Patent Publication Number: US-2021177223-A1

Title: Nozzle for a surface treatment apparatus and a surface treatment apparatus having the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of U.S. Provisional Application Ser. No. 62/949,122 filed on Dec. 17, 2019, entitled NOZZLE FOR A SURFACE TREATMENT APPARATUS AND A SURFACE TREATMENT APPARATUS HAVING THE SAME, which is fully incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to a vacuum cleaner, and more particularly, to a vacuum cleaner nozzle including castellations and/or cambered wheels to maintain suction power while collecting relatively large debris (e.g., cereal) and improve user experience through improved handling and reduction of wheel-induced noise. 
     BACKGROUND 
     The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art. 
     A vacuum cleaner may be used to clean a variety of surfaces. Some vacuum cleaners include a nozzle with a castellated configuration such that dirt and debris gets drawn into a dirty air inlet via a plurality of different inlets (or inlet paths). Such castellated nozzles allow for increased air velocity and higher suction relative to other nozzle configurations. Narrow openings/inlets/channels between castellations generally restrict/confine more area of a suction inlet, and result in higher air velocity during operation. While existing vacuum cleaners with castellated nozzles are generally effective at collecting debris, some larger debris (for example, CHEERIOS™) may not pass through the relatively narrow openings/inlets/channels provided by the nozzle, or worse yet can clog the same. On the other hand, widening the openings/inlets/channels of a castellated nozzle tends to lower air velocity, and by extension, decrease suction power and thus nullify the advantages of having the castellations. Accordingly, vacuums with castellated nozzles may be limited to cleaning applications that do not seek to remove large pieces of debris. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments are illustrated by way of example in the accompanying figures, in which like reference numbers indicate similar parts, and in which: 
         FIG. 1  is an isometric view of one embodiment of a vacuum cleaner nozzle, consistent with embodiments of the present disclosure; 
         FIG. 2  is a front view of the vacuum cleaner nozzle of  FIG. 1 , consistent with embodiments of the present disclosure; 
         FIG. 3  is a side view of the vacuum cleaner nozzle of  FIG. 1 , consistent with embodiments of the present disclosure 
         FIG. 4  is a bottom view of the vacuum cleaner nozzle of  FIG. 1 , consistent with embodiments of the present disclosure; 
         FIG. 5  is a bottom perspective view of the vacuum cleaner nozzle of  FIG. 1 , consistent with embodiments of the present disclosure; 
         FIG. 6A  illustrates an isometric view of one embodiment of a bottom frame of a vacuum cleaner nozzle, consistent with embodiments of the present disclosure; 
         FIG. 6B  illustrates an isometric view of the leading edge of the bottom frame of  FIG. 6A , consistent with embodiments of the present disclosure; 
         FIG. 7A  illustrates a front view of the bottom frame of a vacuum cleaner nozzle of  FIG. 6A , consistent with embodiments of the present disclosure; 
         FIG. 7B  illustrates a front view of the leading edge of the bottom frame of  FIG. 7A , consistent with embodiments of the present disclosure; 
         FIG. 8A  illustrates a side view of the bottom frame of a vacuum cleaner nozzle of  FIG. 6A , consistent with embodiments of the present disclosure; 
         FIG. 8B  illustrates a side view of the leading edge of the bottom frame of  FIG. 8A , consistent with embodiments of the present disclosure; 
         FIG. 9A  illustrates a bottom view of the bottom frame of a vacuum cleaner nozzle of  FIG. 6A , consistent with embodiments of the present disclosure; 
         FIG. 9B  illustrates a bottom view of the leading edge of the bottom frame of  FIG. 9A , consistent with embodiments of the present disclosure; 
         FIG. 10  illustrates an isometric view of the leading edge of the bottom frame of  FIG. 9A , consistent with embodiments of the present disclosure; 
         FIGS. 11A-11B  illustrate cross-sectional views of one embodiment of the leading edge of the bottom frame of  FIG. 6A  take along line  219  of  FIG. 7B , consistent with embodiments of the present disclosure; 
         FIG. 12  illustrates a front perspective view of one embodiment of a castellation, consistent with embodiments of the present disclosure; 
         FIG. 13  illustrates a side view of one embodiment of a castellation, consistent with embodiments of the present disclosure; 
         FIG. 14  illustrates a bottom perspective view of one embodiment of a castellation, consistent with embodiments of the present disclosure; 
         FIG. 15  illustrates a front view of one embodiment of a castellation, consistent with embodiments of the present disclosure; 
         FIG. 16A  is a graph illustrating large debris pickup with castellations of various hull angles. 
         FIG. 16B  is a graph illustrating the relationship between hull angle and debris acceleration in a suction nozzle with castellations. 
         FIG. 17A  and  FIG. 17B  are schematic front diagrams that illustrate nozzles with castellations as the nozzles encounter large debris, consistent with embodiments of the present disclosure; 
         FIG. 18  illustrates a front view of one embodiment of a space between castellations, consistent with embodiments of the present disclosure; 
         FIG. 19A  is a front view of the leading edge of a vacuum cleaner nozzle with castellations and cambered wheels, consistent with embodiments of the present disclosure; 
         FIG. 19B  is a semi-transparent view of the leading edge of a vacuum cleaner nozzle  FIG. 19A , showing the cambered wheels within the castellations. 
         FIG. 19C  illustrates a bottom view of the semi-transparent leading edge of a vacuum cleaner nozzle of  FIG. 19B , consistent with embodiments of the present disclosure; 
         FIG. 19D  illustrates an isometric view of the semi-transparent leading edge of a vacuum cleaner nozzle of  FIG. 19B , consistent with embodiments of the present disclosure; 
         FIG. 20A  is a front view of a cambered wheel, consistent with embodiments of the present disclosure; and 
         FIG. 20B  is an isometric view of a cambered wheel, consistent with embodiments of the present disclosure. 
