Patent Publication Number: US-2021186286-A1

Title: Vacuum cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/951,470, filed Dec. 20, 2019, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     The present invention relates to vacuum cleaners and more particularly to cyclonic vacuum cleaners. 
     SUMMARY 
     In one embodiment, the invention provides a vacuum cleaner including a suction inlet, a suction source configured to generate an airflow through the suction inlet to draw debris with the airflow through the suction inlet, and a separator assembly downstream from the suction inlet. The separator assembly includes a container that defines a first stage cyclonic separator about a separator axis, the container having an upper end, a lower end opposite the upper end, and a dirty air inlet positioned to receive the airflow and debris to rotate around the separator axis in a first direction within the container. The separator assembly also includes a clean air outlet that discharges the airflow from the separator assembly, and a shroud located in the container. The shroud includes an air transfer portion forming an airflow passageway between the dirty air inlet and the clean air outlet and a guide wall extending from an upper end of the air transfer portion toward the upper end of the container. The dirty air inlet defines a perimeter having an upper point closest to the upper end of the container, and the guide wall is positioned substantially above the upper point. The air transfer portion is positioned substantially below the upper point, and the guide wall extends at an oblique angle relative to the separator axis. 
     In another embodiment, the invention provides a separator assembly for a vacuum cleaner, the separator assembly including a container that defines a first stage cyclonic separator about a separator axis, the container having an upper end, a lower end opposite the upper end, and a dirty air inlet positioned to receive an airflow and debris to rotate around the separator axis in a first direction within the container, a clean air outlet that discharges the airflow from the separator assembly, and a shroud located in the container, the shroud including a screen forming an airflow passageway between the dirty air inlet and the clean air outlet and a guide wall extending from an upper end of the screen toward the upper end of the container. The dirty air inlet defines a perimeter having an upper point closest to the upper end of the container, and the guide wall is positioned substantially above the upper point. The screen is positioned substantially below the upper point, and the guide wall extends at an oblique angle relative to the separator axis. 
     In another embodiment, the invention provides a vacuum cleaner including a suction inlet, a suction source configured to generate an airflow through the suction inlet to draw debris with the airflow through the suction inlet, and a separator assembly downstream from the suction inlet, the separator assembly including a container that defines a first stage cyclonic separator about a separator axis, the container having an upper end, a lower end opposite the upper end, and a dirty air inlet positioned to receive the airflow and debris to rotate around the separator axis in a first direction within the container, a clean air outlet that discharges the airflow from the separator assembly, and a shroud located in the container, the shroud including an air transfer portion forming an airflow passageway between the dirty air inlet and the clean air outlet and a guide wall extending from an upper end of the air transfer portion toward the upper end of the container. The dirty air inlet defines a perimeter having an upper point closest to the upper end of the container. The guide wall is positioned substantially above the upper point, and the guide wall is positioned substantially above the upper point. An intersection between the guide wall and the screen is substantially aligned in a radial plane with the upper point. The guide wall is configured to guide the debris toward the lower end of the container. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vacuum cleaner according to an embodiment of the invention. 
         FIG. 2  is a cross-sectional view of a portion of the vacuum cleaner of  FIG. 1 . 
         FIG. 3  is a perspective view of a separator assembly of the vacuum cleaner of  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the separator assembly of  FIG. 3  taken along line  4  in  FIG. 3 . 
         FIG. 5A  is a cross-sectional view of the separator assembly of  FIG. 3  taken along line  5  in  FIG. 3 , illustrating airflow in a first cyclonic separator stage and a second cyclonic separator stage occurring in opposite directions. 
         FIG. 5B  is a cross-sectional view of the separator assembly of  FIG. 3  taken along line  5  in  FIG. 3 , illustrating airflow in the first cyclonic separator stage and the second cyclonic separator stage occurring in the same direction. 
         FIG. 6  is a cross-sectional view of the separator assembly of  FIG. 3  taken along line  6  in  FIG. 3 . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a vacuum cleaner  10  according to one embodiment. The vacuum cleaner  10  includes a foot or cleaning head  14 , an upright frame  18  pivotably connected to the cleaning head  14 , a handle  20  having a shaft portion  20   a  extending from the upright frame  18  along a longitudinal axis A 1  and a grip portion  20   b  extending from the shaft portion  20   a  (e.g., at an oblique angle), and a separator assembly  22  supported by the upright frame  18 . As such, the illustrated vacuum cleaner  10  is an upright style vacuum cleaner. In other embodiments, however, the vacuum cleaner  10  may include other form factors (e.g., handheld, canister, etc.). 
