Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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19585P0033CA01
METHOD AND SYSTEM OF DETECTING A
BLOCKAGE IN A VACUUM CLEANER
TECHNICAL FIELD
[0001] The present teachings are directed toward the improved methods of
detecting
excessive loads from vacuumed objects or from drive belts that indicate
blockages of a vacuum
cleaner. The present teachings can also detect a roller brush binding that can
also indicate a
blockage of a vacuum cleaner. In particular, the disclosure relates to a
vacuum cleaner capable
of sensing the amount of electrical draw of the vacuum motor over a period of
time, and shutting
off power to the motor when the amount of electrical draw exceeds a
predetermined threshold for
a period of time.
BACKGROUND
[0002] A need has been recognized in the vacuum cleaner industry for vacuum
cleaners
to alert a user of an excessive load being placing on a vacuum motor. The
circuit detects
increased loading due to some object being wrapped around the roller brush
such as a tassel,
carpet fringe, a sock etc. getting into the suction fan. Failure to shutdown
the motor can cause
belt damage, motor burning and or line cord over heating and possible fire.
The user may not
become aware of the blockage until the motor ceases to function and is damaged
in some other
manner. An ability to halt the operation of the motor is needed so that a user
can undertake
appropriate corrective measures to remedy the blockage.
SUMMARY
[0003] According to one embodiment, a vacuum cleaner with a blockage sensor is
described. The vacuum cleaner comprises a motor; a power supply to provide
electrical current
to the motor; an amperage flow sensor to determine the electrical current draw
of the motor; and
a blockage determiner to sample the electrical current draw and count the
number of times the
sampled electrical current draw exceeds a threshold amperage within a window
of time.
[0004] In some embodiments the blockage determiner signals that vacuum is
experiencing blockage when the count during the window of time exceeds a
desired percentage
of samples sampled in the window of time.
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[0005] In some embodiments the desired percentage is at least 30% of the
samples
sampled in the window of time.
[0006] In some embodiments the desired percentage is at least 50% of the
samples
sampled in the window of time.
[0007] In some embodiments the blockage determiner samples the amperage draw
60
times a second or more.
[0008] In some embodiments the sliding window of time is greater than or equal
to 10
seconds.
[0009] In some embodiments the sliding window of time is greater than or equal
to 60
seconds.
[0010] In some embodiments the vacuum further comprises a reset switch
connected to
the control board.
[0011] In some embodiments the electrical current to the motor is stopped when
the
blockage determiner signals that vacuum is experiencing blockage.
[0012] In some embodiments the blockage being experienced is an obstructed air
flow
conduit.
[0013] In some embodiments the blockage being experienced is an obstructed
beater bar.
[0014] In some embodiments the circuit board further comprises a variable
speed control
for the motor.
[0015] In some embodiments the circuit board further comprises a light
emitting diode
(LED) power supply.
[0016] In some embodiments the circuit board further comprises a control
circuit to
actuate a diverter valve.
[0017] According to various embodiments, a method of detecting blockage along
an air
path, the method comprises providing a vacuum comprising a motor; providing
electrical current
to the motor; determining the amperage flow of the electrical current;
detecting blockage along
an air path by sampling the amperage flow of the electrical current; and
counting how many
times the sampled amperage draw exceeds a threshold amperage within a window
of time.
[0018] In some embodiments detecting comprises counting the number of times
the
amperage draw exceeds a desired percentage of samples sampled within the
window of time.
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[0019] In some embodiments the method further comprises enabling a blockage
indicator
when a blockage is detected.
[0020] In some embodiments the method further comprises receiving a reset
signal and
enabling the current flow to the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The same reference number represents the same element on all drawings.
It
should be noted that the drawings are not necessarily to scale. The foregoing
and other objects,
aspects, and advantages are better understood from the following detailed
description of a
preferred embodiment of the invention with reference to the drawings, in
which:
[0022] FIG. 1 illustrates a front prospective view of one embodiment of an
upright
vacuum cleaner;
[0023] FIG. 2 illustrates the rear view of one embodiment of an upright vacuum
cleaner;
[0024] FIG. 3 illustrates the bottom of the base of an upright vacuum cleaner
according
to one embodiment;
[0025] FIG. 4 illustrates the bag assembly of a debris capturing device of an
upright
vacuum cleaner according to one embodiment;
[0026] FIG. 5 illustrates the interior of the base of an upright vacuum
cleaner according
to one embodiment;
10027] FIG. 6 illustrates an automated diverter valve assembly of an upright
vacuum
cleaner according to one embodiment;
[0028] FIGs. 7A and 7B illustrate an automated diverter valve and motor
assembly of an
upright vacuum cleaner according to one embodiment;
[0029] FIGs. 8A and 8B illustrate one embodiment of a scroll of an upright
vacuum
cleaner according to one embodiment;
[0030] FIG. 9 illustrates a lifting assembly of an upright vacuum cleaner
according to one
embodiment;
[0031] FIG. 10 illustrates an exploded view of a yoke assembly of an upright
vacuum
cleaner according to one embodiment;
[0032] FIG. 11 illustrates an exploded view of a motor assembly of an upright
vacuum
cleaner according to one embodiment;
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[0033] FIG. 12 illustrates an exploded view of an upright vacuum cleaner
according to
one embodiment;
[0034] FIG. 13A illustrates sound data generated by a prior art cooling fan
blade;
[0035] FIG. 13B illustrates sound data generated by a cooling fan according to
one
embodiment;
[0036] FIG. 14 illustrates a graph of the amperage draw of a motor in a window
of a
selected duration according to one embodiment;
[0037] FIG. 15 illustrates a flow diagram indicating control mechanisms to
shut down a
motor according to one embodiment; and
[0038] FIG. 16 illustrates a logical view of a system to control and manage a
vacuum
cleaner according to one embodiment.
