WO2010112917A1

WO2010112917A1 - Connector

Info

Publication number: WO2010112917A1
Application number: PCT/GB2010/050545
Authority: WO
Inventors: Paul Richard Rowe
Original assignee: Navetas Energy Management Limited
Priority date: 2009-04-01
Filing date: 2010-03-30
Publication date: 2010-10-07
Also published as: WO2010112916A1; GB2471260A; GB2469155A; GB0917467D0; GB0905653D0; EP2414881A1; EP2414790A1

Abstract

The present invention provides a connector for connecting an optical fibre (10) with a utility metering system. In particular, the connector is for use with an optical fibre which transmits signals between a utility meter and communication means. The connector (100) is arranged to secure the end of the optical fibre (10) adjacent to the transceiver (108) through the engagement of a second engagement portion (120) provided on a collet (112) with a first engagement portion (122) on a ferrule (104). In particular, the ferrule (104) includes an outer annular groove (122) defined around the periphery thereof. The collet (112) provides a plurality of lugs (120) which are resilient and can therefore be moved from a disengaged position radially inwardly to an engaged position. A gland nut (114) is tightened to a housing member (110) which thereby causes the engagement of the optical fibre (10) in correct alignment within the housing member (110) of a utility meter (2).

Description

CONNECTOR

BACKGROUND

a. Field of the Invention

The present invention relates to connectors for utility meters and to a method of connecting an optical fibre within a utility meter system and more specifically the present invention relates to automated utility meter reading and smart utility meters.

b. Related Art

Utility bills are often based on estimates of usage and are frequently inaccurate. To generate a bill based on actual usage either requires the customer to take a meter reading and communicate this to the utility supplier or the supplier must send an employee to read the meter in person, which is both time consuming and expensive.

Smart meters can be used to take meter readings automatically. These are then transmitted back to a central database via a network. This has a number of advantages. Meter readings can be taken at regular intervals or on-demand. Furthermore, with meter readings being taken regularly it is possible to monitor energy usage so that a customer and/or utility supplier can see when there are peaks in usage and can introduce energy saving measures or adjust supply accordingly. Another benefit is the ability to easily read meters that would otherwise be difficult to access. Smart meters can also include means for transferring data to the meter allowing the utility companies to control aspects of the meter. This functionality may include, for example, start/stop functionality or the ability to adjust features of the system remotely.

Generally, current systems are battery powered. However, battery life is limited and typically it is the battery that determines the life of the meter. Batteries can last between five and ten years, but with greater functionality being introduced into smart metering such that frequent data transfer is required, this lifetime can be greatly reduced.

Any installation in a utility meter must be intrinsically safe. This is of particular concern with gas meters. A safe distance between the gas meter and any electrical items must be maintained in order to minimise the risk of a potential electrical fault causing an explosion. In many cases, gas meters are encased inside a meter box or other enclosed area. If a gas leak occurred, it is likely that the enclosed area would fill with gas, increasing the safety concerns. The use of mains electricity in water meters is also prohibited due to the risk of electric shock if the electricity supply were to make contact with the water.

There is, therefore, a need to provide smart meters for a range of utility meters that are safe and reliable. Furthermore, it is desirable for these meters to be able to transfer data reliably and frequently over a long time without requiring replacement.

Optical fibres may be used as a safe way of a utility meter connecting with a communication device in order to transmit signals. However, such optical fibres need to be accurately positioned relative to the transceiver in the system. Specialist tools and specialist fitters may be required to connect the optical fibres which makes the installation time consuming and expensive. In addition, the inlet/outlet for the optical fibres may provide problems with the ingress of matter into the utility meter and/or communication device.

It is an aim of the present invention to overcome at least one problem associated with the prior art whether referred to herein or otherwise.

SUMMARY OF THE INVENTION According to a first aspect of the present invention there is provided a connector for a utility meter for connecting an optical fibre relative to the utility meter and adjacent to a respective optical communication means located within a housing, the optical fibre comprising an outer sleeve located around an end thereof, the outer sleeve comprising a first engagement portion on an outer surface, the connector comprising an engagement member including a second engagement portion which is movable between a first engaged position and a second position, the connector comprising a coupling member which is arranged, in use, to be coupled to the housing and thereby locks the second engagement portion into the engaged position to retain the end of the optical fibre within the housing.

