The present invention relates to utility meter transceivers generally and to sealing and or potting them within external enclosures in particular.
In temperate climates, water service lines may be buried in the ground. Access to utility meters attached to such service lines may be via a meter-pit, such as meter pit 1 of
Transceiver assembly 6 may periodically read utility meter 5, or upon command from a data collection device (not shown). Data collected may include indexes, statuses and alarms and other readings. Data collected is transmitted wirelessly to a data collection device.
As described in U.S. Pat. No. 5,825,303, transceivers used in water-pits and external applications need to be sealed into enclosures to protect them against water, humidity, and dust. As shown in
Transceiver board 12 comprises a printed circuit board with a number of sections. For example; an RF-transceiver to communicate with a data collection device (not shown), a central processing unit (CPU) to process meter data and handle data transmission, a battery to power the transceiver (not shown) and an onboard antenna 18. Transceiver board 12 may be connected to one or more utility meters 5 via interface cables 11. It should be noted that when in use, the preferred orientation for transceiver assembly 6 may be so that antenna 18 is topmost, but this is not always the case. In
U.S. Pat. No. 10,164,320 teaches that encasing antenna 18 of such a transceiver assembly 6 in potting compound 14 has a negative impact on the operation of antenna 18 and hence the performance of transceiver assembly 6.
As shown in
There is therefore provided, in accordance with a preferred embodiment of the present invention a sealed utility transceiver assembly. The assembly includes a transceiver board, a sealed housing, and a measure of liquid potting compound. The transceiver board includes multiple components and an antenna, the sealed housing includes a cavity within which to house the transceiver board. The measure of liquid potting compound encapsulates a portion of the transceiver board within the sealed housing, which portion does not include the entirety of the antenna.
Moreover, in accordance with a preferred embodiment of the present invention, the sealed housing includes a first part and a second part, such that the first part and the second part combine to form the sealed housing. and the first part and the second part is either a cylindrical shaped enclosure with an interlocking cylindrical shaped cap, or two parts of a non-uniform shaped enclosure.
Further, in accordance with a preferred embodiment of the present invention, the non-uniform shaped enclosure includes an attachment means to attach the assembly to a utility meter.
Still further, in accordance with a preferred embodiment of the present invention, the utility is water, gas, electricity, energy, or fuel.
Additionally, in accordance with a preferred embodiment of the present invention, the sealed housing includes an interface-opening in the sealed housing to enable an interface cable from the transceiver board to exit the sealed housing.
Moreover, in accordance with a preferred embodiment of the present invention, the interface-opening includes a gasket inside the interface-opening to seal the interface cable within the interface-opening and to stop the measure of liquid potting compound from leaking from the interface-opening.
Alternatively, in accordance with a preferred embodiment of the present invention, the sealed housing further includes a means of ingress, and a means to seal the means of ingress. The means of ingress to enable the measure of liquid potting compound to be added to the sealed housing, and the means to seal the means of ingress after addition of the measure of liquid potting compound.
Further, in accordance with a preferred embodiment of the present invention, the antenna is either a dipole antenna, or a monopole antenna.
Still further, in accordance with a preferred embodiment of the present invention, the dipole antenna includes a printed PCB antenna, multiple antenna-elements, a non-LRC impedance matching antenna element, and a second antenna pole. The printed PCB antenna is printed on two sides of the transceiver board, the multiple antenna-elements are attached to the printed PCB antenna, such that the printed PCB antenna implements a first antenna pole of the dipole antenna. The non-LRC impedance matching antenna element increases the gain of the dipole antenna, and adjusts the total impedance of the dipole antenna to match the output impedance of the transceiver board, and the second antenna pole is implemented with a portion of the electrical components of the transceiver board.
Additionally, in accordance with a preferred embodiment of the present invention, a portion of the non-LRC impedance matching antenna element and the second antenna pole are completely covered by the measure of liquid potting compound.
There is also provided, in accordance with a preferred embodiment of the present invention, a method for assembling a sealed utility transceiver assembly. The method includes partially filling the assembly with a measure of liquid potting compound, the assembly including a transceiver board, multiple components, an antenna, and a sealed housing including a cavity within which to house the transceiver board. The method also includes repositioning the assembly to enable the measure of liquid potting compound to settle away from the antenna.
Further, in accordance with a preferred embodiment of the present invention, partially filling includes pouring the measure of liquid potting compound through the means of ingress.
Still further, in accordance with a preferred embodiment of the present invention, the method also includes, before partially filling, inserting the transceiver board into the sealed housing, the sealed housing including a first part and a second part, connecting the first part and the second part to form the sealed housing, the sealed housing having a means of ingress for the measure of liquid potting compound and a means to seal the means of ingress, and sealing the means of ingress after partially filling.
Additionally, in accordance with a preferred embodiment of the present invention, the first part and the second part is either a cylindrical shaped enclosure with an interlocking cylindrical shaped cap, or two parts of a non-uniform shaped enclosure.
Alternatively, in accordance with a preferred embodiment of the present invention, the non-uniform shaped enclosure includes an attachment means to attach the assembly to a utility meter.
Further, in accordance with a preferred embodiment of the present invention, the utility is water, gas, electricity, energy, or fuel.
