Note: Descriptions are shown in the official language in which they were submitted.
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MONITORING DEVICE FOR VACUUM CLEANER
FIELD OF THE INVENTION
The invention relates to centralized vacuum cleaning systems and more
particularly to a
centralized vacuum cleaning system monitoring device allowing to indicate to
the user
of the system, of any maintenance required on the power unit in order to
maintain high
cleaning capability of the system related in particular to the possible
partial clogging of
the filtration mean and to preventive maintenance in order to get a long term
performance of the central vacuum system.
BACKGROUND OF THE INVENTION
A central vacuum cleaner comprises a power unit usually installed permanently
in an
area of a building and one or more ducts are connected to vacuum system inlets
provided in various zones all over said building. Said cleaner allows to clean
any areas
of said building with the use of a flexible hose or other debris recuperation
device
connected to said inlets. Said central vacuum power unit can be activated by
mere
insertion of the hose in one of said inlets which is electrically wired to
said unit, or by a
switch provided on the hose or in the debris recuperation device or by any
other means.
There are 4 significant advantages to a central vacuum system. The following
shows
some example of possible advantages:
1- The available power output of a central vacuum system is generally higher
than a portable system. The fact that we do not have to move the whole power
unit in a
centralized vacuum system allows for the use of bigger and stronger motors and
also
the use of greater dimensioned filters resulting in higher airflow power
output.
2- With a central vacuum system, there is no need to move a cumbersome
machine that can hit and make an object in the way of the machine's moving
path fall,
as this is often the case with portable systems.
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3- Another advantage is that a central vacuum system easily allows for an
evacuation of the working air outside the building, avoiding any possible
recirculation of
air that could still contain very fine dust particles into the building.
4- Noise level perceived is normally lower than the noise level from a
portable
vacuum since a central vacuum power unit is often located in a remotely
located area of
the building (for instance: in the basement). In a portable system the motor
unit is
generally relatively close to the user so the noise level would be
comparatively higher.
Because the central vacuum power unit is generally located in a remote area of
the
building that is often not the same area where the cleaning work is performed,
then it is
compulsory for the user to go near the power unit if he wants to see the state
of the
system, unless a method of sending information to the user is provided. The
most
preferable way of sending the said information to the user is to have a
perceivable
signal transmitted directly from the hose handle. This could be done by a
light, sound,
vibration or any other means.
Prior art shows that information on the hose handle is available most
particularly for
portable vacuum cleaners. But since the hose length of a portable vacuum
cleaner is
relatively short compared to the hose and duct length of a central vacuum
system, and
also that the hose on a portable vacuum cleaner is not located in the walls of
the
building, it is relatively easy to manufacture multiple (more than two)
conductor wires in
the hose of a portable vacuum cleaner. This is relatively not as easy in a
central
vacuum system since a power unit is often installed in an existing building
installation
using the standard 2 conductor wiring normally running along each duct that
leads to
the valve inlets of the system. Economically, two conductor wires are
generally used
throughout the industry of centralized vacuum systems. Often, some builders
install all
the piping and as a standard, a 2 conductor wire, giving the future owner of
the building
or area of the building the possibility of choosing his own central vacuum
power unit.
This being said, it would be difficult to install different wiring after all
the wall finishing is
done, selected paint is applied etc... This fact known, a central vacuum power
unit that
could transmit a variety of useful information to the user up to the hose
handle area,
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using the industry standard two conductor wire would mean a significant
advantage.
From prior art, systems for indicating the state of a central vacuum power
unit have
demonstrated to be generally complicated systems, often using lots of
electronic
components in the hose handle which is subject to vertical impact on the floor
from a
height of over 3 feet high for example. As this impact or condition can happen
often in
the life of a central vacuum system hose handle, it is mathematically more
likely to fail,
showing here the need for simple and rugged characteristics for a said
indicating device
system.
