GB2295683A - Improvements in or relating to electricity meters - Google Patents

Abstract

An electricity meter comprises terminals for electricity supply conductors and consumer electricity feed conductors respectively, a pair of individually sealable covers 10, 11 which afford access to the supply conductor terminals 8 and the feed conductor terminals 9 respectively a switch 37 effective to connect/disconnect the supply to a consumer, and meter means operative to measure the quantity of electricity supplied via the switch to a consumer, which switch is arranged to be accessible consequent upon removal of one of the sealable covers. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO ELECTRICITY METERS This invention relates to electricity meters and more especially but not exclusively it relates to electricity meters for use by domestic consumers.

It is an object of the present invention to provide a meter wherein consumer electricity feed connection/disconnection is facilitated.

According to the present invention an electricity meter comprises terminals for electricity supply conductors and consumer electricity feed conductors respectively, a pair of individually sealable covers which afford access to the supply conductor terminals and the feed conductor terminals respectively, a switch effective to connect/disconnect the supply to a consumer, and meter means operative to measure the quantity of electricity supplied via the switch to a consumer, which switch is arranged to be accessible consequent upon removal of one of the sealable covers.

By providing separate sealable access for the consumer feed conductors and a switch by means of which the feed conductors may be connected/disconnected, consumer connection or disconnection to the electricity supply, may be effected without the need to provide access to the supply conductors which might require assistance from the utility. Thus visits to the consumer by the utility representatives may be minimised. Moreover, by arranging that the switch can be operated manually after removal of a sealable cover, the supply may be connected or disconnected by switch operation without needing to remove the feed conductors from their associated terminals.

In order to facilitate remote switch operation, and/or for other purposes, the meter may be adapted to receive in operative association therewith a supplementary unit which includes an actuator responsive to predetermined signals for effecting operation of the switch, whereby meter functionality is extended.

The supplementary unit may be adapted to receive from the meter, data appertaining to elecflicity usage and may include a digital display which affords a visual indication of electricity usage.

The predetermined signals may comprise light signals which are transmitted between opto couplers in the meter and the said unit respectively.

The opto couplers may be arranged to operate utilising light in a non-visible spectrum or alternatively light in the visible spectrum.

The supplementary unit may be arranged to include a receiver responsive to actuation signals which are transmitted from a remote source to effect switch operation.

Alternatively, or additionally the supplementary unit may be arranged to include a receiver receptive to predetermined interrogation signals transmitted to the unit from a remotely located source and a transmitter which responsively to the receipt of the interrogation signals is arranged to transmit data to the said source appertaining to the quantity of electricity used by a consumer as indicated in dependence upon the said predetermined signals, whereby remote meter reading is facilitated.

Some embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, in which, FIGURE la is an isometric view of an electricity meter; FIGURE ib is a bottom view of the electricity meter shown in Figure la; FIGURE ic is a side view of the meter shown in Figures la and ib; FIGURE id is a front view of the meter shown in Figure la; FIGURE le is an isometric view of a part of the meter shown in Figure la; FIGURE if is a block schematic circuit diagram of the meter as shown in Figures la to le; FIGURE 2a is an isometric view of an assembly comprising the meter as shown in Figures la to le with a module unit fitted thereto; FIGURE 2b is a bottom view of the assembly shown in Figure 2a;; FIGURE 2c is a side view of the assembly shown in Figure 2a; FIGURE 2d is a front view of the assembly shown in Figure 2a; FIGURE 2e is a front perspective view of a module forming part of the assembly shown in Figure 2a; FIGURE 2f is an underside perspective view of the module shown in Figure 2e; FIGURE 2g is a schematic block circuit diagram of the module shown in Figure 2f as used for pre-payment purposes; FIGURE 2h is a schematic block circuit diagram of the module shown in Figure 2f as used as a telephone module; FIGURE 3a is a front view of the meter which is a part of the assembly as shown in Figures 2a, 2b, 2c and 2d, and which includes a cut away portion to reveal a switch;; FIGURE 3b is a front view of a module unit forming a part of the assembly shown in Figures 2a, 2b, 2c and 2d, which includes a cut away portion to reveal a switch actuator; FIGURE 3c is a front view of the assembly shown in Figure 2a having a cut away portion to reveal a switch and an associated actuator; FIGURE 3d is a front view of the assembly shown in Figure 2g with the switch in a different position; FIGURE 4a is a front view of a meter which corresponds largely to the meter shown in Figure la; FIGURE 4b is a front view of a module for use with the meter shown in Figure 4a showing an optical interface; FIGURE 4c is a front view of an assembly comprising the meter shown in Figure 4a having the module shown in Figure 4b fitted thereto;; FIGURE 4d is a side view of the assembly shown in Figure 4c together with an enlarged view of an optical interface which forms a part of the assembly; FIGURE 5a is an isometric view of an assembly comprising a meter and a radio receiver and load switching module; FIGURE 5b is a rear isometric view of the assembly shown in Figure 5a; FIGURE Sc is a bottom view of the assembly shown in Figure 5a; FIGURE Sd is a side view of the assembly shown in Figure Sa; FIGURE Se is a front view of a module which form a part of the assembly shown in Figures 5a to 5d; FIGURE 5f is a front perspective view of a module which form a part of the assembly shown in Figures 5a to 5e, and, FIGURE Sg is a generally schematic block circuit diagram of the module shown in Figure Sa.