         FIG. 21A  is a front view of the leading edge of a vacuum cleaner nozzle with cambered, cantilevered wheels, consistent with embodiments of the present disclosure; 
         FIG. 21B  is a semi-transparent view of the leading edge of a vacuum cleaner nozzle  FIG. 21A , showing the cambered, cantilevered wheels. 
         FIG. 21C  illustrates a bottom view of the semi-transparent leading edge of a vacuum cleaner nozzle of  FIG. 21B , consistent with embodiments of the present disclosure; 
         FIG. 22A  is a front view of a cambered, cantilevered wheel, consistent with embodiments of the present disclosure; and 
         FIG. 22B  is an isometric view of a cambered, cantilevered wheel, consistent with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the disclosure and do not limit the scope of the disclosure. 
     As discussed above, vacuums with castellated nozzles benefit from high suction power but are unable to be used in a wide-range of cleaning operations, such as those that aim to remove large bits of debris, for example, having at least one dimension that is equal to or greater than 1.27 cm, such as, but not limited to, a CHEERIOS™. Worse yet, castellated nozzles tend to get easily clogged as debris such as CHEERIOS™ can become lodged within the associated openings/inlets/channels. 
     Thus, in accordance with an embodiment of the present disclosure, a nozzle having castellations is disclosed herein that provides high suction pressure while also allowing for large pieces of debris to pass through the inlet openings. In more detail, a nozzle for a surface treatment apparatus is disclosed herein. The nozzle provides a suction channel through which debris passes into a main body of the surface treatment apparatus. Castellations are provided along a leading edge of the nozzle to allow debris to pass through the leading edge to the suction channel and into the main body during, for instance, forward and reverse strokes of the surface treatment apparatus. 
     In an embodiment, the castellations further include receptacles/cavities to receive and securely hold wheels therein. The wheels may be advantageously located at a distance which is offset from the sides of the nozzle. This results in improved edge cleaning as the nozzle  100  can be configured with inlets that allow for side-to-side cleaning movements along, for instance, walls. As discussed in further detail below, the wheels may be configured as a cambered wheels. 
     Nozzles configured consistent with the present disclosure provide numerous advantages and features over existing nozzle configurations. For instance, the castellations disclosed herein allow for vacuum cleaners implementing the same to be used in a wide-range of cleaning operations, and importantly, cleaning operations that aim to draw in large pieces of debris without getting clogged by the same. 
     Turning now to  FIGS. 1-5 , one embodiment of a vacuum cleaner nozzle  100  is generally illustrated. The term vacuum cleaner nozzle as used herein refers to any type of vacuum cleaner nozzle and may be also referred to as a cleaning head, a cleaning nozzle, or simply a nozzle. Such nozzles may be attached to a vacuum cleaner (or any other surface cleaning device) including, but not limited to, hand-operated vacuum cleaners and robot vacuum cleaners. Further non-limiting examples of hand-operated vacuum cleaners include upright vacuum cleaners, canister vacuum cleaners, stick vacuum cleaners, and central vacuum systems. Thus, while various aspects of the present disclosure may be illustrated and/or described in the context of a hand-operated vacuum cleaner or a robot vacuum cleaner, it should be understood the features disclosed herein are applicable to any hand-operated vacuum cleaner, robot vacuum cleaner, and other similar surface cleaning device unless specifically stated otherwise. 
     With this in mind,  FIG. 1  generally illustrates an isometric view of a nozzle  100 .  FIG. 2  generally illustrates a front view of a nozzle  100  of  FIG. 1 .  FIG. 3  generally illustrates a side view of the nozzle  100  of  FIG. 1 .  FIG. 4  generally illustrates a bottom view of the nozzle  100  of  FIG. 1 .  FIG. 5  generally illustrates a bottom perspective view of the nozzle  100  of  FIG. 1 . 
     It should be understood that the nozzle  100  shown in  FIGS. 1-5  is for exemplary purposes only and that a vacuum cleaner consistent with the present disclosure may not include all of the features shown in  FIGS. 1-5 , and/or may include additional features not shown in  FIGS. 1-5 . Again, without limitations, a nozzle consistent with the present disclosure may be incorporated into a robot vacuum cleaner. 
     As shown, the nozzle  100  may include a body or housing  130  that at least partially defines/includes one or more agitator chambers  122 . The agitator chambers  122  include one or more openings (or dirty air inlets)  123  (e.g., as shown in  FIGS. 4-5 ) defined within and/or by a portion of the bottom surface/plate  105  of the housing  130 . At least one rotating agitator or brush roll  180  is configured to be coupled to the nozzle  100  (either permanently or removably coupled thereto) and is configured to be rotated about a pivot axis within the agitator chambers  122  by one or more rotation systems (not shown for clarity). In some instances, the brush roll  180  may at least partially extending through the dirty air inlet  123 . The rotation systems may be at least partially disposed in the nozzle  100 , and include one or more motors, e.g., AC and/or DC motors, coupled to one or more belts and/or gear trains for rotating the agitators  180 . 
     The nozzle  100  may be coupled to a debris collection chamber (not shown) such that the same is in fluid communication with the agitator chamber  122  to draw in and store debris collected by the rotating agitator  180 . The agitator chamber  122  and debris chamber fluidly couple to a vacuum source (e.g., a suction motor or the like) for generating an airflow (e.g., partial vacuum) in the agitator chamber  122 , the dirty air inlet  123 , and debris collection chamber to thereby suck up debris proximate to the agitator chamber  122 , the dirty air inlet  123 , and/or the agitator  180 . 
     Rotation of the agitator  180  operates to agitate/loosen debris from the cleaning surface. Optionally, one or more filters disposed within the nozzle  100  (or other suitable location of a vacuum) remove ultra-fine debris (e.g., dust particles or the like) entrained in the vacuum air flow. 