DETAILED DESCRIPTION
[0039] The present teachings provide an upright vacuum cleaner including
improved
cleaning features. The essential structure of the vacuum comprises a handle,
body, base,
automated diverter valve and air duct including two input ports. An automated
diverter valve
assembly at the junction of the dirty air intake within the base extends the
air duct within the
base and connects to the main air duct of the vacuum to the beater bar input
and an attachment
input. The automated diverter valve causes the air intake of the vacuum to be
drawn from either
the beater bar (floor) air input or the attachment input. The main air duct is
in air flow
communication with a vacuum motor located in the body of the vacuum spaced
from a distal end
of the air duct with respect to the flow of air.
[0040] In some embodiments the vacuum cleaner comprises a servo assembly for
moving
the automated diverter from the beater bar input port to the attachment input
port. In some
embodiments the vacuum cleaner comprises a control board to operate the servo
assembly in a
desired rotational movement between the two input ports for a duration. In
some embodiments
the vacuum cleaner further comprises a signal from a user actuated switch,
wherein the signal
can be used by the control board to determine the valve position between the
first input port and
the second input port. In some embodiments the user actuated switch comprises
a magnetic
sensor disposed fixedly in the vacuum, a magnet disposed in a rotatable
portion of the vacuum,
wherein placing the handle in a locked position rotates the rotatable portion,
and disposes the
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magnet opposite the magnetic sensor. In some embodiments the diverter valve
assembly
comprises a vacuum attitude sensor, wherein a detection signal from the vacuum
attitude sensor
determines the valve position between the first input port and the second
input port. In some
embodiments the vacuum cleaner further comprises an attachment sensor signal
to denote the
absence of an attachment connected to the first input port, and the signal
directs the control board
to direct airflow from the second input port to the output port.
[0041] In some embodiments the servo assembly comprises a servo motor and a
gear
assembly, wherein the servo assembly is able to position the diverter as
desired in two seconds or
less. In some embodiments the diverter valve assembly includes detents to stop
a movement of
the automated diverter. In some embodiments, the rotatable scroll can be part
of an upright
vacuum cleaner in which the vacuum motor is located in the air path that
contains dirt from a
cleaning surface (sometimes referred to as a "dirty-air" type vacuum).
[0042] The result is an upright vacuum with significantly greater cleaning
capability and
ease of use. Since the diverter valve rotates between the beater bar. input
port and the attachment
port automatically, an operator generally need not work as hard to utilize
either the attachment or
floor features of the vacuum. The diverter valve essentially seals the airflow
path to direct air
from only one input, thereby increasing the suction to any one input without
suction loss from
the other input port. Further, the vacuum cleaner need not shut the motor down
when switching
between beater bar and hand held use.
[0043] FIG. 1 is a perspective view of an exemplary embodiment of an upright
vacuum
cleaner 100. A handle 120 can be connected to base 102 via yoke 150 (see FIG.
9). Handle 120
can comprise aluminum. Wheels 104 can be disposed on yoke 150. Ergonomic
aluminum
handle 120 can include control buttons, such as power button 126, high speed
setting button 128
and low speed setting button 129 for easy user controls of the vacuum cleaner.
Bag assembly
144 can be connected to aluminum handle 120 via bag slide 130 (see FIG. 2).
Base 102 can
include a fascia 116. Further, fascia 116, scroll top cover 112, and scroll
bottom cover 114 (see
FIG. 2) can be made of different designs, textures and patterns in order to
appeal to a user's'
preference or to individualize vacuum cleaners. Fascia 116 can be secured to
the base 102 using
means known in the art, for example, tabs (not shown) and slots (not shown) to
receive the tabs.
In some embodiments, scroll top cover 112 and scroll bottom cover 114 can
comprise a fascia.
Base 102 can further comprise side brushes 106, a bumper 108, and a light
emitting diode (LED)
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strip 110 for improved cleaning capabilities of the upright vacuum cleaner
unit. Vacuum 100
can include a power cord 118 and an extendible crevice tool 132.
