Information
-
Patent Grant
-
6810557
-
Patent Number
6,810,557
-
Date Filed
Monday, January 28, 200222 years ago
-
Date Issued
Tuesday, November 2, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 015 353
- 015 352
- 055 337
- 055 429
- 055 4591
- 055 DIG 3
- 055 425
- 055 426
-
International Classifications
-
Abstract
The invention relates to a cyclonic dirt separator comprising a dirt-collection assembly including a dirt tank having an inlet aperture and an outlet aperture, a cyclonic separator, at least one filter element, and a suction source fluidly connected with the dirt collection assembly. In one embodiment, the cyclonic dirt separator includes a separator plate cooperating with the housing to form a toroidal region of the dirt tank for aiding in the separation of dirt from a suction airstream developed by the suction source. The separator plate has an outer diameter smaller than the inner diameter of the dirt tank, creating a gap between the outer edge of the separator plate and the inner wall of the dirt tank. A further embodiment includes fins projecting from a sidewall of the dirt tank, and fingers projecting from a bottom wall of the dirt tank, to reduce re-entrainment of dirt particles.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to suction cleaners, and in particular to a separator for a suction cleaner. In one of its aspects, the invention relates to a separator with a cyclonic airflow path to separate dirt and debris from air drawn into the cleaner. In another of its aspects, the invention relates to a separator that deposits the dirt and debris in a collection receptacle. In another of its aspects, the invention relates to a separator including structure for inhibiting the re-entrainment of debris that vacillates with upward airflows in the collection receptacle.
2. Description of the Related Art
Cyclone separators are well known. Some follow the textbook examples using frusto-conical shape separators and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Separation of the dirt/dust from the air is not difficult, but the problem of keeping the dirt separated from the airflow has not been adequately solved. There is a tendency for the separated debris to re-entrain into the airflow and thereby pass through the separator. Some minor amounts of fine dust usually do get through the cyclone and are filtered in secondary filters downstream to maximize dust removal. These filters are positioned anywhere from the cyclone exit port to the clean air exhaust port.
The U.S. Pat. No. 6,260,234 to Wright attempts to solve the re-entrainment problem by placing a main filter in the cyclonic chamber. In this case, the main filter becomes the main separator and re-entrainment becomes a non-issue. This technique is similar to the filters in utility vacuums; however this approach creates a new problem of blinding the filter. The main filter must be cleaned or replaced frequently due to poor cyclone separation and creates a customer satisfaction problem.
The U.S. Pat. No. 6,221,134 to Conrad et al. discloses another attempt to reduce re-entrainment in a cyclone separator. Conrad et al. disclose a particle-receiving chamber beneath the cyclonic fluid flow region by adding a particle-separating plate that extends across the width of the separator chamber and has a plurality of narrow slots. Even though there continues to be rotational motion in the receiving chamber, the particles find it difficult to re-entrain into the airflow. However, this technique also has a problem. Not all the dirt is small enough to pass through the slots and dirt accumulates in the slots and plugs the slots. This means that a significant amount of debris remains in the cyclonic fluid flow region and is subject to re-entrainment.
The U.S. Pat. No. 6,228,151 to Conrad et al. discloses yet another attempt to reduce re-entrainment in a cyclone separator. In this separator, a plurality of vertical radial vanes extends from the bottom of an outer wall of the separator to a central portion of the separator. A cap covers a significant portion of the inner radial length of the vanes.
The Holm-Hansen et al. U.S. Pat. No. 2,071,975 discloses a vacuum cleaner with a separate dust separator that includes a conical casing in which the dust is separated from air by centrifugal force and a dust receptacle separated from the conical casing by a plate that extends radially from the center of the separation chamber toward the wall of the conical casing. Particles that are separated from air in the conical casing pass through the annular space between the outer wall of the chamber and the outer edge of the plate and into the dust receptacle. A tubular member in the center of the conical casing is formed from four overlapping curved metal strips between which the separated air passes to exit the separator. A pair of parallel, horizontally disposed foraminous screens are mounted in the bottom of the dust receptacle to facilitate settling of the dust.
