioned for entry into the top of a gas meter housing. Utilizing two different gas meter housing configurations, one with top openings and one with bottom openings, would increase manufacturing costs and would be less well received by the gas utilities.

[0006] Accordingly, it would be desirable to provide a gas meter housing configured to reduce liquid accumulation therein when installed. It would also be desirable to provide a gas meter housing adapted for installation in at least two different positions within ultrasonic gas meter systems, thereby providing a single housing useful in multiple installation schemes.

[0007] The present invention is an ultrasonic gas meter housing member configured to provide an associated multi-configuration ultrasonic gas meter assembly. In a preferred embodiment of the invention the housing member is installable in an ultrasonic gas flow meter which includes an internal flow measurement tube along which gas travels for flow measurement, the tube having an inlet end and an outlet end. The ultrasonic gas meter housing member includes a closed back portion generally rectangular in shape and a front portion spaced from the back portion to define a space for receiving the internal flow measurement tube such that the tube extends substantially along at least a portion of a longitudinal axis of the housing member. First, second, third, and fourth wall portions extending between the back portion and the front portion, the first wall portion having a first opening and a second opening therethrough for connection of the housing member to a gas inlet pipe and a gas outlet pipe, the first and second openings facing in substantially the same direction. The gas meter housing member is symmetrical about a plane which divides the housing member into a first half and a second half, the plane being perpendicular to the longitudinal axis. The symmetrical configuration enables the housing member to receive the flow measurement tube in both a first orientation in which the first and second opening face in a first direction and the inlet end of the flow measurement tube is positioned in the first half of the housing member and the outlet end is positioned in the second half, and a second orientation in which the first and second opening face in a second direction substantially opposite to the first direction and the inlet end of the flow measurement tube is positioned in the second half of the gas meter housing member and the outlet end is positioned in the first half. The first and second orientations are particularly useful in enabling the housing member to be used both in gas meter installation sites where the gas pipes extend downward and in gas meter installation sites where the gas pipes extend upward, so that two different housing configurations need not be provided. Further, in installations where the gas pipes extend upward, the first and second openings through the housing member will face downward and will prevent the build up of liquids within the meter by allowing them to drain.

[0008] In another aspect of the invention, a multi-configuration ultrasonic gas meter assembly is provided and includes a first housing member having a back enclosure portion, a front portion spaced from the back enclosure portion to define an internal space, and at least one wall portion extending between the back enclosure portion and the front portion, at least one wall portion having a first opening and a second opening therethrough for connection to a gas inlet pipe and a gas outlet pipe. A gas flow measurement tube is provided for positioning at least partially within the internal space of the first housing member and has a gas inlet end and a gas outlet end. At least one ultrasonic transducer is positioned proximate the gas flow measurement tube for directing an ultrasonic signal along at least a portion of a length of the gas flow measurement tube. An orientation between the first housing member and the measurement tube is selectable between at lest two configurations as necessary for attachment of the gas inlet pipe and the gas outlet pipe, and includes a first assembly configuration in which the first and second openings face in a first direction and gas travels in the first opening, through the gas flow measurement tube from the inlet end to the outlet end, and out of the second opening, and a second assembly configuration in which the first and second openings face in a second direction which is substantially opposite the first direction and in which gas travels in the second opening, through the gas flow measurement tube from the inlet end to the outlet end, and out of the first opening. As above, the two assembly configurations facilitate installation of the gas meter assembly both in gas meter installation sites where the gas pipes extend downward and in gas meter installation sites where the gas pipes extend upward.

[0009] Accordingly, it is an object of the present invention to provide an ultrasonic gas meter housing member configured for attachment to both downwardly extending gas pipes and upwardly extending gas pipes; a multi-configuration ultrasonic gas meter assembly; an ultrasonic gas meter housing positionable to permit drainage of fluid therefrom; and a method of manufacturing an improved ultrasonic gas meter housing member. Other objects and advantages of the present invention may be ascertained from a review of the following description and drawings.

[0010] FIGS. 1A and 1B show front perspective views of an ultrasonic gas meter housing member in accordance with one embodiment of the present invention;

[0011] FIG. 2 shows an exploded view of a multi-configuration ultrasonic gas meter assembly incorporating the housing member of FIGS. 1A and 1B in a first assembly configuration; and

[0012] FIG. 3 shows an exploded view of the multi-configuration ultrasonic gas meter assembly of FIG. 2 in a second assembly configuration.

