U.S. patent application number 12/854569 was filed with the patent office on 2010-12-02 for water heater apparatus with differential control.
Invention is credited to Thomas P. Buescher, Edward B. Evans, Rishi Siravuri.
Application Number | 20100300377 12/854569 |
Document ID | / |
Family ID | 43218771 |
Filed Date | 2010-12-02 |
United States Patent
Application |
20100300377 |
Kind Code |
A1 |
Buescher; Thomas P. ; et
al. |
December 2, 2010 |
WATER HEATER APPARATUS WITH DIFFERENTIAL CONTROL
Abstract
An apparatus for a water heater is configured to control heating
operation of a water heater to maintain a desired water
temperature. The various embodiments comprise a sensor that
provides an output indicative of the sensed temperature of water in
a water heater, and a controller in communication with the sensor.
The controller is operable to initiate a present call for heat
where the sensed temperature is a predetermined amount below a
set-point temperature. The controller is also configured to
determine whether a prior call for heat occurred within a
predetermined elapsed time period preceding the present call for
heat, and to respond thereto by delaying the start of heating
operation in the present call for heat until one of a predetermined
time period or a predetermined sensed temperature change has
occurred.
Inventors: |
Buescher; Thomas P.;
(Webster Groves, MO) ; Siravuri; Rishi; (Maryland
Heights, MO) ; Evans; Edward B.; (St. Louis,
MO) |
Correspondence
Address: |
HARNESS, DICKEY, & PIERCE, P.L.C
7700 Bonhomme, Suite 400
ST. LOUIS
MO
63105
US
|
Family ID: |
43218771 |
Appl. No.: |
12/854569 |
Filed: |
August 11, 2010 |
Current U.S.
Class: |
122/14.1 |
Current CPC
Class: |
F24H 1/186 20130101;
F24H 9/2035 20130101 |
Class at
Publication: |
122/14.1 |
International
Class: |
F24H 9/20 20060101
F24H009/20 |
Claims
1. An apparatus for controlling heating operation of a water heater
to maintain a desired water temperature, comprising: a sensor that
provides an output indicative of the sensed temperature of water in
a water heater; a controller in communication with the sensor, the
controller being operable to initiate a present call for heat where
the sensed temperature is a predetermined amount below a set-point
temperature, wherein the controller is configured to determine
whether a prior call for heat occurred within a predetermined
elapsed time period preceding the present call for heat, and to
respond thereto by delaying the start of heating operation in the
present call for heat until one of a predetermined time period or a
predetermined sensed temperature change has occurred.
2. The apparatus of claim 1 wherein the controller is configured to
delay the start of heating operation until the sensed temperature
decreases by a predetermined sensed temperature change that is
dependent on the number of prior calls for heat within the
predetermined elapsed time period.
3. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a first predetermined sensed
temperature change occurs where a single prior call for heat
occurred within the predetermined elapsed time period.
4. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a second predetermined sensed
temperature change occurs where two prior calls for heat occurred
within the predetermined elapsed time period.
5. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a third predetermined sensed
temperature change occurs where at least three prior calls for heat
occurred within the predetermined elapsed time period.
6. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a first predetermined time period has
occurred where a single prior call for heat occurred within the
predetermined elapsed time period.
7. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a second predetermined time period
has occurred where two prior calls for heat occurred within a
predetermined elapsed time period.
8. The apparatus of claim 1 wherein the controller is configured to
delay heating operation until a third predetermined time period has
occurred where at least three prior calls for heat occurred within
a predetermined elapsed time period.
9. The apparatus of claim 1 wherein the predetermined elapsed time
period is a time period immediately preceding the present call for
heat, of between about 30 minutes to about 120 minutes.
10. An apparatus for controlling heating operation of a water
heater to maintain a desired water temperature, comprising: a
sensor that provides a value indicative of the sensed temperature
of water in a water heater; a controller that initiates a call for
heat when a difference between a set-point temperature and the
sensed temperature exceeds a temperature differential setting, the
controller being configured to delay the start of heating operation
for a given delay time period where the controller identifies a
prior call for heat within a predetermined elapsed time period
preceding the present call for heat.
11. The apparatus of claim 10 wherein the controller is configured
to delay heating operation until a first delay time period has
occurred where a single prior call for heat occurred within the
predetermined elapsed time period.
