Patent Publication Number: US-8533886-B2

Title: Cleaning apparatus with reciprocating brush head

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of application Ser. No. 12/574,865, filed Oct. 7, 2009, which is a continuation of application Ser. No. 12/106,965, filed Apr. 21, 2008, U.S. Pat. No. 7,614,107, which is a continuation of application Ser. No. 11/013,935, filed Dec. 15, 2004, U.S. Pat. No. 7,360,269, which claims priority to U.S. Provisional Application Ser. No. 60/534,010, filed Jan. 2, 2004 which applications are incorporated herein by specific reference. 
     BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     The present invention relates to hand held cleaning apparatus having a reciprocating or rotating brush head. 
     2. The Relevant Technology 
     Household cleaning is a never ending business. Although there are numerous types of sponges and brushes that are specially designed to clean large, open surface areas such as countertops, sinks, and bathtubs, there are fewer resources available for cleaning the difficult cracks, corners, and other hard to reach areas that are ubiquitous in a home. Although conventional sponges and brushes can certainly be used for cleaning corners and other hard to reach areas, the configuration and large size of such conventional cleaners makes them difficult to access such areas. The user is often required to apply extensive force by the ends or tips of the fingers so as to force the cleaner into the crack or corner to be cleaned. Such cleaning is tiring and often results in cramping of the hand and/or fingers. 
     This problem is compounded by the fact that corners and cracks are typically where dirt, mold, soap scum, and other undesirables tend to grow or build-up. As such, extra energy or force is often necessary to clean such locations. 
     Conventional toothbrushes are often used to clean such hard to reach areas. The problem with toothbrushes, however, is that because they are specifically designed for cleaning teeth around sensitive gums, toothbrushes are typically too soft and do not have a good angle for any extended, aggressive scrubbing of hard surfaces. Furthermore, because of the small handles on toothbrushes, any significant scrubbing using a toothbrush again produces fatigue and cramping of the hand. 
     Accordingly, what is needed are improved cleaning apparatus which can be used for cleaning small, hard to reach areas, which can be used for durable, extended scrubbing, and which can be used with minimal fatigue. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the present invention will now be discussed with reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. 
         FIG. 1  is a an elevated side view of one embodiment of the inventive cleaning apparatus; 
         FIG. 2  is a top plan view of the cleaning apparatus shown in  FIG. 1 ; 
         FIG. 3  is an elevated front end view of the cleaning apparatus shown in  FIG. 1 ; 
         FIG. 4  is an elevated front view of the front face of the brush head shown in  FIG. 3 ; 
         FIG. 5  is an exploded view of the cleaning apparatus shown in  FIG. 1 ; 
         FIG. 6  is a cross sectional side view of the cleaning apparatus shown in  FIG. 1 ; 
         FIG. 7  is a perspective view of a subassembly of the cleaning apparatus shown in  FIG. 1  showing a drive shaft coupled with a hub and brush head; 
         FIG. 8  is an enlarged perspective view of the drive shaft shown in  FIG. 7 ; 
         FIG. 9A  is an enlarged perspective view of the hub shown in  FIG. 7 ; 
         FIG. 9B  is an enlarged perspective view of an alternative embodiment of the hub shown in  FIG. 9A ; 
         FIG. 10  is an enlarged perspective view of the coupled parts shown in  FIG. 7 ; 
         FIG. 11  is a perspective view of an alternative embodiment of a cleaning apparatus; 
         FIGS. 12A and 12B  are exploded views of the cleaning apparatus shown in  FIG. 11 ; 
         FIG. 13  is a cross sectional side view of the cleaning apparatus shown in  FIG. 11 ; 
         FIG. 14A  is an enlarged cross sectional side view of the button switch assembly shown in  FIG. 13  in an off position; 
         FIG. 14B  is an enlarged cross sectional side view of the button switch assembly shown in  FIG. 14A  in a momentary position; 
         FIG. 14C  is an enlarged cross sectional side view of the button switch assembly shown in  FIG. 14A  in a on position; and 
         FIG. 15  is an enlarged perspective view of the hub shown in  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention relates to cleaning apparatus having a reciprocating or rotating brush head. The cleaning apparatus is generally designed for domestic use in cleaning small, hard to reach areas such as cracks, corners, grooves and crevices. For example, the cleaning apparatus can be used for cleaning corners and around faucets on counter tops and in showers. It can also be used for spot scrubbing materials such as fabric and carpets. It is appreciated, however, that the apparatus can be used for cleaning any type of surface in commercial, residential, or any other application. The cleaning apparatus, however, is not designed for use as a toothbrush. 
