• Field of Invention:
The present invention is related to a continuous form fitting case of an energy meter with a
tamper proof feature. The present invention further relates to a continuous tamper-proof
energy meter case / cover, said tamper-proof case / cover comprising of:
a} a first part which houses the energy meter; and
b) a second part, comprising of a block and a bar code level.
Background of the Invention:
Energy meters or watt hour meters measures the amount of electrical energy supplied to a
residential or commercial building. The most common unit of measurement made by a meter is
the kilowatt hour, which is equal to the amount of energy used by a load of one kilowatt in one
hour. Power theft is very common and persistent problem and as high as 30% of the total
power generated in the country is lost due to various reasons of such acts of theft and
unauthorized tampering. The major percentage of the above loss is attributed to Energy meter
tampering. Consumers have been found manipulating their electric meters, causing them to
stop, under-register or even bypassing the meter, effectively using power without paying for it.
In order to introduce improved and efficient meter denomination, electronic meters have been
developed to replace existing electro mechanical meters, since 1990. These electronic meters
come with in-built anti-tamper features, so that power theft can be detected and necessary
actions can be taken.
Subsequently, it has been observed that, the meters with anti-tamper features could be easily
tampered by opening the top cover from its base. Another significant tampering method is by
way of introducing some spark dis<;harge device which has been designed whereby the said
device generates high voltage sparks that may be injected inside the meter through the
2• junction of top cover and base. This is another well-known method of tampering of energy
meter.
Significant external tampering includes breaking the meter case, chemical injection or even
burning the meter. All these result ifl changing the electrical characteristics of the components
thereby recording less or no energy usage. One may want to open the meter case to change the
settings or even remove the backup battery so that the meter will reset when the main power
goes off. In order to check this kind of tampering, attempts have been made to introduce anti-
tamper switches on the casing of the meter to trigger a tamper when the casing is opened.
Certain other kind of tampering include High Voltage / Frequency timer that generates spikes or
voltages in the range of 35 kV. This may induce errors in consumption recording or may even
damage the meter. Several other methods of tampering are available wherein it is possible to
tamper without damaging the cover, i.e. by opening the two piece cover, but detection
becoming a difficulty.
To combat the problem meters with 'break to open' feature has been introduced, which
implies, if someone opens the meter, visible marks or likewise evidence should be present.
The meter case is made of poly-carbonate and it has two parts, one base & one cover. At
present, ultrasonic-welding (of plastics) is the most common practice by which meters are
made 'break to open' type.
This ultrasonic-welding (USW) process welds the two plastic bodies (meter top cover & base)
along with the periphery of the meter and seals the meter for life. But, the above process is
very complicated one and some' slight variation/ deviation in the material property/
environmental condition etc. can make the welding weak, which in turn defeats the whole
purpose, i.e. meters can be opened without any physical 'marks' or tale tell evidence.
Additionally, this ultrasonic welding generates heat and vibration along the periphery of the
meter base & cover junction which is very near to the PCB/ electronic components which may
get damaged during the ultrasonic welding.
3• Some of the prior arts attempting to introduce a tamper proof feature which enables the 'break
to open' embodiment have been discussed below. It is important to note that the said prior arts
discuss energy meter cover comprises two prominent parts including a top cover and a base,
both parts of which are essential to carry the energy meter.
US Patent 3753047 teaches an electric power meter and distribution box suitable for use in
mobile home parks and similar outdoor applications in which underground wiring is brought up
through a vertical hollow stand pipe to which is affixed a base member by means of first and
second pairs of set screws. The base member is adapted to support an enclosure in which is
located one or more duplex receptacles, as well as any other similar type of power receptacles.
The first pair of set screws is located external to the enclosure whereas the second pair of set
screws is located within the enclosure. A hinged cover member, which may be locked, is
provided to prevent unauthorized access or tampering with the electrical components.
US Patent 5027061 teaches an electromagnetic and thermal shield for an electronic energy
meter is provided which includes a base, a register and intermediate electronics. The tapered
form fitting shield extends from th~ register to the base and includes intermediate resilient
fasteners formed form the shield to position, secure, and shield the components of the meter.