12. The apparatus of claim 11 wherein the controller is further
configured to delay heating operation until a second delay time
period has occurred where two prior calls for heat occurred within
a predetermined elapsed time period.
13. The apparatus of claim 12 wherein the controller is further
configured to delay heating operation until a third delay time
period has occurred where at least three prior calls for heat
occurred within a predetermined elapsed time period.
14. The apparatus of claim 11 wherein the first delay time period
is at least 10 seconds.
15. The apparatus of claim 13 wherein the first delay time period
is at least 10 seconds, the second delay time period is at least 10
seconds greater than the first delay time period, and the third
delay time period is at least 10 seconds greater than the second
delay time period.
16. An apparatus for controlling heating operation of a water
heater to maintain a desired water temperature, comprising: a
sensor that provides a value indicative of the sensed temperature
of water in a water heater; a controller that initiates a call for
heat when a difference between a set-point temperature and the
sensed temperature exceeds a temperature differential setting, the
controller being configured to delay the start of heating operation
until the sensed temperature decreases by a predetermined amount
where the controller identifies a prior call for heat within a
predetermined elapsed time period preceding the present call for
heat.
17. The apparatus of claim 16 wherein the controller is configured
to delay heating operation until the sensed temperature decreases
by a first predetermined amount where only a single prior call for
heat occurred within the predetermined elapsed time period.
18. The apparatus of claim 17 wherein the controller is configured
to delay heating operation until the sensed temperature decreases
by a second predetermined amount where two prior calls for heat
occurred within the predetermined elapsed time period.
19. The apparatus of claim 18 wherein the controller is configured
to delay heating operation until the sensed temperature decreases
by a third predetermined amount where at least three prior calls
for heat occurred within the predetermined elapsed time period.
20. The apparatus of claim 19 wherein the first predetermined
amount is an offset temperature decrease of at least 5 degrees
Fahrenheit, and the second predetermined amount is an offset
temperature decrease that is at least degrees Fahrenheit lower than
the first predetermined amount, and the third predetermined amount
is an offset temperature decrease that is at least 5 degrees
Fahrenheit lower than the second predetermined amount.
21. An apparatus for controlling heating operation of a water
heater to maintain a desired water temperature, comprising: a
sensor that provides an output indicative of the sensed temperature
of water in a water heater; a controller in communication with the
sensor, the controller being operable to initiate a present call
for heat where the sensed temperature is a predetermined amount
below a set-point temperature, wherein the controller is configured
to determine whether more than 3 prior calls for heat occurred
within a predetermined elapsed time period preceding the present
call for heat, and to respond thereto by delaying the start of
heating operation in the present call for heat until the first
occurrence of either a predetermined time of at least 10 minutes or
the sensed temperature decreases by at least 8 degrees Fahrenheit.
Description
FIELD
[0001] The present disclosure relates to the control of a hot water
heater, and more particularly to apparatus for controlling heating
operation of the heater to maintain a more consistent
temperature.
BACKGROUND
[0002] This section provides background information related to the
present disclosure which is not necessarily prior art.
[0003] In a typical water heater, cold water is introduced into the
bottom of a hot water heater tank where it is detected by a sensor
that triggers a call for heat. When a water heater is subjected to
repeated short draws of hot water in which water draw stops shortly
after a call for heat is initiated, the water temperature in the
tank can stratify and lead to water that is much hotter than the
desired temperature setting. Stacking can be reduced by a large
temperature differential setting, such as 20.degree. Fahrenheit, so
that the water temperature must drop 20.degree. below the water
temperature setting before a call for heat is initiated. However,
over a few hours of inactivity, the water in the tank will cool off
and any hot water draw before a call for heat is initiated will
result in complaints that the water is too cold. For example, where
a hot water heater is set to 120 degrees F., and the differential
is set to 20 degrees F., water in the tank may cool to 101 degrees
F. overnight such that any draw of hot water in the morning would
be too cold. Thus, large differential settings result in cold water
complaints in the morning. A narrower differential setting
decreases energy efficiency, because the water heater turns on more
often as the water temperature drops over time. Thus, there is a
need for control of a water heater that reduces stacking effects
yet maintains a comfortable hot water temperature.