Referring now to Figures la to le wherein corresponding parts of the various Figures bear where appropriate the same numerical designations, an electricity meter comprises a housing 1 which includes apertures 2 and 3 for input conductors from a mains supply and apertures 4 and 5 for output conductors which supply electricity to a consumer. Additional apertures 6 and 7 are provided for earth conductors. Terminals for securing the conductors are provided within the housing 1, which embody conductor fixing screws 8 and 9, as shown in Figure le, which are arranged to be accessible externally of the housing 1 for conductor fixing or removal purposes. The screws 8 which are used to secure the mains input conductors are covered with a cover 10 and similarly the screws 9 which are used to secure the output conductors are covered by means of a cover 11.

The covers 10 and 11 are held in place by means of fixing screws 12 and 13 which engage complementary tapped holes 14 and 15 respectively. The covers 10 and l l are sealed in place by means of wires 16 and 17 which pass through upstanding collars 18 and 19 respectively, which form a part of the covers 10 and 11. In order to prevent tampering, the wires 16 and 17 are sealed in position by means of seals 20 and 21. As shown in the circuit diagram of Figure lf, the meter housing contains apparatus comprising input terminals 22 and 23 for the mains input conductors, and output terminals 24 and 25 which are arranged to feed electricity to a consumer from the input terminals 22 and 23 via a switch 26.In order to measure the power consumed, signals appertaining to the supply voltage are fed to a measurement circuit 27 via conductors 28 and signals appertaining to the current supplied which is developed in a current sensing element 29, connected in series with the switch 26, are fed to the measurement circuit 27 via conductors 30. Output signals from the measurement circuit 27 are fed to a micro processor 31 which feeds a digital display 32. The micro processor 31 is fed also from a miscellaneous functions circuit 33 which may receive external signals appertaining to rate control and/or fraud detection, for example.

Output signals from the micro processor 31 are fed to an LED 34 and omnidirectionally to an opto input and output port 35 which serves as a user interface via which information in the form of light signals may be extracted from the micro processor 31 or injected into the micro processor 31 for various purposes. In order to provide power for the measurement circuit 27, the miscellaneous functions circuit 33, the micro processor 31 and the display 32, a dc power supply 36 is provided which is fed from the conductors 28.

The switch 26 forms part of a switch assembly which includes an actuator 37, as shown in Figure le, which facilitates manual operation of the switch 26 when the cover 11 is removed. As shown in Figure le, an access port 38 is provided in the housing which is normally closed by means of a cover 39 (Figure la), the cover 39 being held in position by the cover 11. The port 38 provides access to live neutral and switch conductors 42, 41 and 40 respectively, as shown in Figure 1 f, via an electrical socket connector (shown in Figure 2f), and an access aperture 43 for a switch actuator pin 49 as will hereinafter be described with reference to Figure 2f.

Although the meter thus far described may be used alone as a standard credit meter, with the port cover 39 (Figure la) in position, it may be alternatively used in association with various modules to provide a meter assembly which has additional functionality.