[0044] FIG. 2 is a rear view of an exemplary embodiment of an upright vacuum
cleaner
100. Power cord 118 can be connected to handle 120 and stored by top cord hook
122 and
bottom cord hook 124 for easy storage and management. Base 102 can further
comprise intake
vent 160 for proper and adequate ventilation of any interior air flow
propulsion devices. In one
aspect of this embodiment, an exhaust vent 162 can be positioned adjacent the
rear wheels 104.
Accordingly, airflow drawn in from the intake vent 160 can be expelled from
exhaust vent 162
and diffused over the surfaces of the rear wheel 104 as it leaves base 102.
The diffusion can
reduce the velocity of the airflow and reduce the likelihood that the airflow
will stir up
particulates on the floor surface. Base 102 can further comprise attachment
hose input 136 for a
hand held attachment. For example, one embodiment of a hand held attachment
includes a
flexible hose 134, a rigid hose 139 and an extendible crevice tool 132. In
some embodiments,
hand held attachments can include, but are not limited to brushes, squeegees,
beater bars,
extension hoses, nozzles, etc. In one embodiment, the upright vacuum cleaner
comprises a tool
caddy 138 for easy and convenient storage of a hand held attachment, for
example, extendible
crevice tool 132. A tool holder 135 can be disposed on bag assembly 144. Tool
holder 135 can
friction fit around extendible crevice tool 132 for easy storage and
management of flexible hose
134, rigid hose 139 and extendible crevice tool 132. Extendible crevice tool
132 can be removed
from tool holder 135 for use.
[0045] FIG. 3 is a bottom view of an exemplary embodiment of an upright vacuum
cleaner 100. Base 102 is supported by wheels 104 and front wheel 178. Base 102
generally
hovers over a cleaning surface, such as a floor. Base 102 can contact a
cleaning surface, for
example, when the cleaning surface is a deep shag carpet. Agitation devices,
such as a beater bar
170, squeegees 126, and side brushes 106 can provide agitation of cleaning
surfaces in order to
dislodge and direct debris into floor air intake port 206 (not shown). Beater
bar 170 can be
driven by a motor assembly 240 (see FIG. 5) via a flexible belt 186 (see FIG.
5) or other
mechanism. Anti-ingestion bars 182 prevent large sized items from being drawn
into the floor
air intake. Beater bar 170 can include a spindle 175 and an arrangement of
bristle tufts 171 that
sweep the particulates into the air intake port 206 (see FIG. 3). As seen in
FIG. 5, a belt receiver
175a can be disposed on spindle 175. Belt receiver 175a can include grooves to
receive
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corresponding grooves disposed in belt 186. Bristle tufts 171 can be arranged
on beater bar in
many different orientations. The fibers of the bristles can be of
substantially identical stiffness,
diameter and geometry or of different stiffnesses, diameters and geometries as
desired. The
fibers of the bristles can be made of natural or synthetic materials, or
combinations thereof,
including but not limited to nylon, plastic, polymers, rubber, hair (e.g.,
boar's hair). In one
embodiment, bristles can be arranged in a double helix pattern.
[0046] In a preferred embodiment, the bristle tufts can be arranged in a
single helix or
helical row. The single helical row can reverse its direction of rotation,
e.g., at bristle tuft 173 in
FIG. 3. The single helical row can reverse its direction of rotation after
about one and a half
turns about spindle 175. The average length of the fibers of the bristle tufts
can be from about
0.300 inches to about 0.500 inches. The average diameter of the fibers of the
bristle tufts can be
from about 0.008 inches to about 0.015 inches. Additionally, the bristle tufts
can be angled out
or placed non-orthogonally from the spindle to maximize the "embedded dirt"
movement
characteristics of the vacuum. The bristle tufts can be offset from the
centerline about 0.08
inches to about 0.15 inches. -In a preferred embodiment, the bristle tufts can
comprise filaments
comprising Nylon 6-6. The mean diameter of each filament can be about 0.012
inches. The
mean amplitude of each filament can be about 0.022 inches. The mean tuft
length of each
filament can be about 0.370 inches. The tuft offset from centerline can be
about 0.120 inches.
In some embodiments, a single helix brush can be advantageously used in high
shag carpets as
its rotational speed is not inhibited to the same degree as the rotational
speed of double helix
brushroll. In embedded dirt cleaning performance tests, a single helix
brushroll as described
above can remove about 15% more dirt than the prior art double helix
brushroll.
[0047] FIG. 4 is a bag assembly 140 of an exemplary embodiment. A debris
collection
device 146 is disposed in outer bag 144. Debris collection device 146 can be
connected to dirty
air inlet 146 to collect and trap and filter debris taken into the vacuum. In
one embodiment,
debris collection device 146 can be a disposable bag. In another embodiment
debris collection
device 146 can be a reusable bag. In another embodiment debris collection
device can be a
reusable canister or container. Bag assembly 140 can optionally further
include a variety of
filters for cleaning dirty air. Such filters can include one or more wire,
mesh, carbon, activated
charcoal, or HEPA filters.
