阅读说明：本技术 用于清洁机器人的清洁垫 (Cleaning pad for cleaning robot ) 是由 M·威廉姆斯 L·C·林 于 2018-06-01 设计创作，主要内容包括：本申请描述了一种用于自动清洁机器人的清洁垫,所述自动清洁机器人被配置为在地板表面移动所述清洁垫以清洁所述地板表面,所述清洁垫包括：垫主体,其包括顶部表面和底部表面；以及背衬层,其附接到所述垫主体的顶部表面并且包括横向边缘、纵向边缘和端部挡块,所述端部挡块定位在所述背衬层的横向边缘并且至少部分地限定所述纵向边缘中的至少一个；其中,所述背衬层被配置为由所述自动清洁机器人的垫固定器容纳以将所述清洁垫附接到所述自动清洁机器人,以及所述背衬层的所述端部挡块配置为与所述垫固定器接合以至少部分地限定所述清洁垫相对于所述垫固定器的方向。(The present application describes a cleaning pad for use with an automatic cleaning robot configured to move the cleaning pad across a floor surface to clean the floor surface, the cleaning pad comprising: a pad body comprising a top surface and a bottom surface; and a backing layer attached to the top surface of the pad body and comprising lateral edges, a longitudinal edge, and an end stop positioned at the lateral edges of the backing layer and at least partially defining at least one of the longitudinal edges; wherein the backing layer is configured to be received by a pad holder of the automatic cleaning robot to attach the cleaning pad to the automatic cleaning robot, and the end stop of the backing layer is configured to engage with the pad holder to at least partially define an orientation of the cleaning pad relative to the pad holder.)

1. A cleaning pad for use with an automatic cleaning robot configured to move the cleaning pad across a floor surface to clean the floor surface, the cleaning pad comprising:

a pad body comprising a top surface and a bottom surface; and

a backing layer attached to the top surface of the pad body and comprising lateral edges, longitudinal edges, and end stops positioned at the lateral edges of the backing layer and at least partially defining at least one of the longitudinal edges;

wherein the backing layer is configured to be received by a pad holder of the automatic cleaning robot to attach the cleaning pad to the automatic cleaning robot, and the end stop of the backing layer is configured to engage with the pad holder to at least partially define an orientation of the cleaning pad relative to the pad holder.

2. A cleaning pad according to claim 1, wherein the end stops project laterally from the lateral edges of the backing layer.

3. A cleaning pad according to claim 1, wherein the end stops are symmetrically positioned about a lateral axis of the cleaning pad.

4. A cleaning pad according to claim 1, wherein the backing layer extends across at least a portion of the width of the pad body, the backing layer extending no further than the longitudinal edges of the pad body.

5. A cleaning pad according to claim 4, wherein a first of the longitudinal edges of the backing layer is aligned with a first of the longitudinal edges of the pad body.

6. A cleaning pad according to claim 5, wherein a second of the longitudinal edges of the backing layer is spaced apart from a second of the longitudinal edges of the pad body.

7. A cleaning pad according to claim 1, wherein the backing layer further comprises an engagement feature along at least one lateral edge of the backing layer, wherein the engagement feature is configured to engage with the pad holder to at least partially define the orientation of the cleaning pad.

8. A cleaning pad according to claim 7, wherein the engagement features comprise grooves.

9. A cleaning pad according to claim 8, wherein the recess is located in a central portion of at least one of the lateral edges.

10. A cleaning pad according to claim 1, wherein the backing layer comprises apertures within the backing layer perimeter configured to provide an indicator detectable by the automated cleaning robot to determine the pad type of the cleaning pad.

11. A cleaning pad according to claim 10, wherein the indicator is disposed on a pad body of the cleaning pad.

12. A cleaning pad according to claim 1, wherein the backing layer further comprises a plurality of apertures configured to engage with corresponding protrusions on the pad holder of the robotic cleaning robot.

13. A cleaning pad according to claim 12, wherein the plurality of apertures are positioned on the backing layer symmetrically about a transverse axis of the backing layer.

14. A cleaning pad according to claim 1, wherein the backing layer has a thickness of about 5 to 7mm, a width of about 68 to 72 mm, and a length of about 92 to 94 mm.

