The invention relates to suction cleaners, and in particular to suction cleaners having cyclonic dirt separation. 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 bottom discharge dirt cup with an integrated filter chamber. In another of its aspects, the invention relates to multiple cyclone separators including a single primary cyclone in series with a plurality of secondary cyclones arranged in parallel.
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. Typically, working air enters and exits at an upper portion of the cyclone separator as the bottom portion of the cyclone separator is used to collect debris. Furthermore, in an effort to reduce weight, the motor/fan assembly that creates the working air flow is typically placed at the bottom of the handle, below the cyclone separator. This arrangement therefore, requires a tortuous air path from the top of the cyclone assembly, down the handle to the inlet of the motor/fan assembly. This creates a long air path with multiple parts which may allow for air leaks and generally negatively impacting airflow and, necessarily, cleaning performance.
Conrad et al., in U.S. Pat. No. 6,129,775 discloses a cyclone separator with at terminal insert which can take a number of forms. In
BISSELL Homecare, Inc. presently manufactures and sells in the United States an upright vacuum cleaner that has a cyclone separator and a dirt cup. A horizontal plate separates the cyclone separator from the dirt cup. The air flowing through the cyclone separator passes through an annular cylindrical cage with baffles and through a cylindrical filter before exiting the cyclone separator at the upper end thereof. The dirt cup has three finger-like projections extending upwardly from the bottom thereof to agglomerate the dirt in the dirt cup. The dirt cup further has a pair of radial fins extending inwardly from the side walls of the dirt cup. The dirt cup and the cyclone separator is further disclosed in the co-pending U.S. patent application Ser. No. 10/058,514, filed Jan. 28, 2002, which application is incorporated herein by reference.
U.S. Pat. No. 6,070,291 to Bair et al. and its progeny attempts to solve the efficiency problem by shortening the air path from the cyclone exhaust to the motor inlet. These patents disclose a pleated main filter element in a cyclonic chamber whereby exhaust air is drawn through the main filter through the bottom of the cyclonic chamber and directly into the motor/fan inlet. The motor/fan assembly is in a vertical position below the cyclone which is undesirable due to the amount of space needed at the bottom of the handle.
U.S. Pat. No. 6,341,404 to Salo et al. discloses a bottom discharge cyclone chamber with the motor/fan assembly mounted horizontally below the cyclone chamber. However, motor exhaust air is redirected back up towards the bottom of the cyclone chamber where it exits the unit in a radial fashion. This path introduces a number of turns which tends to create backpressure and therefore reduce efficiency.
U.S. Pat. No. 6,607,572 to Dyson discloses a cyclonic separating apparatus with upstream and downstream cyclonic units, wherein the downstream units comprise a plurality of cyclones inverted relative to the upstream cyclone and inverted with respect to the upstream cyclone. This arrangement of cyclones necessarily creates a tall unit because the downstream cyclones are located above the upstream cyclone.
The U.S. Pat. No. 3,425,192 to Davis discloses a vacuum cleaner dirt separator that has a primary cyclone separator and a plurality of parallel secondary cyclones.
According to the invention, a vacuum cleaner comprises a housing defining a first cyclonic airflow chamber for separating contaminants from a dirt-containing air stream as it travels around a cyclonic axis in the first cyclonic airflow chamber, a cyclonic chamber inlet and an air stream outlet in fluid communication with the 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 to the housing beneath the first cyclonic airflow chamber and includes a bottom wall, a cylindrical sidewall, and an open top. At least one secondary cyclone has an inlet opening in fluid communication with the first cyclonic airflow chamber outlet. According to the invention, the at least one secondary cyclone has a cyclonic axis that is oriented substantially perpendicular to the cyclonic axis of the first cyclonic airflow chamber.
The number of secondary cyclone separators can vary over a wide range, depending on the relative size and the degree of separation desired. Typically, the number of the secondary cyclones will be in excess of one and not more that 16. Multiple secondary cyclones are arranged in parallel downstream from the first cyclonic airflow chamber and can be arranged in an equi-angular fashion perpendicular to a cyclonic axis of the primary cyclonic airflow chamber.
The at least one and each of the secondary cyclones have a debris outlet that is in communication with a secondary debris collector that is preferably mounted within the dirt-collecting bin. The secondary debris collector of the preferred embodiment has a frustoconical shape and an open top. A removable lid covers the open top of the secondary debris collector and is preferably mounted to the housing, preferably through an annular wall that extends through the first cyclonic chamber.