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[0048] FIG. 5 is an interior view of an exemplary embodiment of base 102.
Beater bar
housing 184 can be connected to the dirty air path via a diverter valve
assembly 190 at input port
206. Automated diverter valve assembly can also contain a second input port
204. A connector
135 can connect to input port 204. A hose and attachments can be connected to
connector 135.
Airflow can be directed from either input port 206 or input port 204 to output
port 208. Servo
assembly 192 can rotationally direct'an automated diverter or diverter valve
212 (see FIG. 7A
and 7B) into. a scroll/volute 218 (only a small portion is visible in FIG. 5).
Airflow can be
generated by motor assembly 240 which draws air in from either input port 206
or input port 204
and out through rotatable scroll 218 into bag assembly 144 where debris can be
contained. An
impeller 226 (see FIG. 8A) is driven by the motor shaft and is housed in
scroll 218. Motor
assembly 240 can drive beater bar 170 via a flexible belt 186. In some
embodiments, flexible
belts of the instant invention can exceed the mean time between failure (MTBF)
of the vacuum
cleaner itself. Thus, flexible belts may never have to be replaced during the
lifetime of the
vacuum. In some embodiments, the belts are circular belts or serpentine belts.
In some
embodiments the belt can include a flat or length-wise grooved surface. If the
belt includes a
grooved surface, the surface can include 1, 2, 3, 4, 5 or more grooves. The
belts can be made of
materials known in the art, including, but not limited to rubber, nylon,
plastics, and polymers
such as polybutadiene, and polyamide, among others. In one embodiment, the
belt can be
provided by Hutchinson FTS of Troy Michigan. Motor assembly 240 can comprise
an end cap
246 that houses fan 250 (not shown) and motor 248.
[0049] Circuit board 260 of FIG. 5 can provide electrical current to motor
assembly 240,
an LED light assembly 110, servo assembly 192, and an attachment sensor 137.
Attachment
sensor 137 can comprise a contact switch which is depressed when connector 135
is disposed
about input port 204. A signal from attachment sensor 137 can be used by
circuit board 260
prior to positioning diverter valve assembly 190 to select input port 204. In
other words, if
connector 135 is not in place, a user cannot inadvertently be injured by the
suction created at
input port 204. Circuit board 260 can also provide electrical current to
various other components
of the vacuum cleaner, such as motorized beater bars, motorized handheld
attachments,
temperature sensors, attitude sensors, magnetic sensors, indicator lights,
etc.
[0050] FIG. 6 is an interior view of an exemplary embodiment of diverter valve
assembly
190. Diverter valve assembly 190 can be assembled with assembly housing top
106 and
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assembly housing bottom 108. When assembly housing top 106 and assembly
housing bottom
108 are attached, the assembly can define input port 204, input port 206
opposite input port 204,
and output port 208. Servo assembly 192 can be disposed opposite output port
208. A diverter
valve 212 can be fixedly attached to servo assembly 192. Airflow can be
directed from either
input port 206 or input port 204 by servo assembly 192 by rotating automated
diverter valve 212
to block either input port 204 or input port 206. Diverter valve assembly can
comprise a
cylindrical conduit 205 having a radius X that is slightly greater than a
radius Y of automated
diverter valve 212. Automated diverter valve 212 can comprise a cylindrical
portion.
[0051] In some embodiments automated diverter valve 192 includes detents to
stop its
movement. For example, diverter valve 212 can include diverter valve detents
198 and 202,
where a wall of diverter valve 212 forms a ridge. A wall 211 of diverter valve
212 can be placed
adjacent to a wall 217 of the diverter valve assembly against which servo
assembly 192 is
secured; this wall can a include bump-out 219 (see FIG. 6) to stop the travel
of diverter valve
212 against detents 198 and 202. As such, detents 198 and 202 define a range
of motion for
diverter valve 212.
[0052] In some embodiments, diverter valve 212 includes a low friction film
215 and a
protective valve sheathing 213 deposed underneath. Protective valve sheathing
213 aids in
sealing the diverter valve 212 over input port 206 or 204 as selected. Low
friction film 215
allows diverter valve 212 to easily rotate between input port 206 and 204.
Protective valve
sheathing 213 can be manufactured from, without limitation to, plastic, foam,
felt, plastic or
other suitable materials, or combinations therein. Low friction film 215 can
be smooth film.
[0053] As seen in FIGs. 7A and 7B servo assembly 192 can drive diverter valve
212
through servo motor shaft 194 which can be fastened to diverter valve shaft
aperture 214 by
fastener 195. The servo motor shaft 194 can be keyed to provide precision of
movement. Servo
assembly 192 can comprise a servo motor (not shown) and a gear assembly (not
shown) that can
rotate diverter valve into position using a desired speed and torque. Such
speeds can include
whole or fractions of a second. For example, the motor can be designed such
that the diverter
valve can be rotated from one input port to the other within or less than one-
half, one, two, three,
five or more seconds. Diverter valve 212 can comprise a shaft aperture 214
through which a
fastener, for example, a screw, can be secured to a servo shaft aperture 197.
