CA2063620C - Induction watt hour meter non-intrusive and concealed pulse initiator - Google Patents

Abstract

An electro-mechanical induction watt hour meter having a rotatable disc and a projection on the base directed into the meter terminating in proximity of the rotatable disc. The projection is part of a pulse initiator system where a pulse signal is transmitted through a selected area of the base that is transparent to the signal. A signal is generated externally of the meter and chopped by rotation of the disc providing a pulse signal that passes through the base of the meter to a receptor externally of the meter. The signal generator and the pulse signal receptor are both located in the enclosure defined by the base of the meter and the receptacle socket for the meter. The generated signal is disclosed as a light beam that, by way of light guides on the meter base, is directed to one side of the rotating dish and is directed by the light guide to the other side of the disc where another light guide returns the chopped or pulsed signal to a receptor externally of the meter.

Description

Title Of Tnvontinn INDUCTION WATT HOUR METER NON-INTRUSIVE
AND CONCEALED PULSE INITIATOR
Field of Invention The invention relates generally to electro-mechanical induction watt hour meters and particularly to improvements for generating a pulse signal correlated to the rate of electrical power usage for further processing to provide additional information as may be required. The 10 invention is particularly directed to locating a device, for use in generating a pulse signal, near the rotatable disc at a position where the disc is in near proximity to the base and passing a pulse signal generated by rotation of the disc through a portion of the meter base that is 15 transparent to such signal. A receptor for the pulse signal is physically located in a secure location namely within the socket on which the electro-mechanical induction watt hour meter is mounted. The invention particularly concerns having a selected area of the base plate for the 2o meter transparent to a signal caused to pulse by rotation of the disc of the meter.
Background of Invention Watt hour meters most commonly used as electric energy billing meters are the simple induction electro 25 mechanical meters. These meters have proven to have a high degree of accuracy and reliability through many years of service under varying ambient operating conditions. The reliability of these meters is exemplified by the fact accrediting authorities in Canada require only sample testing from which a number of meters can be sealed for a 5 period of twelve years and this can be extended for on up to eight years indefinitely depending upon the accuracy criteria.
A more complex form of meter is an electronic meter using solid state electronic circuits providing the 10 advantages of larger varieties of different modes of measuring operations including measurements of different parameters of electric energy consumption such as periods of and off peak periods of usage. The electronic meters also provide the advantage of remote reading by land line 15 which can be either the power transmission line or telephone line.
A meter of intermediate complexity is an electro-mechanical meter with electronic components associated therewith and which normally are mounted inside the meter 20 housing. These latter two meters are not as reliable as the electro-mechanical meter as exemplified by the fact accrediting authorities in Canada require each meter to be tested and then only allow them to remain in the field for a maximum of six years at which time they must be removed 25 and each one reverified before being returned to the field for further use. This reflects a much higher operating cost for the utility.
Solid state electronic circuit billing meters, electro-mechanical induction billing meters and the latter incorporating therein electronic circuits are all required to perform in the same ambient environments and all physically have a transparent cup-shaped cover attached to 5 a base which together form an enclosure for the operating mechanism. The base in all instances is the same for attachment to existing meter sockets of common construction.
There is a growing demand for electricity and 10 existing utilities are forecasting a supply shortage by the year 2000 leaving them one of three options, namely, (a) create new generating facilities: (b) purchase power from independent producers and (c) conserve. A combination or sub-combination of these alternatives may be used by 15 electrical utilities but instead of adding new generating facilities to meet the growing demand for electricity it is more economic to provide incentives for the customers of electric utilities to modify some of their existing habits in the use of electricity. This conserves electricity 20 thereby postponing the requirement for new generating facilities.
To create a conservation of electricity there is what is known as Demand Side Management (DSM) which is electric utilities deliberate activities designed to 25 influence customer use of electricity in a way that will produce the desired changes in the utility's electric load.
Electric utilities are seeing DSM as an alternative to additional generaring capacity. DSM requires a good understanding of how customers use electricity and why.
