Patent Description:
A surface cleaning apparatus may be used to clean a variety of surfaces. Some surface cleaning apparatuses include a rotating agitator (e.g., brush roll). One example of a surface cleaning apparatus includes a vacuum cleaner which may include a rotating agitator as well as a vacuum source. Nonlimiting examples of cleaners include robotic vacuums, robotic sweepers, multi-surface robotic cleaners, wet/dry robotic cleaners, upright vacuum cleaners, canister vacuum cleaners, stick vacuum cleaners, and central vacuum systems.

Within the field of robotic and autonomous cleaning devices, there are a range of form factors and features that have been developed to meet a range of cleaning requirements. However, certain cleaning applications remain a challenge.

<CIT> concerns an automatic cleaning device including an air injector and at least one side brush to clean every nook and corner or wall of a room as well as all open areas. <CIT> concerns a robot vacuum cleaner for the autonomous cleaning of surfaces, which has at least one side brush facing the surface to be cleaned, the at least one side brush having a rotating element, brush elements being arranged on the rotating element, the rotating element being rotatably mounted about an axis of rotation. <CIT> concerns an autonomous coverage vacuum cleaner having a roller brush capable of resilient vertical displacement and roller brush frame unit for the same.

Wet floor cleaning in the home has traditionally involved manual labor and generally a tool consisting of a wet mop or sponge attached to the end of a handle. The mop or sponge is used to apply a cleaning fluid onto the surface of a floor. The cleaning fluid is applied and the tool is used to agitate the surface of the floor through a scrubbing motion. The components of the cleaning fluid and the scrubbing agitation helps suspend any dirt or contaminants on the surface into the cleaning fluid. The contaminants are then removed from the surface of the floor as the tool removes the cleaning fluid, generally by having the mop or the sponge absorb the cleaning fluid, and thus the dirt or contaminants.

Water may be used to perform wet cleaning on floors, but often it is more effective to use a cleaning fluid that is a mixture of water and soap or detergent that reacts with contaminants to emulsify the contaminants into the water. A cleaning fluid may further include other components such as a solvent, a fragrance, a disinfectant, a drying agent, abrasive particulates and the like to increase the effectiveness of the cleaning process, or improve the end-results such as floor appearance.

As referenced above, the sponge or mop may be used as a scrubbing element for scrubbing the floor surface, particularly with stubborn stains and particulate matter. The scrubbing action serves to agitate the cleaning fluid for mixing with contaminants as well as to apply a friction force for loosening contaminants from the floor surface. Agitation enhances the dissolving and emulsifying action of the cleaning fluid and the friction force helps to break bonds between the surface and contaminants.

Dry debris is generally removed prior to the wet floor cleaning either using a vacuum or via dry mopping. This minimizes the contamination of cleaning fluid and cleaning tools used during the wet floor cleaning. But this additional step adds time and labor to the cleaning process.

According to one aspect of the invention, there is provided a robotic cleaner according to appended claim <NUM>. Optional features are provided in the appended dependent claims.

An example of a robotic cleaner, consistent with the present disclosure, may include a chassis, an agitator assembly configured to engage a surface to be cleaned, and a lift mechanism moveably coupling the agitator assembly to the chassis. The lift mechanism may include a biasing mechanism. The biasing mechanism may be configured to generate a biasing force that urges the agitator assembly in a direction away from the surface to be cleaned. The biasing force may be insufficient to lift the agitator assembly from the surface to be cleaned.

The lift mechanism includes a top plate, a bottom plate, and a plurality of linkages, a first end of each linkage being pivotally coupled to the top plate and a second end of each linkage being slidably coupled to the bottom plate. In some instances, the top plate may be coupled to the chassis and the bottom plate may be coupled to the agitator assembly. In some instances, the biasing mechanism may be configured to urge the linkages to pivot towards each other. In some instances, the biasing mechanism may be a tension spring. In some instances, the biasing mechanism may be a leaf spring. In some instances, the agitator assembly may include at least one motor. In some instances, the lift mechanism may include a plurality of biasing mechanisms, the plurality of biasing mechanisms being configured to cooperate to encourage an even weight distribution across the agitator assembly. In some instances, the agitator assembly may include at least one agitator, the at least one agitator being configured to be rotated by the at least one motor. In some instances, the agitator assembly may include at least one counterweight, the at least one counterweight and the at least one motor being positioned on opposing sides of the agitator assembly.

In some instances, a bellow may fluidly couple the agitator assembly to a dust cup. In some instances, the lift mechanism may include a top plate, a bottom plate, and a plurality of linkages, a first end of each linkage being pivotally coupled to the top plate and a second end of each linkage being slidably coupled to the bottom plate. In some instances, the top plate may be coupled to the chassis and the bottom plate may be coupled to the agitator assembly. In some instances, the biasing mechanism may be configured to urge the linkages to pivot towards each other. In some instances, the biasing mechanism may be a tension spring. In some instances, the biasing mechanism may be a leaf spring. In some instances, the agitator assembly may include at least one motor. In some instances, the lift mechanism may include a plurality of biasing mechanisms, the plurality of biasing mechanisms being configured to cooperate to encourage an even weight distribution across the agitator assembly. In some instances, the agitator assembly may include at least one counterweight, the at least one counterweight and the at least one motor being positioned on opposing sides of the agitator assembly.

These and other features and advantages will be better understood by reading the following detailed description, taken together with the drawings wherein:.

The present disclosure is generally directed to a robotic cleaner. The robotic cleaner may include a suction motor, a dust cup, an air inlet, an agitator assembly, and a lift mechanism. The agitator assembly may include a housing and one or more agitators (e.g., a brush roll) rotatably coupled to the housing. The lift mechanism is coupled to the agitator assembly (e.g., the housing) and is configured such that the agitator assembly moves in response to changes in a surface to be cleaned (e.g., in response to a change in surface type such as from carpet to hardwood). Movement of the agitator assembly relative to the surface to be cleaned causes a corresponding movement of the one or more agitators relative to the surface to be cleaned. As such, the one or more agitators may be encouraged to maintain a consistent engagement (e.g., contact) with the surface to be cleaned.

The lift mechanism includes a biasing mechanism (e.g., a tension spring) and at least two pivoting linkages, wherein the linkages pivot in response to movement of the agitator assembly. The biasing mechanism extends between and is coupled to the linkages. The biasing mechanism can be configured such that the biasing mechanism urges the linkages to pivot in a direction that urges the agitator assembly to move away from the surface to be cleaned, wherein the force exerted by biasing mechanism is insufficient to cause the agitator assembly to move away from the surface to be cleaned. As such, the biasing mechanism can generally be described as being configured to reduce an amount of force required to move the agitator assembly. Such a configuration may allow the agitator assembly to move more easily when the robotic cleaner is traversing the surface to be cleaned.