SUMMARY
[0004] This section provides a general summary of the disclosure,
and is not a comprehensive disclosure of its full scope or all of
its features. Various embodiments of an apparatus are disclosed
that are configured to control heating operation of a fuel-fired
water heater. The various embodiments include an apparatus
configured to control heating operation of a water heater to
maintain a desired water temperature. The various embodiments
comprise a sensor that provides an output indicative of the sensed
temperature of water in a water heater, and a controller in
communication with the sensor. The controller is operable to
initiate a present call for heat where the sensed temperature is a
predetermined amount below a set-point temperature. The controller
is also configured to determine whether a prior call for heat
occurred within a predetermined elapsed time period preceding the
present call for heat, and to respond thereto by delaying the start
of heating operation in the present call for heat until one of a
predetermined time period or a predetermined sensed temperature
change has occurred.
[0005] In some embodiments, the controller is configured to delay
the start of heating operation until the sensed temperature
decreases by a predetermined sensed temperature change, which may
be dependent on the number of prior calls for heat within the
predetermined elapsed time period. In such embodiments, the
controller may be configured to delay heating operation until a
first predetermined sensed temperature change occurs where a single
prior call for heat occurred within the predetermined elapsed time
period. The controller may also be configured to delay heating
operation until a second predetermined sensed temperature change
occurs where two prior calls for heat occurred within the
predetermined elapsed time period, or to delay heating operation
until a third predetermined sensed temperature change occurs where
at least three prior calls for heat occurred within the
predetermined elapsed time period.
[0006] In other embodiments, the controller is configured to delay
heating operation until a first predetermined time period has
occurred where a single prior call for heat occurred within the
predetermined elapsed time period. The controller may also be
configured to delay heating operation until a second predetermined
time period has occurred where two prior calls for heat occurred
within a predetermined elapsed time period, or to delay heating
operation until a third predetermined time period has occurred
where at least three prior calls for heat occurred within a
predetermined elapsed time period, which is a given time period
immediately preceding the present call for heat.
[0007] Further areas of applicability will become apparent from the
description provided herein. The description and specific examples
in this summary are intended for purposes of illustration only and
are not intended to limit the scope of the present disclosure.
DRAWINGS
[0008] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0009] FIG. 1 is a cut-away illustration of a water heater having
one embodiment of an apparatus for controlling operation of the
water heater according to the principles of the present
disclosure;
[0010] FIG. 2 is a schematic of one embodiment of an apparatus for
controlling operation of a water heater according to the principles
of the present disclosure;
[0011] FIG. 3 is a flowchart illustrating the operation of a first
embodiment of an apparatus for controlling a water heater; and
[0012] FIG. 4 is a flowchart illustrating the operation of a second
embodiment of an apparatus for controlling a water heater; and
[0013] FIG. 5 is a flowchart illustrating the operation of a third
embodiment of an apparatus for controlling a water heater.
[0014] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0015] Example embodiments will now be described more fully with
reference to the accompanying drawings.
[0016] In the various embodiments, an apparatus is provided that is
configured to control heating operation of a water heater to
maintain a desired water temperature. The various embodiments
comprise a sensor that provides an output indicative of the sensed
temperature of water in a water heater, and a controller in
communication with the sensor. The controller is operable to
initiate a present call for heat where the sensed temperature is a
predetermined amount below a set-point temperature. The controller
is also configured to determine whether a prior call for heat
occurred within a predetermined elapsed time period preceding the
present call for heat, and to respond thereto by delaying the start
of heating operation in the present call for heat until one of a
predetermined time period or a predetermined sensed temperature
change has occurred.
[0017] In some embodiments, the controller is configured to delay
the start of heating operation until the sensed temperature
decreases by a predetermined sensed temperature change that is
dependent on the number of prior calls for heat within the
predetermined elapsed time period. In such embodiments, the
controller may be configured to delay heating operation until a
first predetermined sensed temperature change occurs where a single
prior call for heat occurred within the predetermined elapsed time
period. The controller may also be configured to delay heating
operation until a second predetermined sensed temperature change
occurs where two prior calls for heat occurred within the
predetermined elapsed time period, or to delay heating operation
until a third predetermined sensed temperature change occurs where
at least three prior calls for heat occurred within the
predetermined elapsed time period.
