Abstract:
A method and apparatus for coupling a meter register to a communication device such that output data signals from the meter register can be transmitted to a remote location. The coupling arrangement includes a data transfer wire that is connected to the meter register and is inductively coupled to the communication device such that the data transfer wire does not need to be conductively connected to the communication device. During installation of the communication device, the inductive coupling between the data transfer wire and the communication device eliminates the requirement of a conductive connection.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention generally relates to the automatic reading of utility meters. More specifically, the present invention is related to a method and apparatus for coupling a meter register to an automatic meter reading communication device without any wired connections.  
         [0002]     A long standing problem in the utility industry is the economic reading of the utility meters without inconvenience to the homeowner. The problem is especially acute in connection with the reading of water meters. In geographic areas that are subject to freezing temperatures, it has in the past been necessary to install the meters within the residence to prevent damage to meter when the temperature drops such that the water within the meter freezes. However, the reading of such meter installations presents a number of problems, such as the inconvenience to the homeowner as well as the inconvenience to the meter reader when the homeowner is not present at the time of the individual meter reading.  
         [0003]     In addition, manual meter reading has a significant disadvantage in that it requires a large amount of manpower, leading to significant expense. Further, meter readers may erroneously record the numeral values of the meter register or the homeowner may not be present at the time the meter reading is to take place.  
         [0004]     One solution to these problems in the past was to provide a remote register that is located outside of the residence, preferably on the exterior walls of the residence. The register is typically electrically connected to the device on the meter within the resident that provides pulses or other electrical signal representative of the volumetric flow of the water through the meter. Although this system addresses the problem of inconvenience to the homeowner, the solution still requires the manual reading of the meter on a periodic basis.  
         [0005]     In order to solve the personnel requirements of physical meter reading, a large number of remote meter reading units have been developed. These meter reading units may be, for example, an automatic meter reading (AMR) unit. The meter register comprises a sensor to detect the rotational movement of components within the meter to generate an electronic count of the volume of commodity that flows through the meter. The recorded data from the meter is broadcast by a communication device of the AMR unit using an RF signal. In such types of systems, the meter measurement is broadcast from the communication device using an RF signal that can be read from a remote location. In these remote meter reading systems, the antenna of the communication device typically extends slightly above a pit lid such that the radio frequency signals generated by the antenna can be transmitted away from the meter pit. In many situations, the pit lid is formed from a metallic material, such as iron, that significantly inhibits the transmission of radio frequency signals therethrough.  
         [0006]     In current AMR applications being developed, a radio transmission circuit including an antenna is used to transmit meter-related information over a relatively long distance, such as up to one-half mile. The use of an AMR radio to transmit meter-related information over a relatively long distance allows the meter data to be read from a remote location and eliminates the requirement of a meter reader physically interrogating the meter from a location proximate to the meter. Such an AMR system is able to transmit meter-related information from the meter to a remote location, such as a gateway node, located within the neighborhood of the meter to be read. This type of remote meter reading dramatically reduces the amount of manpower required to obtain meter readings.  
         [0007]     In a typical installation of an AMR communication device, which often times includes an RF transmitter, the communication device is connected to the meter register through a three wire connection. The three wire connection requires the physical interconnection between the communication device and the meter register. Typically, the wire connections are made by a service technician during initial installation by using a gel-cap splicing kit to ensure a weather tight and secure electrical connection between the wires from the meter register and the communication device. Although the gel-cap electrical connection between the communication device and the meter housing functions adequately once installed, the electrical connection requires service personnel to take additional steps when installing a meter or when retrofitting an existing meter with the communication device.  
         [0008]     Therefore, a need exists for an improved method of transmitting information from the meter register to the communication device that eliminates the conductive connections required in most field installations. Further, a need exists for a dependable and secure connection between the communication device and the meter register that can be completed in the field with minimal time requirements and ensures a proper connection. Further, a need exists for a communication device that can be installed quickly and easily with existing, installed meter registers.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention relates to a unique coupling between an electronic meter register and a communication device such that output data signals from the electronic meter register can be received by the communication device and the relevant consumption data from the meter can be transmitted using radio frequency transmission. The signal coupling between the electronic meter register and the communication device is completed without any conductive connection and utilizes inductive coupling between a pair of inductive coils.  