     Depicted in  FIGS. 1-3  is one embodiment of a cleaning apparatus  4  incorporating features of the present invention. Cleaning apparatus  4  generally comprises a body assembly  5  having a removable head assembly  6 . Head assembly  6  includes a head housing  7  having an upper head housing  22  which mates with a lower head housing  24 . Each of head housings  22  and  24  extend between a proximal end  32  and an opposing distal end  34 . 
     Head assembly  6  further includes a rotatable brush head  14  having a brush  16  mounted thereon. As will be discussed below in greater detail, brush head  14  comprises an annular carrier plate  122  having a top surface  124  and an opposing bottom surface  125 . Depicted in  FIG. 4 , a plurality of tufting holes  170  are formed on bottom surface  125 . In one embodiment tufting holes  170  are circular and each have a diameter in a range between about 1 mm to about 4 mm with about 2 mm to about 3 mm being more common. Tufting holes  170  are shown disposed in concentric rings. Alternatively, tufting holes  170  can also be randomly disposed or be in other patterns. 
     In the embodiment depicted, tufting holes  170  from an outer ring  172 , a middle ring  174 , an inner ring  176  and a center tufting hole  178 . As seen in  FIG. 3 , disposed within each tufting hole  170  is a tuft  180  which is comprised of a plurality of bristles  182 . The combined tufts  180  form brush  16 . Bristles  182  can be made of a variety of different materials having different lengths and diameters. By adjusting the properties of the bristles  182 , brush  16  can be formed having different stiffnesses to better suit different uses. In general, bristles having shorter length and increased diameter have increased stiffness. 
     Bristles  182  can be made from a variety of different natural or synthetic materials. In one embodiment, bristles  182  are comprised of a polymer material such as nylon. In other embodiments, such as for use in cleaning a barbeque grill, bristles  182  can be comprised of a metal such as brass, stainless steel, or copper. As depicted in  FIG. 1 , each bristle has an exposed length L which is typically in a range between about 0.3 cm to about 2.5 cm with about 1 cm to about 2 cm being more common. The depicted brush  16  has a substantially cylindrical configuration with a maximum diameter D that is typically in a range between about 1 cm to about 5 cm, with about 1 cm to about 3 cm being common, and about 1.5 cm to about 2.5 cm being more common. Larger brushes may have a diameter in a range from about 3 cm to about 5 cm. In alternative embodiments, brush  16  can have any desired configuration and can have any desired dimensions, including longer lengths and diameters, so as to function for a particular purpose. 
     Because head assembly  6  is removable from body assembly  5 , it is appreciated that a variety of different head assemblies  6  can be made, each having a brush  16  of different configuration and/or properties. For example head assembly  6  can be formed each having a brush  16  with soft bristles, medium bristles, stiff bristles or combinations thereof. In one embodiment the soft bristles are comprised of a polymeric material having a diameter in a range between about 0.15 mm to about 0.25 mm with about 0.18 mm to about 0.23 mm being more common. Medium polymeric bristles typically have a diameter in a range between about 0.30 mm to about 0.48 mm with about 0.37 mm to about 0.42 mm being more common. Finally, polymeric stiff bristles typically have a diameter in a range between about 0.48 mm to about 0.75 mm with about 0.52 mm to about 0.58 mm being more common. By way of comparison, bristles on tooth brushes typically have a diameter less than 0.15 mm so that the bristles are not so stiff as to damage the gums or enamel of the teeth. 
     In one embodiment having a combination of bristles  182 , tufting holes  170  in outer ring  172 , middle ring  174 , and inner ring  176  ( FIG. 4 ) are filled with medium bristles while center tufting hole  178  is filled with stiff bristles forming a stopping tuft. The bristles in the stopping tuft are shorter than the other bristles. During use, the stiffness of the stopping tuft helps limit the collapse of the other tufts as the brush is pressed against the surface to be cleaned. This helps to ensure that the tips of the bristles, as opposed to the sides, are primarily used for scrubbing. Bristles having different properties can also be defined by relative percentages. For example, in a brush having a stopping tuft and cleaning tufts, the bristles of the cleaning tufts can have a length that is at least 20% longer or at least 30% longer than the bristles of the stopping tuft and a diameter that is at least 30% smaller or at least 40% smaller than the bristles of the stopping tuft. 