Utilities are undertaking to gather this information and they are also looking for creative rate structures which may motivate customers to reduce energy consumption. Since 5 the electricity meter is the utility~s cash register varying rate structures are only effective if there is a meter capable of correlating the data and making it available readily in a useable form. This means that the utilities are wanting a lot more than a plain residential 10 watt hour meter as they are looking at multi-rate, pre-payment, time of use and various other functions.
Traditionally enhancing the function of the residential meter required the addition of application specific electronics to the meter. This results in a 15 sophisticated highly specialised and thus expensive meter.
This expensive meter would replace and displace a perfectly operational plain meter. It is also worthy to note that such meter replacement would involve ongoing updating of detailed meter tracking records.
20 For the purpose of surveys and/or continued use of additional functions it is not necessarily economic or cost effective to replace the traditional reliable electro-mechanical meter with the solid state meter.
Examples of multi-function watt hour meters may 25 be found in the teachings of the following patents:
U.S. Patent 4,881,070 issued November 14, 1989 to David E. Burrowes et al; and U.S. Patent 4,465,970 issued August 14, 1984 to Donald V. DiMassimo et al; and U.S. Patent 5,014,213 issued May 7, 1991 to Cree A. Edwards et al.
DiMassimo 4,465,970 discloses a programmable time 5 of use metering system that includes a micro-processing unit incorporating a micro-processor with data input being pulses from a watt hour meter. ' U.S. 5,014,213 discloses a meter that records time of use utilizing an electronics module, a power module 10 and a sensor assembly all of which are located within the meter enclosure provided by the transparent cup-shaped cover that is secured to a base. There is disclosed optical communication with the electronics module through an optical port, in the transparent cover, to retrieve 15 information by a meter reader from the micro-processor memory.
United States Patent 4,881,070 discloses mechanism within the meter for reading the dials producing output signals for transmitting such readings and other 20 information to a remote location. Related to this is the disclosure found in Schutrum et al U.S. Patent 4,803,484 issued February 7, 1989.
Remote meter reading and transmission of other intelligence from electric meters over the electric power 25 distribution network to a central site is disclosed in United States Patent 4,904,995 issued February 27, 1990 to Mark N. Honner et al. The patentee discloses a remote transponder unit located within the enclosure of the meter for obtaining information represented by the data from the measuring means of the meter and connection of that transponder unit to the electric distribution system by way of the meter.
5 United States Patent 4,491,789 issued January 1, 1985 to Eugene C. Benbow discloses enhancing the functions of an energy metering meter by incorporating within the meter enclosure components which connect to a pulse initiator that responds to rotation of the disc of the 10 meter. The patentee indicates that either a mechanical or electro-mechanical pulse initiator may be used with the rotating disc or alternatively a solid state pulse initiator may be used eliminating the need for a disc.
In the foregoing patented apparatus enhancement 15 of the meter function is accomplished by incorporating within the meter additional mechanism and this has the disadvantage of shorter approval periods by the accredited authorizing authorities. They do, however, indicate a desire for retro-fitting or maintaining the integrity of 20 the simple electro-mechanical portion of the meter.
United States Patent 3,268,884 issued ?.ugust 23, 1966 to Conrad Yanis et al discloses apparatus for transmitting data from a meter to a remote location by way of telephone lines and utilizes a shaft angle encoder 25 assembly.
As discussed herein before there are disadvantages to enhancing watt - hour meters by incorporating electronic circuits within the meter.

It is thus most desirable to separate the electronics from the conventional electro-mechanical portion of the watt hour meter but at the same time have a signal generated with a predetermined relationship to the 5 rate of electrical power usage.
Enhancing the function of an electro-mechanical watt hour meter without incorporating additional apparatus within the meter is known as exemplified by the teachings of U.S. Patents 4,415,853; 4,922,187 and 4,646,003.
10 United States Patent 4,646,003, issued February 24, 1987 to Charles E. Phillips, discloses apparatus for verifying the accuracy of a meter and includes externally of the meter means for generating a pulse signal responsive to rotation of the disc. There is a light generating 15 source external to the meter and a light receiving means external to the meter arranged so that the light beam from the source to the receiver is chopped by the revolving disc which has an aperture near the periphery of the disc that comes into and out of alignment with the beam as the disc 20 rotates. The viewing of the disc is done through the glass cover of the meter. The light generating source and receiver is mounted on arms extending from a casing positionable as an intermediate housing between the meter and the meter receiving socket.
25 United States Patent 4,922,187, issued May 1, 1990 to William C. Beverly II, discloses a pulse initiator circuit for utility meters where the pulse initiator is attachable to the meter without breaking the meter seal.