In a preferred embodiment of the invention, a hollow standpipe extends centrally through the dirt-collecting bin, forming the airstream outlet for the housing. The at least one and each of the secondary cyclones have airstream outlets that communicate with the standpipe which also extends through the first cyclonic chamber. The annular wall surrounds the standpipe and defines, with the standpipe, a debris passage between the outlets of the one or more secondary cyclones and the secondary debris collector.
The dirt-collecting bin is separable from the first cyclonic chamber for emptying the contents of the dirt-collecting bin and the secondary debris collector at the same time.
Preferably, the vacuum cleaner further comprises a cylindrical baffle between the first cyclonic chamber and the inlet openings of the secondary cyclones. Further, a separator plate is mounted to the housing of the vacuum cleaner between the first cyclonic chamber and the dirt-collecting bin with an annular space between a side wall of the first cyclonic chamber and an outer edge of the separator plate for passage of debris separated from the airstream in the first cyclonic chamber to pass into the dirt-collecting bin.
A filter for filtering any particles not separated from the airstream in the first cyclonic chamber or the secondary cyclones is preferably placed downstream from the airstream outlet. The filter is further placed upstream of the airstream suction source and can be cylindrical in shape.
In a preferred embodiment, 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 accordance with another embodiment of the invention, a vacuum cleaner comprises a housing defining a first cyclonic airflow chamber for separating contaminants from a dirt-containing air stream as it travels around a cyclonic axis in the first cyclonic airflow chamber, a cyclonic chamber inlet and an air stream outlet in fluid communication with the 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 to the housing beneath the first cyclonic airflow chamber and includes a bottom wall, a cylindrical sidewall, and an open top. At least one secondary cyclone has an inlet opening in fluid communication with the first cyclonic airflow chamber outlet and a debris outlet in communication with a secondary debris collector. According to the invention, the secondary debris collector is in the dirt-collecting bin and has an open top and the dirt-collecting bin is separable from the first cyclonic chamber for dumping of the dirt-collecting bin and the secondary debris collector at same time.
In a preferred embodiment, the open top is covered by a removable lid. The removable lid is preferably mounted to the housing, preferably though an annular wall that extends through the first cyclonic chamber.
In one embodiment, the flow inhibitors comprise at least one finger 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 fingers each positioned radially between a center of the dirt-collecting bin and the sidewall thereof. The fingers extend a portion of the distance between the bottom wall and the separator plate. Further, the fingers 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.
An upright vacuum cleaner 10 with cyclonic dirt separator and dirt cup assembly 12 according to the invention is shown in
Referring to
The cyclonic dirt separator 18 further comprises an exhaust assembly 30. The exhaust assembly 30 comprises a hollow cylindrical louver cage 32 mounted on a separator plate 34. The louver cage 32 further comprises a plurality of louvers 36 cylindrically arranged between a top portion of the louver cage 32 and the separator plate 34. An annular wall 136 in concentrically positioned within louver cage 32 and extends from separator plate 34 and is capped at an upper end by an upper annular wall 137. A working air path is defined between the louver cage 32 and annular wall 136 and through a centrally located aperture on the separator plate 34. The louver cage 32 and separator plate 34 are removably mounted on an annular collar 26 via a friction fit. However, other mechanical fastening means can be used to removably mount the exhaust assembly 30. For example, one quarter turn bayonet fasteners, ramped threads, detents, or any other commonly known fastening method can be used according to the invention.
A secondary cyclone assembly 100 is positioned above and in fluid communication with the exhaust assembly 30 of the cyclone separator 18. The secondary cyclone assembly 100 further comprises a plurality of secondary cyclones 102 spaced about a central vertical axis 104 of the exhaust assembly 30. Each secondary cyclone 102 is frusto-conical in shape with a larger end 106 located toward sidewall 22 and a smaller end 108 located toward a secondary cyclone inner wall 112. The inner wall 112 is capped by a top surface 110 wherein the wall 112 and top surface 110 define an inner plenum 98. The annular collar 26 that mounts the louver cage 32 extends downwardly from inner plenum 98. A longitudinal axis 114 of each secondary cyclone 102 is oriented generally perpendicular to the central vertical axis 104. In an alternate embodiment, the secondary cyclone 102 is concave, or bowed out, relative to the longitudinal axis.