     One or more of the debris chamber, vacuum source, and/or filters may be at least partially located in the nozzle  100 . Additionally, one or more suction tubes, ducts, or the like  136  may be provided to fluidly couple the debris chamber, vacuum source, and/or filters to the nozzle  100 . The nozzle  100  may include and/or may be configured to be electrically coupled to one or more power sources such as, but not limited to, an electrical cord/plug, batteries (e.g., rechargeable, and/or non-rechargeable batteries), and/or circuitry (e.g., AC/DC converters, voltage regulators, step-up/down transformers, or the like) to provide electrical power to various components of the nozzle  100  such as, but not limited to, the rotation systems and/or the vacuum source. 
     The housing  130  may further include a top surface  102  and a front (or leading) edge  101 . Air may generally flow past the front edge  101 , through the dirty air inlet  123 , and into the agitator chamber  122 . A plurality of castellations  110  may be provided in front of the agitator chamber  122  (e.g., in front of the dirty air inlet  123 ). In some instances, the plurality of castellations  110  may be provided along at least a portion of (e.g., all) of the front edge  101  of the nozzle  100 . The castellations  110  may be spaced apart such that the spacing between the castellations  110  defines, at least in part, one or more (e.g., a plurality) of castellation inlets and associated castellation inlet paths which transition to a shared suction channel within the nozzle  100 . 
     As shown more clearly in  FIGS. 4-5 , each of the castellations  110  may be defined by two or more sidewalls or projections  114  that extend away from the plate  105  of the housing  130  such that the castellations  110  have an arcuate profile (e.g., but not limited to, a substantially triangular profile, arrow-head profile, V-shaped profile, and/or U-shaped profile). In some instances, the sidewalls  114  may taper towards the front edge  101  of the nozzle  100  to define an apex, inflection point, and/or tip  115 . The apex, inflection point, and/or tip  115  may be disposed closer to the front edge  101  of the nozzle  100  than an opposing base or rear end  117  of the sidewalls  114 . The opposing base or rear end  117  of the sidewalls  114  may be defined as the portion of the castellation  110  that is closest to the dirty air inlet  123 . 
     In some instances, each castellation  110  may be defined, at least in part, by two sloping/angled edges or sidewalls  114  that extend from the ends  117  (e.g., proximate to dirty air inlet  123  of the nozzle  100 ) the towards each other and substantially transverse relative to the front edge  101 , such that the two sloping/angled edges or sidewalls  114  meet at an apex, inflection point, and/or tip  115  (which may be proximate and/or adjacent to the front edge  101 ). Put another way, the distance between the two sidewalls  114  decreases from the rear of the castellation  110  (i.e., the portion of the castellation  110  closest to the dirty air inlet  123 ) towards the front of the castellation  110  (i.e., the apex, inflection point, and/or tip  115  that is closest to the front edge  101  of the nozzle  100 ). The apex, inflection point, and/or tip  115  of the castellation  110  is therefore furthest from the dirty air inlet  123 . 
     Adjacent castellations  110  collectively define a tapered castellation air inlet  103 . In some instances, the castellation air inlet  103  may taper from the front of the nozzle  100  (e.g., the front edge  101 ) and/or from the apex, inflection point, and/or tip  115  towards the dirty air inlet  123  of the nozzle  100  and/or towards the ends  117 . Each castellation air inlet  103  may include a tapered profile having a first width W 1  (as shown in  FIG. 4 ) proximate and/or adjacent to the front (e.g., the front edge  101 ) of the nozzle  100  that transitions to a second width W 2  proximate and/or adjacent to the dirty air inlet  123  of the nozzle  100 . Alternatively (or in addition), each castellation air inlet  103  may include a tapered profile having a first width W 1  between the apex, inflection point, and/or tip  115  of the adjacent castellations  110  that transitions to a second width W 2  between the ends  117  of the adjacent castellations  110 . It should be appreciated that the first width W 1  is greater than the second width W 2 . The taper of the castellation air inlet  103  may generally inversely correspond to the taper of the adjacent castellations  110 . As discussed further below, the distance between adjacent castellations  110  and castellation characteristics (such as dimensions and surface angles) can be selected to achieve a desired air flow/suction and clearance profile for target debris, e.g., CHEERIOS™. 
     Continuing on, the castellations  110  may be provided adjacent and/or proximate to and along at least a portion of the front edge  101  of the nozzle  100  to allow debris to pass through the front edge  101 , through the castellation air inlets  103 , to the dirty air inlet  123  of the nozzle  100 , and ultimately, into the main body during use of the surface treatment apparatus. As further shown in  FIGS. 4-5 , one or more of the castellations  110  can provide projections with wheel receptacles/cavities  119 . Wheels, e.g., wheels  111 , may be disposed at least partially within (e.g., coupled to) the wheel receptacles  119  and confined therein. The wheels  111  (and associated receptacles  119 ) provided by the castellations  110  advantageously allow for the wheels  111  to be disposed at a position within the nozzle  100  that is offset away from the lateral sides  121  of the nozzle  100  (e.g., the left and right sides), e.g., to allow for improved edge cleaning as discussed above. Moreover, placement of the wheels  111  within the wheel receptacles  119  of the castellations  110  minimizes or otherwise reduces the potential for restricting air flow. 
       FIGS. 6A-11B  illustrate an example embodiment of a bottom frame  200  of a nozzle consistent with embodiments of the present disclosure. The bottom frame  200  includes a plurality of castellations  210 . The castellations  210  are arranged at and/or proximate to the leading edge  201  of the bottom frame  200  and protrude from a lower plane  219  (e.g., of the bottom frame  200 ) towards a floor surface. As discussed above, one or more of the castellations  210  can define a wheel receptacle  219  (best seen in  FIGS. 10 and 11A ) to receive and couple to, for instance, wheel  211  (e.g., best seen in  FIGS. 9A and 9B ). 
