Abstract:
An autonomous cleaning appliance including a housing, a dirt container disposed in the housing, a brushroll disposed in the housing and configured to move dirt into the dirt container, a brush motor disposed in the housing for driving the brushroll, and a power drive assembly mounted in the housing for propelling the appliance. The power drive assembly including a first drive assembly disposed on a first side of the housing, a first drive motor operatively connected to the first drive assembly, a second drive assembly disposed on a second side of the housing (the second side being opposite the first side), and a second drive motor operatively connected to the second drive assembly. A floor sensor system is coupled to the housing for detecting a loss of floor condition and an off edge condition.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation application of U.S. application Ser. No. 12/856,238, filed on Aug. 13, 2010, which is a continuation application of U.S. application Ser. No. 12/174,283, filed on Jul. 16, 2008, which is a divisional application of U.S. application Ser. No. 10/967,551, filed Oct. 18, 2004, which claims the benefit of U.S. Provisional Patent Application No. 60/559,186, filed Apr. 2, 2004, the contents of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    Cleaning appliances having a powered drive mechanism are known. For example, many vacuum cleaners include motors to propel the vacuum cleaner across a surface to be cleaned. Some of these vacuum cleaners include a handle to allow a user to maneuver the vacuum cleaner. Other vacuum cleaners are autonomously propelled. Autonomous vacuum cleaners receive directions via a remote signal or they can be programmed to move across a floor. 
         [0003]    In addition to automatically propelled vacuum cleaners, sweepers having a powered brushroll are also known. Typically, a motor drives the brushroll. The brushroll rotates and contacts dirt and other debris to propel it into a dust cup located adjacent the brushroll. 
       SUMMARY 
       [0004]    In one embodiment, the invention provides an autonomous cleaning appliance having a housing, a dirt container disposed in the housing, a brushroll disposed in the housing and configured to move dirt into the dirt container, a brush motor disposed in the housing for driving the brushroll, and a power drive assembly mounted in the housing for propelling the appliance. The power drive assembly includes a first drive assembly disposed on a first side of the housing, a first drive motor operatively connected to the first drive assembly, a second drive assembly disposed on a second side of the housing (the second side being opposite the first side), and a second drive motor operatively connected to the second drive assembly. A floor sensor system is coupled to the housing for detecting a loss of floor condition and an off edge condition. 
         [0005]    In another embodiment, the invention provides an autonomous cleaning appliance having a housing, a dirt container disposed in the housing, and a power drive assembly mounted in the housing for propelling the appliance. The power drive assembly includes a first drive assembly disposed on a first side of the housing, a first drive motor operatively connected to the first drive assembly, a second drive assembly disposed on a second side of the housing (the second side being opposite the first side), and a second drive motor operatively connected to the second drive assembly. An infrared floor sensor system is coupled to the housing and includes an emitter and a corresponding detector. 
         [0006]    In yet another embodiment, the invention provides an autonomous cleaning appliance having a housing, a dirt container disposed in the housing, a brushroll disposed in the housing and configured to move dirt into the dirt container, a brush motor disposed in the housing for driving the brushroll, and a power drive assembly mounted in the housing for propelling the appliance. The power drive assembly includes a first drive assembly disposed on a first side of the housing, a first drive motor operatively connected to the first drive assembly, a second drive assembly disposed on a second side of the housing (the second side being opposite the first side), and a second drive motor operatively connected to the second drive assembly. An infrared floor sensor system assembly is coupled to the housing and includes a first sensor, a second sensor, a third sensor, and a fourth sensor. Each sensor includes an emitter and a corresponding detector. The first sensor, the second sensor, the third sensor, and the fourth sensor are positioned such that when one of the first sensor, the second sensor, the third sensor, or the fourth sensor detects a loss of floor condition or an off edge condition, the infrared floor sensor system delivers a signal to the power drive assembly to stop propulsion of the appliance. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    A powered cleaning appliance can take form in certain components and structures, an embodiment of which will be illustrated in the accompanying drawings. 
           [0008]      FIG. 1  is a perspective view of a powered cleaning appliance according to an embodiment of the invention. 
           [0009]      FIG. 2  is a perspective view of the powered cleaning appliance of  FIG. 1  with a dirt cup removed from the appliance. 
           [0010]      FIG. 3  is an exploded view of the powered cleaning appliance of  FIG. 1 . 
           [0011]      FIG. 4  is a cross-sectional view of the powered cleaning appliance of  FIG. 6  taken at line  4 - 4  with the appliance oriented in its use position. 