The suction motor is fluidly coupled to the dust cup and the air inlet such that the suction motor urges air to flow along an airflow path that extends through at least a portion of the agitator assembly, into the air inlet, and through the dust cup and suction motor. The air flowing along the airflow path may have debris entrained therein. As the air flows through the dust cup, at least a portion of the debris entrained within the air may fall out of entrainment and be deposited in the dust cup before the air passes through the suction motor. In some instances, the housing may define at least a portion of the air inlet. In this instance, movement of the agitator assembly relative to the surface to be cleaned may encourage air to flow into the agitator assembly at a substantially constant velocity, which may encourage a consistent suction (or vacuum) force to be generated within the agitator assembly.

As used herein, the terms "above" and "below" are used relative to an orientation of the cleaning apparatus on a surface to be cleaned and the terms "front" and "back" are used relative to a direction that the cleaning apparatus moves on a surface being cleaned during normal cleaning operations (i.e., back to front). As used herein, the term "leading" refers to a position in front of at least another component but does not necessarily in front of all other components.

Acoustic sensor, as used herein, may generally refer to a sensor configured to detect sounds within the human audible range (e.g., between <NUM> and <NUM>,<NUM>). Ultrasonic sensor, as used herein, may generally refer to a sensor configured to detect sounds in an ultrasonic range (e.g., greater than <NUM>,<NUM>).

Referring to <FIG>, an embodiment of a robotic cleaner <NUM>, consistent with embodiments of the present disclosure, is shown and described. Although a particular embodiment of a robotic cleaner is shown and described herein, the concepts of the present disclosure may apply to other types of robotic vacuum cleaners or robotic cleaners. The robotic cleaner <NUM> includes a housing or chassis <NUM> with a front side <NUM>, and a back side <NUM>, left and right sides 116a, 116b, an upper side (or top surface) <NUM>, and a lower or under side (or bottom surface) <NUM>. A bumper <NUM> is movably coupled to the housing and/or robotic cleaner chassis <NUM>. The bumper <NUM> may extend around at least a portion (e.g., a substantial portion) of a forward portion of the housing <NUM>. The top of the housing <NUM> may include controls (or a user interface) <NUM> to initiate one or more operations, such as autonomous cleaning, spot cleaning, and docking and indicators (e.g., LEDs) to indicate operations, battery charge levels, errors and other information. For example, the controls <NUM> may include one or more buttons configured to initiate one or more operations.

As shown, the robotic cleaner <NUM> includes a suction conduit (or air inlet) <NUM> fluidly coupled to a dust cup <NUM> and a suction motor <NUM>. The suction motor <NUM> causes debris to be suctioned into the suction conduit <NUM> and deposited into the dust cup <NUM> for later disposal. An air exhaust port <NUM> is fluidly coupled to the suction motor <NUM>. In various embodiments, the air exhaust port <NUM> may be configured such that air exhausted therefrom urges debris towards a common location, encourages a drying of a liquid cleaning fluid, and/or does not cause undesirable debris agitation.

As also shown, the robotic cleaner <NUM> includes a plurality of wheels <NUM> coupled to a respective drive motor contained within a driven wheel assembly <NUM>. As such, each wheel <NUM> may generally be described as being independently driven. The robotic cleaner <NUM> can be steered by adjusting the rotational speed of one of the plurality of wheels <NUM> relative to the other of the plurality of wheels <NUM>.

A displaceable bumper <NUM> can be disposed along a portion of a perimeter defined by a housing <NUM> of the robotic cleaner <NUM>. The displaceable bumper <NUM> is configured to transition between an unactuated position and an actuated position in response to engaging, for example, an obstacle. The displaceable bumper <NUM> can be configured to be moveable along a first axis extending generally parallel to a top surface of the housing <NUM>. As such, the displaceable bumper <NUM> is displaced in response to engaging (e.g., contacting) at least a portion of an obstacle disposed on and extending from a surface to be cleaned. Additionally, or alternatively, the displaceable bumper <NUM> can be configured to be moveable along a second axis that extends transverse to (e.g., perpendicular to) the first axis. As such, the displaceable bumper <NUM> is displaced in response to engaging (e.g., contacting) at least a portion of an obstacle that is spaced apart from the surface to be cleaned. Therefore, the robotic cleaner <NUM> may avoid becoming trapped between the obstacle and the surface to be cleaned.

A user interface <NUM> can be provided to allow a user to control the robotic cleaner <NUM>. For example, the user interface <NUM> may include one or more push buttons that correspond to one or more features of the robotic cleaner <NUM>. Liquid ingress protection may be provided at the user interface <NUM> to prevent or otherwise mitigate the effects of a liquid being inadvertently spilled on the housing <NUM> of the robotic cleaner <NUM>.

The robotic cleaner <NUM> includes an agitator <NUM> (e.g., a main brush roll). The agitator <NUM> is configured to rotate such that is urges debris towards the suction conduit <NUM>. The agitator <NUM> rotates about a rotation axis that extends substantially (e.g., within <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>° of) parallel to a surface to be cleaned. In other words, the agitator <NUM> may generally be described as being configured to rotate about a substantially horizontal axis.

The agitator <NUM> is at least partially disposed within the suction conduit <NUM>. The agitator <NUM> may be coupled to a motor <NUM>, such as AC or DC motor. The motor <NUM> is configured to impart rotation to the agitator <NUM> by way of, for example, one or more of one or more drive belts, one or more gears, and/or any other driving mechanisms. The robotic cleaner may also include one or more rotating side brushes coupled to motors to urge debris towards the agitator <NUM> (not shown). In an alternative embodiment, the robotic cleaner may also include one or more air jet assemblies configured to urge debris toward the agitator <NUM>.

The agitator <NUM> may have bristles, fabric, or other cleaning elements, or any combination thereof around the outside of the agitator <NUM>. The agitator <NUM> may include, for example, strips of bristles in combination with strips of a rubber or elastomer material. The agitator <NUM> may also be removable to allow the agitator <NUM> to be cleaned more easily and allow the user to change the size of the agitator <NUM>, change a type of bristles on the agitator <NUM>, and/or remove the agitator <NUM> entirely depending on the intended application. The robotic cleaner <NUM> may further include a bristle strip (not shown) on an underside of the housing <NUM> and along a portion of the suction conduit <NUM>. The bristle strip may include bristles having a length sufficient to at least partially contact the surface to be cleaned. The bristle strip may also be angled, for example, toward the suction conduit <NUM>.