     As best in  FIG. 11A , each of the castellations  210  may be defined by one or more sidewalls or projections  214  that extend away from the lower plane  219  of the bottom frame  200  such that the castellations  210  have an arcuate profile (e.g., but not limited to, a substantially triangular profile, arrow-head profile, V-shaped profile, and/or U-shaped profile). In some instances, the sidewalls  214  may taper towards the front edge  201  of the nozzle to define an apex, inflection point, and/or tip  215 . The apex, inflection point, and/or tip  215  may be disposed closer to the front edge  201  of the nozzle than an opposing base or opposite end  217  of the sidewalls  214  (e.g., closer to the front of the nozzle than the rear of the nozzle). 
     Adjacent castellations  210  collectively define a tapered castellation air inlet  203 . In some instances, the castellation air inlet  203  may taper from the front of the nozzle (e.g., the front edge  201 ) towards the dirty air inlet of the nozzle. Alternatively (or in addition), the castellation air inlet  203  may taper from the from the apex, inflection point, and/or tip  215  towards the ends  217 . Each castellation air inlet  203  may include a tapered profile having a first width W 1  proximate and/or adjacent to the front (e.g., the front edge  201 ) of the nozzle that transitions to a second width W 2  proximate and/or adjacent to the dirty air inlet of the nozzle. Alternatively (or in addition), each castellation air inlet  203  may include a tapered profile having a first width W 1  between the apex, inflection point, and/or tip  215  of the adjacent castellations  210  that transitions to a second width W 2  between the ends  217  of the adjacent castellations  210 . In any event, the first width W 1  is greater than the second width W 2 . The taper of the castellation air inlet  203  may generally inversely correspond to the taper of the sidewalls  214  of adjacent castellations  210 . 
     The present disclosure has identified that multiple factors of the castellations  210  function in combination and can be selected to achieve a desired function and air flow/suction. 
       FIGS. 12-15  show example dimensions of a castellation  1100  consistent with embodiments of the present disclosure. One aim of the present disclosure is to balance the need to maximize air flow/suction with the ability to allow relatively large debris to enter the nozzle between the castellations  1100  (e.g., through the tapered castellation air inlets). With this in mind, the present disclosure has identified that spacing (or the offset distance) between the adjacent castellations  1100  determines, at least in part, the overall size/dimensions of debris that can enter into the brush roll chamber (e.g., through the castellation air inlets). Preferably, the spacing between adjacent castellations  1100  is set to a predefined uniform offset distance that allows for objects about the size of CHEERIOS™ to pass between the adjacent castellations  1100  and through the castellation air inlets. 
     Continuing on, castellations  1100  protrude from a face  1104  of the nozzle that is closest to the floor during operation. Each castellation  1100  has a bottom surface  1105  that is in contact or adjacent with a floor surface during operation. The overall height  1103  of the castellation  1100  is the distance from the face  1104  of the nozzle to the bottom surface  1105  of the castellation  1100 . Castellation height  1103  is partially determined based on the ground clearance desired for a nozzle. Ground clearance further impacts the maximum size of debris that can pass underneath the castellation  1100  and can affect transitions over thresholds, for example. 
     The horizontal dimension or castellation width  1107  of any individual castellation  1100  is one factor that determines how much area the castellation will restrict. Castellation width  1107  can be determined based on, for instance, the opening width of the nozzle inlet and the spacing between each castellation  1100 . Increasing the castellation width  1107  (e.g., resulting in wider castellations  1100 ) generally increases the surface area coverage of a nozzle for a given number of castellations  1100  and a given nozzle width. The surface area coverage of the nozzle caused by the increased width  1107  of the castellations  1100  creates narrower openings in the nozzle inlet (i.e., narrower castellation air inlets). These narrower openings/castellation air inlets cause higher air velocity through the nozzle during operation. 
     Castellation depth  1108  is the dimension of how far back the castellation  1100  extends from the front edge of the nozzle towards the brush roll chamber. Put another way, the castellation depth  1108  is the dimension of how far back the castellation  1100  extends from the apex, inflection point, and/or tip towards the dirty air inlet of the nozzle. 
     The angle of the front “hull” of the castellation  1100  or Hull Angle (ϕ)  1110  ( FIG. 14 ) is the angle that the front of the castellation  1100  makes between its two edges or sidewalls  1014 . The hull angle  1110  affects how fast large debris will be able to slide through the castellation air inlets and into the brush roll chamber after contact with the castellation  1100 . With a smaller angle  1110 , a castellation  1100  generally mimics a flat blade, and the large debris can readily pass by and/or through the leading edge  1112  of the nozzle and into the brush roll chamber. However, a larger angle  1110  usually means the large debris will face more resistance when entering the castellation air inlets and brush roll chamber. Generally, a larger hull angle  1110  leads to more large debris accumulating and clogging the castellation air inlets and/or front inlet. Smaller hull angles  1110  may not be practical or as desirable on castellations  1100  with larger widths  1107 . 
     As shown in  FIG. 16A , larger hull angles may be acceptable when castellation width is large because the higher air velocity assists in evacuating large debris off of the ramp faster, which prevents or reduces the potential for clogging. 
     Assuming no suction or rolling motion of a CHEERIO™ when sliding down a castellation, its acceleration down the castellation (e.g., through the castellation air inlets) can be approximated as: 
     