One of the most important things to monitor in a central vacuum system for
effective
cleaning performance of a determined system is the state of clogging of the
filter. There
is also a need for a system that would be able to transmit to the user the
information
relating to the maintenance of motor components of the central vacuum power
unit in
order to assist the user and/or owner of the central vacuum power unit in
doing
preventive maintenance. A regular preventive maintenance is known to avoid
costly
repairs in all mechanical products. So an integrated signal reminding the user
that it is
time for preventive maintenance is considered very useful in combination to
the
indications related to clogging of filtration means and together contributes
to maintain
long lasting performance of the system. In prior art related to vacuum
cleaners, various
methods are found. Some methods use electronic circuitry programmed as a
function of
each motor used which takes into account the rotational speed of the motor
and/or
drawn current. These methods can work to some extent but they tend to be
complicated, costly to manufacture and also more subject to failure,
mathematically
speaking due to their degree of complexity.
SUMMARY OF THE INVENTION
It has now been discovered that it is possible to send multiple information
from a central
vacuum power unit to the hose handle using only 2 distinct wires of electrical
cable (i.e.
2 channel), while having a very limited number of components in the hose
handle
(basically a Bicolor LED plugged in a series arrangement), thus showing to be
a very
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robust and reliable way to transmit information to a user of a central vacuum
system
distant from the central vacuum power unit. Also, it has been discovered that
this
information sent from the power unit can be constant, or even a blinking
signal without
affecting the power unit motor from working simultaneously.
In accordance with an aspect of the invention, there is provided a central
vacuum
cleaning system comprising: a flexible hose having a first end terminating in
an air inlet
means and a second end terminating in an air duct connector for connection to
an air
duct, a handle portion having a control switch, and two conductive wires
extending
inside the flexible hose from the control switch to the air duct connector; a
status
indicator on at least one of the handle portion of the flexible hose and an
inlet of the air
duct; and a central vacuum power unit connectable to the air duct and
comprising a
motor for powering the system, a filter for filtering incoming air, a dirt
container for
receiving dirt from the filter, a pressure sensor operatively connected
between a
cleaned air side of the filter and the dirt container, and a control module
connected to
the pressure sensor and adapted to send a first signal to the status indicator
when a
measured pressure exceeds a predetermined pressure threshold, thereby
indicating a
maintenance need.
In one embodiment, the control module also comprises a timer for monitoring
the
activity time of the system, and the control module is adapted to send a
second signal to
the status indicator when time elapsed since a last reset action exceeds a
first
predetermined time threshold.
Components of the system:
In the flexible hose handle: These components are found in the hose handle:
One bi-
color LED, one switch, and two wires coming from the flexible hose.
In the central vacuum power unit: Control module on the information available
in this
document in addition to known ways in the prior art to manufacture central
vacuum
power units (i.e. motor, fan, seals, etc.).
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Link "power unit- hose handle" : Two conductor wires in the flexible hose
linking
electrically the valve wall inlets to the switch & LED present in the hose
handle.
Advantageously, the present invention relates to a new central vacuum
monitoring
device.
Advantageously, the indicating device will be installed on the flexible hose
handle but
could be installed only on the valve vacuum inlets present in various areas in
the
building.
Advantageously, the signal will be given to the user directly from a signal
coming from
the hose handle.
Advantageously, the signal given will be visual.
Advantageously, the visual information will be transmitted by a Bi-color type
LED.
A sensorially perceivable monitoring indicator can be a visual indicator such
as Bi-Color
LED or any other suitable means.
Advantageously, the color obtained from the LED could be perceived has red or
green
or amber.
Advantageously, the signal would be present on both the central vacuum power
unit
and on the hose handle.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention will
become
better understood with regard to the following description and accompanying
drawings
wherein-
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FIG. I is a plan of the main circuit board in accordance with a first
embodiment of the
present invention,
FIG. 2 is a plan of the daughter board in accordance with the first embodiment
of the
present invention,
FIG. 3 is a schematic illustration of a flexible hose in accordance with the
first
embodiment of the present invention,
FIG. 4 is a partial perspective view and partly sectioned of a central vacuum
system
unit, without the cover and the canister walls.