15. A cleaning pad for use with an automatic cleaning robot configured to move the cleaning pad across a floor surface to clean the floor surface, the cleaning pad comprising:

a pad body comprising a top surface and a bottom surface; and

a backing layer attached to the top surface of the pad body, the backing layer including a perimeter defined at least in part by first and second longitudinal edges and first and second transverse edges, wherein the first longitudinal edge of the backing layer is aligned with the first longitudinal edge of the pad body and the second longitudinal edge of the backing layer is spaced apart from the second longitudinal edge of the pad body;

wherein the backing layer is configured to be received by a pad holder of the automatic cleaning robot to attach the cleaning pad to the automatic cleaning robot, the backing layer being insertable into the pad holder of the automatic cleaning robot in a single unique direction at least partially defined by the first and second longitudinal edges.

16. A cleaning pad according to claim 15, wherein the second longitudinal edge of the backing layer is longer than the first longitudinal edge of the backing layer.

17. A cleaning pad according to claim 16, wherein the second longitudinal edge of the backing layer provides an end stop to prevent further insertion of the backing layer into the pad holder.

18. A cleaning pad according to claim 15, wherein the backing layer further comprises an end stop along at least one of the backing layer first and second lateral edges, wherein the end stop is configured to engage with a pad holder of the automatic cleaning robot when the cleaning pad is received by the pad holder to at least partially define an orientation of the cleaning pad relative to the pad holder of the automatic cleaning robot.

19. A cleaning pad according to claim 15, wherein the backing layer comprises apertures within the backing layer perimeter configured to provide an indicator detectable by the automated cleaning robot to determine a pad type of the cleaning pad and to control cleaning operations of the automated cleaning robot based on pad type.

20. A cleaning pad according to claim 15, wherein the backing layer further comprises a plurality of apertures configured to engage with corresponding protrusions on the pad holder of the robotic cleaning robot.

Technical Field

The present application relates to cleaning pads, and more particularly, to cleaning pads for cleaning robots.

Background

The autonomous cleaning robot can navigate the floor surface and avoid obstacles while wiping the floor surface to remove debris and stains from the floor surface. The cleaning robot can include a cleaning pad to wipe the floor surface. The cleaning pad wipes the floor surface and collects debris as the cleaning robot moves across the floor surface.

Disclosure of Invention

The present application describes a pad for an autonomous cleaning robot. The front portion of the pad is thinner than the rear portion of the pad. The varying thickness along the width of the pad provides several advantages. The pad is configured to collect debris uniformly along a surface of the pad during a cleaning operation. The configuration of the pad prevents debris hot spots (debris hot spots) on the pad where debris can accumulate excessively relative to other portions of the pad. The configuration of the pad promotes uniform wetting of the pad during the cleaning operation, rather than front-to-back wetting. The configuration of the pad allows more debris to be collected on the pad relative to a pad having a constant thickness. Debris can contact more of the pad during cleaning because some debris can pass under the front of the pad and contact the back of the pad. The pad does not push liquid and debris across the floor surface in front of the pad and therefore does not leave a pile of accumulated debris on the floor surface after the cleaning operation is completed. The pad is configured to collect debris from the floor surface and avoid leaving debris on the floor surface after a cleaning operation. The pad does not stick (e.g., suck) to the floor surface because the different thicknesses of the different portions of the pad allow air to pass under the portions of the pad during cleaning. Having a smaller overall adhesion (e.g., suction) of the pad reduces the resistance to moving the pad across the floor surface, reducing the torque required by the robot to move the pad across the floor surface. Pads with lower adhesion help reduce the need for a rough layer on the outer surface of the pad, such as a meltblown plastic layer. The soft, rather than rough, outer surface of the pad reduces scratching or abrasion of the floor surface by the pad. The elimination of the rough layer reduces the cost of manufacturing the mat and allows more of the outer surface of the mat to contact the floor surface.