The robotic cleaner <NUM> also includes several different types of sensors. For example, the robotic cleaner <NUM> may include one or more forward obstacle sensors <NUM>. The one or more forward obstacle sensors <NUM> may be integrated with and/or separate from the bumper <NUM>. For example, the one or more forward obstacle sensors <NUM> may be configured to cooperate with the bumper <NUM> such that signals emitted from the one or more forward obstacle sensors <NUM> can pass through at least a portion of the bumper <NUM>. The one or more forward obstacle sensors <NUM> may include one or more of infrared sensors, ultrasonic sensors, time-of-flight sensors, a camera (e.g., a stereo or monocular camera), and/or any other sensor.

By way of further example, one or more floor type detection sensors <NUM>, <NUM> (e.g., an acoustic sensor or ultrasonic sensor) may be used to detect qualities of the floor surface on which the robotic cleaner <NUM> travels and/or changes in the qualities of the floor surface on which the robotic cleaner <NUM> travels. The one or more floor type detection sensors <NUM>, <NUM> can be any suitable sensors operable to detect a physical condition or phenomena and provide the corresponding data to a controller configured to control a behavior of the robotic cleaner <NUM> such as a movement behavior (e.g., avoid carpeted surfaces when wet cleaning), a cleaning behavior (e.g., suction power, agitator speed, or side brush speed), an escape behavior, and/or any other behavior. In some instances, the algorithms that control the behavior of the robotic cleaner <NUM> are selected based on the determination of the surface type by the floor type detection sensors <NUM>, <NUM>. In other embodiments, the algorithms that control the behavior of the robotic cleaner <NUM> are selected based on the identification of a change in the surface type by the floor type detection sensors <NUM>, <NUM>.

In one embodiment, an acoustic sensor <NUM> allows for determination of floor types such as carpet, hardwood, and/or tile based on the reflective conditions of the floor. The acoustic sensor <NUM> may be configured to identify changes between a first floor type and a second floor type during operation of the robotic cleaner <NUM>. As the robotic cleaner <NUM> traverses a target surface, noise from the surrounding area may be detected using the acoustic sensor <NUM>. The volume and quality of that noise may vary based on the qualities of the floor surface such that the acoustic sensor <NUM> allows for determination of floor types such as carpet, hardwood, and/or tile based on the reflective conditions of the floor, or a transition from a first type to a second type of floor covering. In some embodiments, the noise that the robotic cleaner generates while moving is used by an acoustic sensor <NUM> to determine floor type. This noise may be caused by the plurality of wheels <NUM> traveling over a surface or by operation of the suction motor <NUM>. The acoustic sensor <NUM> may be placed into a recessed chamber within the robotic cleaner chassis <NUM>. In some embodiments, the recessed chamber may be cylindrical, such that the location of the source of ambient noise detected by the acoustic sensor <NUM> is more readily identified.

Another embodiment includes a method for detecting the floor using an ultrasonic sensor <NUM>. Such a floor sensor <NUM> comprises an ultrasonic sensor <NUM> transmitting an ultrasonic signal towards the floor surface and receiving the ultrasonic signal reflected from the floor surface. The sensor <NUM> allows for determination of floor types such as carpet, hardwood, and/or tile based on the reflective conditions of the floor. The ultrasonic sensor <NUM> may be configured to identify changes between a first floor type and a second floor type during operation of the robotic cleaner <NUM>.

An example embodiment of the robotic cleaner <NUM> includes at least one ultrasonic sensor <NUM> and at least one acoustic sensor <NUM>. The at least one ultrasonic sensor <NUM> and the at least one acoustic sensor <NUM> may operate together to determine a floor surface and/or a change in the floor surface. That is, the at least one ultrasonic sensor <NUM> may transmit an ultrasonic signal towards the floor surface. The at least one ultrasonic sensor <NUM> and the at least one acoustic sensor <NUM> may both receive the reflected signal and use the signals to determine a floor type and/or a change in the floor type. In some embodiments, the at least one ultrasonic sensor <NUM> may be configured to operate based on signals received by the at least one acoustic sensor <NUM>. That is, should the at least one acoustic sensor <NUM> determine a change in the floor surface, the at least one ultrasonic sensor <NUM> may be configured to emit an ultrasonic signal based on that determination.

The robotic cleaner <NUM> may include a wet cleaning module <NUM> removably affixed to the robotic cleaner chassis <NUM>. The wet cleaning module <NUM> includes a cleaning fluid tank <NUM> and a stopper for the cleaning fluid tank <NUM>. The cleaning fluid tank <NUM> further includes a tank base <NUM> which is connected to a wet cleaning module motor <NUM>. A wet cleaning pad <NUM> is operatively connected to the tank base <NUM> via a wet pad plate (not shown). As the robotic cleaner travels across a floor, the suction conduit <NUM>, which is fluidly coupled to the suction motor <NUM>, collects dry debris from the floor while the wet cleaning module <NUM> applies a cleaning fluid onto the cleaning pad <NUM> at one or more pump outlet locations <NUM> (hidden lines), and uses the cleaning pad <NUM> to scrub the floor. The wet cleaning module motor <NUM> powers one or more pumps configured to apply the cleaning fluid onto the cleaning pad <NUM> and to agitate the cleaning pad <NUM> during cleaning.

A non-driven rear caster wheel <NUM> supports the wet cleaning module <NUM>. The rear caster wheel <NUM> is used to control the engagement of the cleaning pad <NUM> with the target surface. The rear caster wheel <NUM> may be shifted along a vertical axis such that the cleaning pad <NUM> carried by the robotic cleaner <NUM> sits closer to or further from the surface on which it travels. When the rear caster wheel <NUM> rotates at a higher axis relative to the bottom of the robotic cleaner <NUM>, the cleaning pad <NUM> has greater engagement with the floor. This may increase the cleaning effectiveness. However, the increased mechanical engagement with the floor may also produce increased friction from the cleaning pad <NUM> as it moves over the surface being cleaned. The increased friction may decrease the speed of the robotic cleaner <NUM>. Therefore, the rear caster wheel <NUM> can be adjusted such that the pressure caused by the weight of the robotic cleaner <NUM> is balanced between cleaning effectiveness and maneuverability of the robotic cleaner <NUM>. The pressure applied to the cleaning pad <NUM> may be distributed across the surface area of the cleaning pad <NUM> engaging with the surface being cleaned, or in an alternative embodiment, the pressure applied to the cleaning pad <NUM> may be concentrated along a leading edge of the cleaning pad <NUM>. The concentration of the pressure along the leading edge of the cleaning pad <NUM> can be configured to provide improved cleaning as a result of increased mechanical engagement with the floor being cleaned while limiting the amount of drag caused by the cleaning pad <NUM> engagement with the floor.