     Similarly, in one embodiment depicted in  FIG. 3 , brush  16  can comprise a group of central tufts  8  which are surrounded by outer perimeter tufts  9 . The outer perimeter tufts  9  are slightly longer and softer than central tufts  8 . As such, light contact by brush  16  produces soft scrubbing by outer perimeter tufts  9  while harder biasing of brush  16  causes central tufts  8  to engage the surface, thereby producing harder scrubbing. In alternative embodiments, all the tufts/bristles can be the same length, diameter, or stiffness or any combination of lengths, diameters and stiffness can be used. 
     Body assembly  5  includes a body housing  12  having a substantially cylindrical configuration. Body housing  12  can have a circular, elliptical or any other desired transverse cross section and is sized to comfortably fit within the hand of a user. In one embodiment, body housing  12  has a maximum diameter in a range between about 2.5 cm to about 4.5 cm. Other dimensions can also be used. Body housing  12  comprises an upper body housing  18  which mates with a lower body housing  20 . Each of body housings  18  and  20  also extend from a proximal end  26  to an opposing distal end  28 . Upper body housing  18  has an aperture  21  in which a flexible button  23  is mounted (see  FIG. 5 ). Removably mounted to proximal end  26  of body housing  12  is an end cap  30 . It is noted that button  23  is positioned on one side of cleaning apparatus  4  while brush  16  projects from the other side of cleaning apparatus  4 . This configuration enables the user to easily activate button  23  during using of cleaning apparatus  4 . Furthermore, by having this configuration, the force used to press down on button  23 , such as with the thumb of the user, can also be used for pressing the brush against the surface to be cleaned. 
     Head housing  7 , body housing  12 , and end cap  30  combine to form a housing  36 . Housing  36  has a substantially cylindrical configuration with a length extending between proximal end  32  and end cap  30  that is typically in a range between about 15 cm to about 35 cm with about 20 cm to about 30 cm being more common. Other dimensions can also be used. In alternative embodiments housing  36  can have a variety of other configurations. Although housing  36  may not be completely symmetrical along its entire length, housing  36  has a substantially central longitudinal axis  38  extending therethrough. 
     As depicted in  FIG. 5 , body housing  12  bounds a battery compartment  40 , a motor compartment  42 , and a shaft compartment  43 . A partition  44  is formed between compartment  40  and  42  while a partition  46  is formed between compartment  42  and  43 . Battery compartment  40  is accessed through an opening  48  formed at proximal end  26  of body housing  12 . Opening  48  is selectively closed by end cap  30 . An annular seal ring  50  forms a liquid tight seal between body housing  12  and end cap  30 . 
     As depicted in  FIGS. 5 and 6 , cleaning apparatus  4  further includes a motor assembly  58 . Motor assembly  58  comprises a motor  60  having a proximal end  62  and an opposing distal end  64  that is mounted within motor compartment  42 . Projecting from distal end  64  of motor  60  into shaft compartment  43  is a drive shaft  66  terminating at a first coupling  68 . First coupling  68  terminates at an end face  70 . End face  70  comprises a pair of sloping surfaces  72  that are connected by stepped shoulders  74 . An annular shaft seal  76  encircles first coupling  68  and forms a liquid tight seal between first coupling  68  and body housing  12 . 
     Battery compartment  40  is configured to receive a plurality of batteries. For example, in the embodiment battery compartment  40  is configured to receive four batteries  78  of a size AA. Other sizes and numbers of batteries can also be used in alternative embodiments. The positive end of batteries  78  bias against a first contact plate  80  which is in electrical communication with motor  60 . The negative end of batteries  78  bias against a second contact plate  82  which is mounted within end cap  30 . 
     An elongated switch  88  has a first end  90  which is in electrical communication with second contact plate  82  when end cap  30  is mounted to body housing  12 . Switch  88  comprises an elongated base  92  which extends along battery compartment  40 , a riser  94  which extends along partition  44 , and a flexible lever arm  96  which projects so as to be disposed between button  23  and motor  60 . When button  23  is manually depressed, lever  96  is biased against motor  60 , thereby closing the circuit which is energized by batteries  78 . In turn, as the circuit is closed, the energy from batteries  78  causes motor  60  to rotatably drive drive shaft  66 . As button  23  is released, the circuit is broken and motor  60  is turned off. In alternative embodiments, it is appreciated that a variety of different switching mechanisms can be used so that motor  60  can be continually activated without having to continually manually depress button  23 . Furthermore, it is appreciated that batteries  78  can be replaced with an electrical cord. 
