Abstract:
An autonomously movable home cleaning robot that incorporates a sweeper and dust bin as well as a dusting assembly in tandem in the direction of movement of the robot.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/319,723, filed Nov. 22, 2002. 

   BACKGROUND OF INVENTION 
   A home cleaning robot comprising a platform in combination with a cleaning implement, for example a non-woven electrostatic cloth, and a motive force to autonomously move the platform is disclosed in U.S. Pat. No. 6,459,955 to Bartsch et al. The robot moves randomly about a surface while cleaning the surface with the cloth. U.S. Pat. No. 6,481,515 to Kirkpatrick et al. discloses a similar device with a surface treating sheet and also includes a chamber for storing fluid that is applied to the surface through the surface treating sheet. Another robotic floor cleaner disclosed in U.S. Patent Application Publication No. 2002/0002751 to Fisher utilizes disposable cleaning sheets, such as dust cloths, retained by several sheet holder receptacles on a compliant pad. The robotic floor cleaner further comprises an appendage that can have several functions, including a sheet holder or a fluid dispenser. U.S. Pat. No. 6,633,150 to Wallach et al. discloses a mobile robot that mops a surface by pressing a damp towel, which is mounted to the body of the robot, against the ground as the robot moves back and forth. One limitation of these types of robot cleaners is that large debris is pushed in front of the robot without being picked up. Another limitation is that the large debris tends to clog or bind the cloth, thus reducing the useful life of the cloth. 
   Some automatic robots that vacuum or sweep floors and other surfaces are capable of removing large debris. For example, an automatic robotic vacuum cleaner integrating a drive system, a sensing systems, and a control system with a microprocessor is disclosed in U.S. Patent Application Publication No. 2003/0060928. Examples of commercially available robotic vacuum cleaners include the Roomba vacuum cleaner from iRobot, the Karcher Robo-Vac vacuum cleaner, the Robo Vac vacuum cleaner from Eureka, the Electrolux Trilobite vacuum cleaner, and the LG Electronics Robot King vacuum cleaner. The aforementioned U.S. Pat. No. 6,633,150 to Wallach et al. further discloses a mobile robot vehicle with a motor-driven brush that sweeps debris from the floor and into a dustpan positioned close to the brush as the vehicle moves forward and backward. Additionally, U.S. Pat. No. 6,594,844 to Jones discloses an obstacle detection system for a robot configured to dust, mop, vacuum, and/or sweep a surface such as a floor. U.S. Pat. No. 5,815,880 to Nakanishi and U.S. Pat. No. 5,959,423 to Nakanishi et al. disclose similar mobile work robots that comprise a dust collecting unit for vacuuming or suctioning dust from the floor and a wiping unit for spreading fluid, such as detergent, disinfectant, or wax, onto the floor and wiping the floor. Furthermore, a wireless mobile vehicle described in U.S. Pat. No. 5,995,884 to Allen et al. comprises a vacuum system that can be adapted to make the vehicle suitable for a damp-mopping function by including a rotating mop head and reservoirs for clean and dirty water. 
   SUMMARY OF INVENTION 
   According to the invention, an autonomously movable home cleaning robot comprises a base housing; a drive system mounted to the base housing whereby the drive system is adapted to autonomously move the base housing on a substantially horizontal surface having boundaries; a computer processing unit associated with the base housing for storing, receiving and transmitting data; a rotary driven brush mounted for rotation in a sweeper aperture for removing debris particles from the surface; a dust bin in communication with the sweeper aperture for receiving the debris particles removed from the surface; a power source connected to the drive system and computer processing unit whereby the computer processing unit controls horizontal movement of the base housing based upon input data defining said boundaries and a dusting assembly mounted to an underside of the base housing for removing dust from the surface to be cleaned. 
   In a preferred embodiment, the cleaning robot comprises a dusting cloth removably mounted to a dusting pad that is moveable away from the base housing for service of the dusting cloth. In another embodiment, the dusting pad is removably mounted to the base housing. In yet another embodiment, the dusting pad is hinged to the base housing for selectively pivoting the dusting pad between a first, opened position away from the underside of the base housing for removal and mounting of the dusting cloth to the dusting pad and a second, closed position in an operative position with the base housing. In yet another embodiment, the dusting pad comprises at least one dusting cloth engagement member mounted to an upper surface of the dusting pad for retaining a first portion of the dusting cloth. In still another embodiment, the pad is a resilient pad. 