<FIG> and <FIG> show a robotic cleaner <NUM>. As shown, the robotic cleaner <NUM> includes a chassis <NUM>, an agitator assembly <NUM> disposed within the chassis <NUM>, and a lift mechanism <NUM> coupled to the agitator assembly <NUM>. The agitator assembly <NUM> can include a housing <NUM>, a motor <NUM>, one or more agitators (e.g., one or more brush rolls), and a bellow <NUM>. The lift mechanism <NUM> is configured such that the agitator assembly <NUM> can move relative to the chassis <NUM>. The lift mechanism <NUM> can include a plurality of cleaner attachment points <NUM> that are configured to couple the lift mechanism <NUM> to the chassis <NUM>. As such, the agitator assembly <NUM> can generally be described as being configured to float. In some instances, the agitator assembly <NUM> may operate as a floating sole plate. Additional reference is made to <FIG>, which show magnified views of the lift mechanism <NUM> illustrated in <FIG> and <FIG>.

The agitator assembly <NUM> forms a suction conduit (or air inlet) that is fluidly coupled to a dust cup <NUM> and a suction motor. The suction motor causes air to flow along an air flow path that passes through the suction conduit, into the dust cup <NUM>, and through the suction motor. The air flowing along the airflow path may have debris entrained therein. At least a portion of the entrained debris may be deposited in the dust cup <NUM> for later disposal.

The bellow <NUM> is fluidly coupled to the agitator assembly <NUM> (e.g., to the suction conduit) and to the dust cup <NUM>. As such, the bellow <NUM> is disposed between the agitator assembly <NUM> and the dust cup <NUM> such that air flowing along the airflow path passes through the agitator assembly <NUM> and the bellow <NUM> before passing through the dust cup <NUM>. The bellow <NUM> can be constructed of a flexible material such that the agitator assembly <NUM> can move relative to the chassis <NUM> of the robotic cleaner <NUM> while remaining fluidly coupled to the dust cup <NUM>. For example, the bellow <NUM> may include a rubber (e.g., natural or synthetic rubber). In some instances, a first end of the bellow <NUM> is coupled to the agitator assembly <NUM> and a second end of the bellow <NUM> is coupled to the chassis <NUM> such that the bellow <NUM> fluidly couples to the dust cup <NUM>. The first end of the bellow <NUM> is opposite the second end of the bellow <NUM>.

The agitator assembly <NUM> is configured to move between an extended position and a retracted position. When the agitator assembly <NUM> is in the extended position, the lift mechanism <NUM> is fully extended (e.g., the lift mechanism <NUM> may fully extend in response to the robotic cleaner <NUM> being lifted from the surface to be cleaned), preventing further movement of the agitator assembly <NUM> in a direction away from the chassis <NUM>. When the agitator assembly <NUM> is in the retracted position, the lift mechanism <NUM> cannot retract any further, preventing further movement of the agitator assembly <NUM> in a direction towards the chassis <NUM>. During operation, the agitator assembly <NUM> moves between at least two intermediary positions, the intermediary positions being between the extended position and the retracted position.

The maximum extension and retraction of the lift mechanism <NUM> may be limited by one or more stops (e.g., defined by or coupled to the chassis <NUM>). The one or more stops can be configured to engage the agitator assembly <NUM>, preventing additional extension or retraction of the lift mechanism <NUM>. The position of the lift mechanism <NUM> when the agitator assembly <NUM> is engaging a respective stop may generally be described as the position where the lift mechanism <NUM> is fully extended or fully retracted. The one or more stops may be further configured to dampen any sound generated as a result of the agitator assembly <NUM> engaging the one or more stops (e.g., the stops may include a rubber or compressible foam).

The surface on which the robotic cleaner <NUM> travels may displace the agitator assembly <NUM> from the extended position such that the agitator assembly <NUM> moves towards the retracted position and at least partially into the chassis <NUM> of the robotic cleaner <NUM>. For example, while the robotic cleaner <NUM> traverses the surface to be cleaned, the agitator assembly <NUM> may move along an assembly axis <NUM> (e.g., a vertical axis). Carpet, hard wood, tile, rugs, and other flooring types may have different features that influence a magnitude of the displacement of the agitator assembly <NUM>. The displacement of the agitator assembly <NUM> along the assembly axis <NUM> may, for example, measure in a range of <NUM> millimeters (mm) to <NUM>. By way of further example, the displacement of the agitator assembly <NUM> along the assembly axis <NUM> may measure in a range of <NUM> to <NUM>. By way of still further example, the displacement of the agitator assembly <NUM> along the assembly axis <NUM> may measure <NUM>. The total displacement of the agitator assembly <NUM> may allow the robotic cleaner <NUM> to operate effectively on multiple types of surfaces.

During operation, a lower planar surface of the agitator assembly <NUM> extends substantially (e.g., within <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>° of) parallel to the surface to be cleaned. The distance between the agitator assembly <NUM> and the surface to be cleaned may influence a suction force generated at the suction conduit of the agitator assembly <NUM>. The distance between the agitator assembly <NUM> and the surface to be cleaned may further influence an amount of engagement between the agitator of the agitator assembly and the surface to be cleaned. For example, when transitioning from a high pile carpet to a hardwood floor the agitator assembly may move towards the hardwood floor, encouraging a consistent engagement between the agitator and the surface to be cleaned. When compared to a fixed agitator assembly, movement of the agitator assembly <NUM> towards the hardwood floor may increase agitation of the surface, encouraging additional dry debris to be suctioned into the dust cup <NUM>.

The lift mechanism <NUM> is configured to allow the agitator assembly <NUM> to move along the assembly axis <NUM> in response to changes in the surface to be cleaned (e.g., transitions between floor types). In other words, the lift mechanism <NUM> may be described as being configured to allow the agitator assembly <NUM> to move relative to the chassis <NUM> of the robotic cleaner <NUM> (e.g., towards or away from an upper portion of the chassis <NUM>) in response to changes in the surface to be cleaned.