The coupling member may be arranged, in use, to lock the second engagement portion in the first engaged position.

The second position of the second engagement portion may comprise an unlocked position in which the second engagement portion may be free to move and may be free to move (radially) outwardly.

Preferably the coupling member prevents outward (radial) movement of the second engagement portion in the first engaged position.

Preferably, the optical communication means comprises a transceiver.

Preferably the coupling member comprises a nut including a threaded portion for engaging a corresponding threaded portion on the housing.

Preferably the coupling member comprises a gland nut.

The outer sleeve may comprise a short tubular section.

Preferably the outer sleeve comprises a ferrule. Preferably the outer sleeve is adhered to the optical fibre. Preferably the outer sleeve is adhered to a protective sleeve located around the optical fibre. Preferably the outer sleeve is adhered using an adhesive. The adhesive may comprise an epoxy resin adhesive.

Preferably the outer sleeve includes a recessed portion to provide the first engagement portion.

Preferably the recessed portion comprises a groove. Preferably the groove is an annular groove which extends around the complete outer periphery of the outer sleeve.

Preferably the recessed portion comprises a triangular profile.

Preferably a tip of the optical fibre is arranged to protrude from the outer sleeve.

Preferably the engagement member comprises an annular member including a resilient member which provides the second engagement portion. Preferably the second engagement portion includes a lug which may be deflected into and out of engagement with the first engagement portion. The second engagement portion may comprise a plurality of lugs which may deflect into and out of engagement with the first engagement portion.

Preferably the or each lug comprises an angled abutment surface which is arranged to abut a deflection surface provided on the coupling member.

Preferably the engagement member comprises a collet.

Preferably the connector comprises sealing means.

The sealing means may be arranged, in use, to seal the optical fibre within the housing. Preferably the sealing means comprises an annular seal. Preferably the annular seal comprises a compressible annular seal.

Preferably an outer surface of the seal is arranged to cooperate with an inner surface of the housing. Preferably an inner surface of the seal is arranged to cooperate with an outer surface of the outer sleeve.

Preferably the seal comprises an angled abutment surface which is arranged to abut a corresponding abutment surface provided on an inner portion of the housing.

Preferably, in use, engagement of the coupling member with the housing causes the sealing member to compress between an inner surface of the housing and an outer surface of the outer sleeve.

The housing may comprise retaining means to retain the optical communication means within the housing.

The housing may comprise a push fit retainer in order to retain the optical communication means within the housing. The housing may comprise a split tubular member to enable the optical communication means to be pushed into the housing and then to be retained therein.

Preferably the retaining means retains the optical communication means in a predetermined position within the housing.

The connector may be part of a kit which further comprises a blanking member which resembles the shape of an end of an optical fibre such that the blanking member can be engaged in the connector to close and seal an engagement opening in the housing of the utility meter. The connector may be arranged, in use, for incorporation in a metering system comprising a utility meter, communication means for communicating with a remote host and an optical fibre; wherein the optical fibre is arranged in use to transmit signals including a utility meter reading from the utility meter to the communication means, and wherein the communication means is arranged, in use, to be located spaced apart from the utility meter.

Preferably the optical fibre is arranged, in use, to transmit and receive signals.

Preferably the meter comprises an internal power source to power a transmitter in the meter.

Preferably the system comprises an external power source to power the communication means.

Preferably the meter comprises a gas meter or water meter.

Preferably the meter includes a meter interface for processing signals between the utility meter and the optical fibre.

The meter interface may comprise a transmitter and/or receiver and preferably comprises a transceiver. The meter interface may comprise a transmitter-receiver.

Preferably the meter interface comprises a first transceiver which is arranged, in use, to transmit optical signals along the optical fibre to the communication means, and may receive optical signals from the optical fibre from the communication means.

The first transceiver may be an opto-electronic transceiver.

The meter interface may comprise sensors for detecting the status of the utility meter, and control circuitry for controlling functions of the utility meter. The power supply (internal power source) may comprise a battery.