Fig. 5 is a schematic transversal view of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
IPM system (Intelligent Performance Monitoring)
The main purpose of this new electronic module is to help the user in
maintaining the
performance of his central vacuum system. The help in the maintenance is
divided in
two aspects:
1. Short term maintenance:
That includes a way of monitoring.-
- A differential pressure sensor monitoring functionality in order to get
information about the state of clogging of the filter.
- A timer functionality monitoring time elapsed since a last reset of the
15hrs
functioning time. The basic reason for this 15 hours being the need to empty
the debris
receptacle based on manufacturer experiences.
2. Long term maintenance:
- A timer functionality monitoring time elapsed since last reset of the 490
hrs &
500hrs functioning time. Essentially related to preventive maintenance of the
electrical
motor in the power unit.
The intent of the pressure differential monitoring is to be able to tell the
user of the
vacuum of the decreased performance of the central vacuum system ideally
before the
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user notices the degradations in performances due to habituation (not noticing
degradation of performance due to the slow process of degradation in
performance).
However, when the user will go clean his filter he should note that after
cleaning, the
performance of his machine has significantly increased. This operation will
show to be
useful since the result will be more a efficient central vacuum system that
should allow
the user to perform the cleaning task faster since more power is now available
from the
system.
Figures 4 is a partial perspective view, and partly sectioned, of a central
vacuum power
unit 400, without the cover and the canister walls. Fig. 5 is a schematic
transversal view
of FIG. 4. A filter 402 is inside the power unit 400. A pressure sensor 404 is
connected
to an electronic module. One tube 406 of the pressure sensor 404 is connected
to a dirt
laden vacuum air side of the filter (outside). The other tube 408 is connected
to the
cleaned vacuum air side of the filter (inside).
IPM Features
1. Power motor control:
As illustrated in figure 3, using the reliable relay technology, it is
possible to turn
ON/OFF the vacuum motor remotely from the switch 300 located in the hose
handle
310 and wired through the piping with two standard low voltage wires 302. A
daughter
board, as illustrated in figure 2, with bicolor LED 304 (BLED) and a tiny push
switch 300
(reset/demo) is included as part of this module.
2. Low voltage LED Autopolarity:
In addition of the switch 300 located in the hose handle 310, there is a light
emitting diode (LED) 304 used to indicate the motor status, so this LED 304
will light
green, red, amber and/or blink at different speed showing the actual status.
But no
matter how you connect the Low voltage wires (LVW) 302 in the central vacuum
(CV) or
how is it wired through the hose 308, this LED 304 will always show the right
color.
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3. Hi vacuum detection:
If abnormal high vacuum is detected (differential pressure above 40 inches
H2O),
the LED and BLED will blink amber (2 /sec).
4. Timing record:
By using the EEPROM technology (Non volatile memory) the control board
records two types of timing. The user can check them any time by looking at
the BLED:
a. Partial time, the BLED blinks slow no matter the color.
b. Total used, the BLED changes color.
Time used BLED color Meaning Action to be taken
15 hours Slow blink The vacuum has Clean the bag and
been used for at reset by holding this
least 15 hours after switch for 5 seconds
resetting
490 hours Red /10 secs The vacuum has Preventive
Accumulated Green / 20 secs been used for more maintenance
than 490 hours
500 hours Blink Red The vacuum has Priority to perform
Accumulated 2.5 sec been used for more maintenance
than 500 hours
Table 1
5. Self test:
When just connecting the board to the AC line, the board performs a self test,
if
everything is OK the BLED blinks fast green for a few seconds.
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6. Reset/demo switch:
This switch does the following:
Function Action Results
Test/demo Push and release for no The system performs a self
more than 5 seconds when test, so the BLED will light
the motor is OFF or ON through all states (see table
1)
Partial reset push and hold for more The, system will reset the 15
than 5 seconds when the hours timing, if the system
motor is OFF was blinking the current
color becomes solid
Total reset Push and hold for more The system will reset the
than 30 seconds when the accumulated hours
motor is ON recorded
Table 2
7. Night light compatibility:
If desired, it is possible to connect standard LEDs in series) (no matter the
polarity) to perform the nightlight feature, no need for an adaptor or similar
power
supply.