A weight of the agitator assembly <NUM> may interfere with a movement of the agitator assembly <NUM> in response to changes in the surface to be cleaned. As such, in some instances, the lift mechanism <NUM> can be configured to offset at least a portion of the weight of the agitator assembly <NUM>. For example, the lift mechanism <NUM> may include a biasing mechanism (e.g., a spring) configured to urge the lift mechanism <NUM> towards the retracted position, wherein a force exerted by the biasing mechanism is insufficient to cause the agitator assembly <NUM> to move towards the chassis <NUM>. Offsetting at least a portion of the weight of the agitator assembly <NUM> using the lift mechanism <NUM> may encourage better engagement between the agitator assembly <NUM> and the surface to be cleaned. If the agitator assembly <NUM> is not sufficiently displaced, power consumption may be increased when the robotic cleaner <NUM> moves over some surfaces. Additional power consumption on surfaces such as carpet may prevent the robotic cleaner <NUM> from effectively completing tasks. For example, a distance of approximately <NUM> may extend between the agitator assembly <NUM> (e.g., a bottom most portion of the agitator assembly <NUM>) and the surface to be cleaned. Such a configuration may cause sufficient suction to be generated such that debris is removed from the surface to be cleaned while minimizing power consumption.

As shown in <FIG>, the lift mechanism <NUM> includes the plurality of cleaner attachment points <NUM>, a top plate <NUM>, a bottom plate <NUM>, a plurality of assembly attachment points <NUM>, lower pivot pins <NUM>, upper pivot pins <NUM>, a biasing mechanism (e.g., a spring) <NUM>, and a plurality of linkages <NUM>. The plurality of cleaner attachment points <NUM> are configured to couple the lift mechanism <NUM> to the chassis <NUM> of the robotic cleaner <NUM>. As such, a top surface of the top plate <NUM> of the lift mechanism <NUM> faces a top surface of the robotic cleaner <NUM>. For example, the top plate <NUM> may be substantially parallel to the top surface of the robotic cleaner <NUM> (e.g., a top surface of the chassis <NUM> of the robotic cleaner <NUM>).

The plurality of assembly attachment points <NUM> are configured to couple the lift mechanism <NUM> to the agitator assembly <NUM> (e.g., the housing <NUM> of the agitator assembly <NUM>). As such, the bottom plate <NUM> of the lift mechanism <NUM> moves along the assembly axis <NUM> in response to the agitator assembly <NUM> encountering changes in the surface to be cleaned. For example, the bottom plate <NUM> can be configured to move in a direction of (or away from) the top plate <NUM>.

The bottom plate <NUM> may be movably coupled to the top plate <NUM>. As shown, the bottom plate <NUM> may be coupled to the top plate <NUM> using the linkages <NUM>. The linkages <NUM> may be pivotally coupled to the top plate <NUM> and slidably coupled to the bottom plate <NUM>. As shown, the linkages <NUM> include an upper pin <NUM> and a lower pin <NUM>. The upper pin <NUM> is pivotally coupled to the top plate <NUM> and the lower pin <NUM> is slidably coupled to the bottom plate <NUM>. In other words, a first end of the linkage <NUM> is pivotally coupled to the top plate <NUM> and a second end of the linkage <NUM> is slidably coupled to the bottom plate <NUM>. As the linkages <NUM> pivot the lower pins <NUM> slide within a track <NUM> defined in the bottom plate <NUM>.

When the bottom plate <NUM> moves towards the top plate <NUM>, the linkages <NUM> pivot towards each other. When the bottom plate <NUM> moves away from the top plate <NUM>, the linkages <NUM> pivot away from each other. The biasing mechanism <NUM> can be configured to urge the linkages <NUM> towards each other. As shown, the biasing mechanism <NUM> can extend between the plurality of linkages <NUM>. For example, the biasing mechanism <NUM> can be a tension spring that extends between opposing linkages <NUM> such that the tension spring urges the linkages <NUM> to pivot towards each other. In some instances, the biasing mechanism <NUM> may extend substantially parallel to the top and/or bottom plates <NUM> and/or <NUM>.

The biasing mechanism <NUM> may be configured such that a force exerted by the biasing mechanism <NUM> on the linkages <NUM> is insufficient to lift the agitator assembly <NUM> from the surface to be cleaned. Such a configuration may reduce an amount of force required to move the agitator assembly <NUM> towards the chassis <NUM>. Such a configuration may also encourage the agitator assembly <NUM> to maintain a consistent engagement with a surface to be cleaned while allowing the agitator assembly <NUM> to adjust to surface changes more easily.

As shown, the plurality of linkages <NUM> can each define a recess <NUM> configured to receive at least a portion of the biasing mechanism <NUM>. For example, each linkage <NUM> may have a U-shape, wherein the recess <NUM> is defined between opposing sides of the U-shaped linkage <NUM>. Each side of a U-shaped linkage <NUM> may include a corresponding upper pin <NUM> and lower pin <NUM>. The upper and lower pins <NUM>, <NUM> may be coupled to (e.g., using one or more of an adhesive, a press-fit, a threaded coupling, and/or any other form of coupling) or formed from the linkages <NUM>. In some instances, the recess <NUM> can include a coupling feature <NUM> (see, e.g., <FIG> which shows an example of the linkage <NUM>, wherein the linkage <NUM> of <FIG> is configured to form a press fit with the upper and lower pins <NUM>, <NUM>). The coupling feature <NUM> can be configured to couple the biasing mechanism <NUM> to the linkage <NUM>. In some instances, a central longitudinal axis of the biasing mechanism <NUM> may intersect with both coupling features <NUM>. The recess <NUM> may be configured such that the biasing mechanism <NUM> does not engage (e.g., contact) one or more surfaces of the recess <NUM>. In some instances, the recess <NUM> can be configured such that the biasing mechanism <NUM> extends substantially parallel to the top and/or bottom plates <NUM> and/or <NUM>.

In some instances, the linkage <NUM> may have a non-linear shape. For example, and with reference to <FIG>, the linkage <NUM> may include a first linear region <NUM> and a second linear region <NUM>, wherein the first linear region <NUM> extends transverse to the second linear region <NUM> at a linkage angle θ. The linkage angle θ may measure, for example, in range of <NUM>° and <NUM>°. By way of further example, the linkage angle θ may measure <NUM>°.

In some instances, a single motor <NUM> is used to drive one or more agitators of the agitator assembly <NUM>. The weight of the motor <NUM> may unbalance the agitator assembly <NUM>. As such, the biasing mechanism <NUM> may be configured such that it offsets the uneven allotment of weight in the agitator assembly <NUM> resulting from the positioning of the motor <NUM>.

