Note: Descriptions are shown in the official language in which they were submitted.
CA 02858734 2014-08-08
COUNTER MODULE ADAPTOR ASSEMBLY FOR ROTARY GAS METERS
FIELD
[0001] This disclosure relates generally to gas meter equipment, and
more
specifically to an adaptor assembly for rotary gas meters.
INTRODUCTION
[0002] Gas meters may be used to measure volumes of gas transported
and/or used
for heating or cooling purposes. For large-scale and/or industrial uses, most
gases are
typically sold on a price-per-volume basis (e.g. $5 per 1,000 cubic feet).
Accordingly, it is
generally considered desirable to measure gases being transported and/or used
with a
relatively high degree of accuracy. For example, natural gas may be
characterized as a
relatively expensive commodity, and it is important to accurately measure the
amount of
gas being transported and/or consumed, particularly at high volume rates.
Accurate
measurement may prevent a consumer from being overcharged by a provider, and
it may
also ensure that the consumer is charged for the entire volume of gas
provided.
[0003] A common method of providing accurate measurement of a consumed gas
is
the use of one or more positive displacement rotary gas meters. When gas flows
through
such a rotary gas meter, fixed volumes of gas are displaced by, for example,
two figure-
eight impellers that rotate in opposite directions within a cylinder of known
volume. The
impellers of the gas meter rotate because of a lower differential pressure at
the outlet of the
meter than is present at the inlet. As they rotate, a fixed volume of gas or
other fluid is
entrapped and then moved toward the outlet. Therefore, with each full rotation
of the
impellers, a known volume of gas or other fluid is displaced through the
outlet.
[0004] By measuring the number of rotations of the impellers, the
volume of gas or
other fluid displaced over a period of time can be determined. Also, as the
lobed figure-
eight impellers remain in a fixed relative position, it is only necessary to
measure the
rotational movement of one of the impellers. To accomplish this, in the case
of positive
displacement rotary gas meters that are electronically compensated, the
impeller may be
magnetically coupled to an electronic recording device.
[0005] Typically, a magnetic coupling device senses movement of the
impellers by
sensing the passage of magnets fixed to the rotating impellers. This may be
done with a
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Wiegand sensor mounted outside the pressure body of the gas meter. The sensor
then
transfers a signal to the electronic recording device. This electronic device
compensates for
density changes due to fluctuations in the temperature, pressure, and/or
composition of the
gas being metered, resulting in an extremely accurate measurement of the
consumed gas.
[0006] However, electronically compensated gas meters may fail to correctly
record
the amount of gas volume passing through it for a variety of reasons. The most
common
failures are due to power loss, faulty electronic components, failures due to
lightning, or
vandalism. If the electronic module stops recording for any reason, there is a
need for a
device to account for the flow. It is thought that hundreds of millions, if
not billions, of dollars
are contested in disputes each year between gas providers and consumers as a
result of
failures of electronically compensated gas meters.
SUMMARY
[0007] The following introduction is provided to introduce the reader
to the more
detailed discussion to follow. The introduction is not intended to limit or
define any claimed
or as yet unclaimed invention. One or more inventions may reside in any
combination or
sub-combination of the elements or process steps disclosed in any part of this
document
including its claims and figures.
[0008] Alternatively, or additionally, to an electronic recording
device, a gas meter
impeller may be coupled to a mechanical register, either directly or through a
series of
reduction gears. A mechanical register or counter can conveniently account for
the flow in
the event of a failure of an electronically compensated gas meter. Typically,
such
mechanical registers display the unconverted volume of consumed gas (e.g. the
volume of
gas that passed through the gas meter body, without compensating for density
changes
due to fluctuations in the temperature, pressure, and/or composition of the
gas being
metered). This volume displayed by a mechanical register may be used to
determine the
amount of gas that has flowed through the pressure body. Where a gas meter
body is
provided with electronic recording device and a mechanical register, the
mechanical
register may act as a backup to the electronic recording device.
[0009] Typical mechanical registers have a complicated gear assembly
that is
mechanically actuated by the rotation of the impellers of the gas meter. That
is, gas flowing
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through the meter causes rotation of the impeller of the gas meter, the
impeller drives a first
gear member in a series of gear members, and the gear members in turn drive
the
uncorrected volume register.
[0010] A manufacturer of gas meter bodies may provide a common
electronic
counter module mounting surface on a number of models and/or sizes of gas
meter bodies
to which an electronic counter module may be coupled. However, based on the
relative
location of the impeller within the gas meter body, the location of the
impeller (and/or a
counter drive shaft operatively coupled to the impeller) relative to the
mounting surface may
be different for different models and/or sizes of gas meter bodies.