In one aspect, the pad includes a wick having an absorbent layer for absorbing liquid by capillary action and dispersing the liquid within the cleaning pad. The pad comprises an envelope layer surrounding the core, the envelope layer comprising an elastic and absorbent fibrous layer for absorbing liquid by capillary action and transferring the liquid to the core. The pad includes one or more transition regions across a cleaning width of the cleaning pad that divide the cleaning pad into at least two sections. The anterior portion of the at least two portions has a lesser thickness than the posterior portion of the at least two portions.

In one aspect, the front-located portion comprises a leading edge of the cleaning pad, wherein the rear-located portion has an additional absorbent layer located in the core, the rear-located portion being further from the leading edge of the cleaning pad than the front-located portion.

In one aspect, the mat comprises a moisture resistant material disposed between the core and the envelope layer in a rearward portion of the at least two portions, wherein the moisture resistant material slows the rate of moisture transfer from the envelope layer to the core. The moisture resistant material is disposed in a first quantity in the rearward portion and a second quantity in another portion of the cleaning pad, wherein the first quantity is different than the second quantity.

In one aspect, the forward portion includes a moisture resistant material and the forward portion has less moisture resistant material relative to the rearward portion. In one aspect, the moisture resistant material comprises latex fibers.

In one aspect, the one or more transition regions comprise mechanical indentations. In another aspect, the one or more transition regions comprise ultrasonic welding. In one aspect, the core comprises airlaid fillers.

In one aspect, the forward portion extends from the leading edge of the cleaning pad by about 20-30% of the length of the cleaning pad. The forwardly located portion extends from the leading edge of the cleaning pad for about 30-40% of the length of the cleaning pad.

In one aspect, the mat comprises a debris adhering substance covering an exterior of the encapsulating layer. The thickness of the anterior portion is about half of the thickness of the posterior portion, wherein the length of the anterior portion is half of the length of the posterior portion.

In one aspect, the mat includes a backing layer adhered to the top surface of the fibrous layer. The backing layer is configured to be connected to a mobile robot. In one aspect, the backing layer includes a cutout to engage a corresponding feature of a pad holder on the mobile robot. The slit has an asymmetric pattern on the backing layer to allow the backing layer to engage with a pad holder of the mobile robot.

In one aspect, the encapsulating layer comprises a spunlace material.

In one aspect, the pad includes one or more additional transition regions that are generally orthogonal to the cleaning width of the cleaning pad.

In one aspect, the pad includes a stack of absorbent layers that form a wick for absorbing liquid by capillary action and dispersing the liquid in the cleaning pad. The pad includes an envelope layer surrounding the core, the envelope layer including a fibrous layer that is resilient and absorbent. The fibrous layer is adapted to absorb liquid by capillary action and transfer liquid to the wick.

In one aspect, the pad comprises a moisture resistant material disposed between the envelope layer and the core, wherein the moisture resistant material slows the rate of moisture transfer from the envelope layer to the core. In one aspect, the pad includes one or more transition regions spanning the cleaning width of the cleaning pad, the transition regions forming five sections.

In one aspect, the five portions of the pad comprise a first portion forming a leading edge of the cleaning pad, the first portion comprising a first number of absorbent layers in the core. In one aspect, the five portions of the pad include a second portion adjacent to the first portion, the second portion including more absorbent layers in the core than the first portion. In one aspect, the five portions of the pad include a third portion adjacent to the second portion, the third portion including more absorbent layers in the core than the first portion and a quantity of moisture resistant material. In one aspect, the five portions of the pad include a fourth portion adjacent to and substantially identical to the third portion. In one aspect, the five portions of the pad comprise a fifth portion forming a trailing edge of the cleaning pad, the fifth portion comprising more absorbent layers in the core than the first portion and more moisture resistant material than the fourth portion.

In one aspect, the present application describes a robot body including a front portion and a rear portion. The robot includes a drive system that maneuvers the robot body across a floor surface and a cleaning assembly secured to a front of the robot body, the cleaning assembly including a pad holder. The robot includes a cleaning pad secured to a pad holder of the cleaning assembly.