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[0054] FIG. 8A is an illustration of an exemplary embodiment of a scroll 218.
Airflow
for the upright vacuum can be generated via impeller 226. Impeller 226 can be
driven by motor
assembly 240. Impeller 226 draws air in from automated diverter valve assembly
190 via air
intake 220. The drawn air is sent via an air conduit 234 into air output 222.
Air output 222 can
be connected via conduit 219 (see FIG. 12) to bag assembly 144 where debris
can be contained
for discard. Conduit 219 can be removable to allow a user to remove air flow
obstructions from
conduit 219 and/or scroll 218. Scroll 218 and air conduit 234 can include a
cross-sectional area
progression from dirty air intake 220 to the air output 222 that smoothly
varies between the first
cross-sectional area and the second cross-sectional area. Because the intake
passage includes a
smoothly varying area progression, turbulence within the intake passage may be
reduced or
inhibited, and noise generated by the airstream within the intake can be
minimized. Scroll 218
can also comprise ramp 235.
[0055] In some embodiments, scroll 218 comprises a magnet 224. A magnetic
sensor
210 (see FIG. 5) can be disposed fixedly in vacuum base 102. Magnet 224 is
disposed opposite
magnetic sensor 210 when scroll 218 is rotated to a predetermined position,
for example, when
handle 120 is placed in a locked position. In some embodiments magnetic sensor
210 can be
located adjacent, e.g., below, diverter valve assembly 190. Magnetic sensor
can determine an
attitude of vacuum base 102, e.g., is the vacuum at rest, is the vacuum handle
locked, or is the
vacuum handle unlocked. Further, in some embodiments a signal generated from
the magnetic
sensor 210 can determine diverter valve 212 position between first input port
204 and second
input port 206. In one embodiment, magnetic sensor 210 is disposed beneath
output port 208.
Magnetic sensor 210 is fixed to vacuum base 102.
[0056] FIG. 8B is an illustration of an exemplary embodiment of a scroll.
Scroll 218
includes scroll ring receiving groove 228 to receive scroll ring 230. When
scroll ring 230 is
disposed within scroll ring receiving groove 228, scroll ring tab 232 clicks
into place and locks
scroll 218 into a locked upright position. Scroll 2.18 is locked in position
by forming a friction fit
of scroll ring tab 232 against an inner wall of scroll ring receiving groove
228 disposed in scroll
218. When scroll 218 is locked, rotation of handle 218' about yoke axle 151
(see FIG. 10) is also
inhibited. In some embodiments, scroll ring 230 allows for a rotation of about
90 degrees to 120
degrees for scroll 218. This translates into a similar rotation of about 90
degrees to 120 degrees
about yoke axle 151 for handle 120.
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[0057] Scroll ring 230 is disposed about motor housing cap 246. Key tabs 231a,
231b,
and 231c are received by motor housing cap 246 to properly orient scroll ring
230 and scroll ring
tab 232. Motor assembly 240 is fixedly disposed in base 102. As such, scroll
ring 230 is fixedly
disposed in base 102, i.e., scroll ring 230 does not rotate. However, scroll
218 rotates about
scroll ring 232 so that handle 120 can rotate. Rotation of scroll 218 causes
bag slide (see FIG. 2)
to move up and down on handle 120 as needed.
[0058] FIG. 9 is an exemplary embodiment of a lifting mechanism. In some
embodiments, when handle 120 is placed in a locked upright position, scroll
218 is rotated such
that ramp 235 (see FIG. 8A) contacts lift tabs 179 of lifting assembly 172.
When ramp 235
pushes against lift tabs 179, lifting assembly 172 including front wheel 178
protrude out from
base 102. This causes base 102 to be raised off of a cleaning surface. In the
absence of ramp
235 pushing on lift tab 177, a biasing device 177, e.g., a spring, keeps
lifting assembly 172
pulled into base 102. By pushing lifting base 102 against a cleaning surface
the vacuum ceases
to agitate the cleaning surface. This can prevent unnecessary dust and debris
from being
generated by the rotation of the beater bar 170, side brushes 106 or squeegee
176. Moreover, by
raising the beater bar a load on the motor is reduced. This can reduce the
wear and tear on the.
motor, the belt and the beater bar.
[0059] FIG. 10 is an exemplary embodiment of a yoke assembly. As seen in FIGs.
1 and
2, yoke 150 and handle 120 are distinct from scroll 218 and bag assembly 144.
In one
embodiment, yoke assembly 150 can be connected to handle 120. In some
embodiments, handle
insert 158 is inserted into hollow handle 120. Handle 120 can be secured to
yoke 150 via
fasteners (not shown). The fasteners can pass through fastener apertures 155
and be fastened to
fastener receiving apertures 156. Fasteners can include screws, tension clips,
etc. Yoke
assembly 150 can be divided by handle insert 152. Handle insert 152 can
includes two internal
housings within yoke assembly.for passing a power cord 118 therethrough.