One such module which may either comprise a pre-payment module or a telephone module as will now be described with reference to Figures 2a to 2h, wherein parts corresponding to the meter shown in Figure la bear the same numerical designations.

Referring now to Figure 2a to 2d, a meter assembly comprises the meter housing 1, as shown also in Figure la, having fitted thereto a module 44 which is formed to include dove tail slots 45 which cooperate with corresponding dove tail portions 46 of the meter as shown in Figure la and Figure le. The module 44 may thus be slid onto the meter housing 1, lockingly to engage therewith until pins 47 of an electrical connector 48 engage with complementary sockets in the access port 38 of the housing 1, whereby the module is arranged to make contact with the conductors 40, 41 and 42 as shown in Figure If, the conductor 40 and the terminal 25 being arranged to carry heady load current. Additionally, a switch actuator pin 49 enters the access aperture 43, as shown in Figure le, so that the switch 26 may be operated by the module 44.It is arranged that the optical interface 35 in the housing 1 aligns with a corresponding optical interface 50 in the module 44 when the module is fitted to the housing.

The module 44 may be arranged to perform a number of functions in accordance with the facilities required, electronic circuitry being provided to satisfy the requirement. For example, the module 44 may be designed to serve as a pre-payment module wherein input apertures 51 and 52 are provided for card-keys, smart-keys, smart-cards or memory-keys. Such a system is shown in the schematic block diagram of Figure 2g wherein a customer interface unit 53 is provided for a card-key or a smart-card or the like. Input signals from the interface unit 53 are fed to a micro processor 54 which provides signals for a display 55, an opto port 56, a pulsed LED 57 and a solenoid driver 58. A dc power supply 59 is provided for operating the various parts of the module.The solenoid driver 58 is arranged to operate a solenoid 60 (or an alternative electro-mechanical device, to perform a similar function) in accordance with signals provided from the micro processor 54 to control operation of the switch 26 by appropriate operation of the actuator pin 49. Thus it may be arranged that when a predetermined quantity of electricity has been supplied to a consumer, as determined by insertion of a key-card or smart-card or the like, into the customer interface unit 53, the switch 26 will be operated thereby to interrupt the electricity supply to the consumer.

In an alternative arrangement, the module 44 may be provided with electronic circuitry corresponding to the circuitry as shown in the block schematic diagram of Figure 2h. In this arrangement, the module 44 is connected to telephone lines 61 via a modem 62, which feeds a micro processor 63. A micro processor 63 is fed from a user interface opto port 64 and a meter interface opto port 65 as well as from a pulsed LED 66. Information appertaining to electricity used is indicated by a display 67. As will be appreciated by those skilled in the art the functionality of the unit will be determined in accordance with the application required and for example, the meter may be remotely interrogated to determine the quantity of electricity used to provide for automatic billing.Additionally, or alternatively, applied signals from the telephone line 61 may be fed via the micro processor to control a solenoid driver 68, in accordance with the quantity of electricity used for example, whereby a solenoid 69 is activated so as to operate the switch 26 for the purpose of connecting or disconnecting a consumer as the case may be. A dc supply unit 70 is provided which provides operating power for the solenoid driver in the micro processor, the display and other parts of the circuitry as required. It will be appreciated that electrical communication between the unit shown in Figure 2g and the conductors 41 and 42 will be via conductors 71 and 72 respectively, and similarly the arrangement of Figure 2h is fed via conductors 73 and 74.

For a better understanding of the manner in which solenoids 60 and 69 (which may be other equivalent electro-mechanical devices) in Figures 2g and 2h respectively operate the switch 26, further explanation will now be provided with reference to Figures 3a to 3d.

Referring now to Figure 3a, the meter comprising the housing 1 includes a switch assembly which includes the switch 26 having associated with it the access aperture 43 as shown in Figure le for the actuator pin 49. As shown in Figure 3b the module 44, as shown in Figure 2a, includes a solenoid corresponding to the solenoid 60 for example, having an actuator pin 60a. When the unit 44 is fitted to the housing 1, the actuator pin 60a aligns with the actuator 26a as shown in Figure 3c, whereby when the solenoid 60 is energised, the pin 60a is constrained to open the switch 26.