         [0010]     The communication device is positioned at a location remote from the electronic meter register. Typically, the communication device of the present invention is suspended beneath the pit lid that covers a pit enclosing the utility meter including the electronic meter register. The communication device includes electronic circuitry, an internal power supply and an antenna within an environmentally protected inner enclosure. The sealed enclosure of the communication device includes a front wall, behind which is positioned at least one inductive coil. The inductive coil positioned behind the front wall of the inner enclosure is electrically coupled to the electronic circuitry of the communication device. Preferably, the communication device includes more than one inductive coil such that the communication device can be used to receive output data signals from more than one electronic meter register.  
         [0011]     The sealed inner enclosure of the communication device is surrounded by an outer mounting shell that includes multiple attachment openings, each of which can receive a receptacle port. Preferably, each of the attachment openings are aligned with one of the inductive coils included within the inner enclosure of the communication device.  
         [0012]     The receptacle ports can be selectively positioned on the outer shell of communication device depending upon the number of electronic meter registers utilized with the single communication device. In each case, the receptacle port is generally aligned with one of the inductive coils within the sealed inner enclosure. The receptacle ports include an inner cylindrical cavity and include a pair of flexible fingers used to secure a connector module within the receptacle port.  
         [0013]     The electronic meter register includes a data transfer wire that is conductively connected to the electric meter register at a first end prior to installation of the electronic register. The second end of the data transfer wire includes a connector module having an outer enclosure surrounding an inductive coil. The connector module preferably has a cylindrical outer wall and includes a potting material that seals the inductive coil within the connector module. The connector module includes a front face surface, behind which is positioned the inductive coil.  
         [0014]     The connector module of the data transfer wire is sized to be securely retained within the receptacle port formed on the communication device. When the connector module is received and retained within the receptacle port, the first inductive coil of the connector module is spaced from the second inductive coil included in the communication device and generally aligned with the receptacle port. However, the proximity between the first inductive coil and the second inductive coil is sufficient to permit signals present at either coil to be received through an inductive coupling at the other inductive coil. In this manner, the signal connection between the electric meter register and the communication device can be completed through inductive coupling without the requirement of any conductive connection. In addition to the signal transfer between the inductive coils, power can be transferred from the communication device to the meter register through the inductive coupling.  
         [0015]     Once the output data signal is received at the second inductive coil in the communication device, the electronic circuitry contained within the communication device generates an RF signal including the selected portions of the consumption data from the meter register. The RF signal including the relevant consumption data can be transmitted by the antenna included within the communication device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The drawings illustrate the best mode presently contemplated for carrying out the invention. In the drawings:  
         [0017]      FIG. 1  is a partial sectional, perspective view of a utility meter including an electronic meter register coupled to the communication device mounted to the pit lid;  
         [0018]      FIG. 2  is a perspective view illustrating the coupling between the communication device and the connector module of the data transfer wire;  
         [0019]      FIG. 3  is a front view illustrating the data transfer wire secured to the communication device;  
         [0020]      FIG. 4  is a top view taken along line  4 - 4  of  FIG. 3  showing the removable connection of the connector module to the communication device;  
         [0021]      FIG. 5  is a section view taken along line  5 - 5  of  FIG. 3 ; and  
         [0022]      FIG. 6  is a schematic illustration of the electronic circuitry contained within the communication device of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]     Referring first to  FIG. 1 , thereshow is a meter pit  10  that includes a utility meter  12 . In the embodiment of the invention illustrated, the utility meter  12  is a water meter that is positioned in a water supply line  14  buried within the ground  16  and extending through the meter pit  10 . Although the utility meter  12  will be described throughout the following description as being a water meter, it should be understood that the utility meter could be any of a variety of different types of meters for measuring different types of consumable commodities, such as gas, water, electricity or any other type of commodity.  
         [0024]     As illustrated in  FIG. 1 , the meter pit  10  extends below the ground surface  18  and is defined by a pit box  20 . The pit box  20  is a cylindrical, metal enclosure that is submerged in the ground  16 . The pit box  20  includes an upper ledge  22  that supports a pit lid  24 . In the embodiment of the invention illustrated, the pit lit  24  is preferably formed from a metallic material, such as cast iron. The pit lid  24  encloses the meter pit  10 .  