     Referring to  FIG. 2 , the cleaning head  14  includes a suction inlet  26 , and the upright frame  18  supports a suction source  30  operable to generate an airflow through the suction inlet  26  to draw debris with the airflow through the suction inlet  26 . The separator assembly  22  is downstream from the suction inlet  26  and separates the debris from the airflow. 
     The upright frame  18  of the illustrated vacuum cleaner  10  includes a battery mount  34 . A battery  38  (e.g., a rechargeable battery pack enclosing a plurality of lithium-ion battery cells or battery cells of any other suitable chemistry) is removably coupled to the battery mount  34 . In some embodiments, the battery  38  may be slidably received on the battery mount  34  in a direction generally parallel to the longitudinal axis A 1  of the shaft portion  20   a . When the battery  38  is coupled to the battery mount  34 , the battery  38  may power the vacuum cleaner  10 . For example, the battery  38  may power an electric motor of the suction source  30 . The battery  38  may additionally power other components, such as a brushroll motor (not shown) provided on the cleaning head  14 . In other embodiments, the vacuum cleaner  10  may include a power cord to supply power to the vacuum cleaner (e.g., via a wall outlet). 
     Referring to  FIGS. 3-4 , the illustrated separator assembly  22  includes a container  50 , a clean air outlet  54  ( FIG. 4 ), and a lid  58 . The container  50  includes an upper end  62  and a lower end  66 . A separator axis A 2  extends centrally through the upper and lower ends  62 ,  66 . The lid  58  is removably coupled to the upper end  62  of the container  50 . The illustrated clean air outlet  54  extends through the lid  58  at an oblique angle relative to the separator axis A 2 . In other embodiments, the clean air outlet  54  may be positioned or oriented in other ways. 
     In the illustrated embodiment, a filter assembly  59  is provided on an upstream side of the clean air outlet  54  ( FIG. 4 ). The filter assembly  59  may include one or more pleated paper filters, foam filters, mesh filters, HEPA filters, or any other suitable filter media. In some embodiments, the filter assembly  59  may be removable from the lid  58  (e.g., after removing the lid  58  from the container  50 ) to allow for cleaning or replacement of the filter assembly  59 . In other embodiments, the filter assembly  59  may be omitted, or the filter assembly  59  may be positioned elsewhere on the vacuum cleaner (e.g., between the separator assembly  22  and the suction source  30 , or downstream of the suction source  30 ). 
     With continued reference to  FIGS. 3-4 , the illustrated separator assembly  22  further includes a shroud  70  extending from the upper end  62  of the container  50  toward the lower end  66 . In the illustrated embodiment, the shroud  70  is coupled to the lid  58  and may be removable from the container  50  together with the lid  58 . In other embodiments, the shroud  70  may be fixed to the container. 
     The container  50  and the shroud  70  define a first stage cyclonic separator  74  about the separator axis A 2 . In particular, an air passage  78  is defined radially between the shroud  70  and the inner wall of the container  50  ( FIG. 4 ). The container  50  includes a dirty air inlet  82  ( FIG. 3 ) that is positioned to introduce the airflow and debris into the air passage  78 . The first stage cyclonic separator  74  is configured to rotate the airflow and debris that enters the container  50  via the dirty air inlet  74  around the separator axis A 2  within the container  50 . 
     Referring to  FIG. 4 , the illustrated shroud  70  includes an upper portion  86  coupled to the lid  58 , an air transfer portion  90  extending from the upper portion  86 , and a skirt portion  94  extending from the air transfer portion  90 . Debris separated from the airflow by the first stage cyclonic separator  74  may collect in a first dirt collection chamber  97  defined axially between the skirt portion  94  and the lower end  66  of the container  50 . Specifically, a radial gap  95  between the skirt portion  94  and the interior wall of the container  50  forms a debris passageway from the first stage cyclonic separator  74  to the first dirt collection chamber  97 . 
     In the illustrated embodiment, the lower end  66  of the container  50  is sealed by a door  96 , which may be opened to facilitate emptying debris from the first dirt collection chamber  97 . The illustrated door  96  is pivotally coupled to the lower end  66  of the container  50 ; however, the door  96  may be coupled to the container  50  in other ways. 
     With reference to  FIG. 4 , the illustrated separator assembly  22  further includes a second stage cyclonic separator  102  extending along and centered on the separator axis A 2 . The second stage cyclonic separator  102  includes an inlet portion  106 , a vortex finder  110  at least partially disposed within the inlet portion  106 , a frustoconical cyclone portion  114  extending from the inlet portion  106  toward the lower end  66  of the container  50 , and a second dirt collection chamber  118  extending from the cyclone portion  114 . In the illustrated embodiment, the vortex finder  110  extends the entire length of the inlet portion  106  along the separator axis A 2 . 
