Patent Grant
8898844
The invention generally relates to a robotic cleaning system for mopping a floor. In particular, the cleaning system employs a fluid dispenser with a wicking system that effectively regulates the rate at which fluid is dispensed to a cleaning cloth that mops the floor.
There are a variety of robots programmed to clean and mop floors. These robots may traverse a room in a random or pseudo-random manner pre-programmed in the robot navigation system. A pump on the robot is used to squirt cleaning agent or other fluid on the floor as the robot traverses the space. The pump is powered using a battery that is carried onboard the robot and recharged when not in use at a docking station, for example. Wires running to the battery provide power to the pump. Depending on the configuration of the robot, the electrical wiring may further include plugs to remove the pump along with a cleaning attachment. As such, use a pump adds to the complexity, weight, and power consumption of the robot without adding to its reliability. There is therefore a need for a mechanism to passively dispense cleaning fluid in a controlled manner without an electronically controlled pump.
The invention in some embodiments features a mopping assembly for a robotic cleaning system. The mopping assembly includes a reservoir for holding fluid and a fastener for securing a cleaning cloth. The reservoir includes a dispenser for outputting fluid from the reservoir to the cleaning cloth, and an air inlet in contact with the cleaning cloth. The location of the inlet hole relative to the dispenser and the cleaning cloth effectively regulates the rate at which the liquid is dispensed from the fluid reservoir. The dispenser in the exemplary embodiment includes a wick configured to directly contact the cleaning cloth. The wick protrudes from the reservoir on the same side as the air inlet, preferably the bottom side of the reservoir, to aid in regulating the flow of fluid through the wick. In addition, the wick and the air inlet are at the same height when the robotic cleaning system is in an upright storage orientation to prevent leakage of the cleaning fluid when the robotic cleaner is not in use.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, and in which:
The present invention features a mopping assembly for a mobile robot configured to clean floors. The mopping assembly includes a detachable cloth and a fluid reservoir to moisten the cloth with cleaning fluid. The mobile robot is configured to traverse a room using a trajectory designed to effectively scrub the floor with the wet cloth. An exemplary mobile robot is taught in U.S. patent application Ser. No. 12/930,260 filed Dec. 30, 2010, and optimal trajectories are taught in U.S. patent application Ser. No. 12/928,965 filed Dec. 23, 2010, both of which are hereby incorporated by reference herein. An exemplary mobile robot 100 with mopping assembly 120 is shown in
The preferred embodiment of the mopping assembly 100 is shown alone in
A vent hole or inlet 250 may also be incorporated into the chamber to admit air into the chamber as fluid is dispensed. Air must be admitted into the reservoir to prevent a vacuum which would effectively stop the flow of fluid out of the reservoir. In the exemplary embodiment, the air inlet 250 is placed on the bottom surface 260 of the central channel 513 on the same side of the reservoir and the wick and in proximity to the wick where it is in contact with the cleaning cloth. The location of the inlet serves, in part, as a self-regulating mechanism that helps control the rate of fluid dispensed. When the cleaning cloth is dry, air readily passes through the cleaning cloth 910 and into the reservoir which allows fluid to flow out of the reservoir at a relatively high rate. As the cleaning cloth 910 becomes damp in the region immediately in contact with the air inlet, the flow of air through the cloth is inhibited which, in turn, inhibits the flow of fluid dispensed through the wick. The location of the inlet also serves to minimize the leakage of fluid when the robotic cleaner is being stored or otherwise not operated. In particular, the inlet 250 is located in proximity to the wick (within 2 inches), and the inlet and wick are at the same elevation when the robotic cleaner is stored in the vertical orientation as shown in
The wick 920 in the preferred embodiment is a microfiber cloth or cord having a tubular or cylindrical shape to enhance the flow of fluid through the wick. The wick is mounted in a silicon wick cap or plug 240 at the bottom of the reservoir, which allows the wick to contact both the fluid in the reservoir as well as the top side of the cleaning cloth. As shown in the preferred embodiment in
The cleaning cloth 910 is large enough to cover the bottom of the mopping assembly and wrap around at least a portion of the reservoir. In the preferred embodiment, the cloth attaches to Velcro hook and loop fasteners on the top of the reservoir. In other embodiments, the cloth is attached using pins, clips, clasps, straps, or combination thereof. When soiled, the cloth may be conveniently removed for washing or replaced with a fresh cloth. The bottom surface of the moping assembly 710 may include bumps or other protrusions as shown in
Recommended cleaning fluids include water and Ph-neutral detergents such as Bona.