g The pulse initiator circuit detects sensor holes in the watt hour meter rotor. A source of radiation positioned outside of the watt hour meter directs a beam toward a receiver and the beam impinges upon the rotor except for 5 when aligned with the hole in the rotor. This causes a pulse signal having a predetErmined relationship to the rate at which the rotor turns. In the patented structure the light radiating and receiving source is mounted in an annular ring that fits onto the glass cover of the meter.
10 United States Patent 4,415,853 issued November 15, 1983 to Berish M. Fisher, discloses a scanner device mounted so as to detect the presence of a marking on the rotating disc and therefrom generate a pulse signal. In this patented structure, as in the two previously mentioned 15 patented structures, the light source and receiver are of considerable distance from the rotating disc by virtue of the fact they are external to the meter cover. They are further more located in the vicinity of the glass cover making them susceptible to extraneous radiation source 20 signals. Also by virtue of the fact they are located in surrounding relation to the exposed part of the meter they are subjected directly to ambient conditions as well as being prone to vandalism or unwanted manipulation.
A still further form of pulse initiator is 25 disclosed in United States Patent 3,943,498 issued March 9, 1976 to Theodore M. McClelland.
In all of the foregoing the pulse initiator is either disposed internally of the meter along with other electronic components to enhance the meter's function or is located externally of the meter at a position forwardly of the base of the meter in proximity of the glass cover.
Since the traditional residential meter is very reliable and economical it is not cost effective to replace it at present with a solid state meter. Hence enhancing the meter's function involves counting the meter's disc .revolutions and using a micro-processor to manipulate this information to produce whatever rate structures or features are required. Adding these electronics to a meter reduces the meter life in the field. At prese~~t a plain electro-mechanical meter is expected to last 30 to 45 years while the life of an electronic meter is substantially less.
Adding electronics also increases the amount of testing by regulatory authorities to verify the calibration (seal) with each meter having to be done individually.
An object of the present invention is to provide means external to a simple electro-mechanical meter for initiating a pulse in response to the disc revolutions but which is disposed in a secure location and in close proximity to the rotating disc.
Summary of Inyention In accordance with the present invention sensing of the meter disc rotation is through the meter base thereby disposing the sensing means in close proximity to the rotating disc while at the same time being disposed externally of the meter and in a secure and safe location.

In accordance with the present invention there is provided an electro-mechanical watt hour meter with a pulse initiator responsive to rotation of the meter disc wherein apparatus for the initiator is located on the base of the 5 meter. This locates the initiator in a more secure place as it is in an enclosure provided by the meter base and the service box on which the meter is mounted. This position also eliminates the need to expose communication wires etc.
preventing others from tampering with them and also to protecting the wires from direct elements of the environment. Sensing revolutions of the disc is done through the meter base and thus a portion of the base becomes a ~~window~~ to the pulse signals generated by the disc motion regardless of the method of sensing. Optical 15 sensing is disclosed hereinafter but obviously other sensing systems may be used such as capacitive, inductive or magnetic coupling or radio active communication if so desired.
The meter base may be designed to accept a " window" in the shape of dual light-guides, the protruding ends of which face inside the meter and are positioned on either side of the disc. With the dual light-guides molded from a single piece of acrylic, they have a common base which forms the window. Shining a beam of light into the lower 25 half of 'the "window", the light is reflected from the protruding end of the lower light-guide, across the gap, onto the reflecting surface of the protruding end of the upper light-guide. From this surface the light is reflected back out the upper half of the "window". A light receptor (photo-transistor) is positioned against the upper half of the "window" to detect this returning beam of light. If the meter disc is positioned in the gap between 5 the protruding light-guides then the beam of light will be blocked. Holes, properly positioned in the periphery of the disc will allow the beam of light to pass across the gap as the disc turns. In this way the rotation and rate of rotation of the disc can be detected. A single hole in 10 the disc may be used which will give one pulse per disc revolution or a number of holes spaced circumferentially in a ring may be used. Increasing the number of holes, increases the resolution and ten holes fs proposed offering resolution to 1/10 of a disc revolution.
15 The light guide piece may be inserted in an aperture in the base after the base has been formed or the base may be molded around the light guide piece or the two may be formed simultaneously.
The "window" becomes an integral part of the 20 meter base, complying with the profile restrictions for meter bases as required by the Canadian Standards Association (CSA). Since the light source (light emitting diode), receptor (photo-transistor) and all controlling electronics may reside outside of the meter, the integrity of 25 the plain electro-mechanical meter is not compromised.
An adapter called an interbase such as disclosed in U.S. Patent 4,121,147 issued October 17, 1978 to Dale F.
Becker may be used as a housing for the pulse-pickup 2(~~~~~~