SUMMARY OF THE INVENTION
According to the invention, a vacuum cleaner comprises a housing defining a cyclonic airflow chamber for separating contaminants from a dirt-containing airstream and a cyclonic chamber inlet and an airstream outlet in fluid communication with said cyclonic airflow chamber. The vacuum cleaner includes a nozzle housing having a suction opening fluidly connected with the cyclonic chamber inlet, and an airstream suction source fluidly connected to the main suction opening and to the cyclonic airflow chamber for transporting dirt-containing air from the suction opening to the cyclonic airflow chamber. The suction source is adapted to establish and maintain a dirt-containing airstream from the suction opening to the cyclonic chamber inlet.
A dirt-collecting bin is mounted beneath the cyclonic airflow chamber and includes a bottom wall and a cylindrical sidewall. A separator plate between the cyclonic airflow chamber and the dirt-collecting bin separates the cyclonic airflow chamber from the dirt-collecting bin. The separator plate has a diameter less than a diameter of the cyclonic airflow chamber adjacent the separator plate to thereby define a gap between the separator plate and the cyclonic airflow chamber for passage of dirt separated from the dirt-containing airstream in the cyclonic airflow chamber. The passage of dirt through the gap is accompanied by an airflow having horizontal and vertical components between the gap and the bottom wall of the dirt-collecting bin, which airflow tends to entrain dirt particles therein. It is believed that this airflow may be elliptical in form.
Airflow inhibitors are present in the dirt-collecting bin to reduce the vertical component of the airflow, thereby tending to agglomerate and separate the dirt particles from the airflow.
In one embodiment, the flow inhibitors comprise at least one prong extending upwardly from the bottom wall of the dirt-collecting bin and positioned radially between a center of the dirt-collecting bin and the sidewall thereof. Preferably, the airflow inhibitors comprise a plurality of said prongs each positioned radially between a center of the dirt-collecting bin and the sidewall thereof. The prongs extend a portion of the distance between the bottom wall and the separator plate. Further, the prongs are rectangular in cross section with a long axis radially disposed in the dirt-collecting bin.
In another embodiment, the airflow inhibitors further comprise at least one fin that extends radially inwardly from the sidewall of the dirt-collecting bin. Preferably, there are two and only two fins. The fins are generally positioned vertically below the inlet. The fin or fins extend a portion of the distance between the bottom wall and the separator plate. The fin or fins extend between 40% and 60% of the distance between the bottom wall and the separator plate. Generally, the fins have a radial dimension between 2% and 10% of the radius of the dirt-collecting bin, preferably, between 3% and 6% of the radius of the dirt-collecting bin. In a specific embodiment, the fins have a radial dimension equal to about 4% of the radius of the dirt-collecting bin.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1
is a perspective view of an upright vacuum cleaner with cyclone separator according to the invention.
FIG. 2
is a cut-away perspective view of the cyclonic separator of FIG.
1
.
FIG. 3
is a front cross-sectional view of the cyclonic separator of
FIGS. 1-2
.
FIG. 4
is a cross-sectional view taken through line
4
—
4
of FIG.
3
.
FIG. 5
is a cross-sectional view taken through line
5
—
5
of FIG.
3
.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An upright vacuum cleaner
10
with cyclonic dirt separator
550
and dirt cup
560
according to the invention is shown in
FIG. 1
, comprising an upright handle
12
pivotally mounted to a nozzle base
14
. The upright handle
12
mounts the cyclonic dirt separator
550
and dirt cup
560
according to the invention.
Referring to
FIG. 2
, cyclonic dirt separator and dirt cup assembly
51
according to the invention comprises a cylindrical cyclone separator
550
having an upper wall
142
and a sidewall
144
, the sidewall
144
terminating in a lower offset lip
146
. An annular collar
148
depends from upper wall
142
, the collar
148
being centered in the cylindrical cyclone separator
550
. An exhaust outlet
154
in the upper wall
142
and within the annular collar
148
is fluidly connected with a suction source (see FIG.
3
). Sidewall
144
further includes a tangential air inlet
152
aligned proximate the upper wall
142
for generating a tangential airflow in the separator
550
parallel to the upper wall
142
.
The cyclonic dirt separator
550
further comprises a filter assembly
568
. The filter assembly
568
comprises a cylindrical arrangement of louvers
570
depending from the collar
148
that depends from upper wall
142
of the chamber
150
, and terminating in a lower annular collar.