Advantageously,
providing a distinct compartment and path for power cord 1.18 within yoke
assembly 150
protects power cord from damage from with fasteners or handle 120. Yoke
assembly axles 151
and washers 157 can connect yoke 150 to wheels 104. Advantageously, because
yoke assembly
150 and handle 120 are distinct from base 102 and scroll 218, yoke assembly
150 can provide a
moment arm 157 anterior to base 102. Moment arm 157 can be co-linear with
yoke. axle 151. In
some embodiments, yoke axle 151 can comprise a single rod secured to yoke 150.
In some
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embodiments, yoke axle 151 can comprise two rods secured to yoke 150. Yoke
axle 151 can be
secured to yoke 150 via C-rings 153. It is theorized that with an anterior
moment arm, a force
applied to handle 120 causes yoke assembly 150 to be pushed towards a cleaning
surface rather
than pushing base 102 towards the cleaning surface. As such, any downward
component of the
force applied to handle 120 does not push base 102 down also. This reduces a
frictional force of
base 102 against the cleaning surface. The resulting reduction in friction
provides a much easier
vacuum to push and control for a user over a cleaning surface, and provides a
"floating head."
[0060] FIG. 11 is an exemplary embodiment of a motor assembly. Motor assembly
240
can provide air flow for a vacuum cleaner. In one embodiment a shaft of motor
assembly 240
can protrude from both ends of motor assembly 240. Shaft portion 244 can
rotate a fan (see FIG.
8A), such as an impeller, housed within scroll 218 to generate air flow. Shaft
portion 242 can
turn drive belt 186 and rotate beater bar 170. The outer surfaces of shaft
portions 242 or 244 can
be smooth, flat, textured, keyed or may include one, two, three or more
grooves 242a as desired.
Motor assembly cap 246, located on the distal end of motor assembly 240, can
provide.
protection for fan 250, while further defining an air inlet 245 and an air
outlet 256. The motor
assembly cap 246 can propel air over motor assembly 240 disposed within base
102.
Advantageously, air flow generated by fan 250 exiting air outlet 256 can cool
heat .generated by
motor assembly 240, thereby allowing a vacuum to utilize a larger motor than
found in prior art
vacuums.
[0061] Base 102 can be an airtight chamber. As seen in FIG. 12, base 102 can
be
assembled from base top 164 and base bottom 165, which are held together by
fasteners 166.
Base 102 can be sealed by gasket 167 situated between base top 164 and base
bottom 165.
Gasket 167 can be made from any suitable material, including but not limited
to paper, rubber,
silicone, metal, cork, felt, neoprene, nitrile rubber, fiberglass, or a
plastic polymer (such as
polychlorotrifluoroethylene) or any combination thereof. Motor assembly 240
can draw air to
cool the operating parts of the vacuum via air vent 160. The drawn air can be
exhausted via air
vent 162. Air vent 160 and air vent 162 can define an air path through base
102. The air path
can be a straight or convoluted path. The high volume of airflow produced by
fan 250 allows the
placement of a high powered motor in base 102. The high CFM also permits
cooling of
components in the base even when no particular airflow path is defined within
the base. For
example, airflow generated by fan 250 can be circulated throughout base 102 by
placing air
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intake vent 160 along the same wall as air vent 162. Other configurations for
disposing the air
intake and air exhaust in the base can be used.
[0062] Centrifugal fan 250 can include multiple fan blades and a hub.
Centrifugal fan
blades can have a slight backward curve. Alternatively, the fan can be axial
or squirrel cage
fans, or other material handling fans. In some embodiments, fan 250 can be
made of one or
more of a combination of materials, including metals, such as aluminum or
plastic. In some
embodiments fan 250 can be a centrifugal fan with a slight backward curve
including 30 blades
made by injection molding. In some embodiments, fan 250 can generate a blade
pass frequency
(BPF) that is greater than the BPF of prior art fans. The fan BPF noise level
intensity varies with
the number of blades and the rotation speed and can be expressed as BPF = n *
t / 60, where BPF
= Blade Pass Frequency (Hertz (Hz)), n = rotation velocity (rpm), and t =
number of blades. In
noise profiles of a fan, high-amplitude spikes are observed at the BPF and at
the harmonics of the
BPF. Humans perceive sound frequencies ranging from 20 to 15,000 Hz. Moreover,
sounds
between 2,000 to 4,000 Hz are often perceived as very irritating and annoying
to humans.
[0063] Prior art fans for motors used in vacuums generally use a stamped
radial fan
blade, a fan with blades extending out from the center along radii, usually
comprising 2-12
blades. For example, in the prior art a vacuum motor having a 12-blade fan and
operating at
about 20,000 RPM would have a calculated BPF of about 4000 Hz. As can be seen
in FIG. 13A,
the noise data profile for this prior art cooling fan produced decibel spikes
over 50 dB/20u Pa at
approximately 4,000 Hz. At 50 dB/20u Pa, the prior art-fan's noise profile
spike is about 20 dB
greater than the noise observed immediately around the 4000 Hz spike
frequency. The spike at
about 4000 Hz is within the annoying and irritating noise range for humans.