       
         
           
             
               
                 
                   a 
                   ≈ 
                   
                     
                       
                         F 
                         
                           a 
                            
                           p 
                            
                           p 
                         
                       
                       m 
                     
                      
                     
                       [ 
                       
                         
                           sin 
                            
                           
                             ( 
                             
                               
                                 9 
                                  
                                 0 
                               
                               - 
                               
                                 φ 
                                 2 
                               
                             
                             ) 
                           
                         
                         - 
                         
                           μ 
                            
                           
                             cos 
                              
                             
                               ( 
                               
                                 
                                   9 
                                    
                                   0 
                                 
                                 - 
                                 
                                   φ 
                                   2 
                                 
                               
                               ) 
                             
                           
                         
                       
                       ] 
                     
                   
                 
               
               
                 
                   Equation 
                    
                   
                       
                   
                    
                   
                     ( 
                     1 
                     ) 
                   
                 
               
             
           
         
       
     
     Where F app  is the force applied by the vacuum on the CHEERIO™. 
       FIG. 16B  illustrates the relationship between hull angle and acceleration of the exemplar large debris. The lighter region  1601  of the line (between 90 and 130 degrees) represents the usual range of hull angles when modelling castellations. In this region  1601 , acceleration decreases on average 2.8% for each hull angle degree increase, decreasing more per degree as the hull angle gets higher. Lower acceleration CHEERIO™ evacuate into the brush roll chamber slower, leading to more clogs and failures in picking up debris. 
     In the present disclosure, the castellations  1100  are further characterized by at least one chamfer  1120  ( FIG. 12 ). Chamfers  1120  can be created/formed by removing a portion of the castellation  1100 , and its dimensions are then chosen to achieve nominal suction and clearance as discussed above. It should also be appreciated that the chamfers  1120  may be created/formed initially without the portion. For example, the chamfers  1120  may be created/formed by creating/forming (e.g., but not limited to, molding) the castellations  1100  with the geometry described herein such that no portion of the castellations  1100  is removed. The chamfers  1120  may be used with or without the tapered or arcuate profile described above. 
     Chamfers  1120  may be formed through beveled edges and/or surfaces in one or more sidewalls  1214  of the castellations  1100  (e.g., one or more otherwise perpendicular faces). In at least one example, the chamfer  1120  is disposed only in the bottom portion of the castellations  1100  (i.e., the top portion of the castellations  1100  may be generally normal or perpendicular to the surface to be cleaned); however, it should be appreciated that the entire sidewall  1214  (e.g., the top and the bottom portions) may include the chamfer  1120 . The bottom portion of the castellations  1100  is defined as the portion of the castellations  1100  that is closest to the surface to be cleaned, while the top portion of the castellations  1100  is defined as the portion of the castellations  1100  that is furthest from the surface to be cleaned. 
     The chamfer  1120  may extend around the entire bottom periphery or region of the castellations  1100  (e.g., around all of the sidewalls  1214  of the castellations  1100 ) or around only a portion of the bottom periphery or region of the castellations  1100  (e.g., around only a portion of the bottom periphery of one or more of the sidewalls  1214  of the castellations  1100 ). The chamfer  1120  may be the same along the entire bottom periphery or region of the castellations  1100  or may vary along the length of the bottom periphery or region. 
     As seen in  FIG. 12 , chamfers  1120  that are flush with the back of the castellation  1100  generally widen the spacing at the bottom  1105  while keeping the spacing tighter (i.e., smaller) at the top  1104 . This increases the overall surface area restricted by the castellation  1100  and increases air velocity, while importantly still allowing passage of larger debris. Put another way, the chamfer  1120  may include a portion of one or more of the sidewalls  1214  of the castellation  1100  which is not perpendicular or normal to the surface to be cleaned (e.g., the floor). The chamfer  1120  may therefore be thought of as having a vertically increasing taper such the castellation width  1107  proximate the top  1104  of the castellation  1100  is larger than the castellation width  1107  proximate to the bottom surface  1105  of the castellation  1100 . The chamfer  1120  may be planar (as generally illustrated) and/or may have a curved profile. 