     With further reference to  FIGS. 5 and 6 , head assembly  6  further comprises a drive shaft  100 . As depicted in  FIG. 8 , drive shaft  100  comprises an elongated shaft  102  having a proximal end  104  and an opposing distal end  106 . Distal end  106  terminates at a distal end face  108 . Radially encircling and outwardly projecting from shaft  102  at distal end  106  is an annular flange  109 . A bearing or bushing  162  ( FIG. 7 ) is mounted on shaft  102  so as to bias against flange  109 . Mounted at proximal end  104  of shaft  102  is a second coupling  110  having an end face  112  that is complementary to end face  70  of first coupling  68 . That is, second coupling  110  is configured to mesh with first coupling  68  so that stepped shoulders  74  bias against one another. As a result, rotation of drive shaft  66  by motor  60  is transferred through couplings  68  and  110  to cause rotation of shaft  102 . 
     Extending from end face  108  at distal end  106  of shaft  102  is a stem  114 . Mounted on the end of stem  114  is a rounded head  116 . In the embodiment depicted, head  116  is spherical or substantially spherical. Here it is noted, as will be discussed below in greater detail, shaft  102  has a rotational axis and central longitudinal axis  118 , which in the depicted embodiment are the same, and stem  114  has a central longitudinal axis  120 . Stem  114  is eccentrically mounted on end face  108  of shaft  102  so that central longitudinal axis  120  of stem  114  is offset from central longitudinal axis  118  of shaft  102 . Rotational axis  118  can also be the same axis as the rotational axis and central longitudinal axis of drive shaft  66  and can also be the same as central longitudinal axis  38  of housing  36  ( FIG. 1 ). 
     Returning to  FIG. 5 , brush head  14  comprises annular carrier plate  122 , as previously discussed, having top surface  124 . Projecting from top surface  124  is a spindle  126 . Spindle  126  comprises a central axle  128  having an arm  130  projecting from each side thereof. A rotational axis  127 , about which brush  16  and brush head  14  rotate, extends through spindle  126 . Rotational axis  127  can also be the central axis for brush  16  and brush head  14 . Mounted on spindle  126  is a hub  132 . As depicted in  FIG. 9A , hub  132  has opposing side surfaces  136  and  138  which extend between a top surface  140  and an opposing bottom surface  142 . Hub  132  also includes a front face  144  and an opposing back face  146 . A passage  148  extends from top surface  140  to bottom surface  142 . A side channel  150  extends through side surfaces  136  and  138  adjacent to bottom surface  142  so as to intersect with passage  148 . 
     During assembly, hub  132  is received over spindle  126  so that axle  128  extends through passage  148  and arms  130  are received within side channel  150 . A bearing or bushing  151  ( FIG. 5 ) is mounted on axle  128  at top surface  140  of hub  132 . In this configuration, hub  132  is engaged with spindle  126  such that rotation of hub  132  facilitates rotation of spindle  126  and thus the remainder of brush head  14 . In alternative embodiment, it is appreciated that hub  132  can be integrally formed with brush head  14 . 
     Hub  132  further comprises a channel  152  formed on front face  144  and extending to top surface  140 . Channel  152  is vertically aligned with passage  148  and is bounded by a first engagement surface  156 , a spaced apart second engagement surface  158 , and an inside face  159  extending therebetween. Engagement surfaces  156  and  158  are opposingly facing and are in substantially parallel alignment. Recessed along each engagement surface  156  and  158  is a locking channel  160 . Each locking channel  160  is elongated and is slightly arched along the length thereof. The distance between engagement surfaces  156  and  158  of hub  132  is smaller than the diameter of rounded head  116 . 
     As depicted in  FIGS. 7 and 10 , however, hub  132  is configured so that head  116  can be snap-fit between engagement surfaces  156  and  158  so that head  116  is resiliently captured within locking channels  160  formed on engagement surfaces  156  and  158 . In this configuration, head  116  is resiliently biased between faces  156  and  158 . 
     In an alternative embodiment depicted in  FIG. 9B , locking channels  160  can be eliminated so that engagement surfaces  156  and  158  are substantially flat. In this embodiment, head  116  can be sized to snugly or loosely fit between engagement surfaces  156  and  158 . 