The meter interface may comprise a printed circuit board.

Preferably the communication means includes means for processing signals between the remote host and the optical fibre.

The communication means may comprise a transmitter and/or receiver and preferably comprises and transceiver. The communication means may comprise a transmitter-receiver.

Preferably the communication means includes a second transceiver which is arranged, in use, to transmit optical signals along the optical fibre to the utility meter, and may be arranged, in use, to receive optical signals from the optical fibre from the utility meter.

The second transceiver may comprise an opto-electronic transceiver.

The means for processing signals may comprise a printed circuit board.

The communication means may communicate with the remote host via telephone lines, power lines, radio frequency networks, wi-fi, mobile data networks or by satellite communication.

The communication means may be located in another meter.

The communication means may be located in an electricity meter.

Preferably the meter comprises a cover. The cover may comprise a guide for receiving a first end of the optical fibre such that, in use, the optical fibre is held in a fixed position with respect to the first transceiver. Preferably the guide comprises a lens for focussing the light transmitted and/or received by the optical fibre.

The guide may be integral with the cover.

The lens may be integral with the cover.

According to a second aspect of the present invention there is provided a method of connecting an optical fibre relative to a utility meter and adjacent to a respective optical communication means located within a housing of the utility meter, the method comprising providing an outer sleeve around an end of the optical fibre and engaging a second engagement portion on an engagement member with a first engagement portion on the outer sleeve, the engagement comprising engaging a coupling member to a housing of the utility meter in order to move the second engagement portion relative to the first engagement portion in order for the engagement portions to engage.

The method may comprise the steps of transmitting optical signals from the utility meter to the communication means via an optical fibre and transmitting signals from the communication means to a remote host and wherein the communication means is located spaced apart from the utility meter.

The method may comprise receiving optical signals at the utility meter from the communication means.

The method may also include receiving a signal from the host and transmitting signals from the communication means to the meter via the optical fibre.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the present invention will now be further described, by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a cross section of an optical fibre located between a utility meter and a communication means;

Figure 2 is an exploded view of a preferred embodiment of an optical fibre, protective cover and ferrule;

Figure 3 is a side view of a preferred embodiment of an optical fibre including a protective cover and ferrules;

Figure 4 is an exploded view of a preferred embodiment of a connector including a blanking member;

Figure 5 is a cross section of a preferred embodiment of a connector connecting an optical fibre to a utility meter;

Figure 6 is a cross section of a preferred embodiment of a connector including a blanking member in the housing of the utility meter;

Figure 7 is a perspective partially cut away view of a preferred embodiment of an optical fibre including an outer sleeve and an engagement member;

Figure 8 is a schematic cross section of a preferred embodiment of an optical fibre including a protective cover and an outer sleeve;

Figure 9 is a side view of another embodiment of the present invention;

Figure 10 is a schematic view of a smart metering system for use with the present invention; Figure 11 is a detailed view of the means for restraining an end of an optical fibre to a meter; and

Figure 12 is an enlarged view of a part of the retaining means of Figure 11.

DETAILED DESCRIPTION

The present invention provides a connector for connecting an optical fibre with a utility metering system. In particular, the connector is for use with an optical fibre which transmits signals between a utility meter and communication means. The preferred utility metering system will be described in more detail later and the description will initially relate to the connector and associated assembly.

In general, fibre optical cables are normally connected to each other or to items of equipment by specialist connectors that align the optical fibre to the connector. The alignment is critical to achieve the lowest signal attenuation and degradation. The fibre is normally aligned in terms of positional axis alignment, distance from mating entity and rotational position alignment. The present invention is for use in a utility meter system in which the length, grade and communication rate of the optical fibre is limited. Accordingly, a low cost fibre optic connection method can be utilised.