[0011] While a typical electronic counter module may be used with gas meter
bodies
having different relative locations of their common mounting surface and
counter drive
shafts (as the magnetic sensor, typically being connected to the electronic
counter module
by flexible wiring, may be easily repositioned relative to the mounting
surface), the differing
relative positions of counter drive shafts may present problems for the use of
a mechanical
counter with different sizes and/or models of gas meter bodies. This may
require the use of
a different mechanical counter module and/or a different housing with each
different model
and/or size of gas meter body.
[0012] The apparatus and backup counter module disclosed herein may
alternatively
be used with gas meter bodies having different relative positioning of their
counter drive
shaft and mounting surface. The ability to use this universal apparatus and
backup counter
module with multiple gas meter bodies provides a number of advantages. For
example, the
number of different mechanical counter modules and/or housings that are
required to be
brought to a customer's facility when installing and/or repairing backup
counter modules
may be reduced, as the same parts may be used with a wide variety of gas
meters.
[0013] In accordance with a first broad aspect, there is provided an
apparatus for
use with a backup counter module, the apparatus comprising: a housing having a
first end
and a second end, the first end for coupling the housing to a gas meter body,
the second
end for coupling an electronic counter module to the housing; and the second
end having
an inner surface and an outer surface, the inner surface having at least two
sets of backup
counter module engagement features for securing an output end of a backup
counter
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module in one of at least two backup counter module positions; whereby the
housing may
be coupled to a first gas meter body with a first backup counter module
positioned within
the housing with an input end of the first backup counter module coupled to a
counter drive
shaft of the first gas meter body and an output end of the first backup
counter module
secured in one of the at least two backup counter module positions, and
whereby the
housing may alternatively be coupled to a second gas meter body with the first
backup
counter module positioned within the housing with the input end of the first
backup counter
module coupled to a counter drive shaft of the second gas meter body and the
output end
of the first backup counter module secured in another of the at least two
backup counter
module positions.
[0014] In some embodiments, the outer surface of the housing is
adapted to receive
a magnetic sensor operatively coupled to an electronic counter module in one
of at least
two magnetic sensor positions.
[0015] In some embodiments, the outer surface of the housing
comprises at least
two apertures, each aperture for receiving a magnetic sensor therein.
[0016] In some embodiments, the outer surface of the housing
comprises an
aperture shaped so that a magnetic sensor can be secured in one of at least
two magnetic
sensor positions within the aperture.
[0017] In some embodiments, each of the at least two sets of backup
counter
module engagement features comprise at least one recess for receiving a
complimentary
protrusion extending from an output end of a backup counter module.
[0018] In some embodiments, the second end of the housing further
comprises a
bore through which wiring associated with a temperature probe coupled to an
electronic
counter module may be run.
[0019] In some embodiments, the housing further comprises a conduit
extending
from the bore through which wiring associated with a temperature probe coupled
to an
electronic counter module.
[0020] In some embodiments, the at least two sets of backup counter
module
engagement features comprises three sets of engagement features, whereby an
output
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end of a backup counter module may be secured in one of at least three backup
counter
module positions.
[0021] In some embodiments, the housing has at least one viewing
window
positioned such that when a backup counter module is secured in one of the at
least two
backup counter module positions and the housing is coupled to a gas meter
body, a
counter display of the backup counter module is visible through the viewing
window.
[0022] In some embodiments, at least a portion of the housing is
translucent.
[0023] In some embodiments, at least a portion of the housing is
transparent.
[0024] In some embodiments, the first gas meter body comprises a gas
meter body
of a first size, and wherein the second gas meter body comprises a gas meter
body of a
second size.
[0025] In accordance with another broad aspect, there is provided a
backup counter
module having an input end and an output end, the backup counter module
comprising: a
frame; a driven shaft mounted to the frame and having an end for coupling to a
counter
drive shaft of a gas meter body, the driven shaft end located at the input end
of the backup
counter module; a mechanical counter mounted to the frame and coupled to the
driven
shaft so that rotation of the driven shaft increments a value of the
mechanical counter
proportionally to the rotation of the driven shaft; an output shaft connected
to the driven
shaft through a gear train so that rotation of the driven shaft results in a
proportional
rotation of the output shaft, the output shaft having a mount for receiving a
magnet so that
the magnet rotates in direct proportion to rotation of the output shaft, the
mount located at
the output end of the backup counter module; and one or more housing
engagement
features at the output end of the backup counter module for securing the
output end of the
backup counter module in one of at least two backup counter module positions
within a
housing.
[0026] In some embodiments, the one or more housing engagement
features
comprise at least one protrusion for insertion into a complimentary recess on
a housing.
[0027] In some embodiments, the magnet comprises a magnet for use
with a
Wiegand sensor.
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[0028] In some embodiments, a longitudinal axis of the driven shaft
and a
longitudinal axis of the output shaft are offset.