The biasing mechanism <NUM> may be any type of biasing mechanism. For example, the biasing mechanism <NUM> may be a leaf spring, a torsion spring, an elastomeric material, and/or any other biasing mechanism.

While the bottom plate <NUM> is shown as being separate from the housing <NUM> of the agitator assembly <NUM>, the bottom plate <NUM> may be integrally formed from the housing <NUM>. In this instance, the linkages <NUM> may couple directly to the housing <NUM>.

<FIG> and <FIG> show an example of a lift mechanism <NUM> having a leaf spring <NUM> that is configured to urge an agitator assembly <NUM> in a direction away from a chassis <NUM> of a robotic cleaner. Such a configuration may offset at least a portion of a downward force resulting from the weight of the agitator assembly <NUM>.

As shown, the leaf spring <NUM> couples to spring mounting points <NUM> of the agitator assembly <NUM>. The leaf spring <NUM> may have an arcuate shape, wherein a concave surface of the leaf spring <NUM> faces the agitator assembly <NUM>. As shown in <FIG>, the leaf spring <NUM> may have a non-linear shape. For example, the leaf spring <NUM> may define a stepped region <NUM> to accommodate a motor <NUM> of the agitator assembly <NUM>, the motor <NUM> being configured to drive at least one agitator <NUM> of the agitator assembly <NUM>.

<FIG> show an example of an agitator assembly <NUM> coupled to a lift mechanism <NUM>. The agitator assembly <NUM> is configured to be carried by a robotic cleaner (not shown). For example, the agitator assembly <NUM> can be configured to couple to a chassis of the robotic cleaner. As shown, the agitator assembly <NUM> includes a housing <NUM>, a motor <NUM>, a first agitator <NUM>, and a second agitator <NUM>. The lift mechanism <NUM> is configured to couple to the agitator assembly <NUM> using a plurality of attachment points and to be further coupled to a chassis of the robotic cleaner. The lift mechanism <NUM> is further configured such that the agitator assembly <NUM> can move between an extended position and a retracted position in response to changes in a surface to be cleaned. In other words, the lift mechanism <NUM> is configured such that the agitator assembly <NUM> moves (e.g., vertically) relative to the chassis of the robotic cleaner (e.g., towards or away from a top portion of the chassis). As such, the agitator assembly <NUM> may operate as a floating sole plate. In some instances, the lift mechanism <NUM> may include a first and a second biasing mechanism <NUM>, <NUM> configured to urge the agitator assembly <NUM> towards the retracted position, wherein a force exerted by the biasing mechanisms <NUM>, <NUM> is insufficient to lift the agitator assembly <NUM> from the surface to be cleaned.

The agitator assembly <NUM> forms a suction conduit (or air inlet) that is fluidly coupled to a dust cup and a suction motor. The suction motor causes air to flow along an air flow path that passes through the suction conduit, into the dust cup, and through the suction motor. The air flowing along the airflow path may have debris entrained therein. At least a portion of the entrained debris may be deposited in the dust cup for later disposal.

The agitator assembly <NUM> is configured to move between an extended position and a retracted position. When the agitator assembly <NUM> is in the extended position, the lift mechanism <NUM> is fully extended (e.g., the lift mechanism <NUM> may fully extend in response to the robotic cleaner being lifted from the surface to be cleaned), preventing further movement of the agitator assembly <NUM> in a direction away from the chassis of the robotic cleaner. When the agitator assembly <NUM> is in the retracted position, the lift mechanism <NUM> cannot retract any further, preventing further movement of the agitator assembly <NUM> in a direction towards the chassis of the robotic cleaner. During operation, the agitator assembly <NUM> moves between at least two intermediary positions, the intermediary positions being between the extended position and the retracted position.

The maximum extension and retraction of the lift mechanism <NUM> may be limited by one or more stops (e.g., defined by or coupled to the chassis of the robotic cleaner). The one or more stops can be configured to engage the agitator assembly <NUM>, preventing additional extension or retraction of the lift mechanism <NUM>. The position of the lift mechanism <NUM> when the agitator assembly <NUM> is engaging a respective stop may generally be described as the position where the lift mechanism <NUM> is fully extended or fully retracted. The one or more stops may be further configured to dampen any sound generated as a result of the agitator assembly <NUM> engaging the one or more stops (e.g., the stops may include a rubber or compressible foam).

The surface on which the robotic cleaner travels may displace the agitator assembly <NUM> from the extended position such that the agitator assembly <NUM> moves towards the retracted position and, at least partially, into the robotic cleaner chassis. For example, while the robotic cleaner traverses the surface to be cleaned, the agitator assembly <NUM> may move along an assembly axis <NUM> (e.g., a vertical axis). Carpet, hard wood, tile, rugs, and other flooring types may have different features that influence a magnitude of the displacement of the agitator assembly <NUM>. The displacement of the agitator assembly <NUM> along the assembly axis <NUM> may, for example, measure in a range of <NUM> millimeters (mm) to <NUM>. By way of further example, the displacement of the agitator assembly <NUM> along the assembly axis <NUM> may measure in a range of <NUM> to <NUM>. By way of still further example, the displacement of the agitator assembly <NUM> along the assembly axis <NUM> may measure <NUM>. The total displacement of the agitator assembly <NUM> may allow the robotic cleaner to operate effectively on multiple types of surfaces.

During operation, a lower planar surface of the agitator assembly <NUM> extends substantially (e.g., within <NUM>°, <NUM>°, <NUM>°, <NUM>°, or <NUM>° of) parallel to the surface to be cleaned. The distance between the agitator assembly <NUM> and the surface to be cleaned may influence a suction force generated at the suction conduit of the agitator assembly <NUM>. The distance between the agitator assembly <NUM> and the surface to be cleaned may further influence an amount of engagement between the agitator of the agitator assembly and the surface to be cleaned. For example, when transitioning from a high pile carpet to a hardwood floor the agitator assembly may move towards the hardwood floor, encouraging a consistent engagement between the agitator and the surface to be cleaned. When compared to a fixed agitator assembly, movement of the agitator assembly <NUM> towards the hardwood floor may increase agitation of the surface, encouraging additional dry debris to be suctioned into the dust cup.