Referring to
FIGS. 3-4
, a thick-walled cylindrical foam-type filter element
572
is arranged within the cylinder formed by louvers
570
and is held in place by a filter cage
574
. The filter cage
574
includes a perforate cylindrical wall formed on a solid separator plate
158
, and includes a centrally disposed locking insert
576
projecting upwardly within the cylinder of the wall for mounting the cage
574
to the cyclone separator
550
. A filter cage mounting projection
578
depends from upper wall
142
of cyclone separator
550
, within the cylinder formed by louvers
570
, to cooperate with locking insert
576
for mounting cage
574
to cyclonic dirt separator
550
in a substantially sealing fashion. The foam-type filter element
572
is thereby retained between the cage
574
and the louvers
570
. Any air passing from cyclone separator
550
to exhaust outlet
154
must thereby pass through foam-type filter element
572
.
Also in this manner, separator plate
158
is suspended from upper wall
142
, forming a toroidal chamber
180
between the cylindrical arrangement of louvers
570
and the sidewall
144
, and between the upper wall
142
and the separator plate
158
, respectively. In the preferred embodiment, air inlet
152
is vertically aligned between upper wall
142
and separator plate
158
such that the tangential airflow generated from tangential air inlet
152
is directed into the toroidal chamber
180
.
With further reference to
FIGS. 2-4
, the tangential airflow, containing particulate matter, passes through tangential air inlet
152
and into toroidal chamber
180
to travel around the filter assembly
568
. As the airflow travels about the toroidal chamber
180
, heavier dirt particles are forced toward sidewall
144
. These particles fall under the force of gravity through a gap
166
defined between an edge
162
of separator plate
158
and the sidewall
144
. Referring particularly to
FIG. 3
, dirt particles falling through the gap
166
drop through the open end
156
of separator
550
and are collected in the dirt cup
560
. The upper end of dirt cup
560
is received in a nesting relationship in lower offset lip
146
of the sidewall
144
to seal the cyclone separator
550
to the dirt cup
560
. Dirt cup
560
thereby performs the function of collecting the dirt separated from the airflow within the cyclone separator
550
.
As the inlet air traverses through toroidal chamber
180
, casting dirt particles toward sidewall
144
, the inlet air will be drawn inwardly between louvers
570
. As seen in
FIG. 4
, louvers
570
are oriented away from the direction of air flow (indicated by arrows) about toroidal chamber
180
. The velocity of the air flow is altered as the air flow changes direction to pass around and between louvers
570
. This change in the velocity of the air flow causes it to shed additional dirt particles. These dirt particles are urged toward the gap
166
by the circulating air flow in cyclone separator
550
.
The portion of the air flow that passes between louvers
570
then passes through the foam-type filter element
572
, which is composed to filter dirt of a selected particle size. The air then flows through exhaust outlet
154
, exhaust/suction conduit
196
, through a secondary (pre-motor) filter
192
to the suction source
190
. The secondary filter
192
removes additional particulate matter from the exhaust airstreams prior to the airstreams being drawn through the suction source
190
. A post-motor filter
194
can also be provided downstream of the suction source
190
to remove additional fine particulate matter from the exhaust airstream before it is released to the atmosphere.
Referring now to the dirt cup
560
shown in
FIGS. 2-5
, dirt cup
560
is formed with a generally planar bottom wall
582
and an upstanding cylindrical sidewall
584
to form an open-topped receptacle. A plurality of upstanding prongs or fingers
580
project upwardly from bottom wall
582
. The fingers
580
can function in varying arrangements, but in the preferred embodiment are arranged generally symmetrically about a circle concentric with sidewall
584
. The fingers
580
are further found to function best when displaced at least some distance from the center of the dirt cup
560
. Each of the fingers
580
are shown as being generally rectangular in plan view, having a long axis of its plan cross-section aligned with a radius of the circle. The fingers
580
can be of uniform cross-section from top to bottom, or can have a tapering cross-section as depicted in
FIG. 3
, wherein the fingers
580
are narrower at the top and wider at the base where they join the bottom wall
582
. The fingers
580
, as shown in the
FIGS. 2-3
, are approximately one half the height of the dirt cup
560
. Increasing the height of fingers
580
is preferred, but can be limited by production and tooling constraints and, as will be further described, the need to be able to detach dirt cup
560
from cyclone separator
550
.