[0029] In some embodiments, the frame comprises a frame base and two
frame
plates extending from the frame base, and wherein the driven shaft extends
through one of
the two frame plates and is connected to the other of the two frame plates via
a bearing.
[0030] In some embodiments, the gear train is configured such that
the output shaft
rotates at the same speed as the driven shaft.
[0031] It will be appreciated by a person skilled in the art that a
method or apparatus
disclosed herein may embody any one or more of the features contained herein
and that
the features may be used in any particular combination or sub-combination.
[0032] These and other aspects and features of various embodiments
will be
described in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] For a better understanding of the described embodiments and to
show more
clearly how they may be carried into effect, reference will now be made, by
way of
example, to the accompanying drawings in which:
[0034] FIG. 1 is a perspective view of an electronic counter module
and a first gas
meter body;
[0035] FIG. 2 is a partially exploded view of the electronic counter
module and gas
meter body of FIG. 1 with an embodiment of an apparatus and backup counter
module
positioned between the electronic counter module and the gas meter body;
[0036] FIG. 3 is a perspective view of the electronic counter module,
apparatus and
backup counter module, and gas meter body of FIG. 2;
[0037] FIG. 4 is a side view of the electronic counter module,
apparatus and backup
counter module, and gas meter body of FIG. 2;
[0038] FIG. 5 is a perspective view of one end of an apparatus for
use with a backup
counter module 200;
[0039] FIG. 6 is a perspective view of another end of the apparatus
of FIG. 5;
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[0040] FIG. 7A is another end view of the apparatus of FIG. 5 with a
backup counter
module secured in a first backup counter module position;
[0041] FIG. 7B is an end view of the apparatus of FIG. 5 with a
backup counter
module secured in a second backup counter module position;
[0042] FIG. 70 is an end view of the apparatus of FIG. 5 with a backup
counter
module secured in a third backup counter module position;
[0043] FIG. 8 is a perspective view of an embodiment of a backup
counter module;
[0044] FIG. 9 is another perspective view of the backup counter
module of FIG. 8;
[0045] FIG. 10 is another perspective view of the backup counter
module of FIG. 8;
[0046] FIG. 11 is an exploded view of the backup counter module of FIG. 8;
[0047] FIG. 12 is another exploded view of the backup counter module
of FIG. 8;
[0048] FIG. 13 is an end view of the apparatus of FIG. 5 with a
backup counter
module secured in a first backup counter module position;
[0049] FIG. 14 is a perspective view of the apparatus of FIG. 5 with
a backup
counter module secured in a first backup counter module position;
[0050] FIG. 15 is a side view of the apparatus of FIG. 5 with a
backup counter
module secured in a first backup counter module position;
[0051] FIG. 16 is an end view of the apparatus of FIG. 5 with a
backup counter
module secured in a second backup counter module position;
[0052] FIG. 17 is a perspective view of the apparatus of FIG. 5 with a
backup
counter module secured in a second backup counter module position;
[0053] FIG. 18 is a side view of the apparatus of FIG. 5 with a
backup counter
module secured in a second backup counter module position;
[0054] FIG. 19 is a partially exploded view of an electronic counter
module, a second
gas meter body, and the apparatus and backup counter module of FIG. 16
positioned
between the electronic counter module and the gas meter body;
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[0055] FIG. 20 is a perspective view of the electronic counter
module, apparatus and
backup counter module, and gas meter body of FIG. 19;
[0056] FIG. 21 is a side view of the electronic counter module,
apparatus and
backup counter module, and gas meter body of FIG. 19;
[0057] FIG. 22 is an end view of the apparatus of FIG. 5 with a backup
counter
module secured in a third backup counter module position;
[0058] FIG. 23 is a perspective view of the apparatus of FIG. 5 with
a backup
counter module secured in a third backup counter module position;
[0059] FIG. 24 is a side view of the apparatus of FIG. 5 with a
backup counter
module secured in a third backup counter module position;
[0060] FIG. 25 is a partially exploded view of an electronic counter
module, a third
gas meter body, and the apparatus and backup counter module of FIG. 22
positioned
between the electronic counter module and the gas meter body;
[0061] FIG. 26 is a perspective view of the electronic counter
module, apparatus and
backup counter module, and gas meter body of FIG. 25; and
[0062] FIG. 27 is a side view of the electronic counter module,
apparatus and
backup counter module, and gas meter body of FIG. 25.
[0063] It will be appreciated that FIGS. 10 and 11 are for reference
only, and that it
may not be possible to assemble and/or disassemble the backup counter module
with the
components in their illustrated configurations.