         [0025]     The utility meter  12  includes a meter register  26  that is mounted to the meter body  28 . Preferably, the meter register  26  is an electronic meter register that includes internal circuitry that monitors the rotational movement of components contained within the meter body  28 . The electronic meter register is a common commercial component that detects the rotational movement of components within the meter body  28  and generates an electronic count of the volume of commodity that flows through the meter  12 . The electronic meter register  26  records the volumetric flow information received from the meter body  28  in a conventional manner. An example of an electronic meter register is the Sensus ICE meter register.  
         [0026]     As illustrated in  FIG. 1 , the electronic meter register  26  includes a data transfer wire  30  that extends through the top wall  32  of the meter register  26 . The first end of the data transfer wire  30  is conductively connected at the manufacturing facility to the internal circuitry of the electronic meter register  26 . The electronic meter register  26 , including the data transfer wire  30 , are conventional components and are currently in use in automatic meter reading units, such as the Sensus Radio Read® meter transceiver unit (MXU). In the prior art systems, such as the Sensus Radio Read® MXU, the second end of the data transfer wire  30  is conductively connected to an external communication through the use of physical wire connections that are secured using gel caps. As discussed previously, this type of physical interconnection between the data transfer wire  30  and a communication device requires the use of gel caps and manual interconnection to the MXU.  
         [0027]     Referring now to  FIG. 2 , thereshown is the second end  34  of the data transfer wire  30 . The second end  34  includes a connector module  36 . The connector module  36  preferably includes a cylindrical outer wall  38  formed from a molded plastic material. The outer wall  38  is integrally molded with and extends from a front face surface  40  to a back surface  42 . The second end  34  of the data transfer wire  30  extends into the open interior defined by the outer wall  38  and is connected to a first inductive coil  44 . The inductive coil  44  is centered within the cylindrical open interior defined by the outer wall  38  and is spaced inwardly from the front face surface  40 , as can best be seen in  FIG. 4 . The inductive coil  44  is electrically connected to the second end  34  of the data transfer wire  30  such that an output data signal generated by the electronic meter register is present at the inductive coil  44 .  
         [0028]     The connector module  36  includes a sealing or potting material  46  ( FIG. 2 ) that surrounds the inductive coil  44  to prevent water from contacting the inductive coil  44 . The data transfer wire  30  includes an outer, waterproof sheath that prevents water from contacting the electric wires contained within the data transfer wire  30 .  
         [0029]     Referring back to  FIG. 2 , thereshown is a communication device  48  of the present invention. The communication device  48  includes internal circuitry, as will be described in greater detail below, that receives an output data signal from the electronic meter register  26  that includes consumption data for the meter. The internal circuitry extracts to relevant consumption data and broadcasts a signal by radio frequency for reception and reading at a remote location. The communication device  48  is supported beneath the pit lid  24  and electronically coupled to the electronic meter register  26  through the data transfer wire  30 . The communication device  48  includes a main enclosure body  50  suspended beneath the pit lid  24 .  
         [0030]     Referring now to  FIG. 3 , the communication device  48  includes an upper housing  52  that extends through an opening  54  formed in the pit lid  24 . Specifically, the upper housing  52  includes a mushroom shaped top cap  56  having an outer diameter greater than the diameter of the opening  54 . A bottom surface  58  of the top cap  56  contacts the top surface  60  of the pit lid  24 . The upper housing  52  includes an externally threaded body  62  that extends through the opening  54  and is securely attached to the main enclosure body  50 . A locking nut  64  is threadedly received along the body  62  and is tightened into contact with the bottom surface  66  of the pit lid  24 . The threaded movement of the locking nut  64  into contact with the bottom surface  66  prevents the upper housing  52  from being removed from the opening  54 .  
         [0031]     Referring now to  FIG. 5 , the main enclosure body  50  generally includes a sealed inner enclosure  68  that is surrounded by an outer shell or boot  70 . The inner enclosure  68  is a general rectangular member that completely encloses the electronic circuitry  72  of the communication device  48 . The inner enclosure  68  includes an opening that allows an antenna  74  to be connected to the electronic circuitry  72 . The antenna  74  is encapsulated in a protective block  76  that rests on the top wall  78  of the inner enclosure  68 . The protective block  76  is preferably formed from UHMW plastic and received within the corresponding central opening  80  formed in the upper housing  52 . The protective block  76  provides a water tight enclosure surrounding the antenna  74 . The combination of the protective block  76  and the inner enclosure  68  provides a water resistant environment for the electronic circuitry  72  and antenna  74  of the communication device  48 .  