The present invention has a number of aims and these include the alignment of the optical fibre to the optical transceiver devices, and to ensure that the distance from the end of the optical fibre to the transceiver device is within specifications. The present invention also seeks the alignment of the optical fibre to the optical transceiver devices, and to ensure positional axis alignment from the end of the optical fibre to the transceiver device is within specifications. The connector seeks to provide an easy to fit fibre optic cable that requires no specialist tools or training for the Installer. In addition, the present invention provides a method whereby the optical fibre can be installed after the transceivers have been installed. Furthermore, the present invention provides a method of "blanking off' the transceivers until (or after) the optical fibres are installed. Finally, the present invention aims to achieve the Ingress Protection (IP) Rating of the product the fibre is connected to.

As shown in Figure 1 , the present invention is for use with the connection of an optical fibre 10 which is provided to transmit signals from a utility meter 2 to a remote communication device 6. As further shown in Figure 2, the optical fibre is arranged to be surrounded and encased in a protective sleeve 102 or sheath. The optical fibre then has an outer sleeve in the form of a ferrule 104, 106 adhered to each end. In particular, the ferrules 104, 106 are glued in position at each end of the optical fibre 10, as show in Figure 3. The glue 124 may be applied over the surface(s) between the optical fibre 10 and the ferrule 104, as shown in Figure 8.

The present invention provides a connector 100 as shown in Figure 4 and Figure 5. The connector 100 is arranged to retain the optical fibre 10 in position relative to a transceiver 108 of the utility meter 2. The transceiver is arranged, in use, to locate within a housing member 110 of the utility meter 2.

The connector 100 includes an engagement member in the form of a collet 112. The collet is arranged to cooperate with a coupling member in the form of a gland nut 114. The connector also includes sealing means in the form of a seal 116.

The connector 100 is arranged to secure the end of the optical fibre 10 adjacent to the transceiver 108 through the engagement of a second engagement portion 120 provided on the collet 112 with a first engagement portion 122 on the ferrule 104. In particular, the ferrule 104 includes an outer annular groove 122 defined around the periphery thereof. The collet 112 provides a plurality of lugs 120 which are resilient and can therefore be moved from a disengaged position radially inwardly to an engaged position. More specifically, the ends of the lugs 120 can be engaged and locked in the groove 122 of the ferrule 104. In use, a threaded portion on an outer surface of the gland nut 114 engages with a threaded portion on an inner surface of the housing member 110. Relative rotation thereby causes the gland nut 114 to move towards the housing member 110. Inner angled surfaces on the lugs 120 abut with an angled surface 115 of the gland nut 114 which thereby deflects the lugs 120 inwardly into engagement with the annular groove 122 provided around the ferrule 104. The opposite end of the collet 112 is restrained for longitudinal movement by the seal 116.

The purpose of this groove 122 is for the collet 112 to grip the groove 122 when either the blanking piece 118 or optical fibre ferrule 104 is inserted into the housing 110. When the nut 114 is tightened, the collet 112 will grip either the blanking piece 118 or optical fibre ferrule 104 and locate it firmly into the housing 110.

The design of the groove 122 in the optical fibre ferrule 104 is so that the optical fibre 10 is correctly positioned with respect to the transceiver 108 in all respects.

The groove 122 comprises a triangular profile which corresponds with the triangular profile of the ends of the lugs 120. These corresponding triangular profiles ensure that the optical fibre 10 is gripped in an accurate position both longitudinally and radially. In addition, the corresponding triangular profiles help in the initial placement of the ferrule 104 in the connector 100 and also enable the ferrule 104 to be pulled out of engagement.

Similarly, as the gland nut 114 moves towards the housing member 110, the seal 116 is compressed. In particular, as the gland nut 114 moves relatively towards the housing member 110, an angled surface 117 of the seal member 116 abuts with a corresponding angled surface 111 of the housing 110. The opposite end of the seal 116 is restrained by the collet 112. The seal 116 is thereby compressed and forms an integrity retaining seal.

Briefly, when the nut 114 is tightened, the seal 116 is compressed against either the blanking piece 118 or the optical fibre ferrule 104, and provides a seal against penetration of dirt to the transceiver 108 and maintains the IP Rating of the product that the housing 110 is part of.