8. Old system compatibility:
The system can work with the old style CV hose, for example, when using a
standard hose the system will work by short-circuiting the LVW.
9. Customizable features:
Because the system is software based, it is possible to customize the timing
(BLED colors, delays, etc.).
Detailed explanations of respective status levels:
Level 0 No LED on the (optional) hose handle or on the unit
The power cord of vacuum is not plugged in electrical outlet.
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Level 1 Fast blinking green on the unit
The power cord of the vacuum has just been plugged in the outlet or after the
resetting of Level 4.
Level 2 Constant green on the unit only
The power cord of the vacuum is plugged in the electrical outlet, but the
switch on the hose handle is off or the hose is not inserted in the valve.
Level 3 Constant green on the (optional) hose handle or on the unit
The system is remotely activated the vacuum is functioning. In order to
always have high efficiency of your unit and to maintain the unit properly, it
is highly
recommended that you always use your vacuum at Level 3.
Level 4 Slow blinking green on the (optional) hose handle or on the unit
15 hours of use have passed since last reset; this indication recommends to
empty the dust container of your unit. After emptying the dust container,
always
push and hold the IPM reset button until the LED starts fast blinking green
and then
release.
Level 5 Slow blinking amber on the (optional) hose handle or on the unit
This indication suggests that you should clean the filter & empty the dust
container in order to maintain the high performance of your unit. The IPM
basically
detects whether the filter is obstructed enough to hamper the proper
performances
of this unit. Resetting the IPM is not required. The IPM sensor detects the
differential in vacuum by the use of 2 independent sensor tubes connected on
each
side of the filter.
Level 6 Constant red on the (optional) hose or on the unit
This programmed indication for 10 seconds every 30 seconds, recommends
that you have your unit inspected by a qualified technician in order to
prolong the
life of the motor. This indication will appear after 490 hours of usage.
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Level 7 Fast blinking red on the (optional) hose or on the unit (for 10
seconds every 30 seconds)
This is an extension of "Level 6" this routine indication highly recommends
that you have your unit inspected by a qualified technician to prevent damage
to the
motor. This indication will appear at 500 hours of use. (As an indication,
this is, for
an approximate use of 1 hour a week, equivalent to about 100 years).
General Overview of the preferred embodiment
The power Control Modules (PCM) MC-xM and MCE-xM were designed to work as a
Vacuum cleaner power control, their performance is the same, the difference is
the 220-
240 transformer and the filter. So for the European version, there is a
transformer and
EMI filter, but the North-American version has only a 110-120 transformer. The
secondary in both versions are the same: 9 VAC and 24 VAC.
The PCM has two boards: Main board (figure 1) and daughter board (figure 2).
In the
main board are located all the power components. In the daughter board only
the extra
low voltage electronic components are used for control, supervision and
interface.
Since the main board does not show particular interest in respect to the
related
invention presented here, only the description of the daughter board will
follow.
However, we can say that information is transferred form the daughter board
throughout
the flexible hose by passing by the main board.
Daughter board
This board has two main components:
The 8-bit micro-controller 200 (uC) PIC12CE673 with A/D converter, 3 timers,
EEPROM
memory and 6 independent & configurable I/O ports 202 (P to P5). Its software
is able
to convert the incoming Analog and Digital signals and based on programming
and
historic parameters, make a decision to produce a digital output signal to
drive the
power and LED components through their drivers.
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The operational amplifiers 204a-204d are 4 gates for a single power supply.
These
OPAmps with their associated components use 2 gates to drive the external Low
Voltage Wires (LVW) and two to monitor them (get feedback).
There are also some other components that are worth the mention like the
Transistor
206, the LED 208 and the Voltage regulator 210. These components are used
respectively to drive the relay (main board), to show the status in three
colors and to
maintain a stable VDC to power the electronics.
How does it work
Please refer to Daughter Board schematic (figure 2).