         [0032]     Referring back to  FIG. 2 , the outer shell  70  includes a front face surface  82 , a pair of side surfaces  84 ,  86 , a top surface  88 , a bottom surface  90  and an open back. As illustrated in  FIG. 5 , the top surface  88  includes a pair of projecting flanges  92  that engage a corresponding pair of grooves  94  in the upper housing  52  to support the main enclosure body  50 .  
         [0033]     Referring back to  FIG. 2 , the front face surface  82  of the outer shell  70  includes a pair of receptacle attachment openings  96 . In the embodiment shown in  FIG. 2 , one of the attachment openings  96  is shown including a receptacle port  98  securely mounted in front of the attachment opening  96 . The receptacle port  98  can be selectively removed from the front face surface  82  and attached to the other attachment opening  96 . The shell  70  further includes a side opening  100  that is aligned with a programming port of the communication device.  
         [0034]     As best illustrated in  FIGS. 2 and 4 , the receptacle port  98  is defined by a cylindrical outer wall having an inner surface  104  defining a cylindrical open interior. The open interior of the receptacle port  98  is sized slightly larger than the outer surface  106  of the connector module  36 . The receptacle port  98  includes a pair of opposed flexible fingers  108  each having an inwardly extending outer end  110 . As illustrated in  FIG. 4 , each of the flexible fingers  108  can flex outwardly such that the outer ends  110  are separated by a distance greater than the outer diameter of the connector module  36 . As the connector module  36  is moved inwardly as illustrated by arrow  112 , the front face surface  40  contacts a back wall  114 . The back wall  114  generally corresponds to the outer surface of the inner enclosure. Once the connector module  36  is received within the receptacle port  98 , the flexible fingers  108  return to their normal position such that the outer ends  110  engage the back surface  42  of the connector module  36 , as best illustrated in  FIG. 3 . The interaction between the flexible fingers  108  and the back surface of the connector module  36  retains the connector module  36  within the receptacle port  98 , as illustrated.  
         [0035]     As shown in  FIG. 4 , a second receptacle module  98   a  can be positioned adjacent to the receptacle module  98  as shown. Thus, the communication device  48  can be configured to receive more than one connector module  36 , and thus coupled to more than one data transfer wire  30 .  
         [0036]     Referring now to  FIGS. 4 and 5 , the electronic circuitry  72  contained within the communication device  48  includes a second inductive coil  116 . The second inductive coil  116  is connected by a wire  118  to the electronic circuitry  72 . As illustrated in  FIG. 5 , the second conductive coil  116  is aligned with the first inductive coil  44  when the connector module  36  is received in the receptacle port  98 . The first and second inductive coils  44  and  116  are aligned such that a signal present at the first inductive coil  44  is transferred to the second inductive coil  116  by inductive coupling. Likewise, a signal present at the second inductive coil  116  can be transferred to the first inductive coil  44 . Thus, a signal can be transmitted from the first inductive coil  44  through the front face surface  40  of the connector module  36 , through the back wall  114  of the inner enclosure and received by the second inductive coil  116 . In this manner, a signal present on the data transfer wire  30  can be transferred to the electronic circuitry  72  without a conductive connection between the data transfer wire and the electronic circuitry.  
         [0037]     Referring now to  FIG. 4 , another inductive coil  116   a  can also be included in the communication device  48  such that the inductive coil  116   a  can be aligned with an inductive coil  44   a  of another connector module  36   a.    
         [0038]     Referring now to  FIG. 6 , thereshow is a schematic illustration of the internal circuitry for the communication device  48 . As illustrated, the communication device  48  includes electronic circuitry  72  that includes a receiving circuit  120  that receives a digital data signal from the inductive coil  116 . A transmission circuit  121  creates and transmits a RF signal including the relevant consumption data from the meter register. The electronic circuitry  72  is a conventional circuit currently in use, such as in the Sensus Radio Read® meter transceiver unit (MXU). As illustrated, the electronic circuitry  72  is powered by a power supply  120 . The power supply  120  supplies the required power for the transmission circuit  121  to generate an RF signal from the antenna  74  that can be received at a remote monitoring location. In addition to supplying the power to operate the transmission circuit  121 , the power supply  120  provides electric power to the meter register through the inductive coupling between the inductive coil  116  and the inductive coil  44  contained within the connector module. The power supplied through the inductive coupling to the electronic meter register allows the electronic meter register to generate the output data signal back to the communication device  48  through inductive coupling between the first inductive coil  44  and second inductive coil  116 .  