[0013] Referring to the drawings, FIGS. 1A and 1B show front perspective views of an ultrasonic gas meter housing member 10 according to a preferred embodiment of the invention, FIG. 1A showing gas pipe connection openings 12 and 14 of the housing member 10 facing in a generally upward direction and FIG. 1B showing openings 12 and 14 facing in a generally downward direction. Three reference planes A, B, and C are shown in shadow with plane A extending generally parallel to a front portion 16 of the housing member 10, plane B extending vertically across a central portion of the housing member 10, and plane C extending horizontally across a central portion of the housing member 10. As shown, housing member is symmetrical about plane B and partially symmetrical about plane C. With this symmetry about the central planes, the internal features of the housing member are the same, relative to the remaining meter components, whether the body is oriented with the connection openings 12 and 14 facing upward or downward. Such remaining meter components are shown in the exploded views of FIGS. 2 and 3 and generally include a flow tube assembly 18, one or more ultrasonic transducers 20, and a front housing member 22. The flow tube assembly 18 includes a gas flow measurement tube 24 having an inlet end 26 and an outlet end 28, along which gas travels for flow measurement.

[0014] Referring again to FIGS. 1A and 1B, the housing member 10 includes a closed back portion 30 which, in the preferred embodiment, is generally rectangular in shape. The front portion 16, being spaced from the back portion 30, defines an internal space 32 for receiving the gas flow measurement tube such that the tube extends substantially along at least a portion of a longitudinal or horizontal axis of the housing member, which axis extends within plane C. First, second, third and fourth wall portions 34, 36, 38 and 40 extend between the back portion 30 and the front portion 16 of the housing member. The first wall portion includes opening 12 and opening 14 therethrough for connection of the housing member to a gas inlet pipe and a gas outlet pipe. The openings 12 and 14 preferably face in substantially the same direction as shown.

[0015] As noted above, the housing member 10 is symmetrical about plane B which divides the housing member into a first portion 42 and a second portion 44. Such symmetrical configuration enables the housing member 10 to receive the flow measurement tube in both a first orientation in which the openings 12 and 14 face upward and the inlet end 26 of the flow measurement tube 24 is positioned in portion 42 of the housing member and the outlet end 28 is positioned in portion 44 of the housing member 10, and a second orientation in which the openings 12 and 14 face generally downward and the inlet end 26 of the gas flow measurement tube 24 is positioned in portion 44 of the gas meter housing member and the outlet end 28 is positioned in portion 42. The housing member 10 also includes a divider plate 46 which extends across internal space 32 in alignment with and defining plane B. The divider plate 46 includes an outwardly facing edge 48 having at least one recessed portion 50 shaped to receive a portion of the flow measurement tube 24. Preferably, an internal perimeter shape of portion 42 and an internal perimeter shape of portion 44 are the same such that the perimeter shapes are mirror images of each other about plane B. This similarity of internal configuration facilitates receipt of the remaining gas meter assembly components within either portion as necessary.

[0016] Front portion 16 also includes a plurality of attachment apertures 52A and 52B arranged thereabout for connecting the gas flow measurement tube assembly thereto. Attachment apertures 52A are positioned to a first side of the divider plate 46 on portion 42 of the housing member 10 and attachment apertures 52B are positioned to a second side of the divider plate 46 on portion 44 of the housing member 10. Notably, the symmetrical nature of the housing member extends to the positioning of the apertures 52A and 52B about plane B of the housing member 10. As will be explained in greater detail below, the symmetry of the positioning of such attachment apertures 52A and 52B facilitates attachment of the housing member 10 to the remaining components of the ultrasonic gas meter assemblies in an orientation in which openings 12 and 14 extend upward and an orientation in which openings 12 and 14 extend downward.