In one aspect, the cleaning pad includes a wick having an absorbent layer for absorbing liquid by capillary action and dispersing the liquid within the cleaning pad. In one aspect, the cleaning pad includes an encapsulation layer surrounding the core, the encapsulation layer including an elastic and absorbent fibrous layer for absorbing liquid by capillary action and transferring liquid to the core. In one aspect, the cleaning pad includes one or more transition regions spanning a cleaning width of the cleaning pad, the one or more transition regions dividing the cleaning pad into at least two portions, wherein a forward portion of the at least two portions has a smaller thickness than a rearward portion of the at least two portions.

In one aspect, a leading edge of the cleaning pad is aligned with a leading edge of the robot body. In one aspect, the pad holder is configured to push the cleaning pad onto the floor surface, wherein the urging force near the center of the cleaning pad is greater than the urging force near the edges of the cleaning pad.

In one aspect, the present application describes a cleaning pad for use with an automatic cleaning robot configured to move the cleaning pad across a floor surface to clean the floor surface, the cleaning pad comprising: a pad body comprising a top surface and a bottom surface; and a backing layer attached to the top surface of the pad body and comprising lateral edges, a longitudinal edge, and an end stop positioned at the lateral edges of the backing layer and at least partially defining at least one of the longitudinal edges; wherein the backing layer is configured to be received by a pad holder of the automatic cleaning robot to attach the cleaning pad to the automatic cleaning robot, and the end stop of the backing layer is configured to engage with the pad holder to at least partially define an orientation of the cleaning pad relative to the pad holder.

In one aspect, the present application also describes a cleaning pad for use with an automatic cleaning robot configured to move the cleaning pad across a floor surface to clean the floor surface, the cleaning pad comprising: a pad body comprising a top surface and a bottom surface; and a backing layer attached to the top surface of the pad body, the backing layer comprising a perimeter at least partially defined by first and second longitudinal edges and first and second transverse edges, wherein the first longitudinal edge of the backing layer is aligned with the first longitudinal edge of the pad body and the second longitudinal edge of the backing layer is spaced apart from the second longitudinal edge of the pad body; wherein the backing layer is configured to be received by the pad holder of the automatic cleaning robot to attach the cleaning pad to the automatic cleaning robot, the backing layer being insertable into the pad holder of the automatic cleaning robot in a unique orientation at least partially defined by the first and second longitudinal edges.

The details of one or more implementations of the application described in this specification are set forth in the accompanying drawings and the description below. Other potential features, aspects, and advantages will appear from the description, the drawings, and the claims.

Drawings

FIG. 1 is a side view of an exemplary autonomous cleaning robot;

FIG. 2 is a schematic diagram illustrating an exemplary path taken by an autonomous cleaning robot during a cleaning operation;

FIG. 3 is a side view of an exemplary pad illustrating the location of a debris contact pad during a cleaning operation;

4A-4D are bottom views of exemplary pads illustrating the accumulation of debris on the pad during a cleaning operation;

FIG. 5 is a bottom view of an exemplary pad;

FIG. 6 is a side view of an exemplary pad;

FIG. 7 is an exploded perspective view of an exemplary pad;

FIG. 8 is a cut-away perspective view of an exemplary mat, showing the various layers of the mat;

FIG. 9 is a side view of an exemplary pad;

FIG. 10 is a perspective view of an exemplary pad;

FIG. 11 is a schematic diagram illustrating exemplary pad thicknesses;

FIG. 12 is a top view of an exemplary pad showing the backing layer of the pad;

fig. 13 is a bottom view of an exemplary pad holder on a robot.

Like reference numbers and designations in the various drawings indicate like elements.

Detailed Description

The present application describes a cleaning pad attached to an autonomous cleaning robot. The pad is attached to a pad holder of the robot so that the pad can be in contact with the floor surface when the robot traverses the floor surface. The cleaning pad removes debris from the floor surface as the robot moves the cleaning pad over the floor surface. The shape of the cleaning pad is such that debris is captured beneath the pad by the pad profile and is removed from the floor surface rather than being pushed across the floor with the leading edge of the pad. The pad is thinner near the leading edge of the pad as compared to the thickness of the rest of the pad. The pad holder of the robot is configured to push different parts of the pad (to the floor surface) with different pressures. For example, the pad holder may push the central portion of the pad with a higher pressure than the edge portion of the pad. The shape of the pad and pad holder enable the pad to remove debris from the cleaning surface by allowing more of the pad surface to contact debris on the floor surface during a cleaning operation of the robot relative to a pad having a substantially uniform thickness.