[0018] In other embodiments, the controller is configured to delay
heating operation until a first predetermined time period has
occurred where a single prior call for heat occurred within the
predetermined elapsed time period. The controller may also be
configured to delay heating operation until a second predetermined
time period has occurred where two prior calls for heat occurred
within a predetermined elapsed time period, or to delay heating
operation until a third predetermined time period has occurred
where at least three prior calls for heat occurred within a
predetermined elapsed time period. The predetermined elapsed time
period may be a time period immediately preceding the present call
for heat, and may be between about 30 minutes to about 120
minutes.
[0019] Referring to FIG. 1, an apparatus 100 is provided for
controlling heating operation of a water heater 20 to maintain a
desired temperature of water in the water heater. The water heater
20 has a storage tank 22 that stores heated water and receives cold
water via a cold water inlet 26. Cold water entering a bottom
portion 28 of the tank 22 is heated by a fuel-fired burner 30
beneath the tank. Water that is heated leaves the tank 22 via a hot
water outlet pipe 34. Combustion gases from the burner 30 leave the
water heater 20 via a flue 36. The apparatus 100 provides for
control of gas flow via a gas supply line 40 to the burner 30.
[0020] The apparatus 100 includes a sensor 102 that provides an
output or value that is indicative of the sensed temperature of the
water inside of the tank 22. For example, the sensor 102 may be a
tank surface-mounted temperature sensor such as a thermistor, or
the like. However, other embodiments can alternatively use a
temperature probe or other sensor suitable for enabling sensing the
water temperature in the tank. The sensor 102 may be positioned at
the bottom portion 28 of the tank 22 near the cold water inlet pipe
26, where cold water entering the tank 22 affects the output of
sensor 102.
[0021] The water heater 20 includes an apparatus 100 positioned,
for example, adjacent the tank 22. The sensor 102 is in
communication with the apparatus 100, and provides an output or
value that is indicative of the water temperature in the tank 22. A
second sensor (not shown) may be disposed at an upper portion of
the water heater 20, to provide an output or value that is
indicative of the sensed temperature of the water in the upper
portion 32 of the tank 22.
[0022] Referring to FIG. 2, a schematic is shown of the apparatus
100 having a controller 150 that is in communication with sensor
102. The controller 150 may be a microprocessor, for controlling at
least one gas valve actuator 160 for operating a gas valve 162 to
supply gas via supply line 40 to the burner 30, and may further
operate an igniter actuator 164 for actuating an igniter 166 via
connection 42. The controller 150 monitors the sensor 102 and the
sensed temperature of the water in the tank, and controls the
actuators to establish operation of the burner 30 where the sensed
temperature is a predetermined amount below a set-point
temperature, as explained below.
[0023] The water in the tank 22 may lose heat over time, for
example, such that the sensed temperature of the water drops a
given amount below a set-point temperature of the controller 150.
When the controller 150 determines that the sensed temperature of
the water is a predetermined "differential" amount below a
set-point temperature, the controller 150 establishes a call for
heat to raise the water temperature back to the set point
temperature. As long as the sensed temperature of the water remains
below the desired set-point temperature value, the call for heat
will continue and the burner will continue to raise the water
temperature. The call for heat is terminated when the sensed
temperature of the water detected by sensor 102 reaches a desired
set-point temperature value, which may be between about 120 and 150
degrees Fahrenheit. If, for example, the controller 150 has a 120
degree Fahrenheit set-point temperature and a 15 degree Fahrenheit
temperature differential setting, the controller 150 would initiate
a call for heat when the sensed temperature from sensor 102 drops
15 degrees Fahrenheit below the 120 degree Fahrenheit set-point
temperature. Thus, the controller 150 is operable to initiate a
call for heat where water temperature drops and a difference
between set-point temperature and the sensed temperature of the
water exceeds a predetermined temperature differential setting.