   In a preferred embodiment, the cleaning robot comprises a dust bin that is removably mounted to the base housing. In one embodiment, the dust bin is removable from the bottom of the base housing. In another embodiment, the dust bin is removed from the top of the base housing. The sweeper assembly is typically mounted to the base housing forwardly, i.e., in the direction of movement of the base housing, of the dusting assembly. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     In the drawings: 
       FIG. 1  is a perspective view of the robotic sweeper cleaner with dusting pad according to the invention. 
       FIG. 2  is a perspective bottom view of the robotic sweeper cleaner with dusting pad in the operating position as shown in  FIG. 1 . 
       FIG. 3  is an exploded view of the robotic extraction sweeper with dusting pad shown in  FIG. 1 . 
       FIG. 4  is a partial cross-sectional side view of the base housing taken across line  4 - 4  of  FIG. 1 . 
       FIG. 5  is a schematic block diagram of the robotic sweeper cleaner with dusting pad as shown in  FIG. 1 . 
       FIG. 6  is a plan view of the robotic sweeper cleaner with dusting pad as shown in  FIG. 1 . 
       FIG. 7  is a perspective bottom view of the robotic sweeper cleaner with dusting pad in open position as shown in  FIG. 1 . 
       FIG. 8  is a perspective bottom view of the dusting pad of the robotic sweeper cleaner with dusting pad as shown in  FIG. 1 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1-3 , a robotic sweeper cleaner with dusting pad  10  is described and comprises robotic platform further comprising a top enclosure  12  and a base housing  14 . The base housing  14  provides the basic structure for the robotic platform on which all other components depend for structural support. A plurality of proximity sensors  24 ,  26  are located within corresponding sensor apertures  22  around the outer periphery of the top enclosure  12 . The proximity sensors  24 ,  26  comprise any one or combination of commonly known sensors including infrared sensors  24 , pressure sensitive sensors  26 , or ultrasonic sensors affixed to the top enclosure  12  in alternating or parallel fashion. Alternating the arrangement of proximity sensors  24 ,  26  provides redundancy and allows for improved motion control of the robotic platform as it encounters obstacles within the room being cleaned. An electrical power switch  28  is located on a top surface of the top enclosure  12  and controls the flow of power from one or more batteries  44  to a logic board  46 , both mounted to the base housing  14  within a cavity formed by the top enclosure  12 . 
   Alternatively, or in combination with the proximity sensors  24 ,  26 , a predetermined path is programmed in to the central processing unit by the user. In yet another embodiment, the path is dictated to the central processing unit via a remote control device. 
   Referring to  FIGS. 2 and 3 , a drive system comprises a pair of drive wheels  30  protrude through corresponding drive wheel apertures  32  which are located in spaced relation near the outer perimeter of the base  14 . A brush roll  34  protrudes through a corresponding sweeper aperture  36  forming a forward portion of the base  14 . A dusting pad  40  is attached to a bottom surface of the base  14  behind and in spaced relation to the brush roll  34  and the drive wheels  30 . The dusting pad  40  is preferably hinged to a bottom surface of the base  14 , however other commonly known fastening methods such as detents, latches, screws, snaps or hook and loop fasteners can also be used to secure the dusting pad  40  to the base  14 . The dusting pad  40  and brush roll  34  are positioned in a generally parallel fashion with respect to the drive wheels  30 . A removable dusting cloth  42  wraps around, and is held by, the dusting pad  40  as will be described further herein. The dusting assembly is disclosed in more detail in commonly owned U.S. patent application Ser. No. 10/248,101, filed Dec. 18, 2002, which disclosure is incorporated herein by reference. 