Fig. 1 shows a perspective view of a cleaning pad 100 attached to an autonomous cleaning robot 110. The autonomous cleaning robot 110 is configured to travel over a floor surface. Robot 110 is an autonomous mobile robot that weighs less than 10 pounds, travels over a floor surface, and cleans the floor surface. The robot 110 may include a main body 120 supported by a drive system (not shown) that may maneuver the robot across a floor surface. In some embodiments, the robot body 120 has a square shape. However, the body 120 may have other shapes including, but not limited to, circular, oval, teardrop, rectangular, square, or a combination of a rectangular front and a circular back, or a longitudinally asymmetric combination of any of these shapes, and the like. The robot main body 120 has a front 140 and a rear 150. The body 120 also includes a bottom portion (not shown) and a top portion.

The bottom of the robot body 120 includes one or more rear cliff sensors (not shown) in one or both rear corners of the robot 110 and one or more front cliff sensors in one or both front corners of the robot 110. The cliff sensor may be a mechanical drop sensor or a light-based proximity sensor, such as an IR (infrared) pair, a dual emitter single receiver or a dual receiver single emitter IR light-based proximity sensor aimed downward at the floor surface. The cliff sensor extends between the side walls of the robot 110 and covers the corners as close as possible to detect floor height changes that exceed a threshold value, which is adjusted by reversible robot wheel drops, before the robot crosses the respective floor portion. For example, the placement of sensors near the corners of the robot 110 ensures that the cliff sensors trigger when the robot 110 hangs from the floor drop (floor drop), thereby preventing the robot wheels from traveling over the drop edge.

The robot 110 carries a pad holder (not shown) on the front 140 of the robot. The pad holder extends across the front edge of the robot 110 behind the shock absorbing part 160 and is configured to fix the pad 100. The pad holder is described in further detail below with reference to fig. 13.

The front portion 140 of the body 120 carries a movable shock absorbing portion 160 for detecting a collision in a longitudinal or transverse direction. The shock absorbing part 160 has a shape complementary to the robot main body 120 and extends beyond the robot main body 120 such that the front part 140 has an overall size wider than the rear part 150 of the robot main body. The cleaning pad 100 is supported by the bottom of the robot main body 120. In an embodiment, the pad 100 extends to the edge of the cushioning portion 160 or beyond the width of the cushioning portion 160 so that the robot 110 can place the outer edge of the pad 100 to and along a wall surface, or into a gap. For example, when the robot 110 moves in a wall following motion, the pad 100 may be manipulated by the robot 110 to clean near the wall-floor interface by extending edges of the pad 100. Extending the pad 100 beyond the width of the shock absorbing part 160 enables the robot 110 to clean in cracks and crevices beyond the range of the robot main body 120. In some embodiments, the pad 100 does not extend beyond the edges of the robot body 120.

The robot 110 may include a liquid applicator. The liquid applicator may have a single nozzle or multiple nozzles. The plurality of nozzles are configured to spray liquid in different directions from each other, at different distances from the robot 110, or may be configured to spray liquid in substantially the same direction. The liquid applicator applies the liquid downward and outward, dropping or spraying the liquid in front of the robot 110. Alternatively, the liquid applicator may be a cloth or strip of ultra-fine fibers.

The liquid applicator is a sprayer comprising at least two nozzles. Each nozzle uniformly distributes the fluid across the floor surface in the form of two application liquids. The two nozzles are each configured to spray liquid at a different angle and distance from the other nozzle. Two nozzles are stacked vertically in a trough in the liquid applicator, the two nozzles being angled from the horizontal and spaced from each other such that one nozzle sprays a relatively long length of liquid forward and downward to cover the area in front of the robot 110 with a front feed of application liquid. The other nozzle sprays a relatively short length of liquid forward and downward to leave a rear supply of application liquid on an area that is in front of the robot 110 but closer to the robot 110 than the area of application liquid dispensed by the top nozzle. The one or more nozzles dispense fluid in a zone pattern that extends in size by one robot width and at least one robot length. The top and bottom nozzles apply the liquid in two different spaced apart application fluids that do not extend the full width of the robot 110. The nozzle completes each spray cycle by drawing a small amount of liquid at the opening of the nozzle so that no fluid leaks from the nozzle after each spray.