     It should be appreciated that the castellation air inlets defined between adjacent castellations  1100  may also have a profile that generally inversely corresponds to the chamfer  1120  of the adjacent castellations  1100 . For example, the castellation air inlets may therefore be thought of as having a vertically decreasing taper such the castellation air inlet width proximate the top  1104  of the adjacent castellations  1100  is smaller than the castellation air inlet width proximate to the bottom surface  1105  of the adjacent castellations  1100 . As such, adjacent castellations  1100  with chamfers  1120  may be considered to at least partially define chamfered castellation air inlets. 
     The primary dimensions of the chamfer  1120  are its horizontal (x)  1102  and vertical (y)  1101  dimensions. These dimensions  1102 ,  1101  help determine the size and type of debris that can get through the castellation air inlets and to the brush roll chamber. 
     As stated above, the dimensions of the castellation  1100  affect the possible dimensions  1102 ,  1101  of any potential chamfer  1120 . 
     Extrusion Angle (a)  1106  ( FIG. 13 ) is the angle that the castellation  1100  makes with respect to the horizontal (side view). The extrusion angle  1106  affects both the x and the y component of the chamfer  1120 . 
     Radius (R)  1109  ( FIG. 14 ) is the radius of the front fillet on the castellation  1100  (i.e., the apex, inflection point, and/or tip), and affects primarily the x component of the chamfer  1120 . The radius  1109  affects primarily the x component of the chamfer  1120 . 
     Castellation height  1103  ( FIGS. 12 and 15 ) affects both the x and the y component of the chamfer  1120 . 
     Castellation width  1107  ( FIG. 12 ) affects primarily x component of the chamfer  1120 . 
     Castellation depth  1108  ( FIG. 14 ) affects primarily the x component of the chamfer  1120 . 
     Hull angle  1110  ( FIG. 14 ) affects primarily the x component of the chamfer  1120 . 
     Offset (O)  1111  ( FIGS. 12 and 14 ) is the distance that the angled walls  1114  of the castellation  1100  are shifted towards the front of the plate. 
     With standard castellations, the determination of the spacing between castellations is straightforward and can be based on factors such as the size of the debris that needs to pass through a suction nozzle. 
     For instance, if a maximum dimension of a debris to be picked up, is 13.95 mm, then in a non-chamfered castellations, a minimum spacing of about 13.95 mm is required. Moreover, testing suggests that an additional 2 mm clearance reduces clogging at the intake nozzle. Testing and simulation has shown that additional clearance space does not further reduce clogging of debris at the nozzle and lowers air velocity through the nozzle (i.e., through the castellation air inlets). Therefore, spaces of 16 mm+−2 mm between each castellation allows passage of the target debris size through the castellation air inlets without clogging while also benefiting from the increased air velocity from castellations. 
       FIG. 17A  and  FIG. 17B  are schematic diagrams that illustrate nozzles with castellations as the nozzles encounter large debris.  FIG. 17A  illustrates an adjacent castellations  2100 A without one or more chamfers.  FIG. 17B  illustrates adjacent castellations  2110  with chamfers  2111 . Large debris  2200 , for example a CHEERIO™, cannot pass through the castellation air inlets  2103  defined between the adjacent castellations  2100 A shown in  FIG. 17A , but a piece of debris with the same dimensions is able to pass through the castellation air inlets  2103  defined by the adjacent castellations  2110 B of  FIG. 17B  because of the increased spacing provided by the chamfers  2111 . 
       FIG. 17A  shows castellations  2100 A with no chamfer and spacing of 12 mm. The example large debris  2200  has a height  2201  of 7.58 mm and an outer diameter  2202  of 13.95 mm. 
       FIG. 17B  shows castellations  2110 B with 4 mm×4.75 mm chamfers  2111  with spacing S of 12 mm between the non-chamfered portions of the sidewalls  2114  of the castellations  2110 B. The x dimension of the chamfer  2111  extends the spacing S to 20 mm at the bottom. However, the use of the chamfer  2111  retains 29 mm 2  of inlet area per space as opposed to no chamfers with 20 mm spacing. Thus, larger debris  2202  is picked up without the decrease in air velocity caused by castellations  2110 B with 20 mm spacing. It should be appreciated that the dimension described herein are for exemplary purposes only unless specifically claimed as such. 
     Just as the size of debris  2200  to be picked up is used to determine spacing for a standard castellation (i.e., the castellation air inlets), the dimensions of debris (e.g., the height  2201  and the width  2202 ) of the debris  2200  can be used to determine the dimensional components of a chamfer  2111 . In addition to the width  2202 , the height  2201  of a piece of debris  2200  may be used to calculate the vertical component (e.g., y component) of the chamfer  2111  (i.e., a distance substantially perpendicular or normal to the surface to be cleaned such as the floor). After the desired height has been calculated, the following formula may be used to determine the initial y component of the chamfer  2111 : 
         y =height−ground clearance  Equation (2)
 