   Referring again to  FIG. 3 , a power source comprising a plurality of batteries  44 , which may be any commonly known battery source including alkaline, rechargeable nickel-cadmium, NiMH, or LiMH are located on base assembly  14 . When rechargeable batteries are used, a commonly known recharging circuit is used to transform available facility voltage to a level usable for the batteries  44 . A charging plug connected to the transformer is manually or automatically attached to a corresponding jack connected to the batteries thereby completing the circuit and allowing the batteries to charge. A commonly known computer processing unit further comprising a logic board  46  is located between the base  14  and the top enclosure  12 . The logic board  46  comprises a commonly known printed circuit board upon which commonly known computer processing and electronic components are mounted configured in a manner similar to that described by U.S. Pat. No. 6,459,955 to Bartsch et al. which is incorporated by reference herein in its entirety. Power from the batteries  44  is controlled by the switch  28 . When switch  28  is on, power flows to the logic board  46 . When the switch  28  is off, no power flows to the logic board  46 . The logic board  46  receives inputs from the various sensors  24 ,  26 ,  38  and provides conditioned output to drive the drive wheels  30  and regulate a brush drive source. One example of such a logic board is that used in the commercially available TALRIK II robot manufactured by Mekatronix which is incorporated herein by reference. 
   Referring to  FIG. 3 , a drive system further comprising a plurality of reversible direct current (DC) drive motors  48  are preferably mounted on an upper surface of the base  14  perpendicular to each of the drive apertures  32 . Alternatively, the drive motors  48  may be mounted on the lower surface of the base  14  or on a separate suspension plate (not shown). The drive motors  48  are directly coupled to the center of each drive wheel  30  such that rotation of the motor results in a corresponding rotation of the drive wheel  30 . Energy to power the drive motors  48  is delivered from the logic board  46  to the drive motors  48  via commonly known wiring (not shown). 
   Referring to  FIGS. 3 and 4 , a dust bin  50  is removably mounted to the base housing  14  within a centrally located aperture as more fully described in U.S. Pat. No. 4,369,539 to Nordeen which is hereby incorporated by reference in its entirety. The dust bin  50  further comprises a bottom pan  52 , two side walls  54 , a rear wall  56 , and a forward lip  58 . In an alternate embodiment, the dust bin is rotated to an open position to allow for disposal of contained debris. 
   Referring to  FIGS. 2 ,  3  and  4 , an agitation system is described comprising at least one brush roll  34 , a brush roll gear  68 , a belt  70 , and a brush drive source. The brush roll  34  is mounted horizontally within, and protrudes below the sweeper aperture  36  formed in the base  14 . The brush roll  34  resides in a cavity formed within the sweeper aperture  36 . The brush roll  34  is preferably a cylindrical dowel with flexible bristles protruding therefrom. Alternatively, the brush roll  34  comprises a plurality of pliable paddles in combination with, or separate from the bristles. An axle runs longitudinally through the center axis of the brush roll  34 . In another embodiment, pair of counter-rotating brush rolls  34  are used in place of the single brush roll  34 . Alternatively, the brush rolls  34  may rotate in the same direction. The brush roll gear  68  is fixedly attached to one of the axles. The axles rotate within commonly known bearings located on both sides of the sweeper aperture  36 . A belt  70  engages the brush roll gear  68  on one end and is attached to a drive gear on the other. This commonly known agitation system is also described in U.S. Pat. No. 6,467,122 to Lenkiewicz which is incorporated herein by reference in its entirety. In another embodiment, brush drive is accomplished via the drive wheel motor  48  through a secondary gear attached to a protruding shaft. In the preferred embodiment, brush drive is provided by an electric brush motor  72 . Power to the brush motor  72  is supplied by outputs from the logic board  46 . The brush motor  72  is suitably mounted on an upper surface of the base  14  in such a manner that the drive gear on the brush motor  72  is in alignment with the brush roll gear  68 . 
   The various components work together to control the robotic sweeper cleaner  10  as depicted schematically in  FIG. 5  and shown in plan view in  FIG. 6 . Power is supplied to the logic board  46  through the batteries  44  via the power switch  28 . The proximity sensors  24 ,  26  and provide inputs to the logic board  46 . The logic board  46  processes the inputs and selectively sends appropriate output signals to the drive wheels  30 . 
   The infra-red proximity sensors  24  emit an infra-red light beam that is reflected from surrounding objects and detected by the sensor  24 . The pressure-sensitive proximity sensors  26  are activated by direct contact with a stationary object, closing a conductive path within the sensor  26  and providing a signal to the logic board  46 . When activated, the robot sweeper cleaner  10  normally moves in a generally straight and forward direction because equal outputs are provided to each drive motor  48 . Output signals to the individual drive motors  48  change as inputs from the various sensors change. For example, when one or more of the proximity sensors  24 ,  26  detect a stationary object, output to a corresponding drive wheel  30  is slowed. Since the drive wheels  30  are now moving at different speeds, the robot sweeper turns in the direction of the slower turning wheel. 