Fig. 2 is a schematic diagram of a path 200 taken by a robot (e.g., the robot 110 of fig. 1) during a cleaning operation. The path 200 taken by the robot 110 details the spraying, pad wetting and scrubbing actions of the robot. The robot 110 is configured to cover the floor surface by moving back and forth across the floor surface in substantially parallel rows (rank). Once the floor is covered, the robot 110 may perform perimeter cleaning operations to collect any debris or liquid left on the floor surface as the robot turns between columns.

The robot 110 uses a pattern of generally parallel rows to clean the floor surface. For example, the robot 110 may advance in a generally forward direction along the first column during a cleaning operation. The robot 110 continues to advance until a boundary of the floor surface is reached, such as a wall, carpet, cliff, etc. The robot 110 is configured to perform a 180 degree turn and return in a parallel but opposite direction to clean along a second column that is offset from the first column. The robot may rotate to offset the width of the robot to clean along the second column. Alternatively, the robot is turned to clean along the second row with an offset less than the width of the robot to ensure excessive cleaning coverage of the floor surface. The robot 110 has an overlap of 60-70% from the first column to the second column. During the cleaning operation, the robot 110 cleans a portion of the floor surface 2-4 times. This ensures that the floor surface has been cleaned. For example, the robot 110 loosens stains and debris in earlier passes, leaving time for any cleaning liquid that has been applied to wet the stains. The pad 100 of the robot 110 absorbs stains and remaining debris and fluid in a later pass.

The robot 110 cleans the floor surface by advancing generally forward in a straight row. The robot 110 performs a back-and-forward maneuver (back-and-forward) to inspect a portion of the floor surface prior to applying a liquid (e.g., cleaning solution, water, etc.) to the portion of the floor surface for a cleaning operation. In an embodiment, the robot 110 applies liquid to an area of the floor surface that the robot has passed through. In other embodiments, the robot 110 does not apply liquid, such as performing a dry cleaning operation. The robot 110 moves in substantially parallel columns without performing the backward and forward liquid applying operations.

The robot performs the liquid application operation by moving forward along the floor surface and then moving backward or backward. The robot 110 drives a first distance in a forward drive direction to a first position, for example from position 2 to position 3 in fig. 2. The robot 110 moves a second distance back to a second position, for example, from position 3 to position 1 shown in fig. 2. The spray nozzles spray liquid forward and/or downward from the robot 110 at longer and shorter distances onto a floor surface in front of the robot. After performing the previous liquid application operation, the robot 110 repeats the liquid application manipulation after the robot passes through a predetermined distance. The predetermined distance is approximately the length of the robot main body 120.

The liquid application operation ensures that the robot 110 applies liquid to an unobstructed portion of the floor surface. The area of the robot 110 applying the liquid is substantially equal to or less than the area of the robot 110. The robot 110 determines that the floor area not occupied by an obstacle (e.g., furniture, a wall, a cliff, a carpet, or other surface or obstacle) is a clear floor surface. The robot 110 identifies boundaries, such as floor changes and walls, and prevents liquids from damaging those items.

The robot 110 stores a map and tracks the positions that the mat 100 has occupied. During the cleaning routine, the robot 110 stores the coverage location on the map in a non-transitory memory of the robot or on an external storage medium accessible by the robot by wired or wireless means. The robotic sensor may include a camera and/or one or more ranging lasers for constructing a spatial map. In some examples, the robot controller uses maps of walls, furniture, floor variations, and other obstructions to cause the robot 110 to set a position and attitude at a distance of at least one spray length from the obstruction and/or floor variation prior to applying the cleaning liquid. This has the advantage of applying liquid to a floor surface without known obstructions. In some examples, the robot 110 moves in a back-and-forth motion to wet the pad 100 and/or scrub a floor surface to which liquid has been applied.