electronics and whatever other circuits required to manipulate the pulse data to perform the appropriate functions and features. The interbase .is a socket to socket adapter which plugs into the service box arid, in turn, has the meter plugged into it. The current terminals in the interbase simply extend those of the service box to meet the meter while providing the space to house the electronics and access to line voltage to power the electronics. The interbase may have a chamber which extends below the profile of the meter. This chamber can be equipped with a door, a wire trap and/or knock-outs.
Each of these offer alternate methods of accessing the interbase electronics. For example, the interbase may be equipped with a modem for communication of the metering data directly to the Electric Utility. The wire trap provides secure access for a telephone cable to tie into the lower chamber of the interbase. Once inside the lower chamber of the interbase a wire can be routed directly to an appropriate connector on the circuit board.
Alternately, a strip holding a number of terminal connectors may be provided in the lower chamber as a common point to connect wires and cables for communication outside the interbase, and hence outside the meter.
There is particularly provided in accordance with the present invention pulse initiating apparatus responsive to energy consumed as measux°ed by an electro-mechanical induction watt hour meter that includes a cover, a base and a disc that rotates at a rate proportional to the energy being consumed, such disc having a peripheral edge in proximity of the base, the improvement comprising locating a device for use in generating a pulse signal near the rotatable disc at a position where the disc is in near 5 proximity to the base and directing a generated pulse signal from said device through a selected area of the base of the meter which is transparent to the generated signal.
In another aspect, there is particularly provided in accordance with the present invention an 10 elctro-mechanical induction Watt-hour meter, comprising: a transparent cover attached to a base and together forming an enclosure containing an electro-mechanical apparatus with a disc that rotates in proportion to an amount of energy being consumed, a peripheral portion of said disc 15 being located in near proximity to said base; means on said base projecting into said enclosure for generating a pulse signal responsive to a rate of rotation of said disci and means for passing the pulse signal through said base to a receptor disposed external to the meter: wherein 20 a Portion of said projecting means extends beyond the peripheral portion of said disc.