     Returning to  FIG. 5 , head housing  7  is enclosed over drive shaft  100  and hub  132  so that head housing  7  rides against bearings  151  and  162 . Bayonet slots  164  are formed on distal end  28  of body housing  12  while bayonet prongs  166  project from proximal end  32  of head housing  7 . As such, head assembly  6  can be removably connected to body assembly  5  using the bayonet connection ( FIG. 1 ). 
     In the above assembled configuration, couplings  68  and  110  are mated. Accordingly, as button  23  is depressed, motor  60  is energized causing drive shaft  66  and drive shaft  100  to each rotate about their rotational or central longitudinal axis. In turn, because stem  114  and rounded head  116  are mounted eccentrically on shaft  102 , head  116  rotates in a circle. That is, as shaft  102  spins or rotates, head  116  begins to rotate in an enlarged circle so as to bias against engagement surface  158  of hub  132  causing hub  132  with connected brush head  14  and brush  16  to rotate in a first direction about axle  128 . The length and arch of locking channels  160  allows for free rotation of head  116  within locking channels  160 . 
     Once head  116  has moved to its furthest extent in one direction, head  116  then begins to bias against the opposing engagement surface  156  causing hub  132 , with connected brush head  14  and brush  16 , to rotate in the opposing direction about axle  128 . As such, rapid rotation of drive shaft  100  with head  116  causes hub  132  with connected brush head  14  and brush  16  to rapidly reciprocate. By securing head  116  within locking channels  160 , a snug engagement can be formed between hub  132  and head  116 . This snug fit optimizes the transfer of movement between drive shaft  100  and hub  132 . That is, the snug fit eliminates slop between hub  132  and drive shaft  100  even after head  116  has begun to wear within locking channels  160 . 
     Once cleaning apparatus  4  is energized, brush  16  can be biased against a surface for cleaning. It is noted that brush  16  is positioned at an orientation relative housing  36  so as to optimize convenience and use. For example, with reference to  FIG. 6 , in one embodiment brush  16  projects relative to the central longitudinal axis of body assembly  5  or head assembly  6  so as to form a set inside angle θ therewith typically in a range between about 90° to about 180° with about 110° to about 140° being more common. Other angles can also be used. Expressed in other terms, rotational axis  127  of brush head  14  or brush  16  intersects with rotational axis  38  of the drive shaft or of central longitudinal axis  118  of housing  36  so as to form the set inside angle θ as discussed above. By having the angle θ at about 110° to about 140° , the user is able to more conveniently place and use brush  16  while holding onto housing  36 . 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. For example, it is appreciated that locking channels  160  need not merely be recessed within inner side walls  156  and  158  but can completely extend through hub  132 . Furthermore, it is not necessary that head  116  be spherical. In alternative embodiments, it is appreciated that head  116  can be elliptical or have a variety of other configurations that mate with complementary locking channels. 
     Depicted in  FIG. 11  is an alternative embodiment of a cleaning apparatus  200  incorporating features of the present invention. Like elements between cleaning apparatus  4  and  200  are identified by like reference characters. Cleaning apparatus comprises a head assembly  202  and a body assembly  204 . Turning to  FIG. 12A , body assembly  204  comprises a body housing  206  which is molded as a tubular member. Body housing  206  comprises a handle portion  208  having a proximal end  210  and an opposing distal end  212 . Distal end  212  terminates at and end face  214  from which a tapered, tubular stem  216  projects. A pair of opposing bayonet slots  217  are formed along stem  216 . Handle portion  208  and stem  216  are typically comprised of a substantially rigid plastic such as ABS. An overlay  218 , comprised of a softer, flexible plastic such as TPE or rubber, is molded over a section of handle portion  208 . Overlay  218  allows improved gripping of cleaning apparatus  200 . 
     Body housing  206  has an interior surface  220  which bounds a chamber  222 . Turning to  FIG. 12B , secured within chamber  222  is a guide  224 . Guide  224  comprises an elongated partition wall  226  having a proximal end  228  and an opposing distal end  230 . The sides of partition wall  226  are curved so that batteries  78  can be complementary received on each side thereof. A cantilevered latch  232  is formed at proximal end  228  at both the top and bottom of partition wall  226 . Each latch  232  terminates at a barb  234 . A spring  236  is positioned between partition wall  226  and each latch  232  so that each latch  232  can be selectively compressed toward partition wall  226  and, when released, each latch  232  resiliently rebounds. As depicted in  FIG. 13 , holes  235  are formed through each side of handle portion  208  at proximal end  210 . An engaging portion  238  of overlay  218  is molded over holes  235 . Guide  224  is positioned within chamber  222  so that each latch  232  is aligned with a corresponding hole  235 . A user is thus able to manually press inward on the flexible engaging portions  238  of overlay  218  so as to selectively inwardly press latches  232 . 