[0064] The drawings included herewith are for illustrating various
examples of
articles, methods, and apparatuses of the teaching of the present
specification and are not
intended to limit the scope of what is taught in any way.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0065] Various apparatuses, methods and compositions are described below to
provide an example of an embodiment of each claimed invention. No embodiment
described below limits any claimed invention and any claimed invention may
cover
apparatuses and methods that differ from those described below. The claimed
inventions
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are not limited to apparatuses, methods and compositions having all of the
features of any
one apparatus, method or composition described below or to features common to
multiple
or all of the apparatuses, methods or compositions described below. It is
possible that an
apparatus, method or composition described below is not an embodiment of any
claimed
invention. Any invention disclosed in an apparatus, method or composition
described below
that is not claimed in this document may be the subject matter of another
protective
instrument, for example, a continuing patent application, and the
applicant(s), inventor(s)
and/or owner(s) do not intend to abandon, disclaim, or dedicate to the public
any such
invention by its disclosure in this document.
[0066] While the apparatus and methods disclosed herein are described
specifically
in relation to conventional positive displacement rotary gas meters, it will
be appreciated
that the apparatus and methods may alternatively be used with other types of
gas meters.
[0067] FIG. 1 illustrates a positive displacement rotary gas meter
and an electronic
counter module. Gas meter body 10A has an aperture 16 for providing access to
a counter
drive shaft of the gas meter, and an aperture 14 for receiving a temperature
probe. As used
herein, a counter drive shaft is any shaft of the gas meter body that rotates
proportionally to
the rotation of the impellers (e.g. lobed figure-eight impellers, or other
rotors) and may be
used to drive a counter module. For example, a rotor shaft may be used as a
counter drive
shaft. Gas meter body 10A also has a mounting surface 12 to which an
electronic counter
module 20 may be secured.
[0068] Electronic counter module 20 has a magnetic sensor 22 that may
be
positioned within aperture 16 of gas meter body 10A for sensing the rotation
of the counter
drive shaft. A display 24 is provided on electronic counter module 20 for
outputting the
measured amount of gas that has traveled through the gas meter. Electronic
counter
module 20 may also have a temperature probe (not shown) for insertion into
aperture 14,
allowing electronic counter module 20 to provide a temperature-corrected
measurement of
the volume of gas that has flowed through the gas meter, as is conventionally
known.
[0069] For example, electronic counter module 20 may be an AdEMTm
series
electronic counter module as available from Romet Limited.
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[0070] It will be appreciated that electronic counter module 20 may
be coupled
directly to gas meter body 10A, and used to measure a volume of gas that has
flowed
through the gas meter. But electronic counter module 20 may fail to correctly
record the
amount of gas volume passing through it for a variety of reasons. The most
common
failures are due to power loss, faulty electronic components, failures due to
lightning, or
vandalism. To account for a flow of gas without relying on electronic counter
module 20, a
mechanical counter module may also be coupled to gas meter body 10A.
[0071] FIGs. 2-4 illustrate an apparatus for positioning a backup
counter module
(e.g. a mechanical counter module) between a gas meter body and electronic
counter
module. More specifically, a first end 112 of a housing 110 of the apparatus
100 is
configured to be coupled to the mounting surface 12 of gas meter body 10A, and
a second
end 114 of housing 100 is configured to be coupled to electronic counter
module 20. As will
be discussed further below, backup counter module 200 is positioned within
housing 110
such that an input end of backup counter module 200 may be coupled to the
counter drive
shaft of gas meter body 10A, and an output end of backup counter module 200 is
secured
to an inner surface of the second end 114 of housing 110. In this way, when
electronic
counter module 20 is coupled to the second end 114 of housing 110, magnetic
sensor 22
may be used to sense the rotation of an output shaft of backup counter module
200. Since
rotation of the output shaft of backup counter module 200 is proportional to
(or equal to,
depending on the gearing of backup counter module 200) the rotation of the
counter drive
shaft of the gas meter, electronic counter module 20 may use magnetic sensor
22 to
indirectly sense the rotation of the counter drive shaft of the gas meter.
[0072] As exemplified in FIGS. 5 and 6, apparatus 100 comprises a
housing 110
having a first end 112 and a second end 114. First end 112 is configured to be
coupled to
the mounting surface 12 of a gas meter body 10. As shown, first end 112 has an
annular
flange 111 with a plurality of holes 113 for receiving mechanical fasteners
used to secure
housing 110 to gas meter body 10. It will be appreciated that first end 112 of
housing 110
may be alternatively or additionally coupled to mounting surface 12 of a gas
meter body 10
by any suitable means, for example, using a magnetic coupling system.
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[0073] As best seen in FIG. 5, the outer surface 118 of second end
114 is adapted
such that an electronic counter module 20 may be coupled to second end 114.
For
example, outer surface 118 may be provided with a ridge 117 dimensioned so
that ridge
117 and a complementary surface feature on electronic counter module 20 may be
placed
in abutting relation with each other. It will be appreciated that one or more
other surface
features may be provided, or no such surface feature may be provided.