- 13a -List of Drawinaa The invention is illustrated by Way of example in the accompanying drawings wherein:
Figure 1 is an exploded side-elevational view 5 illustrating the major components of the electro-mechanical watt hour meter;
Figure 2 is an oblique view of the register housing and rotatable disc portion of the meter illustrated in Figure 1;
Figure 3 is an enlarged, oblique, partial 10 diagrammatic, view of the base of the meter without the potential and current induction coils mounted thereon illustrating co-positioning of the two prong light guide and the rotatable disc;
Figure 4 is a partial side elevational view, on 15 a larger scale, illustrating the two prong light guide;
Figure 5 is a top plan view of Figure 4;
Figure 6 is a left hand side elevational view of Figure 5;
Figure 7 is a diagrammatic illustration of different rotational positions of the disc and a hole therein chopping the light beam; and Figure 8 is a diagrammatic illustration of the logic sequence for two receptors relative to the rotational 5 positions for the disc shown in Figure 7.
Description of Prefe ~"P~ Rmhnr3imr~nt Figure 1 is an exploded view of the electro-mechanical induction watt hour meter the major components of which are a base 10, an electro magnetic unit 20 with a l0 disc brake magnet mounted thereon, a register and rotary unit 30 and a glass cover 70.
The electro magnetic unit 20 has a core unit 21 with respective current and potential coils 22 and 23 mounted thereon. A magnetic brake 24 is carried by the 15 unit 20 and has a gap 25 for receiving a portion of the rotor. The unit 20 securely attaches to the molded base 10 and has pairs of current spades li and 12 projecting through and anchored to the base. Hase 10 is molded conventionally from a hard thermoset plastics material such 20 as a henolic resin (bakelite). A licant P pp prefers using a rigid thermoplastic such as a polycarbonate material identified as #9417 Makrolon* available from the Bayer Company of Germany.
The polycarbonate material is preferably glass fiber reinforced *T.M.