Each secondary cyclone 102 comprises a cone 116, a working air inlet opening 118, a debris exhaust 120, and a working air outlet 122. The large ends 106 of the cones 116 are closed by an end cap 107. The working air outlet 122 is located along the longitudinal axis 114 at or near the larger end 106 and extends through the end cap 107 while the debris exhaust 120 is located at the smaller end 108, radially inward of the inlet opening 118 and in line with the longitudinal axis 114. The working air inlet opening 118 is an aperture formed in a side wall of the cone 116 near the larger end 106.
A first cyclonic chamber 48 is defined between the cylindrical arrangement of louvers 36 and the sidewall 22, and between secondary cyclone assembly 100 and the separator plate 34, respectively. In the preferred embodiment, the air inlet 28 is vertically aligned between the secondary cyclone assembly 100 and the separator plate 34 such that the tangential airflow generated from the tangential air inlet 28 is directed into the first cyclonic chamber 48.
The tangential airflow, containing particulate matter, passes through the tangential air inlet 28 and into the first cyclonic chamber 48 to travel around the exhaust assembly 30. As the airflow travels about the first cyclonic chamber 48, heavier dirt particles are forced toward the sidewall 22. These particles fall under the force of gravity through a gap 50 defined between an edge 52 of the separator plate 34 and the sidewall 22. Referring particularly to
The dirt cup/filter chamber 54 is removably connected to the housing 12. The dirt cup/filter chamber 54 is generally vertically adjustable relative to the cyclone separator 18, 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 18. The upper edge of sidewall 64 is received within offset lip 24, which prevents the dirt cup/filter chamber 54 from being dislodged from the cyclone separator 18.
The dirt cup/filter chamber 54 comprises a pair of vertically oriented regions. The upper region comprises a dirt-collecting bin 58 for collecting dirt as previously described and the lower chamber region comprises a filter chamber 60. The dirt-collecting bin 58 is formed with a generally planar dirt cup bottom wall 62 and an upstanding cylindrical dirt cup sidewall 64 to form an open-topped receptacle. A plurality of upstanding prongs or fingers 66 project upwardly from the bottom wall 62. The fingers 66 can function in varying arrangements, but in the preferred embodiment the fingers 66 are arranged generally symmetrically about a hollow standpipe 68 concentric with sidewall 64. The fingers 66 are found to function best when displaced at least some distance from an outer wall of the standpipe 68. Each of the fingers 66 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 66 can be of uniform cross-section from top to bottom, or can have a tapering cross-section as depicted in
The filter chamber region 60 further comprises a bottom wall 76 in spaced relation to the dirt cup bottom wall 62 and with a side wall 80. The bottom wall 62 further comprises a centrally located aperture that is in fluid communication with a bottom portion of the standpipe 68. The bottom wall 76 further comprises an aperture 88 to removably receive a filter assembly 82. The filter assembly 82 further comprises a filter cage 84 which supports a cylindrical foam filter 86. The filter assembly mates with the bottom wall 76 via a ¼ turn bayonet fastener or any other suitable mechanical fastening means as previously described. As can be appreciated, air flow enters the filter chamber region 60 from aperture in bottom wall 62, passes through the foam filter 86 where particulate matter is captured, and continues on through an inlet 90 to a suction source 92 where the air is exhausted to the atmosphere though an open grid 96. In an alternate embodiment, the filter is a flat foam filter. Optionally, the suction source exhaust air may pass through a final filter 94 before re-entering the atmosphere through grid 96.
Referring particularly to
Referring to
The size and shape of the secondary cyclones 102 is important for maximizing separation efficiency. The relationship that various cyclone geometries have on separation efficiencies is disclosed in “Separation of Particles from Air and Gasses: Volume II” by Akria Ogawa, copyright date 1984 and published by CRC Press, Inc. Boca Raton, Fla. (pp. 1-49), which is incorporated herein by reference. In the preferred embodiment, the larger end 106 of the cone 116 has an opening that is 10 times the surface area of the smaller end 108. However, acceptable performance is obtained within a range of ratios of the larger end to the smaller end of about 2 to 1 to about 20 to 1, preferably between about 3.5 to 1 to about 8.5 to 1. Furthermore, the number of secondary cyclones 102 utilized in the secondary cyclone assembly 100 impacts the overall separation efficiency. In the preferred embodiment, seven secondary cyclones are arranged generally equi-angularly about the vertical axis 104, however, spacing between some of the secondary cyclones 102 can vary to provide space for the work air conduits 138, 140. The number of secondary cyclones 102 utilized can, however, vary between two and sixteen and preferably between four and ten.