The dirt cup
560
further includes a pair of fins
586
,
588
affixed to and contiguous with sidewall
584
. Fins
586
,
588
are generally rectangular in cross-section, in plan view, projecting inwardly from sidewall
584
toward a center of dirt cup
560
. The distance fins
586
,
588
project from sidewall
584
can range from 2% to 10% of the radius, but is preferably 3% to 6% of the radius, and optimally 4% of the radius of the dirt cup
560
. Fins
586
,
588
extend generally upwardly from bottom wall
582
of dirt cup
560
. In the preferred embodiment, fins
586
,
588
are perpendicular to bottom wall
582
and extend approximately one-half of the height of dirt cup
560
, although fins
586
,
588
can vary in height from 40% to 60% of the distance from bottom wall
582
to separator plate
158
and still be effective. Also in the preferred embodiment, fins
586
,
588
are generally aligned in the direction of inlet airflow entering cyclone chamber
150
through air inlet
152
. As shown in
FIG. 5
, fins
586
,
588
are arranged with respect to a radial
590
perpendicular to the tangential alignment of inlet
152
, with fin
586
angularly displaced from radial
590
by angle cc and fin
588
displaced from radial
590
by angle β. These angles can vary over a range of about 10° to 45°, and preferably in the range of 15° to 25°. It has been found that a satisfactory placement of the fins results when the angle α is about 19° to 20° and the angle β is about 19° to 20°.
A known phenomenon in cyclone separators is the re-entrainment of dirt into the cyclonic airflow after it is apparently deposited in a dirt containment vessel positioned beneath the cyclone chamber. It has been discovered that this re-entrainment is due to the vertical component of air circulation within the dirt cup between the gap
166
at one side of the dirt-collecting bin and the bottom wall
582
at an opposite side of the dirt-collecting bin. Generally, the airflow pattern has the strongest vertical component at the bottom portion of the dirt-collecting bin
560
below the inlet
152
to the cyclone chamber
550
. This air circulation is shown in phantom lines in FIG.
3
.
These vertical components of the air circulation are manifested in the “vacillating” of the dirt deposited within the dirt cup
560
. Disruption of, or a decrease in the magnitude of, these vertical components or vectors serves to minimize the re-entrainment of dirt in the cyclonic airflow and agglomeration of the dirt in the dirt cup. Disruption of the airflow tends to agglomerate the dirt particles in the dirt cup
560
, forming clumps or balls unlikely to be re-entrained. It has been found that fingers
580
and fins
586
,
588
function in concert to inhibit the vacillation of the debris deposited in dirt cup
560
, disrupting the elliptical vectors that generate upward currents that would tend to carry the smaller dirt particles upwardly and back into the cyclonic air flow. Fingers
580
further deflect dirt particles within the dirt cup
560
to further encourage agglomeration of the dirt particles. Fingers
580
are generally arranged symmetrically about dirt cup
560
, but have been found to cooperate with fins
586
,
588
optimally when none of fingers
580
are directly aligned with either of fins
586
,
588
.
Dirt cup
560
is removably connected to separator
550
. Dirt cup
560
is generally vertically adjustable relative to cyclone separator
550
, such as by a cam mechanism on a vacuum cleaner, so that it can be raised into an engaged and operative position underneath the cyclone separator
550
. Upper edge of sidewall
584
is received within offset lip
146
, which prevents dirt cup
560
from being dislodged from cyclone separator
550
. To remove dirt cup
560
from cyclone separator
550
, such as to discard accumulated dirt, dirt cup
560
is displaced downwardly from cyclone separator
550
. Once disengaged from offset lip
146
, dirt cup
560
can be removed from separator
550
.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the forgoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.