US Patent 7821776 teaches an electrical meter is provided that includes a cover configured for
securement onto a base. The meter includes features that resist meter tampering, and features
that provide evidence of meter tamRering.
US Patent 4068288 teaches a watt-hour meter cover is permanently locked to the meter base
assembly by an irremovable fastener applied to the base at a concealed location.
4• US Patent 4106344 teaches a tamper-proof housing for a remote register for a utility meter,
constructed of impact-resistant materials and designed for ease of mounting, assembly and
accessibility.
US Patent 5861742 an electric meter cover of an integrally molded construction which reduces
cost of manufacture and increases performance by reducing number of seals required. The
cover of the invention includes provision for an optic probe, a viewing window and a reset
arrangement allowing the meter to be reset without removing the cover and in a one
movement operation, which simplifies the reset operation.
In the above prior art documents the cases / covers of energy meters are two piece which could
be easily tampered with. The present invention has been worked upon by the Applicant with a
view to introduce and develop a one piece cover which permanently locks in the energy meter
and tampering the same results in breaking the energy meter case cover completely and
irreparably.
The instant invention is explained in the description as illustrated herein supported by
necessary illustrations and working protocols.
Objective of the present invention:
The principal objective of the present invention is to provide a continuous form fitting case of
an energy meter with a tamper proof feature. The present invention further relates to a
continuous tamper-proof energy meter case / cover, said tamper-proof case / cover comprising
of:
a) a first part which houses the energy meter; and
b) a second part, comprising of a block and a bar code level.
5• A further objective of the present invention is to provide a continuous tamper proof energy
meter case / cover is that the aforesaid case / cover which is futuristic in nature for tampers
such as 55Kv and beyond.
Yet another objective of the present invention is to provide a continuous form fitting case of an
energy meter with a tamper proof feature, wherein the aforesaid continuous tamper-proof
energy meter case / cover is permanently sealed once manufactured, thus preventing ingress of
spark, allowing air gap towards tampering unless the said case / cover of the present invention
is irreparably broken.
Statement of the present invention:
The present invention is related to a continuous form fitting case of an energy meter with a
tamper proof feature. The present invention further relates to a continuous tamper-proof
energy meter case / cover, said tamper-proof case / cover comprising of:
a) a first part which houses the energy meter; and
b) a second part, comprising of a block and a bar code level.
Brief Description of the Drawings I Figures:
Fig 1 A conventional Energy Meter in a cover comprising of a top cover and a base cover
Fig 2 Energy Meter with a continuous tamper-proof cover of the present invention.
Fig 3 Block containing locking grooves .; (I)
Fig 4 Bar Code level containing locking teeth with fitting flanges, (2.)
Fig 5 Locking of cover &bar code level;
Fig 6. Fixing of block & cover with screw along with sealing provision
Fig 7 (a) and (b) Locking of Bar code level and block
Fig 8(a) & (b) Fixing of Block and cover with the screw along with sealing provision C!!»
Fig 9 Conventional Energy Meter Base Cover
Fig 10 Continuous one-piece tamperproof energy meter case of the present invention
Fig 11 Continuous Tamper-proof Energy Meter Case of the present invention ( operative
illustration)
6•
Detailed Description of the present invention:
The Applicants of the present invention, in order to solve the above problem, have introduced a
novel meter case, wherein base &' cover are no longer two different parts but one single
continuous unit. The continuous form-fitting cover has been designed in a manner wherein no
gap is possible between top cover and base to allow sparks such as ESD sparks to flow and as a
result the meter become difficult to reconstruct or reassemble once opened. Additionally, the
above changes have been made without sacrificing the conventional sealing provision (e.g.
Hologram Sticker etc.) & communication port (RS232).