Figure 7 shows a detailed view of the ends of the lugs 120 engaged (but not locked) in the annular groove 122 of the ferrule 104. In this view, it can be seen that the ends of the lugs 120 may be arranged to locate within the lugs in their rest position. However, it will be appreciated that without the gland nut 114 the lugs 120 are free to move radially inwardly and outwardly such that the ferrule 104 can be simply pushed into and out of alignment. The natural rest position of the lugs 120 may help an operator to feel when the ferrule 104 is in the correct insertion depth. In further embodiments, the rest position of the lugs 120 may be different such that the lugs 120 may be in contact with the groove 122. Alternatively, the lugs 120 may be separated by a distance greater than the diameter of the outer periphery of the ferrule 104 such that the ferrule 104 can be inserted without contacting the lugs 120.

Overall, the present invention provides a quick and easy to use connector 100 for connecting an optical fibre 10 to a device (in particular, a utility meter 2 and/or an associated communication device 6) in which the connector 100 ensures an accurate alignment with the transceiver 108 and the IP rating of the device is retained.

The connector 100 is provided with a blanking member 118 as shown in Figure 6. The blanking member 118 resembles the end of the optical fibre 10 and the associated ferrule 104. In particular, the blanking member 118 has the same dimensions and profile as the end of the optical fibre 10 and the associated ferrule 104. In addition, the blanking member 118 includes a retaining groove 119 to replicate the groove 122 provided on the ferrule 104. When the optical fibre 10 is not connected to the utility meter 2 the blanking member 118 can be inserted and retained in the opening in order to protect the utility meter 2 and retain the integrity of the device. When the device is ready for connection, the blanking member 118 can be simply removed to enable the optical fibre 10 to be connected to the device.

As shown in Figure 8, the optical fibre 10 includes a tip 126 which is arranged to protrude slightly with respect to the ferrule 104. The tip 126 is arranged to protrude by a small distance 128 so that the light diverges into and out of the optical fibre 10.

The connector also comprises means for retaining and securing the transceiver 108 in the correct position, as shown in Figure 9. The housing member 110 includes a rear housing portion 134 which is arranged, in use, to locate within the main housing of the utility meter 2. The rear housing portion 134 includes a retainer 130 in the form of a push fit retainer 130. The push fit retainer 130 includes a short tubular section which includes a split or gap 132 extending longitudinally along a short length of the tubular section. The short tubular section may include two (or more) such gaps 132 which may be located 180 degrees apart around the circumference of the short tubular section. These gaps 132 enable the effective circumferential profile of the retainer 130 to be temporarily expanded to enable the transceiver to be pushed in. Once the transceiver 108 has been pushed in the retainer snaps back in to place behind the body of the transceiver in order to securely retain the transceiver 108. Accordingly, the retainer 130 has a split end design so that as the transceiver 108 is inserted into the end of the housing member 110 the end of the housing member 110 expands and snaps back into place. This clip feature grips the body of the transceiver 108.

In summary, the connector 100 of the present invention uses a gland nut 114, collet 112 and seal 116 as a means of achieving a low cost method of positional axis alignment of the optical fibre 10, optical fibre positional distance from the transceiver 108 and maintaining the IP Rating of the product that the optical fibre 10 is connected to. The gland nut 114, collet 112 and seal 116 are fitted to the housing 110 (in the product the optical fibre 10 is fitted to). The transceiver 108 is also fitted to the housing 110. The gland nut 114 is inserted but not tightened. It is then possible to insert a blanking piece 118. This blanking piece 118 mimics the size and shape of the optical fibre assembly, and prevents any unwanted items passing by it and reaching the transceiver 108. The blanking piece 118 can easily be removed at a later stage, by loosening the gland nut 114 and pulling out the blanking piece 118.

The blanking member 118 is arranged to have the same shape, size and profile as the end of the optical fibre 10 including the ferrule 104, 106. Accordingly, when the optical fibre 10 is not connected to the utility meter 2 the blanking member 118 can be used to protect the utility meter 2.

Figure 10 shows a schematic of a smart metering system 1 which is suitable for use with connectors 100 of the present invention. In this example the metering system 1 is being used to take readings from a gas meter 2. However, the system may be applied to any utility meter or similar and, in particular, may relate to water meters or electricity meters.