When the appliance is plugged-in what happens electronically:
1. When the appliance is connected, the uC 200 is energized and does the
following:
a. Turn OFF the monitor ( P5 )
b. Measures the AC line frequency through P3
c. Verify, read and update the timing from the EEPROM memory
d. Autocheck all the inputs/outputs and activate the watch-dog feature
e. Start scanning the LVW through 204c & 204d. That means it changes the
polarity every 8 mSEC. Because 204a-204d are powered by 24VDC, the LVW
will be 24 VAC @ 62.5Hz
If everything is OK, the LED on the PCN blinks twice ( ports PO and P2 ).
When the appliance is plugged in and the hose is plugged in the valve of the
system,
what happens electronically when the LED becomes constant green (Power on
condition ):
2. When a bicolour LED (BLED) is connected remotely through the LVW, it is
detected
by 204c and 204d, then by changing the LVW polarity through 204a and 204d, the
uC
200 detects how it is connected to the BLED and what color is displayed. If it
is the
wrong color, it corrects the polarity. This detection is made fast, however,
to avoid false
detection, and the system verifies many times before taking the signals as
correct.
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The LVW are driven through two 620 ohm resistors (212 and 214) which protect
204a-
204d from over current and limit the LVW current to 20 mA.
When the appliance is plugged in and the hose is plugged in the valve of the
system,
what happens electronically when the LED becomes constant green (15 hrs
condition):
3. Every second is recorded by EEPROM if the vacuum motor is energized, so
when
the uC 200 detects 15 hours accumulated it makes both LEDs (on hose and on
PCM)
blink. The local LED is made to blink by turning ON/OFF PO and P2, and the one
on
hose is made to blink by turning ON/OFF PO and P1 the drivers (204a and 204b).
When the appliance is plugged-in & the hose is plugged in the valve of the
system & the
pressure switch detects a pressure higher than a predetermined setting, what
happens
electronically when the LED slowly blinks amber (differential pressure
condition):
4. The Hi vacuum condition is detected by a electro-mechanic component located
in the
main board. It is normally open, so when it closes, this condition is detected
by P3.
Before any LED starts blinking, the uC 200 filters this signal to avoid false
conditions. By
changing the polarity of both the LED 208 the uC 200, the color shown is
changed to
amber. Actually there is no amber, like television it comes from the
combination of red
and green, so the 8 mSEC period is divided 70% green and 30% red. But the
human-
eye persistence combines these two colors in order to perceive an amber color.
When the appliance is plugged-in & the hose is plugged in the valve of the
system & the
elapsed time since a last maintenance has reached a predetermined setting of
490hrs,
what happens electronically when the LED becomes a constant red (490hrs
condition):
5. When the uC 200 detects the accumulated time has reached 490 hours, it
changes
the polarity on both LEDs to light the red color.
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When the appliance is plugged-in & the hose is plugged in the valve of the
system & the
elapsed time since a last maintenance has reached a predetermined setting of
500hrs,
what happens electronically when the LED becomes a fast blinking red (500hrs
condition):
6. The same as above but for 500 hours. In this case the blinking is made
faster by
changing the duty cycle ON/OFF.
When the appliance is plugged-in & the hose is plugged in, what happens
electronically
in order to be able to get a DEMO mode for the module:
7. The push switch located on the daughter board is monitored by P1 (working
as input),
so after being digitally filtered by the uC 200, if the switch has been pushed
for more
than 5 seconds, the uC 200 interprets it as a test/demo status and starts an
internal
routine that injects internal signals to test all software and hardware. This
way the
system has to pass all the events that it was programmed for. As a result all
the colors
and blinking combinations are shown.
How does the automatic detection of polarity work in this module:
8. The OpAmp gates 204c and 204d and fast diodes D3 and D4 are polarized
symmetrically to amplify and detect small DC differences in the LED connected
on the
LVW. This way the signal injected to the uC through PO is always positive.
This signal is
digitized, filtered and compared with pre-programmed parameters to keep the
right
color. Again, as mentioned above the signal is filtered to reject noise coming
from or
around the LVW.
This type of design involves the relationship between hardware and software,
this was
completed using the most recent advances in the technology.
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Other advantages of the system:
The simple fact of having an intelligent module:. Generally the central vacuum
power
units available in this industry are manufactured without an intelligent
module. So the
sole fact of having such a module represents an advantage.