Furthermore,
harmonic frequencies of the BPF within a human's average hearing range, e.g.,
8000 and 12000
Hz, also produce large noise peaks.
[0064] By using a fan with a greater number of blades, the BPF can be
manipulated to
fall outside a desired sound frequency band. For example, the fan can comprise
20, 22, 24, 26,
28, 30, 32, 34, 36, 38, 40 or more blades. A further advantage is that the
unique design of motor
assembly 240 and blade 250 includes a bigger blade surface area. Furthermore,
this increase in
blade area coupled with the greater number of blades in the fan can generate a
greater airflow.
The greater airflow can by generated by a motor assembly cap having the same
or less volume
than a motor assembly cap housing of prior art. By manipulating the number of
blades and the
13
CA 02736288 2011-04-05
RPMs of the fan, the BPF can be adjusted to spike at a frequency greater than
about 5000, 5500,
6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, 10,000 or more Hz. A change in
the blade pass
frequency of the fan provides a reduction in perceived motor and fan noise. In
some
embodiments, the noise spikes generated by the fan is selected such that a BPF
spike is outside a
human ear's irritation noise range. Further in some embodiments, a BPF spike
is generated
outside of a human ear's audible noise range. In some embodiments motor
assembly 240 can
operate at about 10,000 to about 20,000 rotations per minute (RPM). In some
embodiments
assembly 240 can operate at about 10,000 or about 20,000 RPM. In some
embodiments
assembly 240 can operate at about 13,000 or about 18,000 RPM.
[0065] As seen in FIG. 13B, the BPF of fan 250 of the present vacuum is about
9000 Hz,
when the fan is rotated at about 18000. Furthermore, a switch to centrifugal
fans from the radial
fans of the produce reduces the amplitude of the spike at the BPF. The spike
at 9000 Hz is only
about 4 dB/20u Pa greater than the noise observed immediately around the 9000
Hz spike
frequency. The use of the centrifugal also lowers the acoustic characteristic
of noise at the BPF
by an order of 5.
[0066] Vacuum cleaner 100 can be capable of detecting blockage along an
airpath of
vacuum 100 by determining the amperage flow of the electrical current, and
detecting blockage
along an airpath by sampling the amperage flow of the electrical current and
counting how many
times the sampled amperage draw exceeds a threshold amperage within a window
of time.
When the samples sampled exceeds the percent threshold determined, power to
motor assembly
240 is terminated. The blockage can be detected using electronic over current
sense circuitry
known in the art. In some embodiments, the over current sense circuit can be
reset by turning the
vacuum off and then on. In some embodiments, the over current sense circuit
can be reset by a
reset switch. Optionally, an indicator light can be illuminated when power is
shut-off. After
receiving a reset signal the current flow to the motor can be restored.
[0067] An electrical fuse can be utilized with the over current sense circuit.
The
electrical fuse can be non-replaceable in the field. The electrical fuse can
be an 8 Ampere non-
replaceable in the field fuse. In some embodiments, the electrical fuse can be
field replaceable.
The electrical fuse can backup the over current sense circuit. The over
current sense circuit can
be used to implement a blockage determiner.
14
CA 02736288 2011-04-05
[0068] FIG. 14 illustrates a graph of the amperage draw of a motor in a window
of a
selected duration of an upright vacuum cleaner. Circuit board 260 can provide
electrical current
to motor assembly 240. Measurements of current drawn by vacuum motor can
determine
whether there is blockage with the vacuum air duct or beater bar. Depending
upon the severity
of the blockage, circuit board 260 can shut off power to motor assembly 240.
For example,
circuit board 260 can comprise an amperage flow sensor (not shown) to
determine or measure
the electrical current draw of motor assembly 240. Circuit board 260 can also
comprise a
blockage determiner 262 to sample the electrical current draw with the
amperage flow sensor and
count the number of times the sampled electrical current draw exceeds a
threshold amperage
within a sliding window of time. As seen in FIG. 14, the sliding window of
time period or
duration A illustrates that circuit board 260 counted three (3) instances or
samples out of seven
(7) instances where the current draw of the motor exceeded a threshold
amperage (shown as the
dashed line parallel to the horizontal axis). As such, during time period A
about 43% (3/7*100)
of samples exceeded the threshold amperage. In contrast, circuit board 260
counted only one (1)
instance out of seven (7) for time period B where the current draw of the
motor exceeded the
threshold amperage. Windows A and B can overlap along the time (horizontal)
axis. In some
embodiments the blockage determiner can signal that upright vacuum cleaner 100
is
experiencing blockage when the count exceeds a desired percentage of samples
sampled in the
window of time. In some embodiments, the desired percentage is at least 10,
20, 30, 40, 50 or
more of the samples sampled in the window of time. In some embodiments,
blockage
determiner 262 samples the amperage draw 15, 30, 60, or 90 times a second or
more. In some
embodiments the sliding window of time 264 is greater than or equal to 5, 10,
15, 20, 30, 45, 60,
90, or 120 seconds.