     Latches  232  are used for securing an end cap  240  to proximal end  210  of body housing  206 . Specifically, end cap  210  has an interior surface  242  with a pair of opposing catches  244  formed thereon. When end cap  240  is pushed onto proximal end  210  of body housing  206 , barbs  234  on latches  232  engage catches  244  so as to securely lock end cap  240  on body housing  206 . To remove end cap  240 , engaging portions  238  are manually depressed as discussed above so as to inwardly flex latches  232  and thus release barbs  234  from catches  244 . 
     Returning to  FIG. 12B , cupped support  246  is formed at distal end  230  of partition wall  226  and is used to support motor  60 . Motor  60  rotates an initial shaft  250  which in turn rotates a drive shaft  254 . Drive shaft  254  has a head  255  formed at a distal end thereof. Head  255  typically has a non-circular transverse cross section such that it can engage with a coupler as discussed below in greater detail. In the embodiment depicted, head  255  comprises a flattened portion of drive shaft  254 . In alternative embodiments, head  255  can have any number of different polygonal or non-circular transverse cross sections. 
     A conventional gear assembly  252  extends between initial shaft  250  and drive shaft  254  so that the torque produced by drive shaft  254  is adjusted relative to the torque produced by initial shaft  250  by a ratio in a range between about 1.5:1 to about 3.5:1. Increasing the torque capacity of drive shaft  254  enables brush  16  to continue to reciprocate or rotate even when substantial bearing force is applied to brush  16  while scrubbing. This is contrary to many conventional electric toothbrushes where it is desired that the brush stop moving or significantly slow when too much force is applied so that the toothbrush does not damage the gums. 
     It is appreciated that there are a variety of different mechanism that can be used to transfer electricity from batteries  78  to motor  60 . In the illustrated embodiment, the four batteries  78  are disposed in parallel. The negative end of the back two batteries  78  bias against a corresponding spring  256  which are each in electrical communication with a transfer spring  258 . The springs are mounted on a plate  255  which is secured within end cap  240 . Transfer spring  258  biases against a contact  260 . An electrical lead  262  extends from contact  260  to motor  60 . The positive end of the front two batteries  78  bias against a corresponding contact  264  which are each in electrical communication with a flexible switch  266 . Switch  266  is positioned above motor  60  such that when switch  266  is biased against motor  60 , the circuit is complete and motor  60  is energized. 
     In an alternative embodiment, batteries  78  can be positioned in series rather then parallel. In this embodiment, springs  256  are in electrical communication with each other but transfer spring  258 , contact  260 , and lead  262  are eliminated. Likewise, the two contacts  264  are separated from each other. One of contacts  264  is in direct electrical communication with motor  60  while the other contact  264  remains connected with switch  266 . Placing batteries  78  in series increases the voltage to provide more power to the motor. 
     Turning to  FIG. 12A , an opening  270  is formed on a top surface body housing  206  so as to communicate with chamber  222 . Opening  270  is aligned with motor  60  and switch  266 . Secured within opening  270  is a flexible diaphragm  272 . Diaphragm  272  has a top surface  274  and an opposing bottom surface  276 . A projection  278  is formed on top surface  274 . A cover plate  280  has an elongated hole  282  extending therethrough and is secured over opening  270  so that hole  282  is aligned with projection  278 . A button  284  is slidably mounted to cover plate  280  by a catch  286  and a retainer  288 . 
     As depicted in  FIG. 14A , button  284  comprises a generally cup-shaped body  290  having an interior surface  292  with a stem  294  projecting therefrom. Button  284  is comprised of a resiliently flexible material which is typically a natural or synthetic rubber. Retainer  288  comprises a substantially circular frame  296  having an opening  298  extending therethrough. Opening  298  is at least partially bounded by a lip  300 . Retainer  288  is comprised of a substantially rigid material or at least a material that is more rigid than the material used for button  284 . Button  284  is secured to retainer  288  so that stem  294  passes through opening  298 . In one embodiment, button  284  is secured to retainer  288  by being molded directly onto retainer  288  during the formation of button  284 , i.e., overlay molding process. 