The information is available preferably on the hose handle: The fact that the
information
is available directly on the hose handle and is far from the power unit makes
it
unnecessary to go see the information directly on the power unit, and it
allows
information on the status of the system without delay.
Only necessary information is transmitted: This system will not transmit
unnecessary
information to the user. If the status light on the hose handle changes, it
means that
there is a requirement for action from the user. This prevents the user from
getting
confusing information from the system.
Minimal quality of components in the hose handle: Allows for more economical
and
reliable system.
Only a two conductor wire is used for bi-directional communication: Our
invention only
needs 2 wires in order to be able to communicate multiple information to the
user. The
same wires are used to transmit control information from the user to the
central vacuum
power unit. Even blinking signals can be sent to the user without affecting
the
performance of the motor unit.
Indications given by the system are intuitive and essentially recognized
worldwide: The
LED advantageously present on the hose handle show strong similitude with ones
used
in transportation circulation indication which is quite well recognized
worldwide.
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Transportation circulation Indication from IPM
(control module
Green You can go You can go
Amber For security, it is For better performance, it
suggested to stop if you is suggested to stop and
can go clean your filter/debris
canister
Red You need to stop to You need to stop to
prevent damage prevent damage
Also: A slow blinking refers to a not so urgent thing to do, while a fast
blinking refers to
an urgent thing to do.
It is possible to activate the DEMO of possible indications given by the
system: This is a
really significant advantage when presenting the central vacuum power unit to
a new
customer. The consumer then knows and sees exactly how the information will be
given
to him during the use of his future machine. This advantage is particularly
good during
commercial presentation of the product to a potential new customer.
Easy Integration of an Intelligent system to an existing ducting and wiring
Installation: It
is possible thanks to this invention, to easily integrate an intelligent
control module to an
existing building where all ducting work and electrical wiring has been done
without any
modification to the piping and wiring usually nested into walls of the
building. This
proves to be particularly useful considering that otherwise a much more
complicated
and/or inconvenient and/or costly solution would have to be put in place in
order to
"patch" the problem (opening the wall, seeing an apparent outside cable in an
elegantly
crafted room).
Easy reset of the timer is allowed by the use of this system : Compared to
some other
central vacuum manufacturers that will ask to replace the whole control module
when a
preset time is reached, ours just needs to be reset by the simple push of a
button
present on the central vacuum power unit. This proves to be a significant
advantage
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since it is simple and NOT a costly operation. The same reset button is used
for the 15
hrs reset and for the 490 hrs and 500 hrs reset timer.
No decision to control the machine for the user: The module is preferably just
an
indicating device. So the electronic module would never take the decision of
shutting
down the motor, an indication will recommend the user to do so, and the final
decision
to take action will be his.
The fact of combining pressure sensor and timer: This offers 4 significant
advantages:
- Prevent long propagation of bacteria, molds, etc Do to too much time between
cleanings of the system.
- Prevent overflow of debris tank if a lot of big low density particles are
vacuumed
(based on experience this 15 hrs time is adequate).
- The fact of not having just a pressure sensor but a timer for preventive
maintenance allows to maintain not only short term performance but to maintain
performance over the years of use of the central vacuum system equipped with
the invention presented in this document.
- Since there is a 490 - 500 hrs timer included in this invention, it is not
mandatory for the user to write down on a separate sheet of paper a reminder
to
remind him when the last inspection of his power unit was done. Furthermore,
he does not even have to bother to evaluate the time when his power unit will
have reached 500 hrs of use since the object of this invention does it for
him.
It will be understood that numerous modifications thereto will appear to those
skilled in
the art. Accordingly, the above description and accompanying drawings should
be taken
as illustrative of the invention and not in a limiting sense. It will further
be understood
that it is intended to cover any variations, uses, or adaptations of the
invention following,
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in general, the principles of the invention and including such departures from
the
present disclosure as come within known or customary practice within the art
to which
the invention pertains and as may be applied to the essential features herein
before set
forth, and as follows in the scope of the appended claims.
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