   Referring to  FIGS. 2 ,  7 , and  8 , a dusting assembly is described comprising a dusting pad  40 , a dusting cloth  42 , and a plurality of hinges  74 . The dusting pad  40  further comprises a plurality of engagement members  76  that rest along the bottom surface of the base  14 . The cloth engagement members  76  are made from a resilient material including any number of commonly known plastics and further comprise a plurality of slots  78 . The cloth engagement members  76  are similar to those disclosed in U.S. Pat. No. 6,305,046 to Kingry, specifically in  FIGS. 4 through 7 , which is hereby incorporated by reference herein in its entirety. 
   The dusting pad  40  is attached to the base  14  via the plurality of hinges  74  affixed along a length of one side of the dusting pad  40  and at the rear of the base  14  on the other. A commonly known magnetic latch  80  is affixed to a top surface of the dusting pad  40 . A steel catch  82  is located on the underside of the base  14  such that the catch  82  aligns with the latch  80  when the dusting pad  40  is placed in the closed position as defined by the upper surface of the dusting pad  40  being in direct contact with the lower surface of the base  14 . Magnetic force between the latch  80  and the catch  82  maintains contact between the top of the dusting pad  40  and the bottom of the base  14  during use. To open the dusting pad  40 , the user applies hand force to overcome the magnetic force, allowing the dusting pad  40  to rotate about the hinges  74  which then allows access to the engagement members  76 . Alternatively, the dusting pad  40  is fixedly attached to the bottom surface of the base  14 . The cloth engagement members  76  are accessible from the bottom and the dusting cloth  42  is removed directly from the bottom. 
   The dusting cloth  42  is wrapped around the dusting pad  40  in a longitudinal direction. In the preferred embodiment, the dusting cloth  42  is an electrostatically charged dry cloth that attracts oppositely charged debris particles. In an alternate embodiment, the dusting cloth  42  is a pre-moistened cloth suitable for removing sticky stains. The dusting cloth  42  is attached to the pad  40  by forcing the cloth  42  into the slots  78 , thus providing an easy method of inserting and removing the dusting cloth  42  from the unit as disclosed in FIG. 2 of U.S. Pat. No. 6,305,046 to Kingry. 
   In operation, the user connects the robot sweeper cleaner  10  to facility power to energize the charging circuit. Once a full charge on the batteries  44  is achieved, the user removes the charging circuit from the robot sweeper cleaner  10  and engages the electrical switch  28 . Power is then delivered to the logic board  46 . The logic board  46  controls output based on input from the proximity sensors  24 ,  26 . The robot sweeper cleaner  10  moves across the surface to be cleaned in a random fashion, changing speed and direction as the proximity sensors  24 ,  26  encounter. The logic board  46  directs the robot sweeper cleaner  10  to move in a direction that prefers the brush roll  34  in a forward position and the dusting cloth  42  in a rearward position. As such, larger loose debris is removed from the surface before the dusting cloth  42  passes. This sequence allows for longer life of the dusting cloth  42  and improved cleaning of the surface. After use, the user turns the electrical switch  28  to the off position, thus interrupting power to the logic board  46 . The user removes the dust bin  50  from the top enclosure  12 . Debris from the dust bin  50  is dumped into an appropriate disposal receptacle. The now dirty dusting cloth  42  is removed from the dusting pad  40  by overcoming the magnetic latch  80 , rotating the dusting pad  40  to the open position, removing the dusting cloth  42 , and similarly properly disposing of the dusting cloth  42 . A new dusting cloth  42  is attached. The dust bin  50  is reattached to the top enclosure  12 . The robot sweeper cleaner  10  is reattached to the charging circuit to replenish power to the batteries  44 , whereby the entire cleaning process may begin again. 
   While the invention has been specifically described in connection with certain specific embodiments, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the foregoing disclosure and drawings without departing from the spirit of the invention which is embodied in the appended claims.