Alternatively or
additionally, second end 114 may be provided with one or more holes 119 for
receiving
mechanical fasteners used to secure electronic counter module 20 to housing
110. It will be
appreciated that electronic counter module 20 may be alternatively or
additionally secured
to second end 114 by any suitable means, for example, using a magnetic
coupling system.
[0074] Second end 114 of housing 110 may also be adapted to
receive magnetic
sensor 22 of electronic counter module 20 in one or more magnetic sensor
positions. For
example, second end 114 has a circular aperture 142 dimensioned to receive
magnetic
sensor 22 therein. Second end 114 also has a peanut-shaped aperture 144
dimensioned to
receive magnetic sensor 22 in one of two positions (e.g. in either lobe 144a
or 144b of the
peanut-shaped aperture). It will be appreciated that other shapes and/or sizes
of apertures
may be provided, depending for example on the dimensions of the magnetic
sensor being
used.
[0075] A bore 150 may optionally be provided in second end 114 to
allow a
temperature probe and/or associated wiring of electronic counter module 20 to
be inserted
therethrough, for insertion into aperture 14 of gas meter body 10.
[0076] Turning to FIG. 6, inner surface 116 of second end 114 is
adapted such that a
backup counter module may be alternatively secured in one of a plurality of
backup counter
module positions. In the illustrated embodiment, a first set of engagement
features 120a,
126a each have a corresponding recess 122a, 128a, and each recess 122a, 128a
is
dimensioned to receive a complimentary protrusion extending from an output end
of
backup counter module 200. Thus, backup counter module 200 may be secured in a
first
backup counter module position 130a (see e.g. FIG. 7A) by positioning the
complementary
protrusions within the recesses 122a, 128a.
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[0077] It will be appreciated that securing backup counter module 200
in the first
backup counter module position 130a aligns the output end of backup counter
module 200
in a predetermined position relative to the second end 114 of housing 110.
Also, an input
end of backup counter module 200 will be aligned in a predetermined position
relative to
the first end 112 of housing 110.
[0078] In a similar manner, a second set of engagement features 120b,
126b allow
an output end of backup counter module 200 to be secured in a second backup
counter
module position 130b (see e.g. FIG. 7B), and a third set of engagement
features 120c,
126c allow an output end of backup counter module 200 to be secured in a third
backup
counter module position 130c (see e.g. FIG. 7C).
[0079] Optionally, one or more visual aids 129a-c may be provided on
inner surface
116 to assist in positioning backup counter module 200 for insertion into
engagement
features 120a-c, 126a-c.
[0080] Returning to FIG. 6, a conduit 152 may optionally be provided
between bore
150 and first end 112 of housing 110 to guide and/or protect wiring associated
with a
temperature probe of electronic counter module 20.
[0081] A viewing window 160 may optionally be provided in housing 110
so that a
display of a backup counter is visible when housing 110 and backup counter
module 200
are installed on a gas meter body and electronic counter module.
[0082] It will be appreciated that housing 110 may be made of any suitable
rigid
material, such as metal, plastic, and the like. Optionally, some or all of
housing 110 may be
made of a material that is translucent or transparent. For example, viewing
window 160
may be made of a translucent or transparent material.
[0083] FIGS. 8-12 illustrate a backup counter module (e.g. a
mechanical counter
module) for use with apparatus 100. Backup counter module 200 has an input end
202 for
coupling to a counter drive shaft of a gas meter body, an output end 204 for
securing the
backup counter module to the housing 110. Backup counter module 200 includes a
mechanical counter 230 for tracking a number proportional to the number of
rotations of the
counter drive shaft.
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[0084] An advantage of the backup counter module disclosed herein is
that, in
general, the more complicated the gear train, the more difficult it is to
ensure proper
measurement of low gas flow rates. By using a gear train with minimal
components, the
friction in the gear train is reduced and the energy needed to move the gear
train and
counter is reduced. With a more complicated gear train, a significant
proportion of the
energy embodied in the gas flow is used to overcome the torque created by the
gear train
and counter. This may create errors in measuring low flow rates and should be
avoided.
Also, a simple gear train produces a minimal pressure drop which in turn
allows the
impellers of the gas meter to rotate in a normal manner. This may increase the
accurately
of the measurement of relatively low gas flow rates.
[0085] In the embodiment illustrated in FIG. 8, backup counter module
200 includes
a frame 210 having a frame base 210 and two frame plates 212, 214 for
rotatingly
supporting a driven shaft 220 and an output shaft 240. In the illustrated
embodiment,
bearings 260 are provided to facilitate rotation of the driven and output
shafts relative to
frame 10, although it will be appreciated that other arrangements (e.g. using
one or more
bushings) may alternatively or additionally be used.