           [0012]      FIG. 5  is another cross-sectional view of the powered cleaning appliance of  FIG. 6  taken at line  5 - 5  with the appliance oriented in its use position. 
           [0013]      FIG. 6  is a bottom plan view of the powered cleaning appliance of  FIG. 1 . 
           [0014]      FIG. 7  is a perspective view of a dirt cup for use with the powered cleaning appliance of  FIG. 1  with a door of the dirt cup open. 
           [0015]      FIG. 8  is a cross-sectional view of the powered cleaning appliance of  FIG. 6  taken at line  8 - 8  with the appliance oriented in its use position. 
           [0016]      FIG. 9  is a top view of a cover stop boss and a bumper stop boss depicted in  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    A powered appliance  10  includes a housing  12 , a removable dirt cup  14  located in the housing, a brushroll assembly located in housing, a drive assembly located in the housing, and a bumper  16  mounted to the housing. The appliance  10  will be described as an autonomous sweeper since in the depicted embodiment it does not include a suction source like that of a conventional vacuum cleaner. Alternative embodiments could include a suction source, such as a motor driven fan, that would direct airflow into the dirt cup  14 . Furthermore, the appliance  10  will be described as having no upright handle to allow a user of the appliance to direct the movement of the appliance, similar to a conventional upright vacuum cleaner. Nevertheless, if desired, a handle can easily be attached to the appliance for directing its movement. 
         [0018]    In the depicted embodiment, the housing  12  of the appliance  10  can be a generally circular plastic casing that encloses internal components of the appliance. With reference the  FIG. 3 , the housing includes a cover  18  that attaches to a base  22  in a manner that will be described below. The cover  18  includes a rectangular central opening  24  that is shaped to receive the dirt cup  14 . A handle  26  attaches to the cover  18  via fasteners  28  and handle clamps  32 . The handle  26  can be generally U-shaped and two clamps  32 , one at each end of the handle, can attach the cover  18  so that the handle  26  can pivot in relation to the cover  18 . The cover  18  also includes a plurality of openings  36  that can be tapered (more clearly visible in  FIG. 4 ) to facilitate attachment of the cover  18  to the base  22  as well as the housing  12  to the bumper  16 . 
         [0019]    The base  22  of the housing  12  can also be generally circular and include a central cavity  38  that is dimensioned to receive the dirt cup  14 . With reference to  FIG. 5 , the base  18  defines a first brushroll chamber  42  positioned on a first side of the central cavity  38  and a second brushroll chamber  44  positioned on an opposite side of the central cavity  38 . A first upwardly angled wall  46  extends from a base wall  48  of the base  18  towards the central cavity  38  and a downwardly angled wall  52  connects to the first wall  46  and the base wall  48 . Wall  46  is referred to as upwardly angled because dirt traveling into the dirt cup  14  moves upward in relation to the base wall  48  and through a dirt inlet  54  en route to the dirt cup. With respect to the second brushroll chamber  44 , an upwardly angled wall  56  extends from the base wall  48  and connects to a downwardly angled wall  58 . The second brushroll chamber  44  also communicates with an inlet opening  62  that communicates with the dirt cup  14 . As more clearly seen in  FIG. 6 , the base wall  48  of the base  18  also includes a large generally rectangular opening  64  between the brushroll chambers to receive a power source for the appliance  10 , which will be described in more detail below. A nozzle guard  66  can also attach to the base wall  48  via fasteners  68 . The nozzle guard  66  includes a central opening  70  aligned with the opening  64  in the base. 
         [0020]    As indicated above, in the embodiment disclosed, the dirt cup  14  is received through the central opening  24  of the cover  18  and in the central cavity  38  of the base  22 . With reference to  FIG. 3 , the dirt cup can include a generally W-shaped housing  72  to which both a dirt cup lid  74  and a dirt cup door  76  mount. The dirt cup lid  74  attaches to the top of the dirt cup housing  72  via conventional fasteners  78  ( FIG. 3 ), or other conventional manners. The dirt cup door  76  mounts to a side of the dirt cup housing  72  and allows for easy emptying of the dirt cup when it gets full. While a W-shaped housing is disclosed, it should be appreciated that the housing could instead by rectangular in cross-section if the power pack of the cleaning appliance were relocated. If this were done the dirt cup could hold more dirt before needing to be emptied. 