The mopping assembly 120 is detachably attached to the robot housing. In an exemplary embodiment, magnets (not shown) are used to retain the mopping assembly. Magnets affixed to the robot housing and ferrous metal on the mopping assembly, together, produce a biasing force that holds the mopping assembly in contact with the housing. In the alternative, magnets may be embedded in the housing and the top portion of the mopping assembly to produce an attractive force that holds the mopping attachment to the robot housing.
The mopping assembly in some embodiments includes one or more apertures 540 configured to receive drop sensors 270. The drop sensors include probes that press downward against the top of the cleaning cloth. When the mopping assembly is over a flat surface, the bottom of the probes are approximately flush with the bottom surface of the mopping assembly. When the mopping assembly losses contact with the floor, however, one or more of the probes drop or push through outward through the aperture. Displacement of the drop sensors 270 indicates a staircase, step, or rug, for example, which triggers the robotic cleaner to back up and change course.
In some embodiments, a plurality of wicks may be used to dispense cleaning fluid at multiple points of the cleaning cloth. The silicon cap 240 employed to retain the one or more wicks may be placed at different locations on the bottom, side, or top of the reservoir provided the wicks make contact with the cleaning cloth. Multiple interchangeable silicon caps may be selected and inserted in the reservoir by the user to effectively change the rate at which cleaning fluid is dispensed from the reservoir, each cap having slits with a different size, width, length, and/or shape. Similarly, different sizes of air inlets 250 may be employed to alter the fluid rate as well. In other embodiments, an electronically controlled valve (not shown) for regulating the size of the air inlet may be used to dynamically control the fluid rate during the same cleaning session or between different cleaning sessions. The flow rate may be dynamically changed during a session to, for example, begin with a higher flow rate if the cleaning cloth is dry, and then reduce the rate based on elapse time or in response to a sensor indicating that the cleaning cloth is damp. In still other embodiments, the air inlet has a truncated conical shape, the small hole facing the interior of the reservoir and the large hole facing outward, to inhibit dust and dirt from plugging the inlet over time.
In the preferred embodiment, the reservoir and wick are incorporated in the mopping assembly, which is detachable from the main robot housing. In other alternative embodiments, the reservoir and/or wick may be integrated in the housing and therefore not removable. Similarly, the cleaning cloth may be detachably attached to the mopping assembly or directly to the robot housing.
Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention.
Therefore, the invention has been disclosed by way of example and not limitation, and reference should be made to the following claims to determine the scope of the present invention.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/505,914 filed Jul. 8, 2011, entitled “Mopping assembly for a mobile robot,” which is hereby incorporated by reference herein for all purposes.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4991250 | Young | Feb 1991 | A |
| 5377378 | Cutler | Jan 1995 | A |
| 6584990 | Shaw | Jul 2003 | B2 |
| 8069520 | Mattucci et al. | Dec 2011 | B2 |
| 8205293 | Rosenzweig et al. | Jun 2012 | B2 |
| 8245351 | Rosenzweig et al. | Aug 2012 | B2 |
| 8353074 | Krebs | Jan 2013 | B2 |
| 8387193 | Ziegler et al. | Mar 2013 | B2 |
| 8407848 | Pung et al. | Apr 2013 | B2 |
| 8483881 | Ermakov et al. | Jul 2013 | B2 |
| 20050229340 | Sawalski et al. | Oct 2005 | A1 |
| 20060293794 | Harwig et al. | Dec 2006 | A1 |
| 20070209139 | Carlucci et al. | Sep 2007 | A1 |
| 20090281661 | Dooley et al. | Nov 2009 | A1 |
| 20120145191 | Williams et al. | Jun 2012 | A1 |
| 20120227763 | Hayes et al. | Sep 2012 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 61505914 | Jul 2011 | US |