[0024] A decrease in water temperature may also occur, for example,
when hot water that is being drawn out of the tank 22 through
outlet pipe 34 is replaced by cold water entering inlet pipe 26,
which causes the temperature of the water in the lower portion 28
of the tank 22 to drop substantially below the set-point
temperature (such as a 10 or 15 degree drop). The controller 150
may determine, for example, that a rapid drop in temperature has
occurred, such as when hot water is being drawn from the tank 22
and cold water is entering the bottom of the tank through cold
water inlet 28. Cold water entering the tank 22 significantly
reduces the temperature of the water in the lower portion 28 of the
tank 22, while water in the upper portion 32 of the tank 22 still
remains hot. When hot water is drawn from the tank 22 for more than
a given time, the cold water entering the lower portion 28 creates
a temperature difference between the upper and lower portions of
the tank. The cold water entering the lower portion 28 of the tank
22 thus affects the output of the sensor 102, and the controller
150 initiates a call for heat when the difference between the
set-point temperature and the sensed temperature exceeds the
predetermined temperature differential setting. If, however, hot
water is drawn via outlet pipe 34 from the tank 22 for a brief
interim just long enough to affect the output of the sensor 102 and
cause the controller 150 to initiate a call for heat, the burner 30
would heat the water in the lower portion 28 which by convection
would increase the temperature of hot water in the upper portion
32. When hot water is successively drawn for brief interim periods
to establish intermittent calls for heat, the repeated operation of
the burner could cause temperature stratification in the tank 22
and potentially result in hot water in the upper portion of the
tank exceeding the set-point temperature.
[0025] To address this issue, the controller 150 of the first
embodiment is further configured to delay the start of heating
operation for a given delay time period where the controller 150
identifies a prior call for heat within a predetermined elapsed
time period preceding the present call for heat. The controller 150
is configured to delay heating operation until a predetermined
sensed temperature change occurs (the sensed temperature drops by 5
degrees, for example) when only a single prior call for heat has
occurred within a predetermined elapsed time period preceding the
present call for heat (such as a two hour period, for example). The
controller 150 may also be configured to delay the start of heating
operation until the sensed temperature decreases by a predetermined
sensed temperature change that is dependent on the number of prior
calls for heat within the predetermined elapsed time period, as
explained below.
[0026] Referring to FIG. 3, a flow chart is shown illustrating the
operation of the controller of the first embodiment. The controller
150 of the apparatus 100 is configured to determine at step 100
whether the sensed temperature (Tsensed) is within a differential
setting of 15 degrees of the set point temperature (Tset-point).
The controller 150 is operable to initiate a present call for heat
at step 110 where the sensed temperature is a predetermined amount
(e.g., 15 degrees for example) below the set-point temperature. At
step 120, the controller is configured to determine whether a
single prior call for heat occurred within a predetermined elapsed
time period (e.g., 2 hours, for example) preceding the present call
for heat, and to respond thereto by delaying the start of heating
operation in the present call for heat until a predetermined sensed
temperature change (or temperature offset) has occurred at step
130. Once the sensed temperature has decreased by the predetermined
sensed temperature change or temperature offset, the controller 150
is configured to start burner operation at step 180 and continue
operation at step 190 until the set point temperature is reached.
At step 140, the controller is further configured to determine
whether two prior calls for heat occurred within a predetermined
elapsed time period (e.g., 2 hours, for example), and to delay the
start of heating operation until the sensed temperature decreases
by a second predetermined sensed temperature change (or temperature
offset) at step 150. At step 160, the controller is further
configured to determine whether three or more prior calls for heat
occurred within a predetermined elapsed time period (e.g., 2 hours,
for example), and to delay the start of heating operation until the
sensed temperature decreases by a third predetermined sensed
temperature change (or temperature offset) at step 170. Thus, the
controller 150 is configured delay the start of heating operation
until the sensed temperature decreases by a predetermined sensed
temperature change that is dependent on the number of prior calls
for heat within the predetermined elapsed time period.
[0027] In a second embodiment, an apparatus is provided for
controlling heating operation of a water heater based on sensed
temperature, as explained below. The apparatus includes a sensor
such as sensor 102 in FIG. 1 that provides a value indicative of
the sensed temperature of water, and also includes a controller
similar to apparatus 100 in FIG. 1. The controller of the second
embodiment initiates a call for heat when a difference between a
set-point temperature and the sensed temperature exceeds a
temperature differential setting. The controller of the second
embodiment is also configured to delay the start of heating
operation until a predetermined time period has occurred or
elasped.