         [0039]     Referring back to  FIG. 1 , the operation of the system for transmitting consumption measurement data from the utility meter to a remote monitoring location will now be discussed. Initially, the meter body  28  is installed within the meter pit  10  in line with the water supply pipe  14 . Once the utility meter  12  is in place, the electronic meter register  26  is installed onto the meter body  28 . As described previously, the meter register  26  is a conventional component that converts mechanical movement within the meter body  28  into an electronic measurement that is stored within the electronic meter register  26 . Alternatively, the meter register  26  can be integrated with the meter body  28 .  
         [0040]     As illustrated in  FIG. 1 , the electronic meter register  26  includes the pre-installed data transfer wire  30  that extends through the top wall  32  of the meter register  26 . The data transfer wire  30  is attached at its first end to the electronic components contained within the electronic meter register  26 . As illustrated in  FIG. 2 , the second end of the data transfer wire includes the cylindrical connector module  36  that surrounds the first inductive coil  44 . When required, the electronic meter register  26  can generate an output data signal that includes the commodity consumption data to the first inductive coil  44 .  
         [0041]     As described previously, the communication device  48  is attached to the pit lid  24  by the interaction between the top cap  56  of the upper housing  52  and the locking nut  64 . As best shown in  FIG. 5 , the sealed inner enclosure  68 , which includes the electronic circuitry  72  for the communication device  48 , is received within the outer shell  70 . The outer shell  70  engages the upper housing  52  to support the inner enclosure  68  in the position shown in  FIG. 5 .  
         [0042]     As clearly illustrated in  FIG. 5 , the electronic circuitry  72  includes at least one inductive coil  116 . The inductive coil  116  is positioned behind the back wall  114  of the inner enclosure  68 . As illustrated, the inductive coil  116  is generally aligned with the first inductive coil  44  when the connector module  36  is received within the receptacle port  98 . In this manner, the output data signal from the electronic meter register can be inductively transmitted from the first inductive coil  44  to the second inductive coil  116 . The inductive coupling of the first inductive coil  44  and the second inductive coil  116  allows electronic signals to be transferred bi-directionally between the electronic meter register and the electronic circuitry  72  contained within the communication device  48 .  
         [0043]     Once the electronic signal is received by the electronic circuitry  72 , the electronic circuitry  72  extracts the relevant consumption data and the transmission circuit transmits the relevant consumption data using the antenna  74  that extends past the top surface  60  of the pit lid  24 , as illustrated in  FIG. 5 .  
         [0044]     As discussed previously, the outer shell  70  includes multiple attachment openings  96  that each can selectively receive one of the receptacle ports  98 , as best shown in  FIGS. 2 and 4 . As illustrated in  FIG. 4 , the electronic circuitry within the communication device  48  can be configured to have multiple internal inductive coils  116 ,  116   a  such that the communication device  48  can inductively receive information from more than one connector module  36 .  
         [0045]     Although the present invention has been described as including an inductive coupling between the data transfer wire  30 , which is conductively connected to the meter register, and the communication device  48 , it is contemplated by the inventors that the data transfer wire  30  could include an inductive coil contained within a connector module on both of its ends. The inductive coil and connector module on the first end of the data transfer wire would be received within a similar receptacle placed on the meter register. In this way, the consumption data from the meter register could be transferred to the data transfer wire using an inductive coupling similar to the inductive coupling shown and described between the data transfer wire and the communication device. Additionally, it is contemplated the inductive coupling between the communication device and the data transfer wire could be replaced by a conductive connection such that the inductive coupling would exist between the data transfer wire and the meter register, rather than between the data transfer wire and communication device.  
         [0046]     As can be understood by the above description of the present embodiment of the invention, the interconnection between the electronic meter register and the communication device is created by an inductive coupling between the two devices. Specifically, a connector module on the data transfer wire of the electronic meter register is inductively coupled across the enclosure of the communication device such that the physical wiring connections can be replaced. Eliminating the physical wire connections dramatically decreases the amount of time required to create the electrical connection while at the same time reducing the complexity of such connection.