Claims
- 1. A vacuum cleaner comprising:a housing defining a cyclonic airflow chamber for separating contaminants from a dirt-containing airstream, said housing further comprising a cyclonic chamber inlet and an airstream outlet in fluid communication with said cyclonic airflow chamber; a nozzle housing including a suction opening, said suction opening being fluidly connected with said cyclonic chamber inlet; an airstream suction source fluidly connected to said main suction opening and to the cyclonic airflow chamber for transporting dirt-containing air from the main suction opening to the cyclonic airflow chamber, said suction source is adapted to establish and maintain a dirt-containing airstream from said main suction opening to said cyclonic chamber inlet; a dirt-collecting bin mounted beneath said cyclonic airflow chamber, the dirt-collecting bin comprising a bottom wall and a sidewall; a separator plate between the cyclonic airflow chamber and the dirt-collecting bin and separating the cyclonic airflow chamber from the dirt-collecting bin, the separator plate having a diameter less than a diameter of the cyclonic airflow chamber adjacent the separator plate to thereby define a gap between the separator plate and the cyclonic airflow chamber for passage of dirt separated from the dirt-containing airstream in the cyclonic airflow chamber whereby the passage of dirt through the gap is accompanied by airflow pattern having horizontal and vertical components between the gap at one side of the dirt-collecting bin and the bottom wall at an opposite side of the dirt-collecting bin, which airflow tends to entrain dirt particles therein; and airflow inhibitors in the dirt-collecting bin to reduce the vertical component of an elliptical airflow, thereby tending to agglomerate and separate the dirt particles from the elliptical airflow.
- 2. The vacuum cleaner according to claim 1 wherein the airflow inhibitors comprise at least one prong extending upwardly from the bottom wall of the dirt-collecting bin and positioned radially between a center of the dirt-collecting bin and the sidewall thereof.
- 3. The vacuum cleaner according to claim 2 wherein there are a plurality of said prongs each positioned radially between a center of the dirt-collecting bin and the sidewall thereof.
- 4. The vacuum cleaner according to claim 3 wherein the prongs extend a portion of the distance between the bottom wall and the separator plate.
- 5. The vacuum cleaner according to claim 3 wherein the prongs are rectangular in cross section.
- 6. The vacuum cleaner according to claim 5 wherein the prongs in cross-section have a long axis that is radially disposed in the dirt-collecting bin.
- 7. The vacuum cleaner according to claim 3 wherein the prongs are equal- angularly spaced about the bottom wall of the dirt-collecting bin.
- 8. The vacuum cleaner according to claim 3 wherein the airflow inhibitors further comprise at least one fin that extends radially inwardly from the sidewall of the dirt-collecting bin.
- 9. The vacuum cleaner according to claim 2 wherein the airflow inhibitors further comprise at least one fin that extends radially inwardly from the sidewall of the dirt-collecting bin.
- 10. The vacuum cleaner according to claim 9 wherein there are two and only two fins.
- 11. The vacuum cleaner according to claim 10 wherein the fins are generally positioned vertically below the inlet.
- 12. The vacuum cleaner according to claim 9 wherein the at least one fin is positioned vertically below the inlet.
- 13. The vacuum cleaner according to claim 12 wherein the at least one fin extends a portion of the distance between the bottom wall and the separator plate.
- 14. The vacuum cleaner according to claim 13 wherein the at least one fin extends between 40% and 60% of the distance between the bottom wall and the separator plate.
- 15. The vacuum cleaner according to claim 9 wherein the fins have a radial dimension between 2% and 10% of the radius of the dirt-collecting bin.
- 16. The vacuum cleaner according to claim 9 wherein the fins have a radial dimension between 3% and 6% of the radius of the dirt-collecting bin.
- 17. The vacuum cleaner according to claim 9 wherein the fins have a radial dimension equal to about 4% of the radius of the dirt-collecting bin.
- 18. The vacuum cleaner according to claim 1 wherein the airflow inhibitors comprise at least one fin that extends radially inwardly from the sidewall of the dirt-collecting bin.
- 19. The vacuum cleaner according to claim 18 wherein there are two and only two fins.
- 20. The vacuum cleaner according to claim 19 wherein the fins are generally positioned vertically below the inlet.
- 21. A vacuum cleaner The vacuum cleaner according to claim 19 wherein the fins extend a portion of the distance between the bottom wall and the separator plate.
- 22. The vacuum cleaner according to claim 19 wherein the fins have a radial dimension between 2% and 10% of the radius of the dirt-collecting bin.
- 23. The vacuum cleaner according to claim 22 wherein the fins have a radial dimension between 3% and 6% of the radius of the dirt-collecting bin.
- 24. The vacuum cleaner according to claim 23 wherein the fins have a radial dimension equal to about 4% of the radius of the dirt-collecting bin.
- 25. The vacuum cleaner according to claim 18 wherein the at least one fin is positioned generally below the inlet.
- 26. The vacuum cleaner according to claim 18 wherein the at least one fin extends a portion of the distance between the bottom wall and the separator plate.
US Referenced Citations (17)