[0028] Referring to FIG. 4, a flow chart is shown illustrating the
operation of the controller of the second embodiment. The second
embodiment of a controller is configured to determine at step 200
whether the sensed temperature (Tsensed) is within a differential
setting of 15 degrees of the set point temperature (Tset-point),
and is operable to initiate a present call for heat at step 210
where the sensed temperature is a predetermined amount (e.g., 15
degrees for example) below the set-point temperature. At step 220,
the controller is configured to determine whether a single prior
call for heat occurred within a predetermined elapsed time period
(e.g., 2 hours, for example), and to respond thereto by delaying
the start of heating operation in the present call for heat until a
first predetermined time delay period has occurred or elasped at
step 230. Once the first predetermined time delay period has
occurred or elasped, the controller is configured to start burner
operation at step 280 and continue operation at step 290 until the
set point temperature is reached. At step 240, the controller is
further configured to determine whether two prior calls for heat
occurred within a predetermined elapsed time period (e.g., 2 hours,
for example), and to delay the start of heating operation until a
second predetermined time delay period has occurred or elasped at
step 250. At step 260, the controller is further configured to
determine whether three or more prior calls for heat occurred
within a predetermined elapsed time period (e.g., 2 hours, for
example), and to delay the start of heating operation until a third
predetermined time delay period has occurred or elasped at step
270. Thus, the controller of the second embodiment is configured
delay the start of heating operation by a predetermined time delay
period that is dependent on the number of prior calls for heat
within the predetermined elapsed time period.
[0029] Referring to FIG. 5, a flow chart is shown illustrating the
operation of the controller of a third embodiment. The third
embodiment of a controller is configured to determine at step 300
whether the sensed temperature (Tsensed.) is within a differential
setting of 15 degrees of the set point temperature (Tset-point),
and is operable to initiate a present call for heat at step 310
where the sensed temperature is a predetermined amount (e.g., 15
degrees for example) below the set-point temperature. At step 320,
the controller is configured to determine whether at least 4 calls
for heat, or over three calls for heat, occurred within a
predetermined elapsed time period (e.g., 2 hours, for example). At
step 330, the third embodiment of a controller is configured to
respond thereto by delaying the start of heating operation in the
present call for heat until either the sensed temperature decreases
by a predetermined sensed temperature change (e.g., 8.degree. F.
temperature offset), or a first predetermined time delay period has
occurred or elasped (e.g., 10 minutes). Once the first
predetermined time delay or temperature change has occurred or
elasped, the controller is configured to start burner operation at
step 380 and continue operation at step 390 until the set point
temperature is reached. Thus, the controller of the third
embodiment is configured delay the start of heating operation by a
predetermined time delay period that is dependent on the number of
prior calls for heat within the predetermined elapsed time
period.
[0030] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
[0031] Example embodiments are provided so that this disclosure
will be thorough, and will fully convey the scope to those who are
skilled in the art. Numerous specific details are set forth such as
examples of specific components, devices, and methods, to provide a
thorough understanding of embodiments of the present disclosure. It
will be apparent to those skilled in the art that specific details
need not be employed, that example embodiments may be embodied in
many different forms and that neither should be construed to limit
the scope of the disclosure. In some example embodiments,
well-known processes, well-known device structures, and well-known
technologies are not described in detail.
[0032] The terminology used herein is for the purpose of describing
particular example embodiments only and is not intended to be
limiting. As used herein, the singular forms "a," "an," and "the"
may be intended to include the plural forms as well, unless the
context clearly indicates otherwise. The terms "comprises,"
"comprising," "including," and "having," are inclusive and
therefore specify the presence of stated features, integers, steps,
operations, elements, and/or components, but do not preclude the
presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. The
method steps, processes, and operations described herein are not to
be construed as necessarily requiring their performance in the
particular order discussed or illustrated, unless specifically
identified as an order of performance. It is also to be understood
that additional or alternative steps may be employed.
[0033] Although the terms first, second, third, etc. may be used
herein to describe various elements, components, regions, layers
and/or sections, these elements, components, regions, layers and/or
sections should not be limited by these terms. These terms may be
only used to distinguish one element, component, region, layer or
section from another region, layer or section. Terms such as
"first," "second," and other numerical terms when used herein do
not imply a sequence or order unless clearly indicated by the
context. Thus, a first element, component, region, layer or section
discussed below could be termed a second element, component,
region, layer or section without departing from the teachings of
the example embodiments.
* * * * *