and ultraviolet light stabilized. This material is somewhat more resilient than the hard phenolic bases conventionally used. The magnetic coil unit 20 attaches to the base in a convenient manner, for example, lugs 5 projecting from the base which position and snap fit onto the unit 20.
The register and rotor 30 is a module that includes a molded plastics (preferably Ryton* PPS) housing 31 having a plurality of spacer lugs 32 projecting 10 therefrom and attaching lugs 33 for precisely locating unit 30 relative to unit 20 and attaching unit 30 to the base with a coil unit 20 mounted thereon. The unit 30 has a register, diagrammatically illustrated by its face designated 30A, driven through a gear train by a worm gear 15 36A on the shaft 36 of the rotatable disc 34. A name plate 35 attaches to and extends downwardly from the molded plastic housing 31. The locating lugs 32 position the unit 30 relative to unit 20 such that rotating disc 34 fits into the gap 25 and lugs 33 snap fasten onto as previously 20 mentioned the coil unit 20 and/or base unit l0.
The disc 34, which is caused to rotate by the electro magnetic unit 20 in a known manner, is mounted on a spindle or shaft 36 having respective upper and lower bearing units 37 and 38 on the molded plastic housing unit 25 31. A pintle 39, associated with the upper *Trade-Mark bearing 37, projects therefrom into a pintle receiving unit 39A on the molded plastic housing 31. The rotor shaft 36 has a worm gear 36A on the upper end thereof that meshes with a drive gear, not shown, for driving the gear train of 5 the registry unit. Dials of the registry unit visually indicate cumulatively the energy consumed.
The glass cover 70 has an outwardly directed flange 71 and a seat portion 72 that abuts against a seal forming rib 14 on the base 10. The outwardly directed 10 flange 71 carries a metal ring 73 provided with lugs that engage tapered ramps on the flange 15 of the base forming a bayonet type of mount whereby the glass cover and base may be rotated relative to one another to detachably join them together with the rib 14 on the base being pressed 15 against the seat 72 on the glass cover.
The present application is particularly directed to apparatus and the physical location of such apparatus for initiating a pulse signal in response to rotation of the disc 34. Figure 3 diagrammatically illustrates an 20 embodiment of the invention wherein the base 10 has a fork type two prong light guide unit 50 mounted on the base. The light guide unit projects inwardly into the meter to overlap a selected peripheral portion of the disc 34.
The light guide unit 50 has an upper leg 51 and 25 a lower leg 52 spaced a selected distance from one another providing a gap therebetween to receive a peripheral edge portion of the disc 34 as will be seen more clearly from.
Figure 4. The disc for example may have a thickness of about 40/1000 of an inch while the gap may be for example approximately 110/1000 of an inch. The arms 51 and 52 project forwardly from a base 54 that has an outwardly directed rib 55 for snap fitting into a suitably shaped and 5 formed aperture 16 in the base 10. A sloped shoulder 54A
on the base limits the inward movement of the unit when press fit in place and co-operates with rib 55 to ensure a snug fit. Projecting outwardly from the base 54 is a locating rib 56 that slip fits into a slot 17 in a wall of 10 the aperture 16. The locating lug 56 and slot 17 ensure appropriate positioning along with rib 55 of the legs 51 and 52 relative to an aperture 34A (or series of apertures) through disc 14. There may be only one aperture 34A or a series of apertures 34A as illustrated in Figure 3 equally 15 spaced from one another in a circle around the disc and spaced inwardly from the peripheral edge thereof. one light guide leg is shorter than the other and in this embodiment the lower leg 52 is longer than the upper leg 51.
20 Diagrammatically illustrated in Figures 4 and 5 is a light emitting diode E1 associated with the lower leg 52 for directing a beam of light 81 along the leg 52.
Associated with the upper leg are respective ones of a pair of phototransistor receivers designated Q1 and Q2, 25 The unit 50 mounted on the base is a translucent light receptor-transmitter made for example from clear acrylic. The phototransistors Q1 and Q2 and light emitting diode E1 are preferably mount.. on a separate printed circuit board designated CB1 in Figure 5 mounted in a conventional service socket or an interbase assembly inserted between the electric service socket and the meter.
Light emitted by the light emitting diode E1 5 enters the receptor-transmitter unit 50 forming a beam of light B1 transmitted on the lower leg 52 toward a light reflecting surface 57 that directs the light into a reflected beam B2. This reflected beam H2 is directed by a reflecting surface 58 on leg 51 resulting in a further 10 reflected beam or beams directed to the receptor(s). The reflected beam H2 passes through a hole 34A in the disc 34 when aligned therewith during rotation of the disc. The reflecting surface 58 on leg 51 can be either a single plane or grooved or have a projecting V-shaped rib 15 providing respective angularly related planar faces 58A and 58B causing two reflected beams designated B3-1 and H3-2 (see Figure 5) to travel along leg 51. The multi-faced reflecting surface 58 directs light beams B3-1 and B3-2 to respective photo-transistor receptors Q1 and Q2.
20 Since Q1 and Q2 are physically displaced from one another, the light beam generated by E1 passing through the hole will appear first on either Q1 or Q2 depending upon the direction of rotation of the disc. Additional circuity therefore can be used to determine the direction of 25 rotation of the disc and hence forward or reverse energy flow. This is diagrammatically illustrated in Figures 7 and 8 wherein 7 diagrammatically illustrates the disc 34 with the hole 34A in 5 different rotational positions designated A, H, C, D and E. A representative hole 74A in the disc is shown moving in Figure 7 from right to left.
Figure 8 diagrammatically illustrates the logic for respective disc positions A, B, C, D & E for the reflected 5 beam as viewed at respective photo-transistor units Q1 and Q2.
The main advantage of the above is that the meter does not contain any active electronic components and hence is generally unaffected by additional complexity.
10 Directional rotation of the disc is detected by the reflected light beams resulting from the slightly angled planes of reflecting surface 58. As the leading edge of the hole in the disc crosses the light beam it reveals first one reflecting surface and then both. As the 15 trailing edge of the hole crosses the light beam it blocks the first reflecting plane and slides across to block the beam completely. In this method the receptor pairs Q1 an Q2 see logic 0-o as the disc completely blocks the light beam, logic 1-0 as the leading edge of the hole exposes the 20 first reflecting plane, logic 1-1 as the light hits both reflecting planes, logic 0-1 as the trailing edge of the hole blocks light from the first reflecting surface then finally 0-d as the hole passes and the disc again blocks the beam of light. Similarly the same results could be 25 achieved if the beam of light were split before it reaches the disc. In such instance the split beams would be directed onto the disc in such a manner that the hole would pass first in front of one beam then the other permitting ~~~J~~~