         [0021]    In the embodiment illustrated in  FIG. 5 , the dirt cup housing  72  includes an upwardly arched lower wall  82  to accommodate the power source, which will be described in more detail below. The dirt cup housing  72  also includes two inlet openings: a first inlet opening  84  that communicates with the first brushroll chamber  42  and a second inlet opening  86  that communicates with the second brushroll chamber  44 . With reference to  FIG. 5 , inside the dirt cup  14  a first shelf  88  extends inwardly from a lower edge of the first inlet  84  and second shelf  92  extends inwardly from the second inlet opening  86 . The shelves  88 ,  92  help retain the dirt inside of the dirt cup  14  and prevent the dirt from falling out of the inlet openings  84 ,  86  and back into the respective brushroll chamber. 
         [0022]    As most clearly seen in  FIG. 7 , the dirt cup door  76  hingedly attaches to the dirt cup housing  72  so that it can pivot between an open position and a closed position. A dirt cup handle  94  attaches to the dirt cup housing  72  and can pivot between a stored position ( FIG. 1 ) where the handle is positioned slightly below the dirt cup lid  74  in a recessed area and an extended position, shown in  FIG. 2 , to facilitate removal of the dirt cup  14  from the housing  12 . 
         [0023]    As mentioned, the dirt cup  14  can take alternative configurations. For example, in lieu of the door  76 , the dirt cup can include a removable dirt cup tray that can slide into the bottom of the dirt cup housing. The dirt cup tray can be removed when the user desires to empty the dirt cup. Other possible configurations include a hinged lid that can open so that the contents of the dirt cup can be dumped out from the top of the dirt cup. 
         [0024]    With reference back to the embodiments depicted in the figures, two brushroll assembles are provided to propel dust and dirt into the dirt cup  14 . With reference to  FIG. 3 , a first brushroll motor  102  drives a pinion  104  that engages a toothed belt  106 . The brushroll motor  102  rests in a compartment defined in the housing  12 , and more specifically in the base  22 . The brushroll belt  106  engages a toothed portion of a brushroll dowel  108  that has plurality of bristles  112  extending from it. The brushroll dowel  108  rotates about a brushroll shaft  114  that mounts to an end cap  116 . Also adjacent the end cap  116 , a brush bearing  118  mounts on the brushroll shaft  114 . The end cap  116  mounts inside the first brushroll chamber  42  ( FIG. 5 ) so that the brushroll dowel  108  can rotate within the brushroll chamber. Another end cap and brush bearing are disposed at an opposite end of the brushroll dowel  108  and for the sake of brevity will not be described in further detail. This other end cap also mounts in the first brushroll chamber  42 . The nozzle guard  66  sandwiches the end caps into the housing. 
         [0025]    A second brushroll assembly made up of a second brushroll motor  122 , a pinion  124  and a belt  126  is disposed on opposite side of the housing  12  and the dirt cup  14  as the similar components of the first brushroll assembly. The second brushroll motor  122  also rests in a compartment formed in the housing  12 . The belt  126  drives a second brushroll dowel  128  that is disposed on an opposite side of the dirt cup  14  from the first brushroll dowel  108 . The second brushroll dowel  128  is disposed in the second brushroll chamber  44  ( FIG. 5 ) in a manner similar to the first brushroll chamber  108  described above and therefore will not be described in further detail. Even though brushroll assemblies have been described as each having a pinion that drives a toothed belt, the brushroll motor can drive the brushroll through interengaging gears or another known transmission. 
         [0026]    Turning now to the manner in which the appliance moves across the floor, a drive assembly propels the appliance  10 . In the embodiment disclosed, a first drive motor  132  drives a drive sprocket  134  through a gear reduction transmission assembly  136  encased in a gear housing  138  and a gear housing cover  142 . In this embodiment, the first drive motor  132  is a reversible electric motor. The drive sprocket  134  engages and drives a toothed drive belt  144 , which drives a toothed first track pulley wheel  146 . In turn, the first track pulley wheel  146  drives a first belt tread  148  that surrounds the first track pulley wheel  146  and a second track pulley wheel  152  spaced from the first track pulley wheel. The first and second track pulley wheels  146  and  152  receive first and second drive pins  154  and  156 , respectively, that attach to the housing  12  so that the pulley wheels are attached to the housing. 
         [0027]    A second drive motor  162  drives a second belt tread  164  through components similar to the drive assembly described above. The second belt tread  164  surrounds a first track pulley wheel  166  and a second track pulley wheel  168 , both mounted to the housing  12 . The second belt tread  164  is disposed on an opposite side of the appliance  10  from the first drive tread  148  and can be driven independently thereof. Such a configuration allows for the appliance  10  to rotate about its central axis easily by driving one motor at one speed while driving the other motor at another speed or, perhaps, in the opposite direction. Because the appliance includes two separate drive assemblies, it can easily turn without the requirement of complicated differential gears and the like. In an alternative embodiment, the appliance  10  need not include the belt treads; instead the appliance could simply include one or more driven wheels that are driven through one or more suitable known transmissions. 