Referring to
As the inlet air traverses through first cyclonic chamber 48, casting dirt particles toward sidewall 22, the inlet air is drawn inwardly between the louvers 36. As seen in
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 50 at one side of the dirt-collecting bin 58 and the bottom wall 62 at an opposite side of the dirt-collecting bin 58. Generally, the airflow pattern has the strongest component at the bottom portion of the dirt-collecting bin 58 below the inlet 28 to the cyclone chamber 18. This air circulation is shown in phantom lines in
These vertical components of the air circulation are manifested in the “vacillating” of the dirt deposited within the dirt-collecting bin 58. 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-collecting bin 58, forming clumps or balls unlikely to be re-entrained. It has been found that the fingers 66 and the fins 70, 72 function in concert to inhibit the vacillation of the debris deposited in the dirt-collecting bin 58, 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. The fingers 66 further deflect dirt particles within the dirt-collecting bin 58 to further encourage agglomeration of the dirt particles. The fingers 70, 72 are generally arranged symmetrically about the dirt-collecting bin 58, but have been found to cooperate with the fins 70, 72 optimally when none of the fingers 66 are directly aligned with either of the fins 70, 72. path of air flow through the cyclonic dirt separator and dirt cup assembly 12 is illustrated by arrows in
The working air is then forced to change direction and enters the working air outlet 122 at the larger end 106 of the cone 116. Working air passes through the working air outlet conduit 140 and enters the collective exhaust chamber 140 within the upper standpipe 126 where it is drawn through exhaust chamber 142 to the filter chamber region 60. The working air passed though filter 86 where particulate matter is captured and continues through the suction source inlet 90. Optionally, the working air may pass through a final filter 94 before re-entering the atmosphere through grid 96.
To remove the dirt cup/filter chamber 54 from the cyclone separator 18, such as to discard accumulated dirt, the dirt cup/filter chamber 54 is displaced downwardly from the cyclone separator 18. Once disengaged from the offset lip 24, the dirt cup/filter chamber 54 can be removed from the separator 18. Lid 148 is removed from the secondary debris collection chamber 144 so that the entire content of the dirt can be emptied at the same time.
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.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/521,466, filed Apr. 30, 2004, which application is incorporated herein by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
3425192 | Davis | Feb 1969 | A |
6238451 | Conrad et al. | May 2001 | B1 |
6334234 | Conrad et al. | Jan 2002 | B1 |
6344064 | Conrad | Feb 2002 | B1 |
6482252 | Conrad et al. | Nov 2002 | B1 |
6578230 | Park et al. | Jun 2003 | B2 |
6582489 | Conrad | Jun 2003 | B2 |
6607572 | Gammack et al. | Aug 2003 | B2 |
6607575 | Oh et al. | Aug 2003 | B2 |
6840972 | Kim | Jan 2005 | B1 |
7070636 | McCormick et al. | Jul 2006 | B2 |
20010052166 | Park et al. | Dec 2001 | A1 |
20020062632 | Oh | May 2002 | A1 |
20020116907 | Gammack et al. | Aug 2002 | A1 |
20030014953 | Oh | Jan 2003 | A1 |
20030200734 | Conrad | Oct 2003 | A1 |
20030221277 | Oh et al. | Dec 2003 | A1 |
20040068827 | Dyson | Apr 2004 | A1 |
20040088956 | Gammack | May 2004 | A1 |
20040112018 | Vuijk | Jun 2004 | A1 |
20040144070 | Gammack et al. | Jul 2004 | A1 |
Number | Date | Country |
---|---|---|
0 885 585 | Jun 1997 | EP |
1 268 076 | Mar 2001 | EP |
2360719 | Oct 2003 | GB |
52014775 | Feb 1977 | JP |
WO 9712660 | Apr 1997 | WO |
WO 0044272 | Aug 2000 | WO |
WO 0160226 | Aug 2001 | WO |
WO 0174493 | Oct 2001 | WO |
WO 0195780 | Dec 2001 | WO |
WO 02067754 | Sep 2002 | WO |
WO 02067755 | Sep 2002 | WO |
WO 02067756 | Sep 2002 | WO |
WO 02067757 | Sep 2002 | WO |
WO 02082966 | Oct 2002 | WO |
WO 03068407 | Aug 2003 | WO |
Number | Date | Country | |
---|---|---|---|
60521466 | Apr 2004 | US |