detecting forward and reverse disc rotation.
While an optical solution has been chosen to initiate a pulse, other technologies could achieve the same results, for example, technology such as magnetic coupling, capacitive coupling, inductive coupling and radio active communication are possible. Other optical solutions are also available and while disclosed herein is chopping of a beam of light by the apertured disc the same could be achieved if the light were reflected off the surface of disc or its outer peripheral edge. Similarly various optical solutions could implement a range of optical wavelengths from visible to infrared and laser, infrared being preferred by the applicant.
From the foregoing it will be clearly evident the l5 pulse initiator apparatus is hidden from view, is protected by Deing located in the mounting base and is located closely adjacent a peripheral edge of the rotary disc.
There are no active components mounted within the enclosure thereby avoiding the risk of requiring additional testing of the meter while at the same time providing means to generate information not possible with a conventional electro-mechanical induction watt hour meter.
The plastics for the molded housing, pilot bearings and meter base are engineering grade resins and preferably rigid thermoplastic materials such as those identified hereinbefore.

Claims (13)

1. A device for use with an electro-mechanical induction watt-hour meter, said meter including a cover, a base and a disc mounted to rotate at a rate proportional to an amount of energy being consumed, said disc having a peripheral edge in proximity to the base, said device comprising:
means for generating a pulse signal near the rotatable disc at a position where an edge of the disc is in proximity to the base; and means for directing the generated pulse signal through a selected area of the base of the meter which is transparent to the generated pulse signal;
wherein said device is mounted on the base of the meter and includes a projection extending away from said base and terminating at a free outer end disposed in close proximity to the rotatable disc.

2. The device as defined in claim 1, further comprising a receptor for receiving the generated signal and wherein said receptor is mounted in an enclosure defined by the base of the meter and a socket on which the meter is mounted.

3. The device as defined in claim 1, wherein a portion of said projection extends beyond the peripheral edge of said disc towards a center of said disc.

4. The device as defined in claim 1, wherein said free outer end of the projection has a gap, said gap receiving therein a portion of the peripheral edge of the disc, said gap defining an upper arm and a lower arm in said free outer end of said projection.

5. The device as defined in claim 4, including means on said disc for causing a signal, transmitted by way of said arms, to pulse in response to rotation of the disc.

6. The device as defined in claim 4, wherein said arms project from said base toward said disc and are Wave guides for a light beam, said wave guides including means for directing a light beam from one arm to the other disc arm, said light beam being interrupted as the disc rotates.

7. The electro-mechanical induction watt-hour meter of claim 1, wherein said base includes a transparent cover attached thereto, which together with said base forms an enclosure containing said disc, said device further comprising:
means for passing the generated pulse signal through said base to a receptor disposed externally of the enclosure.

8. A meter as.defined in claim 7, further comprising:
means located externally of the enclosure for generating a signal, means for directing said generated signal to said disc at said location, and means, associated with said disc, for interrupting said generated signal in response to the rate of rotation of said disc, producing pulse signal.

9. The meter of claim 8, further comprising:
means. associated with said disc, for interrupting said generated signal in response to the rate of rotation of said disc, thereby producing said pulse signal;
wherein said meter is mounted on a mater socket enclosure external to the meter and wherein said signal generating means and said receptor for the pulse signal are located in said meter socket enclosure.

10. An electro-mechanical induction watt-hour meter, comprising:
a transparent cover attached to a base and together forming an enclosure containing an electro-mechanical apparatus with a disc that rotates in proportion to an amount of energy being consumed, a peripheral portion of said disc being located in near proximity to said base;
means on said base projecting into said enclosure for generating a pulse signal responsive to a rate of rotation of said disc; and means for passing the pulse signal through said base to a receptor disposed external to the meter;

wherein a portion of said projecting means extends beyond the peripheral portion of said disc.

11. A watt-hour meter as defined in claim 10, wherein a free outer end of said projecting means has a gap receiving said peripheral portion of said disc, said gap being defining an upper arm and a lower arm of said projecting means.

12. A watt-hour meter as defined in claim 11, including means on said disc causing a signal, transmitted by way of said arms, to pulse in response to rotation of the disc at a rate proportional to said rate of rotation.

13. A watt-hour meter as defined in claim 11, wherein said arms are wave guides for a light beam and including means for directing a light beam from one arm to the other arm, said light beam being interrupted as the disc rotates.