A weight of the agitator assembly <NUM> may interfere with a movement of the agitator assembly <NUM> in response to changes in the surface to be cleaned. As such, in some instances, the lift mechanism <NUM> can be configured to offset at least a portion of the weight of the agitator assembly <NUM>. For example, the lift mechanism <NUM> may include a biasing mechanism (e.g., a spring) configured to urge the lift mechanism <NUM> towards the retracted position, wherein a force exerted by the biasing mechanism is insufficient to cause the agitator assembly <NUM> to move towards the chassis of the robotic cleaner. Offsetting at least a portion of the weight of the agitator assembly <NUM> using the lift mechanism <NUM> may encourage better engagement between the agitator assembly <NUM> and the surface to be cleaned. If the agitator assembly <NUM> is not sufficiently displaced, power consumption may be increased when the robotic cleaner moves over some surfaces. Additional power consumption on surfaces such as carpet may prevent the robotic cleaner from effectively completing tasks. For example, a distance of approximately <NUM> may extend between the agitator assembly <NUM> (e.g., a bottom most portion of the agitator assembly <NUM>) and the surface to be cleaned. Such a configuration may cause sufficient suction to be generated such that debris is removed from the surface to be cleaned while minimizing power consumption.

As shown, the lift mechanism <NUM> includes the plurality of cleaner attachment points, a top plate <NUM>, a bottom plate <NUM>, a plurality of assembly attachment points <NUM>, lower pivot pins <NUM>, upper pivot pins <NUM>, a fist and second biasing mechanism (e.g., a spring) <NUM>, <NUM>, and a plurality of linkages <NUM>. The plurality of cleaner attachment points are configured to couple the lift mechanism <NUM> to the chassis of the robotic cleaner. As such, a top surface of the top plate <NUM> of the lift mechanism <NUM> faces a top surface of the robotic cleaner. For example, the top plate <NUM> may be substantially parallel to the top surface of the robotic cleaner (e.g., a top surface of the chassis of the robotic cleaner).

The bottom plate <NUM> may be movably coupled to the top plate <NUM>. As shown, the bottom plate <NUM> may be coupled to the top plate <NUM> using the linkages <NUM>. The linkages <NUM> may be pivotally coupled to the top plate <NUM> and slidably coupled to the bottom plate <NUM>. As shown, the linkages <NUM> include an upper pin <NUM> and a lower pin <NUM>. The upper pin <NUM> is pivotally coupled to the top plate <NUM> and the lower pin <NUM> is slidably coupled to the bottom plate <NUM>. In other words, a first end of the linkage <NUM> is pivotally coupled to the top plate <NUM> and a second end of the linkage <NUM> is slidably coupled to the bottom plate <NUM>. As the linkages <NUM> pivot the lower pins <NUM> slide within a track <NUM> defined in the bottom plate <NUM>. The upper and lower pins <NUM>, <NUM> may be coupled to (e.g., using one or more of an adhesive, a press-fit, a threaded coupling, and/or any other form of coupling) or formed from the linkages <NUM>.

When the bottom plate <NUM> moves towards the top plate <NUM>, the linkages <NUM> pivot towards each other. When the bottom plate <NUM> moves away from the top plate <NUM>, the linkages <NUM> pivot away from each other. The biasing mechanisms <NUM>, <NUM> can be configured to urge the linkages <NUM> towards each other. As shown, the biasing mechanisms <NUM>, <NUM> can extend between the plurality of linkages <NUM>. For example, the biasing mechanisms <NUM>, <NUM> can be a tension spring that extends between opposing linkages <NUM> such that the tension spring urges the opposing linkages <NUM> to pivot towards each other. In some instances, the biasing mechanisms <NUM>, <NUM> may extend substantially parallel to the top and/or bottom plates <NUM> and/or <NUM>.

The biasing mechanisms <NUM>, <NUM> may be configured such that a force exerted by the biasing mechanisms <NUM>, <NUM> on the linkages <NUM> is insufficient to lift the agitator assembly <NUM> from the surface to be cleaned. Such a configuration may reduce an amount of force required to move the agitator assembly <NUM> towards the chassis of the robotic cleaner. Such a configuration may encourage the agitator assembly <NUM> to maintain a consistent engagement with a surface to be cleaned while allowing the agitator assembly <NUM> to adjust to surface changes more easily.

In some instances, a single motor <NUM> is used to drive one or more agitators of the agitator assembly <NUM>. The weight of the motor <NUM> may unbalance the agitator assembly <NUM>. As such, the biasing mechanisms <NUM>, <NUM> may be configured such that the biasing mechanisms <NUM>, <NUM> offset the uneven allotment of weight in the agitator assembly <NUM> resulting from the positioning of the motor <NUM>. For example, the biasing mechanism <NUM> proximate the motor <NUM> may be configured to exert a greater biasing force than the biasing mechanism <NUM>. Such a configuration may result in the biasing mechanism <NUM> at least partially offsetting the weight of the motor <NUM>, encouraging the agitator assembly <NUM> to be balanced.

The biasing mechanisms <NUM>, <NUM> may be any type of biasing mechanism. For example, the biasing mechanisms <NUM>, <NUM> may be a leaf spring, a torsion spring, an elastomeric material, and/or any other biasing mechanism.

As shown in <FIG> and <FIG>, a lift mechanism <NUM> may use a plurality of springs <NUM>, <NUM> that include one or more extended arms <NUM>. The plurality of springs <NUM>, <NUM> may be attached to a plurality of linkages <NUM> using one or more headed pins <NUM>. The one or more extended arms <NUM> allow the plurality of springs <NUM>, <NUM> to be shaped (e.g., by including one or more transition regions <NUM>) to avoid other portions of an agitator assembly. As shown in <FIG>, a central longitudinal axis <NUM> of the springs <NUM>, <NUM> may extend through both connection ends <NUM> of the extend arms <NUM>.

As shown in <FIG>, a counterweight <NUM> may be coupled to an agitator assembly <NUM>. As described herein, in some instances, a single motor <NUM> is used to drive one or more agitators. The weight of the motor <NUM> may unbalance the agitator assembly <NUM>. The counterweight <NUM> may be constructed such that it offsets the uneven allotment of weight in the agitator assembly <NUM>. A lift mechanism <NUM> may use a plurality of springs <NUM>, <NUM> that include one or more extended arms <NUM>. The one or more extended arms <NUM> allow the plurality of springs <NUM>, <NUM> to be shaped to avoid the counterweight <NUM> and the motor <NUM>.