     The y component of the chamfer  2111  may also generally correspond to the y component of the castellation air inlets. 
     The x component of the chamfer  2111  should be preferably selected such that it creates the desired spacing between adjacent castellations  2100  (e.g., the width of the castellation air inlets) without chamfers at the midpoint of the chamfer  2111 . Thus, the initial desired spacing for castellations  2100 B is located in the middle of the space/castellation air inlets. For example, as mentioned above, when determining spacing without chamfers, 16 mm spacing between adjacent castellations  2100  was used to pick up 100% of debris  2200  with an outer dimension of 13.95 mm. The w component of the chamfer  2111  may also generally correspond to the w component of the castellation air inlets (e.g., a distance between adjacent castellations  2100  and/or the width of the castellation air inlets that is generally perpendicular to the y component and generally parallel to the surface to be cleaned such as the floor). 
     As illustrated in  FIG. 18 , if a line  1801  is extended between the chamfers  2111  of two adjacent castellation  2011 B at the midpoint of the chamfer&#39;s hypotenuse, this value may equal whatever nominal spacing was initially calculated without the use of a chamfer  2111  (e.g., the w component of the chamfer  2111 ). In the present embodiment, a 4 mm×4.75 mm chamfer  2111  is used on top of a 12 mm wide spacing to create a 16 mm space at the midpoint of the chamfer  2111 . Again, it should be appreciated that these values are for exemplary purposes only, and the present disclosure is not limited to these values unless specifically claimed as such. 
     Once the requirements of a castellation  2110  for a suction nozzle are determined, the following dimensions can be determined:
         Chamfer Dimensions: x and y   Castellation Height: H (usually determined based on the suction nozzle requirements)   Extrusion Angle: α (45° may be used for initial calculations, but can be increased or decreased to achieve a desired radius)   Castellation Depth: D (determined based on the suction nozzle requirements)   Castellation Width: W (determined from front inlet width, spacing, and number of castellations)       

     Using the above dimensions, the following measurements may be calculated for castellations: Offset (O), Extrusion Length (E), Hull Angle (ϕ), and Radius (R). 
     
       
         
           
             
               
                 
                   E 
                   = 
                   
                     H 
                     
                       sin 
                        
                       α 
                     
                   
                 
               
               
                 
                   Equation 
                    
                   
                       
                   
                    
                   
                     ( 
                     3 
                     ) 
                   
                 
               
             
             
               
                 
                   φ 
                   = 
                   
                     2 
                     * 
                     
                       
                         tan 
                         
                           - 
                           1 
                         
                       
                        
                       
                         ( 
                         
                           
                             x 
                              
                             
                               ( 
                               
                                 H 
                                 - 
                                 y 
                               
                               ) 
                             
                           
                           
                             O 
                              
                             
                                 
                             
                              
                             y 
                           
                         
                         ) 
                       
                     
                   
                 
               
               
                 
                   Equation 
                    
                   
                       
                   
                    
                   
                     ( 
                     4 
                     ) 
                   
                 
               
             
             
               
                 
                   R 
                   = 
                   
                     
                       
                         W 
                         2 
                       
                       - 
                       
                         [ 
                         
                           
                             ( 
                             
                               D 
                               - 
                               O 
                             
                             ) 
                           
                            
                           tan 
                            
                           
                             φ 
                             2 
                           
                         
                         ] 
                       
                     
                     
                       tan 
                        
                       
                         ( 
                         
                           
                             4 
                              
                             5 
                           
                           - 
                           
                             φ 
                             4 
                           
                         
                         ) 
                       
                     
                   
                 
               
               
                 
                   Equation 
                    
                   
                       
                   
                    
                   
                     ( 
                     5 
                     ) 
                   
                 
               
             
           
         
       