[0086] Driven shaft 220 has an end 202 configured to be coupled to a
counter drive
shaft of a gas meter body, so that the driven shaft 220 rotates at a rate
proportional to, and
preferably at the same rate as, the counter drive shaft. In the illustrated
embodiment, a
magnet 222 is provided at the end of driven shaft 220. This magnet 222 may be
magnetically coupled to a rotor shaft of a gas meter body. It will be
appreciated that driven
shaft 220 may alternatively or additionally be coupled to a counter drive
shaft using any
suitable means.
[0087] A worm 224 is mounted on driven shaft 220 for meshing with a
worm gear
234, which in turn drives mechanical counter 230. In this way, when the
counter drive shaft
is rotated (e.g. in response to gas flowing through gas meter body 10),
mechanical counter
230 is operable to count a number directly proportional to the number of
rotations of
counter drive shaft. This number is displayed on a display 232 of mechanical
counter 230.
[0088] While it is preferable to use a worm 224 and worm gear 234 so
that the
mechanical counter records a fraction of the number of rotations of the driven
shaft (and, by
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extension, of the counter drive shaft), it will be appreciated that any
suitable gearing may
be used. For example, the gearing may be configured so that the mechanical
counter 230
records the number of rotations of the counter drive shaft on a 1:1 basis, or
records a
multiple of the number of rotations of the driven shaft.
[0089] Mechanical counter 230 is illustrated as being mounted to the frame
base
210, although it will be appreciated that mechanical counter 230 may
alternatively, or
additionally, be mounted to one or both frame plates 212, 214.
[0090] Also notable in the arrangement shown is that the mechanical
counter 230
and its display 232 are oriented transverse to driven shaft 220 and output
shaft 240. Such
an arrangement may have a number of advantages. For example, rotating
mechanical
counter 230 may reduce the overall size of backup counter module 200, and in
particular
the length of the backup counter module 200 between the first end 202 and
second end
204 may be shorter than may be required if the mechanical counter were
positioned
parallel to driven shaft 220 and output shaft 240.
[0091] Also, as will be discussed further below, orienting display 232
transverse to
driven shaft 220 and output shaft 240 may allow a smaller viewing window 160
to be
provided in housing 110 while still allowing display 232 to be visible through
viewing
window 160 when backup counter module 200 is secured in any one of multiple
backup
counter module positions 130a-c.
[0092] It will be appreciated that that the value appearing on the display
232 of
mechanical counter 230 may be manipulated in a variety of ways to determine
the amount
of gas consumed (e.g. flowed through the gas meter body) over a period of
time. For
example, a conversion factor based on the type of gas meter being tracked
(e.g. by part or
make number) may be used. For example, a suitable conversion factor may be
determined
by calculating the specific displacement generated by each type (or size) of
gas meter.
Such a conversion factor may be proportional to the size of the gas meter and
the gear
ratio between the impeller shaft of the gas meter and the mechanical counter
230.
[0093] It will also be appreciated that, in addition to acting as a
backup for electronic
counter module 20, mechanical counter 230 may be used to track a total number
of
rotations of the counter drive shaft (and thus of the gas meter's impeller)
over the life of the
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gas meter. This may be valuable, as typically it is difficult to measure the
life of a gas
meter. Since mechanical counter 232 may be operable to count throughout the
operational
life of the gas meter, the value displayed on the display 232 may be used as a
proxy for the
operational age of the gas meter, e.g. to provide a measure of future life
expectancy and/or
the future operational value of the gas meter.
[0094] Turning to FIG. 9, also mounted on driven shaft 220 is a
driven gear 226,
which meshes with an output gear 246 (in the Figures, most of the gear teeth
have been
omitted for clarity). Thus, rotation of driven shaft 220 results in a
proportional rotation of
output shaft 240. While the illustrated embodiment has two gears providing a
1:1 ratio, it
will be appreciated that other gear arrangements and/or other gear ratios may
be used.
[0095] Also notable in the arrangement shown is that the
longitudinal axis 225 of
driven shaft 220 is offset from the longitudinal axis 245 of output shaft 240.
Such an
arrangement may have a number of advantages. For example, in this arrangement
the
location of magnet holder 242 is offset from the position of the end 222 of
driven shaft 220
that, in use, is coupled to a counter drive shaft of a gas meter. As will be
discussed further
below, a backup counter module 200 with offset driven and output shafts may
facilitate the
use of backup counter module 200 with a number of different sized of gas meter
bodies.
Also, offsetting the shafts 220, 240 may reduce the overall size of backup
counter module
200.