     Catch  286  ( FIG. 14B ) comprises a base  302  having an opening  304  extending therethrough. A pair of barbed prongs  306  upwardly project from a top surface of base  302  on opposing sides of opening  304 . Catch  286  is used to secure button  284  on cover plate  280 . Specifically, button  284  and retainer  288  are positioned on the top surface of cover plate  280  so that stem  294  is aligned with opening  282  of cover plate  280 . Prongs  306  of catch  286  are then pushed up through opening  282  of cover plate  280  from the bottom surface thereof so that prongs engage with lip  300  of retainer  288  by a snap fit connection. 
     In this assembled configuration, button  284  can selectively side on cover plate  280  between an off position as shown in  FIG. 14A  and an on position as shown in  FIG. 14C . In the off position, projection  278  of diaphragm  272  is disposed between stem  294  of button  284  and switch  266  and is at least partially disposed within opening  304  of catch  286 . In this position, switch  266  is spaced apart from motor  60  so that no electrical contact is made. From the off position, there are two ways in which a user can energize motor  60 . In one approach, as depicted in  FIG. 14B , a user can simply press down on the center of button  284 . In so doing, stem  294  is pressed down against projection  278  which in turn pushes down switch  266  so that switch  266  contacts motor  60 , thereby energizing motor  60 . When the user releases button  284 , button  284  resiliently returns to the off position. 
     In the second approach as depicted in  FIG. 14C , the user manually slides button  284  along cover plate  280 . In so doing, base  302  of catch  286  rides over projection  278  which pushes projection  278  downward again causing switch  266  to contact motor  60 , thereby energizing motor  60 . Motor  60  remains energized until button  284  is again moved back to the off position. The button assembly thus enables a single, integral button to activate the motor in two different modes of operation. 
     Returning to  FIG. 12A , head assembly  202  comprises a head housing  201  which includes upper head housing  22  and lower head housing  24  each having proximal end  32  and opposing distal end  34 . Head housing  201  bounds a channel  316  extending along the length thereof which is at least partially divided by complementary partition walls  317  formed on housing  22  and  24 . Secured between housing  22  and  24  at proximal end  32  is an engagement ring  312 . Engagement ring  312  has opposing bayonet prong  318  formed on an interior surface thereof. Head assembly  202  is removably secured to body assembly  204  by inserting stem  216  of body housing  206  within proximal end  32  of head assembly  202  so that bayonet prongs  318  are received within bayonet slots  217  and then rotating head assembly  202  relative to body assembly  204 . 
     Head assembly  202  comprises a drive shaft  320  having a proximal end  322  and an opposing distal end  324 . Proximal end  322  has a coupler  326  secured thereto. Coupler  326  has a socket  328  formed on the free end thereof that is designed to removably engage with head  255  on drive shaft  254  extending from motor  60 . Specifically, socket  328  has a configuration complementary to head  255  such that when head  255  is received within socket  328 , rotation of drive shaft  254  causes rotation of drive shaft  320 . Head  255  is removably received within socket  328  when head assembly  202  is removably coupled with body assembly  204  as discussed above. 
     An enlarged disk  330  is secured to distal end  324  of drive shaft  320 . In the embodiment depicted, disk  330  has a substantially cylindrical configuration that includes a proximal end face  332  and an opposing distal end face  334 . Distal end  324  of drive shaft  320  is centrally secured to proximal end face  332 . In contrast, stem  114  and rounded head  116  are mounted on distal end face  334  at a location spaced radially outward from the rotational axis of drive shaft  320 . That is, stem  114  is eccentrically mounted on end face  334  in the same manner as discussed above with regard to cleaning apparatus  4 . 
     It is noted that centrally positioning enlarged disk  330  at the end of drive shaft  320  helps to stabilize drive shaft  320  during the rotation of eccentrically mounted rounded head  116 . In alternative embodiments, however, drive shaft  320  can have the same diameter as disk  330  or disk  330  can be eliminated and an arm formed between drive shaft  330  and stem  114 . Other conventional techniques can also be used to eccentrically position rounded head  116 . A cylindrical bushing  336  encircles drive shaft  320  toward distal end  324  and is supported within supports  338  formed on the interior surface of head housing  201 . 