The smart metering system 1 comprises a meter 2, a communication means 6 for communicating with a remote host 8 and an optical fibre 10 connecting the meter 2 and to the communication means 6. The optical communication means 10 may comprise a single optical fibre or may comprise a bundle of optical fibres.

The remote host 8 may be a utility company or other company responsible for billing or for maintenance of the meter 2. The remote host 8 may be one or more computers, which may be linked by a local network, and which may be located in a central building. Alternatively, the remote host 8 may be a person, possibly employed by a utility company, who is able to collect data from a number of meters using a handheld device. The handheld device may be able to collect data from individual meters at a distance so that the person does not have to approach each meter, but may simply walk or drive past a row of houses.

Each gas meter 2 typically has a display 16 which shows the current meter reading. This display 16 may be mechanical, in the form of a dial or a counter with numbered rings that rotate as gas flows through the meter 2, or the display 16 may be a battery powered LCD display. The gas meter 2 includes a conventional mechanical bellows system which records the volume of gas through the meter 2. The hazards and specific regulations specify that electrical measuring systems cannot be used in gas meters and the like.

The meter 2 also includes a meter interface 4 which is permanently installed in the meter 2. This interface 4 is adapted to receive data from and transmit data to the meter 2. The meter interface 4 will typically comprise a printed circuit board. The meter interface 4 includes one or more sensors 18 for collecting data from the meter 2 and in particular for obtaining the current meter reading. Other forms of data may also be collected from the meter 2, for example gas flow rates or battery life. In order to power the meter interface 4, a very low voltage power supply 20 is required. This will generally be a battery 20 connected to the printed circuit board. Alternatively, if a battery is already used within the meter to power, for example, the display 16, then the meter interface 4 may be connected to this battery. The meter interface 4 also includes control circuitry 22, used to control various aspects of the running of the meter 2. This control circuitry 22 may also be provided on a printed circuit board.

The present invention provides an optical fibre 10 which connects the meter interface 4 of the utility meter 2 to a communication means 6 which is located at a distance from the meter 2. In particular, the communication means is able to be located spaced apart at a safe distance from the utility mater. The communication means is, therefore, not restricted to the use of a very low power source which would present a significant risk if it was located in or near the utility meter. This distance thereby enables the communication means to be used frequently and as and when required. As previously explained, previous utility meters may have had to use very low power sources within a meter so as to avoid the risks associated with a gas leak etc. Such low power sources therefore restrict the amount of use of a communication means since these are generally relatively high in power consumption. These meters may only be able to transmit the meter reading infrequently and have a short life span as the power source expires.

If only a low powered communication device is enabled then this may be restricted to a radio frequency device. Such communications may not be secure and are susceptible to interference and are may not be available in some locations due to obstructions etc.

Removable batteries for recharging purposes would introduce further problems with users being able to tamper with the system and/or introduce the opportunity of problems associated with theft. An electronic communication connection from the utility meter also introduces significant risks and expense. For example, expensive isolation boxes and equipment may be required to try and minimise the risks.

Accordingly, the present invention provides optical communication means to transmit the meter reading to a communication device which can be located at a safe distance from the utility meter. In particular the communication means and the associated power sou rce can be located in a free air space . The communication means may be spaced apart from the gas meter by less than 1 metre or possibly 2 metres or at any intrinsically safe distance. However, in the present system the minimum distance can be specified by the utility company or operating company.