     Referring to  FIG. 5A , the inlet portion  106  includes a plurality of vanes  122 . An airflow passage into the second stage cyclonic separator  102  is defined by openings  126  between adjacent vanes  122 . In some embodiments, the first stage cyclonic separator  74  may be configured to circulate the airflow and debris in the direction of arrow  130 . The openings  126  may open toward or face in a direction that is opposed to the flow direction (arrow  130 ) of the first stage cyclonic separator  74 . As such, the openings  126  and the vanes  122  may be positioned to direct the airflow (and any debris not yet separated from the airflow) entering the second stage cyclonic separator  102  in the direction of arrow  134 . 
     In the embodiment illustrated in  FIG. 5A , the flow direction (arrow  134 ) through the openings  126  between the vanes  122  is at least partially opposed to the flow direction (arrow  130 ) in the first stage cyclonic separator  74 . Thus, the airflow in the second stage cyclonic separator  102  is redirected in a generally opposite direction  134  from the flow direction  130  in the first stage cyclonic separator  74 . This redirection of airflow may further help to separate the debris from the airflow and minimizes the debris that travels through the openings  126  between the vanes  122 . In other embodiments, such as the embodiment illustrated in  FIG. 5B , the flow direction  134  in the second stage cyclonic separator  102  is the same as the flow direction  130  in the first stage cyclonic separator  102 . In such embodiments, the vanes  122  direct the airflow entering the second cyclonic separator  102  in the same direction as the flow direction  130 . In either or both the embodiments of  FIGS. 5A and 5B , adjacent sidewalls  138  of the vanes  122  may converge to define a gap having a decreasing area in the direction of arrow  134 . This causes air to increase in speed as the air travels through the openings  126  and into the second stage cyclonic separator  102 . 
     The airflow and remaining debris may circulate in a vortex within the second stage cyclonic separator  102  to separate the remaining debris from the air. The debris separated by the second stage cyclonic separator  102  may collect in the second dirt collection chamber  118  below the cyclone portion  114  ( FIG. 4 ). The door  96  seals the bottom of the second dirt collection chamber  118 , and the first and second dirt collection chambers  94 ,  118  may be emptied simultaneously by opening the door  96 . 
     With reference to  FIGS. 4 and 5A -B, the shroud  70  surrounds the inlet portion  106  of the second stage cyclonic separator  102  and may inhibit passage of debris from the first stage cyclonic separator  74  into the second stage cyclonic separator  102 . In particular, the air transfer portion  90  of the shroud  70  includes a screen  142  with a plurality of openings  144  through which the airflow must pass before reaching the inlet portion  106  of the second stage cyclonic separator  102 . The screen  142  extends around the separator axis A 2 . The screen  142  may be a perforated metal mesh with punched or etched pores. Alternatively, the screen  142  may be a wire or fiber mesh. In yet other embodiments, the screen  142  may be made of perforated plastic. In the illustrated embodiment, there is a radial gap  146  between the mesh screen  142  and vanes  122 , such that the mesh screen  142  does not press directly against the vanes  122 . 
     Referring to  FIG. 6 , the illustrated dirty air inlet  82  defines a perimeter with an upper-most point  150  (i.e. a point or area closest to the upper end  62  of the container  50 ). The upper portion  86  of the shroud  70  includes an attachment portion  154  coupled to the lid  58  and a transition portion  158  extending between the attachment portion  154  and the air transfer portion  90 . The transition portion  158  includes a guide surface  162  that extends at an oblique angle θ relative to the separator axis A 2 . In some embodiments, the oblique angle θ is between 5 degrees and 85 degrees. In some embodiments, the oblique angle θ is between 30 degrees and 80 degrees. In some embodiments, the oblique angle θ is between 50 degrees and 70 degrees. In the illustrated embodiment, the oblique angle θ is about 60 degrees. In some embodiments, the guide surface  162  may be frustoconical. In the illustrated embodiment, the guide surface  162  extends radially outwardly from the air transfer portion  90 , and axially toward the lid  58 . 
     In some embodiments, the transition portion  158  may define a height H (in a direction parallel to the separator axis A 2 ) greater than 0 millimeters, such as between 1 and 30 millimeters. In some embodiments, the height H may be between about 5 millimeters and about 30 millimeters. In some embodiments, the height H may be between about 8 millimeters and about 20 millimeters. In some embodiments, the height H may be between about 8 millimeters and about 15 millimeters. In some embodiments, the height H may be between about 8 millimeters and about 12 millimeters. 