[0096] Turning to FIG. 10, a magnet holder 242 is mounted to output shaft
240 at the
output end 204 of backup counter module 200. Thus, rotation of driven shaft
220 (e.g.
when coupled to and driven by a counter drive shaft of a gas meter body)
results in: i)
incrementation of mechanical counter 230; and ii) rotation of magnet holder
242. While any
desired gearing may be provided, the gear ratio between driven shaft 220 and
mechanical
counter 230 is preferably 100:1 (i.e. 100 rotations of driven shaft 220
results in mechanical
counter being incremented by one digit), and the gear ratio between driven
shaft 220 and
magnet holder 242 is preferably 1:1.
[0097] As shown in FIGS. 8-11, worm 224, gears 226, and/or magnet
holder 242
may be mounted to their respective shafts using set screws, flats, and/or keys
and
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keyways. It will be appreciated that any suitable mounting system may be used,
such as
splined shafts.
[0098] Turning to FIG. 11, also provided at the output end 204 are
protrusions 250,
256. These protrusions cooperate with engagement features 120a-c, 126a-c to
secure
backup counter module 200 in one of a number of backup counter module position
130a-c
(see e.g. FIGS. 7A-C). In the illustrated embodiment, backup counter module
200 may be
secured in housing 110 by positioning protrusions 250, 256 within recesses
122a, 128a,
within 122b, 128b, or within 122c, 128c. As discussed above this allows backup
counter
module 200 to be secured in one of a number of backup counter module position
130a-c.
[0099] For example, as shown in FIGS. 13-15, backup counter module 200 may
be
secured in a first backup counter module position 130a by positioning
protrusions 250, 256
within recesses 122a, 128a of engagement features 120a, 126a, respectively. As
perhaps
best seen in FIG. 13, by providing a reference against which a corner of frame
210 can be
aligned, visual aid 129a may assist in positioning backup counter module 200
into position
for insertion into engagement features 120a, 126a.
[00100] The location of the end 222 of output shaft 220 relative to
the first end 112 of
housing 110 when backup counter module 200 is secured in first backup counter
module
position 130a is significant. More specifically, the relative position of end
222 and flange
111 allows housing 110 with backup counter module 200 secured in backup
counter
module position 130a to be coupled to a gas meter body having a counter drive
shaft in a
complementary position relative to a mounting surface. For example, as perhaps
best seen
in FIG. 2, gas meter body 10A has an aperture 16 for providing access to a
counter drive
shaft in certain relative position to mounting surface 12.
[00101] Also significant when backup counter module 200 is secured in
backup
counter module position 130a is the location of magnet holder 242 relative to
the inner
surface 116 of housing 110. More specifically, the relative position of magnet
holder 242
and aperture 142 allows magnetic sensor 22 of electronic counter module 20 to
be
positioned in aperture 142 (see e.g. FIG. 2) such that the magnetic sensor 22
is operable to
track the rotation of output shaft 240 via the rotation of a magnet held in
magnet holder
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242. For example, a Wiegand magnet and corresponding magnet sensor may be
used,
although any suitable tracking system may alternatively be used.
[00102] Thus, with the backup counter module 200 secured in position
130a,
apparatus 100 and backup counter module 200 may be coupled to gas meter body
10A
and used to i) track the relative rotation of the counter drive shaft via
mechanical counter
230; and ii) allow electronic counter module 20 to track the relative rotation
of the counter
drive shaft via the rotation of a magnet positioned in magnet holder 242.
[00103] Advantageously, the same apparatus 100 and backup counter
module 200
may alternatively be used with a gas meter body having a different relative
positioning of its
counter drive shaft and mounting surface. For example, this may be a gas meter
body of a
different size, and/or a different model of gas meter.
[00104] For example, as shown in FIGS. 16-21, backup counter module
200 may be
secured in a second backup counter module position 130b by positioning
protrusions 250,
256 within recesses 122b, 128b of engagement features 120b, 126b,
respectively. As
perhaps best seen in FIG. 16, by providing a reference against which a corner
of frame 210
can be aligned, visual aid 129b may assist in positioning backup counter
module 200 into
position for insertion into engagement features 120b, 126b.
[00105] As with first backup counter module position 130a, the
location of the end 222
of output shaft 220 relative to the first end 112 of housing 110 when backup
counter
module 200 is secured in second backup counter module position 130b is
significant. More
specifically, the relative position of end 222 and flange 111 allows housing
110 with backup
counter module 200 secured in backup counter module position 130b to be
coupled to a
gas meter body having a counter drive shaft in a complementary position
relative to a
mounting surface. For example, as perhaps best seen in FIG. 19, the relative
position of
aperture 16 and mounting surface 12 for gas meter body 10B is different than
their relative
position on gas meter body 10A.
[00106] Also, when backup counter module 200 is secured in second
backup counter
module position 130b, the relative position of magnet holder 242 and aperture
144 allows
magnetic sensor 22 of electronic counter module 20 to be positioned in
aperture 144b (see
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e.g. FIG. 19) such that the magnetic sensor 22 is operable to track the
rotation of output
shaft 240 via the rotation of a magnet held in magnet holder 242.