     
     The calculated dimensions may be used to construct castellations  2110 B that allow the targeted debris  2200  to pass through the castellation air inlets and into suction nozzle (e.g., the dirty air inlet). Further considerations including aesthetics and structural support may dictate additional castellations characteristics. 
     As seen in  FIGS. 19A-19D , some embodiments further include one or more wheels  1901  placed at least partially within wheel receptacles/cavities  1919  of one or more wheel castellations  1902  (e.g., which may include a chamfered and/or an arcuate/tapered profile as described herein). The wheel receptacles/cavities  1919  may be positioned such that the wheels  1901  are located away from the sides  1921  (e.g., the left and right lateral sides) of the nozzle. Thus, the dimensions of the wheel castellations  1902  should allow the inclusion of the wheels  1901 . 
     During operation of a vacuum cleaner, wheels  1901  that are forward of the dirty air inlet are exposed to debris. In order to reduce and/or generally prevent the wheels  1901  from clogging with debris, at least the top and/or upper portion of the wheels  1901  (e.g., the portion of the wheel  1901  above the axis of rotation) is enclosed/surrounded by the nozzle (e.g., disposed within the wheel receptacles/cavities  1919 ). In at least one example, at least 75% of the wheel  1901  is disposed within the wheel receptacles/cavities  1919 . If the one or more wheels  1901  are located on the lateral sides  1921  of the suction nozzle, then the enclosure of the wheel  1901  by the suction nozzle constraints the ranges of shapes for the side castellations  1903 . Furthermore, the side castellations  1903  may need to accommodate other hardware such as attachment points, leaving relatively small amount of room for the one or more wheels  1901 . In the present embodiment, the side castellations  1903  allow for improved edge cleaning without having to necessarily accommodate wheels. 
     As shown in  FIGS. 20A-20B , the one or more wheels shown in  FIGS. 19A-19D  may be cambered wheels  2000 . Camber is the angle at which the wheel stands relative to the floor. Put another way, camber is it is the angle between the vertical axis of a wheel and the vertical axis of the nozzle when viewed from the front or rear. In the present embodiment, the wheels  2000  may have a negative camber (e.g., static negative camber) such that the top of each wheel  2000  is leaned in closer to the center of the suction nozzle when not in motion. Camber angle alters the handling qualities of a particular suspension design; in particular, negative camber improves grip while in motion. In general, each wheel  2000  operates independently and rolls in an arc. When both wheels  2000  have symmetrical negative camber (i.e., the wheels  2000  at opposite lateral ends of the nozzle), the lateral forces substantially cancel each other out. Thus, a user can easily steer the cleaning device during operation, and there is an improved perception of control due to the increased “grip.” The cambered wheels  2000  may be at least partially disposed within the wheel receptacles/cavities (e.g., wheel receptacles/cavities  1919 ). 
     In addition to the perception of control, the noise generated during the operation of a vacuum cleaner can have a significant impact on user experience. Increased noise, particularly noise not associated with a suction motor, is seen as a negative and undesirable quality. Wheel chatter (that is the noise created by the wheels of the vacuum cleaner during operation) should be reduced as much as possible. The cambered wheels  2000  of the present embodiment allow for decreased wheel chatter during operation. 
     The cambered wheels  2000  generate force substantially perpendicular to the direction of travel. This force results in the cambered wheels  2000  being pushed into the wheel housings on the nozzle. Since one of the sources of wheel chatter noise is the knocking of wheels against the housing, cambered wheels  2000  limit the range of motion of the wheels relative to the housing. As may be seen, the cambered wheels  2000  may have a floor contacting surface  2001  that has a generally frustoconical or tapered profile. In particular, the conical profile may be arranged such that the diameter of the floor contacting surface  2001  reduces when moving from a lateral side of the nozzle (e.g., side  119 ) towards the center of the nozzle. The conical profile of the floor contacting surface  2001  may allow the wheel  2000  to have negative camber and to be made from a generally solid material, while increasing the contact surface area of the floor contacting surface  2001  of the wheel  2000 . The cambered wheels  2000  may rotate about one or more pins or axles  2003 , for example, that pass through the center of the cambered wheels  2000 . The pins  2013  may be mounted within the wheel receptacles/cavities (e.g., wheel receptacles/cavities  1919 ) such that the pins  2013  (e.g., the axis of rotation of the cambered wheels  2000 ) are arranged at an angle that generally corresponds to the camber angle (e.g., as shown in  FIG. 19B ) of the cambered wheels  2000 . 
     As shown in  FIGS. 21A-21C  and in  FIGS. 22A-22B , one or more wheels  2100  shown may extend from one end of a pin or axle  2113  such that the wheels  2100  are cantilevered. Some embodiments, the cantilevered wheels  2100  may also be cambered as described herein (e.g., having a generally frustoconical or tapered floor contacting surface  2115 ). In some instances, cantilevered wheels  2100  may be disposed within the wheel receptacles/cavities  2119  such that the wheels  2100  are completely underneath the nozzle (e.g., are not exposed on from the side of the nozzle when viewed from the top of the nozzle). 
     During operation of a vacuum cleaner, wheels  2100  that are in front of the dirty air inlet are exposed to debris. In order to reduce and/or generally prevent the wheel from clogging with debris, at least the top and/or upper portion of the wheel  2100  (e.g., the portion of the wheel  2100  above the axis of rotation) is enclosed/surrounded by the nozzle (e.g., disposed within the wheel receptacles/cavities  2119 ). In at least one example, at least 80% of the wheel  2100  is disposed within the wheel receptacles/cavities  2119 . If the one or more wheels  2100  are located on the lateral sides of the suction nozzle, then the enclosure of the wheel  2100  by the suction nozzle constrains the ranges of shapes for the side wheel cavity  2119 . 
     In the present embodiment, the fixed end of the cantilevered wheels  2100  (e.g., the end of the axle  2113  opposite the wheel  2100 ) is towards the exterior edge (e.g., left/right lateral sides  2123 ) of the suction nozzle. The placement of the wheel cavities  2119  allow the cantilevered axles  2113  to be supported from the exterior or lateral edge/side  2123  of the nozzle. In the embodiment shown in  FIGS. 21A-21C , the cantilevered wheels  2100  have a static negative camber of approximately 25 degrees. A camber angle of 15 degrees to 70 degrees allows the wheel  2100  to spin freely on the cantilevered axle  2113 . 
     Hair wrapping around wheel axles  2113  has a negative impact on user experience. Hair forming tight loops around an axle  2113  can interfere with the steering of the vacuum cleaner in addition to being visually unappealing. The use of a cantilevered wheel  2100  improves the ability to remove hair wrapped around the axle  2113  or wheel  2100 . A gap  2102  between the axle  2113  and the wheel housing (e.g., the wheel cavity  2119 ) provides a space in which hair may move and then be removed. 
     The camber in the present invention further decreases the effect of hair wrap. During normal operation, cambered wheels  2100  generate force substantially perpendicular to the direction of travel. This force pushes hair wrapped towards the non-fixed side of the cantilevered wheel  2100 . Hair caught in the wheel  2100  falls off the wheel  2100  through the gap  2102  and then may be pulled into the dirty air inlet during operation. 
     While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. It will be appreciated by a person skilled in the art that a surface cleaning apparatus and/or agitator may embody any one or more of the features contained herein and that the features may be used in any particular combination or sub-combination. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the claims.