In order to facilitate a better understanding of the arrangement of the opto couplers in the housing 1, and the unit 44, reference will now be made to Figures 4a to 4d, wherein it can be seen that an opto port corresponding to the opto port 35 of Figure la is arranged to align with the opto port 50 of a module unit as shown in Figure 2f and thus an opto coupler 75 aligns with a corresponding opto coupler 76, so that active elements 75a and 76a respectively align to facilitate the transmission of light therebetween.

Although as herein before described, the module unit may be arrange to operate a switch which is contained in the meter, alternatively, or additionally, the module unit may include its own switch as will now be described with reference to Figure 5a to Sg, wherein corresponding parts bear the same numerical designations.

Referring firstly to Figures Sa to Sf, a meter assembly comprises a meter housing 77 to which a radio module 78 is fitted having apertures 79 and 80 for input and output cables respectively, but additionally, the module unit provides an additional output aperture 81 for a further output conductor. The unit is arranged to include a radio receiver module 82, as shown in the circuit diagram, Figure Sg, which feeds a micro processor 83 connected to a display unit 84. As herein before described, the micro processor feeds pulsed LED 85 and opto ports 86 and 87, data appertaining to additional functions being fed to the micro processor via a miscellaneous functions circuit 88. In operation, the meter may be switched in dependence upon received radio signals via the micro processor 83 which appropriately operates a solenoid driver 99 which feeds a solenoid 100.Operation of the solenoid causes a switch 101 to operate so as to connect or disconnect as the case may be, power to a conductor 106 which enters the additional port 81. In order to provide power to the various units, a dc power supply 102 is provided, electrical connection between the module unit 78 and parts within the meter housing 77 being made as hereinbefore described via conductors 103, 104 and 105.

In the present example the switch 101 corresponds to the switch 26, shown in Figure if, but in alternative arrangements, a further switch may be provided in the radio module which may be arranged to be independently operated.

It will be appreciated that the foregoing embodiments are given by way of example only, and that various modifications may be made as will be appreciated by those skilled in the art, without departing from the scope of the invention.

Claims (11)

1. An electricity meter comprising terminals for electricity supply conductors and consumer electricity feed conductors respectively, a pair of individually sealable covers which afford access to the supply conductor terminals and the feed conductor terminals respectively, a switch effective to connect/disconnect the supply to a consumer, and meter means operative to measure the quantity of electricity supplied via the switch to a consumer, which switch is arranged to be accessible consequent upon removal of one of the sealable covers.

2. An electricity meter as claimed in Claim 1, adapted to receive in operative association therewith a supplementary unit effective to extend meter functionality.

3. An electricity meter as claimed in Claim 2, wherein the supplementary unit includes an actuator responsive to predetermined signals for effecting operation of the switch, whereby meter functionality is extended.

4. An electricity meter as claimed in Claim 3, wherein the supplementary unit is adapted to receive from the meter, the said predetermined signals comprising data appertaining to electricity usage, in dependence upon which predetermined signals the switch is arranged to be operated by the actuator.

5 An electricity meter as claimed in Claim 3 or Claim 4, wherein the supplementary unit includes a digital display which affords a visual indication of electricity usage.

6. An electricity meter as claimed in Claim 1 or Claim 2, including a digital display which is arranged to afford a visual indication of electricity usage.

7. An electricity meter as claimed in any of Claims 3 to 6, wherein the predetermined signals comprise light signals which are transmitted between opto couplers in the meter and the said unit respectively.

8. An electricity meter as claimed in Claim 7, wherein the opto couplers are arranged to operate utilising light in a non-visible spectrum.

9. An electricity meter as claimed in any of Claim 3 to 9, wherein the supplementary unit is arranged to include a receiver responsive to actuation signals which are transmitted from a remote source to effect switch operation.

10. An electricity meter as claimed in any of Claims 2 to 9, wherein the supplementary unit is arranged to include a receiver receptive to predetermined interrogation signals transmitted to the unit from a remotely located source and a transmitter which responsively to the receipt of the interrogation signals is arranged to transmit data to the said source appertaining to the quantity of electricity used by a consumer as indicated in dependence upon the said predetermined signals.

11. An electricity meter as claimed in Claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.