A first transceiver 24 is connected to or provided on the meter interface 4 and is in communication with a first end of the optical fibre 10. The transceiver sends signals from the meter 2 along the optical fibre 10, and receives signals from the optical fibre 10 from the communication means 6. Typically the first transceiver 24 is an opto-electronic transceiver able to both transmit and receive electrical and optical signals. In the preferred embodiment, the first transceiver comprises a Light Emitting Diode (LED). The LED acts as both a transmitter and a receiver. Typically, a gas meter 2 will be fully enclosed within a casing 3 which is usually including a clear plastics material. In particular, the gas meter 2 includes a front panel of a clear plastics material which enables a user to view the mechanism, and in particular, the display 16. In a preferred embodiment, the meter interface 4 is permanently fixed within this casing 3 and a hole 13 is provided in the casing 3 through which the optical fibre 10 passes. In order to allow the optical fibre 10 to be simply pushed into position from the outside of the casing 3, a guide 5 may be fixed to inside of the casing 3. The guide 5 acts to hold the end of the optical fibre 10 in the correct position so that it is in alignment with the first transceiver 24. The guide 5 is also preferably made from a clear plastics material. As shown in Figure 11 , the guide 5 is in the form of a tube 7 projecting from the inner surface of the meter casing 3. The tubular guide 5 may have a flange 9 at one end to allow the guide 5 to be joined to the inner surface of the casing 3, by, for example, adhesive or ultrasonic welding. Alternatively, the guide may be integrally formed with the casing 3. The distal end 11 of the tube 7 is closed so that no path exists between the outside and the inside of the casing 3. The end 11 of the tube 7 is made from a clear plastics material or glass, and may be moulded or otherwise shaped so as to form a lens to focus the light entering or leaving the optical fibre 10.

It is advantageous that the optical fibre 10 may be easily inserted into the guide 5 but should not pull out easily. To achieve this, the edges of the hole 13 in the casing 3 are bevelled, so that the diameter of the hole 13 at the inner surface 15 of the casing 3 is smaller than the diameter of the hole 13 at the outer surface 17 of the casing 3, as shown in Figure 12. The bevel is such that the diameter of the hole 13 at the inner surface 15 of the casing 3 is also smaller than the diameter of the bore of the tubular guide 5. Part of the casing 3 therefore projects into the hole 13 and acts to grip the optical fibre as it is pushed into the guide 5. The direction of the slope of the bevel means that it is relatively easy to push the optical fibre 10 into the guide 5, but much more difficult to pull the optical fibre 10 back out the other way.

The retaining means may comprise any suitable retaining means for retaining the end of the optical fibre in position with respect to the relevant transceiver. The retaining means mat comprise a flexible gripping edge to retain the optical fibre or may comprise another device (for example, an arrangement similar to a household appliance plug).

The optical fibre 10 may have an outer covering, for example a (plastic) sheath to protect the optical fibre from scratches or dents. Alternatively, the optical fibre 10 may be encased within trunking or similar extending between the meter 2 and the communication means 6.

The second end of the optical fibre 10 is aligned with and in communication with a second transceiver 26 provided in the communication means 6. This second transceiver 26 is typically an opto-electronic transceiver and sends signals from the communication means 6 along the optical fibre 10, and receives signals from the optical fibre 10 and transmits them to the communication means 6.

The communication means 6 is used to transmit data from the meter 2 to the remote host 8 via a network 26 or other wireless means and to process control signals from the remote host 8, which are subsequently used to control the meter 2. Data and control signals may be transmitted using any of a number of well- known technologies. These include sending data via telephone lines or mobile networks, using radio frequency systems or by satellite communication.

The communication means 6 is powered using a low voltage power supply 28. In one embodiment the communication means 6 is installed in an electricity meter. The communication means 6 is then powered by a low voltage connection inside the electricity meter isolated from any mains voltage circuits. This has the advantage that the communication means 6 is powered by an existing supply, and in addition, the communication means 6 may also be set up to communicate with the electricity meter. In general, the communication means 6 should be situated away from the gas meter 2 so that there is sufficient distance between any electrical systems used in the communication means 6 and the gas supply. The communication means comprises a plastic guide/lens holder, a printed circuit board comprising electrical components. Wires extend from the communication unit to a low voltage power supply which may reside in an electricity meter.

Using this system, meter readings may be collected automatically at set periods or meter readings may be collected on-demand. In an on-demand system, a request is sent by the remote host 8 for a current meter reading. This request is sent via a suitable network to the communication means 6. The communication means 6 processes the request and an appropriate demand signal is sent along the optical fibre 10 by the second transceiver 26. The demand signal is received by the first transceiver 24 and processed by the meter interface 4. The sensors 18 obtain the current meter reading and this data is sent back to the communication means 6 via the optical fibre 10. The meter reading data is then transmitted to the remote host 8 via the network 26.

The present invention provides an intrinsically safe system of remotely communicating with a utility meter and, in particular, with a gas (or water) meter.