<FIG> shows an example of an agitator assembly <NUM> coupled to a lift mechanism <NUM>. The lift mechanism <NUM> is configured to couple to a robotic cleaner (e.g., a chassis of the robotic cleaner), wherein the lift mechanism <NUM> is further configured such that the agitator assembly <NUM> moves relative to the chassis of the robotic cleaner in response to changes in the surface to be cleaned. For example, the lift mechanism <NUM> may be configured such that the agitator assembly <NUM> can move between an extended position (as shown in <FIG>) and a retracted position (as shown in <FIG>). As shown, the lift mechanism <NUM> includes a plurality of linkages <NUM> that collectively define one or more scissor mechanisms. A torsion bar may couple scissor mechanisms at opposing ends of the agitator assembly <NUM>, wherein the torsion bar encourages both sides of the agitator assembly <NUM> to move together. The lift mechanism <NUM> may further include a biasing mechanism <NUM> (e.g., a spring) configured to urge the agitator assembly <NUM> towards the retracted position.

<FIG> shows an exploded cross-sectional view of a robotic cleaner chassis <NUM>, an agitator assembly <NUM>, and a lift mechanism <NUM>. As shown, the agitator assembly <NUM> is configured to be movably received within a receptacle <NUM> of the robotic cleaner chassis <NUM>. The agitator assembly <NUM> may include a housing <NUM>, one or more agitators <NUM>, a comb <NUM> configured to engage at least one of the one or more agitators <NUM>, and at least one motor <NUM> configured to drive at least one of the one or more agitators <NUM>. The engagement between the comb <NUM> and an agitator may be configured to remove fibrous debris (e.g., hair) from a respective one or more agitators <NUM>.

The lift mechanism <NUM> includes a first set of linkages <NUM>, a second set of linkages <NUM>, and a plurality of biasing mechanisms <NUM>, wherein each biasing mechanism <NUM> extends between a corresponding set of linkages <NUM>. The lift mechanism <NUM> is configured to couple to the housing <NUM> such that the housing <NUM> is movable within the receptacle <NUM>. For example, and with additional reference to <FIG>, the first and second sets of linkages <NUM>, <NUM> may be pivotally coupled to a top plate <NUM> of the lift mechanism <NUM> and slidably coupled to the housing <NUM> of the agitator assembly <NUM> at corresponding tracks <NUM>. The top plate <NUM> is configured to couple to the robotic cleaner chassis <NUM>.

<FIG> shows a magnified view of a portion of the robotic cleaner chassis <NUM> coupled with the lift mechanism <NUM>. As shown, the housing <NUM> of the agitator assembly <NUM> includes a plurality of stops <NUM> configured to move within respective slots <NUM>. When the stops <NUM> reach distal ends of a respective slot <NUM> further movement of the agitator assembly <NUM> is prevented (e.g., as a result of contact with the robotic cleaner chassis <NUM> and/or the top plate <NUM>, which may define a distal end of a respective slot <NUM>). As such, the stops <NUM> can generally be described as defining the maximum extension and retraction positions of the lift mechanism <NUM>. In some instances, the stops <NUM> may include a sound dampening material (e.g., a rubber or compressible foam) configured to reduce a quantity of noise generated when the stops <NUM> engage a distal end of the slot <NUM>.

Additionally, or alternatively, the slot <NUM> may include a sound dampening material (e.g., at one or more distal ends of the slot <NUM>).

<FIG> shows a magnified cross-sectional view of a portion of the robotic cleaner chassis <NUM>. As shown, one or more sidewalls <NUM> defining the receptacle <NUM> may extend transverse to (at a non-perpendicular angle) the agitator assembly <NUM>. For example, and as shown, a separation distance <NUM> between the one or more sidewalls <NUM> and the agitator assembly <NUM> may increase with increasing distance from the lift mechanism <NUM>.

Embodiments of the methods described herein may be implemented using a controller, processor and/or other programmable device. To that end, the methods described herein may be implemented on a tangible, non-transitory, computer readable medium having instructions stored thereon that, when executed by one or more processors, perform the methods. Thus, for example, a controller may include a storage medium to store instructions (in, for example, firmware or software) to perform the operations described herein. The storage medium may include any type of tangible medium, for example, any type of disk including floppy disks, optical disks, compact disk read-only memories (CD-ROMs), compact disk rewritables (CD-RWs), and magneto-optical disks, semiconductor devices such as read-only memories (ROMs), random access memories (RAMs) such as dynamic and static RAMs, erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), flash memories, magnetic or optical cards, or any type of media suitable for storing electronic instructions.

The functions of the various elements shown in the figures, including any functional blocks described as "controller," may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. The functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read-only memory (ROM) for storing software, random access memory (RAM), and non-volatile storage.

The term "coupled" as used herein refers to any connection, coupling, link or the like by which signals carried by one system element are imparted to the "coupled" element. Such "coupled" devices, or signals and devices, may be, but are not necessarily directly connected to one another and may be separated by intermediate components or devices that may manipulate or modify such signals. Likewise, the terms "connected" or "coupled" as used herein in regard to mechanical or physical connections or couplings is a relative term and may include, but does not require, a direct physical connection.

Elements, components, modules, and/or parts thereof that are described and/or otherwise portrayed through the figures to communicate with, be associated with, and/or be based on, something else, may be understood to so communicate, be associated with, and/or be based on in a direct and/or indirect manner, unless otherwise stipulated herein.

Unless otherwise stated, use of the word "substantially" or "approximately" may be construed to include a precise relationship, condition, arrangement, orientation, and/or other characteristic, and deviations thereof as understood by one of ordinary skill in the art, to the extent that such deviations do not materially affect the disclosed methods and systems. Throughout the entirety of the present disclosure, use of the articles "a" and/or "an" and/or "the" to modify a noun may be understood to be used for convenience and to include one, or more than one, of the modified noun, unless otherwise specifically stated.

Claim 1:
A robotic cleaner (<NUM>) comprising:
a chassis (<NUM>);
an agitator assembly (<NUM>) configured to engage a surface to be cleaned; and
a lift mechanism (<NUM>) moveably coupling the agitator assembly (<NUM>) to the chassis (<NUM>), the lift mechanism (<NUM>) including a biasing mechanism (<NUM>), the biasing mechanism (<NUM>) is configured to generate a biasing force that urges the agitator assembly (<NUM>) in a direction away from the surface to be cleaned, the biasing force being insufficient to lift the agitator assembly (<NUM>) from the surface to be cleaned, wherein the lift mechanism (<NUM>) includes a top plate (<NUM>), a bottom plate (<NUM>), and a plurality of linkages (<NUM>), a first end of each linkage being pivotally coupled to the top plate (<NUM>) and a second end of each linkage being slidably coupled to the bottom plate (<NUM>).