[00107] Thus, with the backup counter module 200 secured in position
130b,
apparatus 100 and backup counter module 200 may be coupled to gas meter body
10B
and used to i) track the relative rotation of the counter drive shaft via
mechanical counter
230; and ii) allow electronic counter module 20 to track the relative rotation
of the counter
drive shaft via the rotation of a magnet positioned in magnet holder 242.
[00108] Similarly, as shown in FIGs. 22-27, backup counter module 200
may be
secured in a third backup counter module position 130c by positioning
protrusions 250, 256
within recesses 122c, 128c of engagement features 120c, 126c, respectively. As
perhaps
best seen in FIG. 22, by providing a reference against which a corner of frame
210 can be
aligned, visual aid 129c may assist in positioning backup counter module 200
into position
for insertion into engagement features 120c, 126c.
[00109] Again, the location of the end 222 of output shaft 220
relative to the first end
112 of housing 110 when backup counter module 200 is secured in third backup
counter
module position 130c is significant. More specifically, the relative position
of end 222 and
flange 111 allows housing 110 with backup counter module 200 secured in backup
counter
module position 130c to be coupled to a gas meter body having a counter drive
shaft in a
complementary position relative to a mounting surface. For example, as perhaps
best seen
in FIG. 25, the relative position of aperture 16 and mounting surface 12 for
gas meter body
10C is different than their relative position on either of gas meter bodies
10A or 10B.
[00110] Also, when backup counter module 200 is secured in third
backup counter
module position 130c, the relative position of magnet holder 242 and aperture
144 allows
magnetic sensor 22 of electronic counter module 20 to be positioned in
aperture 144a (see
e.g. FIG. 25) such that the magnetic sensor 22 is operable to track the
rotation of output
shaft 240 via the rotation of a magnet held in magnet holder 242.
[00111] By allowing backup counter module 200 to be alternatively
secured within
housing 110 in more than one backup counter module position, the same
apparatus 100
and backup counter module 200 may alternatively be used with a gas meter body
having a
different relative positioning of its counter drive shaft and mounting
surface.
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[00112] For example, a manufacturer of gas meter bodies may provide a
common
mounting surface on a number of models and/or sizes of gas meter bodies.
However,
based on the relative location of the impeller within the gas meter body, the
location of the
counter drive shaft relative to the mounting surface may be different for
different models
and/or sizes of gas meter bodies. For example, compare and contrast the
relative locations
of mounting surfaces 12 and counter drive shafts 16 in FIGs. 2, 19, and 25.
[00113] However, the differing relative positions of counter drive
shafts may present
problems for the installation of a mechanical counter between the gas meter
body and an
electronic counter module. For example, a different mechanical counter module
and/or a
different housing may be required for each different model and/or size of gas
meter bodies
having different relative mounting surface / counter drive shaft arrangements.
[00114] The ability to use the same universal apparatus 100 and backup
counter
module 200 with gas meter bodies having different relative positioning of
their respective
counter drive shafts and mounting surfaces may have a number of advantages.
[00115] For example, the ability to use a universal apparatus 100 and
backup counter
module 200 with multiple gas meter bodies may reduce the number of different
mechanical
counter modules and/or housings that are required to be brought to a
customer's facility
when installing and/or repairing backup counter modules, as the same parts may
be used
with a wide variety of gas meters.
[00116] Also, as noted above, an advantageous result of using a backup
counter
module with a display oriented transverse to a driven shaft is that display is
located the
same distance along the housing 110 regardless of which backup counter module
position
it is secured in. As seen in e.g. FIGS. 4, 21, and 27, this allows display 232
to be visible
through a relatively small viewing window 160 in housing 110 regardless of
which backup
counter module position 130a-c the backup counter module 200 is secured in.
[00117] As used herein, the wording "and/or" is intended to represent
an inclusive - or.
That is, "X and/or Y" is intended to mean X or Y or both, for example. As a
further example,
"X, Y, and/or Z" is intended to mean X or Y or Z or any combination thereof.
[00118] While the above description describes features of example
embodiments, it
will be appreciated that some features and/or functions of the described
embodiments are
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susceptible to modification without departing from the spirit and principles
of operation of
the described embodiments. For example, the various characteristics which are
described
by means of the represented embodiments or examples may be selectively
combined with
each other. Accordingly, what has been described above is intended to be
illustrative of the
claimed concept and non-limiting. It will be understood by persons skilled in
the art that
other variants and modifications may be made without departing from the scope
of the
invention as defined in the claims appended hereto. The scope of the claims
should not be
limited by the preferred embodiments and examples, but should be given the
broadest
interpretation consistent with the description as a whole.
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