In a further embodiment of the present invention, the smart metering system includes a first optical fibre or first bundle of optical fibres for transmitting a signal from the meter to the communication means and a second optical fibre or a second bundle of optical fibres for transmitting a signal from the communication means to the meter. This provides an extra intrinsically safe communication method. This system may, therefore, include a first transmitter and a first separate receiver in the meter and a second transmitter and a second receiver in the communication means.

Claims

1. A connector for a utility meter for connecting an optical fibre relative to the utility meter and adjacent to a respective optical communication means located within a housing, the optical fibre comprising an outer sleeve located around an end thereof, the outer sleeve comprising a first engagement portion on an outer surface, the connector comprising an engagement member including a second engagement portion which is movable between a first engaged position and a second position, the connector comprising a coupling member which is arranged, in use, to be coupled to the housing and thereby locks the second engagement portion into the engaged position to retain the end of the optical fibre within the housing.

2. A connector according to Claim 1 in which the optical communication means comprises a transceiver.

3. A connector according to Claim 1 or Claim 2 in which the coupling member comprises a nut including a threaded portion for engaging a corresponding threaded portion on the housing.

4. A connector according to Claim 3 in which the coupling member comprises a gland nut.

5. A connector according to any preceding claim in which the outer sleeve comprise a short tubular section.

6. A connector according to any preceding claim in which the outer sleeve comprises a ferrule.

7. A connector according to any preceding claim in which the outer sleeve is adhered to the optical fibre.

8. A connector according to any preceding claim in which the outer sleeve is adhered to a protective sleeve located around the optical fibre.

9. A connector according to any preceding claim in which the outer sleeve includes a recessed portion to provide the first engagement portion.

10. A connector according to Claim 9 in which the recessed portion comprises an annular groove which extends around the complete outer periphery of the outer sleeve.

11. A connector according to any preceding claim in which a tip of the optical fibre is arranged to protrude from the outer sleeve.

12. A connector according to any preceding claim in which the engagement member comprises an annular member including a resilient member which provides the second engagement portion.

13. A connector according to any preceding claim in which the second engagement portion includes a lug which deflect into and out of engagement with the first engagement portion.

14. A connector according to any preceding claim in which the second engagement portion comprises a plurality of lugs which deflect into and out of engagement with the first engagement portion.

15. A connector according to any preceding claim in which the engagement member comprises a collet.

16. A connector according to any preceding claim in which the connector comprises sealing means.

17. A connector according to Claim 16 in which the sealing means is arranged, in use, to seal the optical fibre within the housing.

18. A connector according to Claim 16 or Claim 17 in which, in use, engagement of the coupling member with the housing causes the sealing member to compress between an inner surface of the housing and an outer surface of the outer sleeve.

19. A connector according to any preceding claim in which the housing comprises retaining means to retain the optical communication means within the housing.

20. A connector according to any preceding claim in which the housing comprises a push fit retainer in order to retain the optical communication means within the housing.

21. A connector according to Claim 19 or Claim 20 in which the retaining means retains the optical communication means in a predetermined position within the housing.

22. A connector according to any preceding claim in which the connector is part of a kit which further comprises a blanking member which resembles the shape of an end of an optical fibre such that the blanking member can be engaged in the connector to close and seal an engagement opening in the housing of the utility meter.

23. A method of connecting an optical fibre relative to a utility meter and adjacent to a respective optical communication means located within a housing of the utility meter, the method comprising providing an outer sleeve around an end of the optical fibre and engaging a second engagement portion on an engagement member with a first engagement portion on the outer sleeve, the engagement comprising engaging a coupling member to a housing of the utility meter in order to move the second engagement portion relative to the first engagement portion in order for the engagement portions to engage.

24. A connector for a utility meter for connecting an optical fibre relative to the utility meter and adjacent to a respective optical communication means located within a housing substantially as herein described, with reference to, and as shown in, any of the accompanying drawings.

25. A method of connecting an optical fibre relative to a utility meter and adjacent to a respective optical communication means located within a housing of the utility meter substantially as herein described, with reference to, and as shown in, any of the accompanying drawings.