Still further, in accordance with a preferred embodiment of the present invention, the method also includes, after partially filling, inserting the transceiver board into the sealed housing, the sealed housing including a first part and a second part, connecting the first part and the second part to form the sealed housing, the sealed housing having a means of ingress for the measure of liquid potting compound and a means to seal the means of ingress, and sealing the means of ingress after partially filling.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention.
Applicant has realized that the antenna does not need to be completely free of potting compound and the transceiver can operate adequately with small quantities of potting compound on the antenna, as explained herein below.
Reference is now made to
Reference is now made to
First, as shown in
As shown in
Then, as indicated in
Then, as indicated in
After liquid potting compound 56 solidifies, it may seal transceiver board 47 within housing 40 and may leave antenna 54 in a cavity at the closed end 45 of first part 40A.
Applicant has tested exemplary antennas described hereinbelow, in an anechoic chamber, with and without residual potting compound 58 on them, and the recorded antenna gain is not materially affected within the 902-928 MHz frequency range. The table of results in
As can be seen by a comparison of the tables of results in
Thus, antennas which are generally, though not entirely, free of potting compound, may still perform acceptably. It should be noted that this residual potting compound method may be applicable to antennas operating in all frequency bands and across all antenna designs.
In an alternative embodiment, as illustrated in
However, in this embodiment, as illustrated in
Reference is now made to
As illustrated hereinabove, the preferred embodiments of the present invention may comprise a sealed housing 40 that may further comprise a first part 40A with cylindrical profile, and a second part 40B with a similar interlocking cylindrical profile. First part 40A may have a single cavity, and may be manufactured as a single part, with a closed end 45 and an open end 43 into which transceiver board 47 may be inserted and second part 40B used to seal open end 43.
Applicant has realized that the abovementioned method to seal transceiver boards is not limited to housings with cylindrical profiles, that may be manufactured from a first part 40A with an attached second part 40B, or even as a housing 40 comprising a single cavity.
Reference is now made to
It will be appreciated that the enclosure and associated transceiver board used with the above-mentioned potting method, may not be limited in shape, size or method of construction. Any enclosure and transceiver design may be appropriate as long as such an enclosure has a means of ingress, such as a port, hole, or other opening for liquid potting compound to be introduced into the enclosure, and a means to seal the ingress such that the liquid potting compound stays within the enclosure. The assembly may also allow liquid potting compound to flow away from the antenna of the transceiver board during sealing, by inverting or otherwise repositioning the assembly, leaving only small quantities of potting compound on the antenna. Likewise, it will be appreciated that the number of cavities, and the number of openings and the number of associated transceiver boards may also not be limited, as long as potting compound may flow away from any antennas during the sealing process. It will also be appreciated that in a multi-cavity embodiment, potting compound may be added in a plurality of steps and an enclosure inverted or otherwise repositioned a plurality of times, such that potting compound may settle away from all antennas within the enclosure.
It will also be appreciated that the type of transceiver being sealed may not be limited to a specific utility such as water, and also not be limited to the type of meter, whether it be a mechanical meter reader as in
It will be appreciated that sealing transceivers in enclosures that may be left for extended periods of time in, wet, corrosive, dusty environments, may extend the operational lifespan of such devices. by protecting them from ingress of damaging pollutants.
Reference is now made to
Multi-element array PCB antenna 71 comprises vertical array elements 76 attached to one side of transceiver board 47, as shown in
Applicant has realized that a printed circuit board (PCB) antenna implementation significantly reduces the cost of manufacture, transceiver failure rate and cost. The arrangement of elements 76 and 77 minimizes the effects of transmission wave reflections on obstacles near to the antenna, described in the art as a low voltage standing wave ratio (VSWR) antenna. Low VSWR antennas are highly desirable in water-pit applications as pits contain many such obstacles. Low VSWR antennas have longer transmission distances and reduced power drain on the transceiver board battery 79. This gives transceiver installations a longer maintenance lifecycle.
Applicant has realized that by using components 74 on transceiver board 47 as a second antenna pole, the gain of antenna 70 may be higher than antennas previously utilized in utility pit applications, specifically those mentioned in US patent publications: U.S. Pat. Nos. 10,164,320, 5,825,303 and 2010/0026515A.
Applicant has also realized that antenna 70 can operate adequately when its first pole, i.e. multi-element array PCB antenna 71, may be covered with small amounts of potting compound 58 (as shown in
Impedance matching element 73 may be an additional transmitting and receiving element of antenna 70, and may be a calibrated PCB trace that adjusts the total impedance of antenna 70 to match the output impedance of transceiver 78. It may not be an impedance matching circuit, or pad, comprising inductive, resistive, and capacitive components (known in the art as an LRC circuit). The length and shape of impedance matching element 73 may be calibrated to sufficiently adjust the impedance of dipole antenna 70 to equal 50-ohms. It will be appreciated that employing an LRC pad in a transceiver, increases the manufacturing cost and complexity, and increases failure rates.
Applicant has realized that by connecting antenna 70 to transceiver 78 with an antenna element that may be a calibrated PCB trace, manufacturing complexity may be reduced, and reliability increased.
Applicant has also realized that power that would be wasted in an LRC pad can be used to increase the gain of antenna 70.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
This application claims priority from U.S. provisional patent application 63/112,679, filed Nov. 12, 2020, which is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/IL2021/051342 | 11/11/2021 | WO |
Number | Date | Country | |
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63112679 | Nov 2020 | US |