[0017] Referring to FIG. 2, one configuration for an ultrasonic gas meter assembly incorporating the housing member 10 is shown in which the housing member 10 is positioned with openings 12 and 14 facing substantially upward for connection to downwardly extending gas inlet pipe 54 and gas outlet pipe 56. Any known gas pipe connection arrangement can be used with the present invention. The flow tube assembly 18 includes gas flow measurement tube 24 and a connection plate 58 to which the gas flow measurement tube 24 is attached by fasteners 60. Thus, the gas flow measurement tube 24 secures to plate 58 and the plate 58 is then secured to the housing member 10. In this regard, plate 58 is provided with a plurality of apertures 61 for attaching the flow tube assembly to the housing member 10 via alignment with the attachment apertures 52A and 52B thereof. The mounting apertures 61 align with the attachment apertures 52A and 52B. Fasteners 62 are then inserted within the aligned apertures. Importantly, the apertures 61 of plate 58 align with apertures 52A and 52B of housing member 10 both when the housing member 10 is positioned with openings 12 and 14 extending upward as shown in FIG. 2 and when the housing member 10 is positioned with openings 12 and 14 extending downward as shown in FIG. 3. In this regard, FIG. 3 shows a second configuration for the assembly. The recessed portion 50 of divider plate 46 is shaped and configured to receive a central portion of the gas flow measurement tube 24 when the flow tube assembly 18 is attached to the housing member 10.

[0018] Also shown in FIGS. 2 and 3 are transducers 20 which extend through openings 64 in the plate 58 so that they are positioned proximate the gas flow measurement tube 24 to direct ultrasonic signals along the length of the tube for gas flow measurement purposes. A battery 66 is provided for powering the transducers 20 and their associated electronics which are included on circuit board 68. In a preferred embodiment, the transducers 20 include a first transducer positioned toward the inlet end 26 of the gas flow measurement tube 24 and a second transducer positioned toward the outlet end 28 of the gas flow measurement tube 24. A third transducer may also be provided as is known in the art for speed of sound measurement. Front housing member 22 also includes a plurality of attachment apertures 70 which are positioned for alignment with a corresponding plurality of attachment apertures 72 which are also positioned on plate 58, particularly on projections 74 which extend from plate 58.

[0019] In the first assembly configuration shown in FIG. 2, when assembled the gas flow measurement tube 24 is positioned with inlet end 26 within portion 42 of the housing member 10 and with outlet end 28 positioned in portion 44 of the housing member 10. During operation in this configuration gas flows in inlet pipe 54, through opening 12, into inlet end 26 of gas flow measurement tube 24 and along the length thereof to outlet end 28, out of opening 14 and into gas outlet pipe 56. In the second assembly configuration shown in FIG. 3, the gas flow measurement tube 24 is positioned with inlet end 26 within portion 44 of housing member 10 and with outlet end 28 within portion 42 of housing member 10. In this configuration, during operation gas flows in gas inlet pipe 54, through opening 14 of housing member 10, into gas inlet end 26 of gas flow measurement tube 24 and along the length thereof to outlet end 28, through opening 12 of housing member 10 and into gas outlet pipe 56. In both configurations, the components of the gas meter assembly, other than the housing member 10, remain in a single configuration which is adapted for flow measurement from left to right relative to the front of the assembly. The housing member 10 is simply rotated 180 degrees as necessary to attach to either downwardly extending pipes 54 and 56 of FIG. 2 or upwardly extending pipes 54 and 56 of FIG. 3. Thus, the housing member 10 and its manner of connection to the remaining components of the system facilitates a multi-configuration gas meter assembly which can be used in both types of installations. This multi-configuration assembly therefore eliminates the need for manufacturing two different gas meter assemblies and the related cost which would be associated therewith.

[0020] Housing members 10 and 22, and plate 58 may be formed from any suitable material such as a molded plastic, or other materials commonly used in the art.

[0021] While the forms of the apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and changes may be made therein without departing from the scope of the invention.

[0022] For example, slight differences between the internal perimeter shape of portions 42 and 44 of the housing member 10 could exist where such differences do not interfere with connection to the remaining components of the ultrasonic gas meter assembly. Further, while attachment apertures are provided on both housing member 10 and plate 58 for alignment in both assembly configurations, it is recognized that housing member 10 could instead be provided with similarly positioned threaded extensions which would pass through the attachment apertures of plate 58, with nut-type members then being threaded onto the threaded extensions. Still further, while a generally rectangular shaped housing is shown in the preferred embodiment, it is contemplated that other housing shapes could be provided without departing from the scope of the invention.