[0069] Vacuum cleaner 100 and circuit board 260 can comprise multiple sensors
and
switches. In a broad sense, a "sensor" as used herein, is a device capable of
receiving a signal or
stimulus (electrical, temperature, time, etc.) and responds to it in a
specific manner (opens or
closes a circuit, etc.). A "switch," as used herein, can be a mechanical or
electrical device for
making or breaking or changing the connections in a circuit. In some
embodiments sensors can
be switches. In other embodiments the sensors are connected to indicator
lights or the like to
inform a user of a malfunction or the need to perform a necessary function.
Vacuum cleaner 100
or circuit board 260 can comprise flow blockage, light, temperature, "bag
full" sensors, and
CA 02736288 2011-04-05
handle attitude sensors. Signals from these sensors can aid the user in using
and assessing
various states of the vacuum. Sensors can comprise electric, magnetic,
optical, gravity, etc.,
sensors, as known in the art. Vacuum cleaner 100 or circuit board 260 can
further comprise a
"deadman" or "kill" switch which is capable of terminating power to the vacuum
should the user
become incapacitated. A temperature sensor 266 can determine the temperature
of motor
assembly 240, base 102, or other parts. Circuit board 260 can turn on an
indicator light and/or
terminate power to vacuum 100. Further, vacuum cleaner 100 or circuit board
260 can include a
reset switch which is capable of resetting power to. vacuum cleaner 100 or
circuit board 260.
[0070] As shown in FIG. 15, control mechanisms to shut down a vacuum motor are
described. At step 280, the window of time slides or moves forward. At step
282, a samples of
the amperage drawn by the motor is measured or determined. At step 284, the
control
determines if the amperage flow exceeds a predetermined maximum or threshold
amperage. At
step 286, the control counts the number of time the amperage samples exceeded
the
predetermined maximum amperage. The control determines if the number from step
286
exceeded the acceptable percentage within the single window of time at step
288. If the
percentage of samples that exceeded the threshold is acceptable, the control
repeats the process
and begins at step 280 again. If the percentage of samples that exceeded the
threshold is not
acceptable, then the control turns off the current to the motor and shuts down
the motor at step
300. The disablement of the motor can trigger the illumination of an indicator
light at step 304.
The motor can be enabled by the user via manually activating a reset switch at
step 302.
[0071] In some embodiments, vacuum cleaner 100 includes a temperature sensor
266 that
is capable of determining the operating temperature of motor assembly 240 at
step 290. In some
embodiments, when the operating temperature exceeds a predetermined high
temperature
threshold at step 292, power to motor assembly 240 is shut off at step 300.
Optionally, an
indicator light is illuminated at step 304 to notify the user of the
temperature exceeded error
condition. The current flow to the motor can be restored after receiving a
reset signal at step
302. In some embodiments, the reset can be automatic if the operating
temperature comes down
to be within a temperature operating range. In some embodiments, the threshold
temperature can
be greater than 150, 175, 200 degree Celsius.
[0072] FIG. 16 is a logical diagram of a system 400 to control and manage a
vacuum
cleaner. System 400 comprises a processor 402, a volatile memory 404 to store
operating
16
CA 02736288 2011-04-05
variables and a non-volatile memory to store computer instructions and data
necessary to operate
system 400. System 400 can include an attachment sensor 406 that can signal
the presence or
absence of an attachment, e.g., hose 135 (see FIG. 5). Attachment sensor 406
can include sensor
137 seen in FIG. 5. System 400 can include an attitude sensor 408 that can
signal whether a
vacuum handle is in a locked or unlocked position. Attachment sensor 406 can
include sensor
210 seen in FIG. 5. System 400 can include a temperature sensor 410 that can
signal an
operating temperature of a motor. In some embodiments, an amperage sensor 412
can determine
or measure the current being drawn by the vacuum and/or its various
components. In a preferred
embodiment, the current being drawn by a motor is determined or measured by
amperage sensor
412. In some embodiments, system 400 includes one or more of a power supply
414, an LED
power supply 414, an indicator light 418, a variable speed control 420, and a
reset switch 422. In
some embodiments, system 400 includes instructions 424. Instructions 424 can
include a
blockage determiner module 426 to implement the method of FIGs. 12 and 13. In
some
embodiments, instructions 424 include a diverter valve control 430. In some
embodiments, a
variable speed control 430 is included in system 400.
[0073] The various embodiments described above are provided by way of
illustration
only and should not be constructed to limit the invention. Those skilled in
the art will readily
recognize the various modifications and changes which maybe made to the
present invention
without strictly following the exemplary embodiments illustrated and described
herein, and
without departing from the true spirit and scope of the present invention,
which is set forth in the
following claims.
17