         [0028]    Both the drive assemblies and the brushroll assemblies are driven by a power source. A rechargeable battery type power source is disclosed in this embodiment; however, the power source can be any conventional power source including an AC power source from a wall outlet, a solar power source, or a disposable battery power source. As most clearly seen in  FIG. 5 , a battery pack assembly can fit into the space below the arch shaped lower wall  82  of the dirt cup housing  72 . With reference back to  FIG. 3 , an arch shaped battery pack housing  172  fits underneath the dirt cup housing  72 . A removable lower lid  174  selectively attaches to the battery pack housing  172  and a plurality of batteries  176  can fit into the battery pack housing  172 . Battery pack contacts  178  are provided to electrically connect the brushroll motors  104  and  122  and the drive motors  132  and  162  to the power source. Also, a charging jack  182  can be provided in electrical communication with the batteries  176  so that the batteries can be recharged. 
         [0029]    In the depicted embodiment, the battery pack assembly is centrally located in the base  22  of the housing. If batteries are the desired power source, as mentioned, they can be located elsewhere in the housing, especially if an increase in the size of the dirt cup  14  is desired. As just one example, a set of batteries can be located toward each belt tread  148  and  164  or toward each brushroll chamber  42  and  44 . The batteries could also be located elsewhere in the appliance, so long as they electrically connect to the brushroll assemblies and the drive assemblies. 
         [0030]    The bumper  16  is movably mounted to the housing  12 . In the depicted embodiment, the bumper  16  is a substantially circular shell that at least substantially surrounds the housing  12 . The bumper  16  includes a central opening  184  that allows the dirt cup  14  to be lifted away from the housing  12  without having to remove the bumper. Two bottom brackets  186  and  188  are provided to attach the bumper  16  to the housing  12 . Each bracket  186 ,  188  can be a generally rectangular plate having openings that receive fasteners to attach each bracket to the bumper. Fasteners  192  attach the first bottom bracket  186  to the bumper  16  and fasteners  194  attach the second bottom bracket  188  to the housing  16 . As more clearly seen in  FIG. 6 , the first bracket  186  fits into a recess  196  formed in the bottom wall  48  of the base  22  of the housing  12 . The recess  196  is generally rectangular in configuration, similar to that of the bracket  186 , and is slightly larger than the bracket  186  to allow for movement of the bracket in the recess. Similarly, the second bottom bracket  188  fits into a second recess  198  in the bottom wall  48 . The second recess  198  is similarly shaped to and on an opposite side of the appliance  10  from the first recess  196 . 
         [0031]    With reference to  FIG. 3 , a plurality of biasing members  202 , which in this embodiment are coil springs, attach the housing  12  to the bumper  16 . More specifically, the base  22  of the housing  12  includes a plurality of upwardly extending bosses  204  and the coil springs  202  receive the bosses such that the coil springs extend upwardly from the base  22 . The tapered openings  36  in the cover  18  of the housing  12  receive the upwardly extending bosses  204  of the base  22  and the springs  202  that are mounted on the bosses. The bumper  16  includes a plurality of downwardly depending bosses  206  that receive the springs  202  so that the bumper  16  is resiliently coupled to the housing  12 . In lieu of the coil springs other types of known resilient members, such as flexible plastic members, can be used to attach the bumper  16  to the housing  12 . 
         [0032]    Movement of the bumper  16  in relation to the housing  12  is limited. With reference to  FIG. 8 , an extension or a cover stop boss  208  extends upwardly from the cover  18  of the housing  12  towards the bumper  16 . A socket or bumper stop boss  210  extends downwardly from the bumper  16  and is received inside the cover stop boss  208 . With reference to  FIG. 9 , bumper stop boss  210  has a diameter slightly larger than the cover stop boss  208  and is aligned concentrically with the cover stop boss  208  when the bumper  16  has no lateral force applied to it. In an alternative embodiment, the cover stop boss could receive the bumper stop boss, such that the socket and the extension arrangement can be reversed. In one embodiment, the radial space between the cover stop boss  208  and the bumper stop boss  210  is less than ¼ of an inch. Accordingly, movement of the bumper  16  in relation to the housing  12  is less than ¼ of an inch in any direction since the cover stop boss  208  and the bumper stop boss  210  are in a concentric circular configuration. With reference to  FIG. 2 , a bumper supporting ring  212  can attach to a lower edge of the bumper  16 . 