     With continued reference to  FIG. 6 , in the illustrated embodiment, the upper-most point  150  of the dirty air inlet  82  is aligned in a radial plane P with the intersection of the transition portion  158  and the air transfer portion  90 , such that all or a substantial portion of the screen  142  is below the upper-most point  150  (in a direction parallel to the separator axis A 2 ), and all or a substantial portion of the guide surface  162  is above the upper-most point  150  (in a direction parallel to the separator axis A 2 ). 
     In some embodiments, the screen  142  may not extend the entire length of the air transfer portion  90 , such that the air transfer portion  90  of the shroud  70  may include one or more impermeable portions that air cannot flow through. For example, the illustrated air transfer portion  90  includes a first or upper band  145 A and a second or lower band  145 B. There are no openings  144  in either of the bands  145 A,  145 B. In the illustrated embodiment, the upper band  145 A has a height T 1  measured from the intersection of the transition portion  158  and the air transfer portion  90 , and the lower band  145 B has a height T 2  measured from the intersection of the skirt  94  and the air transfer portion  90 . The height T 1  and the height T 2  are greater than 0 millimeters, such as between about 0.5 millimeters and about 12 millimeters. In some embodiments, the height T 1  and the height T 2  may be between about 3 millimeters and about 12 millimeters. In some embodiments, the height T 1  and the height T 2  may be between about 5 millimeters and about 12 millimeters. 
     In some embodiments, the height T 1  may be equal to the height T 2 , or the heights T 1  and T 2  may be different. In yet other embodiments, the air transfer portion  90  of the shroud  70  may include only a single impermeable band  145 A or  145 B. In yet other embodiments, the screen  142  may extend the entire length of the air transfer portion  90 . 
     In operation, the vacuum cleaner  10  is used to remove debris from a surface (e.g., carpet, hard flooring, upholstery, etc.). The suction source  30  generates an airflow that draws the debris and airflow through the suction inlet  26 . The airflow and debris travels into the cyclonic separator  28  through the dirty air inlet  82 . Debris is separated from the airflow by the first stage cyclonic separator  74  and collected in the first dirt collection chamber  97 . 
     The angled guide surface  162  inhibits buildup of debris adjacent the guide surface  162 . For example, during operation, the airflow in the first stage cyclonic separator  74  may tend to move debris generally radially inward. The angled guide  162  surface provides a downward component to the movement of the debris, inhibiting packing and buildup of debris around the guide surface  162 . In addition, because the dirty air inlet  82  is positioned entirely or substantially below the angled guide surface  162 , the guide surface  162  also inhibits debris from building up around the attachment portion  154  of the shroud  70 . By reducing buildup of debris, separation efficiency is improved, and it may be easier for a user to remove debris from separator assembly  22 . 
     Providing the guide surface  162  at or above the upper point  150  of the dirty air inlet  82  may provide improved efficiency and increased capacity of the first dirt collection chamber  97  when compared with embodiments in which the guide surface  162  is positioned below the upper point  150  of the dirty air inlet  82 . In such embodiments, the shroud  70  would be moved downward within the container  50 , thereby reducing the height of the first dirt collection chamber  97  and reducing the separation efficiency of the first stage cyclonic separator  74 . In contrast, by locating the guide surface  162  at or above the upper point  150  of the dirty air inlet  82  as illustrated in  FIG. 6 , the height of the first dirt collection chamber  97  is advantageously increased, leading to improved separation efficiency. 
     The construction and arrangement of the angled guide surface  162  relative to the dirty air inlet  82  may be particularly advantageous for compact vacuum cleaners. Increased improvements in separation efficiency were observed as air flow through the separator assembly  22  decreased. Accordingly, the embodiments of the separator assembly  22  described and/or illustrated herein may be particularly advantageous for use in a small, relatively low air power vacuum cleaner, such as some battery-powered vacuum cleaners, and particularly those with relatively short dust collection regions. 
     After passing through the first stage cyclonic separator  74 , the airflow travels through the screen  142  in the shroud  70  that further separates debris from the airflow. After traveling through the screen  142 , the airflow travels into the second stage cyclonic separator  102  through the openings  126  between the vanes  122 . The redirection of the airflow by the vanes  122  (discussed above) in some embodiments may further separate debris from the airflow. The second stage cyclonic separator  102  further separates debris from the airflow, and the separated debris may fall into the second dirt collection chamber  118 . The airflow then passes through the filter assembly  59  to further remove relatively fine debris from the airflow. The cleaned airflow passes through the clean air outlet  54 , before being exhausted from the vacuum cleaner  10 . 
     Various features and advantages of the invention are set forth in the following claims.