The present invention has been carried out with an objective to provide a tamper-proof energy
meter case / cover wherein the meter readings are easily visible, without the need to open the
cover and read the same. The meter case is built with materials that are resistant to high
temperatures, thus preventing problems like overheating, retention of shape, dangerous shocks
from voltages present within and also becomes a safety shield. The energy meter case / cover
of the present invention is compliant with current regulatory standards of compliance for
energy meters such as IS 13779, IP 51.
The present invention relates to a watt-hour meter case / cover, in other words an energy
meter case / cover, said case / cover including a base and a top-cover, mechanically molded in
one continuous cover. The form fitting case / cover of the present invention extends from the
base to the entirety of the energy meter in a such a manner that the said meter is sealed
permanently, and can only be uncovered or disassembled when the case / cover is broken
open. The present invention also thus relates to a continuous form fitting case of an energy
meter with a tamper proof feature, wherein the aforesaid continuous tamper-proof energy
meter case / cover is permanently sealed once manufactured, thus preventing ingress of spark,
allowing air gap towards tampering unless the said case / cover of the present invention is
irreparably broken.
7• The present invention provides a continuous form-fitting tamper-proof energy meter cover
which is permanently lockable and is a one-piece continuous enclosure which prevents ingress
ESD spark from entering the energy meter, thereby successfully preventing tampering of the
energy meter. A significant feature of the continuous tamper proof energy meter case / cover is
that the aforesaid case / cover is futuristic in nature for tampers such as 55Kv and beyond.
A principal embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, said tamper-proof case / cover comprising of:
a) a first part which houses the energy meter; and
b) a second part, comprising of a block and a bar code level.
Another embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, wherein the block may be made of a group of materials selected from a
group of polycarbonates.
Another embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, wherein the bar code level may be made of materials selected from a group
of polycarbonates.
Yet another embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, wherein the PCBA / energy meter is fitted in the case / cover with the help
of guides (4).
One more embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, wherein the first part and second part are permanently locked by screw
along with sealing provision (3) .
8• Yet one more embodiment of the present invention provides a continuous tamper-proof
energy meter case / cover, wherein the block and the bar code level is locked by push fitting
the locking teeth with fitting flanges (2.) into locking grooves (I ).
Further, another embodiment of the present invention provides a continuous tamper-proof
energy meter case / cover, wherein the energy meter is permanently encased in the tamper-
proof case / cover.
Another embodiment of the present invention provides a continuous tamper-proof energy
meter case / cover, wherein the case / cover prevent ingress of ESD spark into the energy
meter.
Advantages of the present invention:
The advantages of the continuous tamper-proof energy meter case / cover present are given
below:
a) No gap between base and cover as it is one integrated unit
b) Really Break to Open
c) Reduction in part count
d) 25-30% reduction in raw material volume - plastic
e) Quick & simple assembly
f) Ultrasonic welding not required
g) Truly production friendly
h) Metal shield may not be required

We claim:
1) A continuous tamper-proof energy meter case / cover, said tamper-proof case / cover
comprising of:
a) a first part which houses the energy meter; and
b) a second part, comprising of a block and a bar code level.
2) The continuous tamper-proof energy meter case / cover of claim 1, wherein the block may
be made of a group of materials selected from a group of polycarbonates.
3) The continuous tamper-proof energy meter case / cover of claim 1, wherein the bar code
level may be made of materials selected from a group of polycarbonates.
4) The continuous tamper-proof energy meter case / cover of claim 1, wherein the PCBA /
energy meter is fitted in the case / cover with the help of guides (4).
5) The continuous tamper-proof energy meter case / cover of claim 1, wherein the first part
and second part are permanently locked by screw along with sealing provision(3)
6) The continuous tamper-proof energy meter case / cover of claim 1, wherein the block and
the bar code level is locked by push fitting the locking teeth with fitting flanges (2.) into
locking grooves (1.).
7) The continuous tamper-proof energy meter case / cover of claim 1, wherein the energy
meter is permanently encased in the tamper-proof case / cover.
8) The continuous tamper-proof energy meter case / cover of claim 1, wherein the case /
cover prevent ingress of ESD spak into the energy meter.
9) A continuous tamper-proof energy meter case / cover substantially as described herein.