         [0033]    Movement of appliance  10  can be controlled by sensing the movement of the bumper  16  in relation to the housing  12 . In one embodiment, a joystick sensor assembly is disclosed as the sensing device; however, other known motion sensors can be used. With reference to  FIG. 5 , a lever  214  mounts to a joystick sensor  216  which is an electrical communication with a main printed circuit board (PCB)  218  ( FIG. 3 ). The main PCB  218  can mount to the base  22  of the housing  12  and can be covered by a board cover  222  that attaches the housing  12 . Movement of the lever  214  on the joystick sensor  216  can result in a signal being sent from the sensor  216  to the main PCB  218 , which can be an electrical communication with the drive motors  132  and  162  to control the movement of the appliance  10 . Furthermore, a signal can also be sent, if desirable, to the brushroll motors  102  and  122  in response to movement of the lever  214  on the joystick sensor  216 . 
         [0034]    The bumper  16  includes a downwardly depending hollow cylindrical boss  224  that is dimensioned to receive the lever  214 . Movement of the bumper  16  results in movement of the boss  224  which results in movement of the lever  214 . An appropriate signal can be sent to the drive motors in response to movement of the lever. Examples of the types of signals that can be delivered by the sensor are further described in co-pending patent application entitled “Robotic Appliance with On-Board Joystick Sensor and Associated Methods of Operation” filed Sep. 21, 2004, which is incorporated herein by reference in its entirety. 
         [0035]    In alternative embodiments, the location of the sensor assembly can be moved. For example, the joystick and lever shown in  FIG. 5 , can be mounted to the bumper and a boss can extend upwardly from the housing so that movement of the bumper will still result in movement of the lever. The joystick sensor would move with the bumper resulting in the lever moving while the boss would remain relatively stationary. Additionally, other known sensors, such as switch sensors and the like could be mounted to the bumper and/or the housing. For example, movement of the bumper in relation to the housing could activate an on/off type sensor that could deliver an appropriate signal to the main PCB. 
         [0036]    Movement of the appliance  10  can also be controlled by floor sensor assemblies  226  that can deliver a signal to the drive motors  132  and  162  via the main PCB  218 . As seen in  FIG. 6 , four floor sensor assemblies  226  can be provided where one floor assembly is located forward the first belt tread  148  and one floor sensor assembly is located forward the second belt tread  164 . Also, one floor sensor assembly is located rearward the first belt tread  148 , and one floor sensor assembly is located rearward the second belt tread  164 . The floor sensor assemblies can include infrared sensors with an emitter and corresponding detector. The emitter can have a field of emission directed downward toward the floor at a location forward or rearward of the corresponding belt tread. The detector can have a field of view that can intersect the field of emission of the corresponding emitter so that off edge and loss of floor conditions can be detected before the robotic appliance, for example, becomes hung up in a depression or tumbles down a staircase. Of course, other types of known sensor assemblies could be used instead, is so desired. 
         [0037]    A plurality of switches can be provided to control power to the motors as well as the mode in which the appliance will work. With reference back to  FIG. 3 , a power button  232  can be provided to activate a push button power switch  234  to control power to the motors. The power switch  234  is an electrical communication with the batteries  176  and the main PCB  218 . A biasing member  236  can be provided to bias the power button  232  away from the power switch  234 . Additionally, a start button  238  can activate a first momentary switch  242 . The momentary switch  242  is in electrical communication with the power source  176  and the main PCB  218  to control power delivery to the drive motors  132  and  162 . The start button  238  is biased by a spring  244  away from the momentary switch  242 . Additionally, a mode button  246  can activate a second momentary switch  248  to control the mode in which the appliance works. Also, a biasing member  252  can be used to bias the mode button  246  away from the momentary switch  248 . The mode button  248  is in electrical communication with the main PCB  218  to control, for example, whether only one brushroll motor or two brushroll motors will be activated. Other modes of operation can also be programmed into the main PCB  218 . A plurality of indicator lights  254  can also be provided. The indicator lights  254  can also be in electrical communication with the batteries  176  and the main PCB  218 . The indicator lights  254  can light up to indicate different modes of operation. 
         [0038]    While the appliance has been described above with reference to certain embodiments, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art upon reading and understanding the preceding description. The above embodiments are intended to be illustrative, rather than limiting, of the spirit and scope of the invention. It is intended that the invention embrace all alternatives, modifications, and alteration that fall within the spirit and scope of the appended claims and the equivalents thereof.