     As with cleaning apparatus  4 , cleaning apparatus  200  includes brush head  14 . Brush head  14  comprises carrier plate  122  having bottom surface  125  with brush  16  comprised of bristles formed thereon. Plate  122  also has top surface  124  with spindle  126  and arms  130  projecting therefrom. Axle  128  centrally projects from spindle  126  and has a rotational axis extending therethrough. A tubular bushing  340  is secured to upper head housing  22  and encircles axle  128  ( FIG. 13 ). Axle  128  and spindle  126  are received within a hub  342  with a wear plate  341  positioned between bushing  340  and spindle  126 . 
     As depicted in  FIG. 15 , hub  342  comprises a substantially cylindrical base  344  having a front face  346 , a back face  348 , and opposing side faces  350  and  351  which each extend between a top surface  352  and an opposing bottom surface  354 . A passage  356  centrally extends through base  344  from top surface  352  to bottom surface  354 . A side channel  358  extends through side surfaces  350  and  351  adjacent to bottom surface  354  so as to intersect with passage  356 . Side channel  358  is configured so that when spindle  126  is received within passage  356 , arms  130  are received within side channel  358  so that hub  342  is interlocked with brush head  14 . Wear plate  341  also has tabs projecting from the side thereof which are received within side channel  358  of hub  342  so that wear plate  341  is secured to hub  342 . In one embodiment where bushing  340  is metal and spindle  126  is plastic, wear plate  341  prevents bushing  340  from producing undue wear on spindle  126 . 
     Projecting from back face  348  of base  344  is a guide  360 . Guide  360  comprises a first side wall  362 , a complementary spaced apart second side wall  364 , and a back wall  366  extending therebetween. Guide  360  partially bounds a channel  368  that is vertically aligned with passage  356 . Channel  368  is bounded by a first engagement surface  370 , a spaced apart second engagement surface  372 , and an inside face  374  extending therebetween. Engagement surfaces  370  and  372  are opposingly facing, are substantially flat, and are in substantially parallel alignment. The distance between engagement surfaces  370  and  372  of hub  342  is substantially equal to the diameter of rounded head  116 . 
     Comparable to the embodiment depicted in  FIG. 10  and as illustrated in  FIG. 13 , rounded head  116  is received within channel  368 . As rounded head  116  is continuously rotated about the rotational axis of drive shaft  320  due to the rotation of drive shaft  254 , rounded head  116  alternatingly pushes against opposing engagement surfaces  370  and  372  so as to cause hub  342 , brush head  14 , and brush  16  to reciprocate in a rotational pattern about the rotation axis extending through spindle  126 . 
     As with cleaning apparatus  4 , in cleaning apparatus  200  the rotational axis of drive shaft  320  intersects with the rotational axis of brush head  14  so as to form an inside angle θ that is typically greater than 95° and is more commonly in a range between about 110° to about 140° . As rounded head  116  travels in its circular pattern, rounded head  116  travels longitudinally along the length of side walls  362  and  364 . Because of the above discussed angular orientation of brush head  14 , rounded head  116  is disposed farther away from the rotational axis of brush head  14  when rounded head  116  is disposed at the bottom of side walls  362  and  364  and is closer to the rotational axis of brush head  14  when rounded head  116  is disposed at the top of side walls  362  and  364 . Accordingly, to ensure that rounded head  116  is retained within channel  368  during its circular movement, side walls  362  and  364  are wider at the bottom than at the top. 
     In one embodiment rounded head  116  has a substantially spherical configuration. This design has a number of benefits. For example, in part because of the above discussed angular orientation of brush head  14 , rounded head  116  contacts engagement surfaces  370  and  372  along a number of different points on rounded head  116  that are longitudinally spaced proximal to distal and top to bottom. By making rounded head  116  spherical, this helps to ensure continued minimal contact between rounded head  116  and engagement surfaces  370  and  372  so as to minimize wear. 
     Furthermore, due to tolerances in mounting brush head  14 , on occasion as brush  16  is biased against a surface for cleaning, brush head  14  will tilt slightly causing the distal end of rounded head  116  to bias against inside face  374  of hub  342  ( FIG. 15 ). This contact between rounded head  116  and inside face  374  helps to stabilize and reinforce brush head  14 . By making rounded head  116  spherical, the contact surface between rounded head  116  and inside face  374  is minimized. It is also noted that both of side walls  362  and  364  terminate at an outside edge  376 . These outside edges  376  are designed so that they can bias against distal end face  334  of disk  330  as brush head  14  is tilted during use so as to also help stabilize and reinforce brush head  14 . 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.