Fig. 3 is a side view of a pad 300 (e.g., pad 100 of fig. 1) illustrating the location where debris (e.g., debris 360) contacts the pad during a cleaning operation. As described below with respect to fig. 5-9, the pad 300 is thicker near the rear 320 of the pad than near the front 330 of the pad. When the robot 110 is moving forward, the pad 300 moves across the floor surface 310 from left to right as shown in FIG. 3. The front portion 330 of the mat passes through the floor surface before the rear portion 320 passes through the floor surface. The mat 300 contacts the floor surface 310 at the rear 320 of the mat, rather than near the front 330 of the mat. The front portion 330 of the pad 300 may be suspended above the floor surface 310 from the pad holder such that the leading edge 370 of the pad does not contact the floor surface. This configuration reduces or eliminates adhesion (e.g., suction) of the pads 300 on the floor surface 310 due to molecular suction applied between the wet pads and wet floor surface contact. This is because the surface area of the pad 300 that is in contact with the wet floor surface is reduced to an area that is less than the entire surface area of the pad 300 so that the robot 110 can overcome the molecular suction and push the wet pad 300 through the floor 310. For example, a small gap between portions of the pad 300 and the floor surface 310 may be maintained when the pad is suspended from the robot 110. This configuration may eliminate the need for a rough layer (e.g., a meltblown plastic layer) that would otherwise be required to reduce adhesion of the mat to the floor surface 310. For example, a mat having a constant thickness may adhere to the floor surface 310 when the mat is wet and the molecular suction between the mat and the floor surface requires a significant force to overcome and break the suction. Adhesion increases the force required to move the mat 300 across the floor surface 310 and causes the mat to push debris across the floor surface rather than clean the debris 360 from the floor surface. By reducing the surface area of the pad 300 that is in contact with the wetland surface 310, adhesion can be reduced.

Additionally, the front portion 330 of the pad 300 allows debris 360 and/or liquid to pass under the pad and contact the rear portion 320 of the pad. The different thicknesses of the front portion 330 and the back portion 320 facilitate uniform distribution of debris 360 on the pad 300, eliminating or reducing the occurrence of severe spots of deposited debris on the pad (e.g., relative to the rest of the pad). For example, debris accumulation on the front 330 of the pad is prevented. Severe spotting occurs when the debris 360 accumulates excessively on certain portions of the pad while other portions of the pad are clean or near clean and no or relatively little debris is collected in the pad 300. The different thicknesses of the front 330 and back 320 promote uniform wetting of the pad 300, for example, for wet cleaning operations. The liquid is absorbed by the rear portion 320 of the pad 300 and the front portion 330 of the pad. The pad 300 does not push debris and/or liquid along the floor surface 310, but rather lifts and collects debris and/or fluid from the floor surface. Taller, less compact debris 340 is collected by the front 330 of the pad 300, while more compact debris 350 is collected by the back 320 of the pad.

Fig. 4A-4D are bottom views of embodiments of cleaning pads (e.g., pad 300 of fig. 3) at various cleaning stages 400, 410, 430, 440, illustrating debris accumulation on the pad during cleaning operations. The increased thickness of the pad from the front 330 of the pad 300 to the rear 320 of the pad 300 promotes uniform wetting and debris collection of the pad 300 during cleaning operations. The varying thickness of the pad 300 may eliminate hot spots that accumulate excessive debris. Fig. 4A shows an exemplary pad 300 before a cleaning operation begins. The pad 300 is free of debris. Fig. 4B shows the exemplary pad 300 after a light cleaning operation or after one third of the cleaning tasks have been performed. The pad 300 has debris collected on both the front 330 and rear 320 portions of the pad. Fig. 4C shows the pad 300 after a medium cleaning operation or after two-thirds of the cleaning task has been performed. Although some portions of the pad 300 collect more debris than others, the pad 300 collects debris and wets relatively uniformly compared to a pad having a uniform thickness. Fig. 4D shows the pad 300 after a heavy cleaning operation or at the end of a cleaning task. The vast majority of the pad 300 is dirty, collecting debris during the cleaning operation. Both the front 330 and rear 320 of the pad 300 collect a significant amount of debris. In some embodiments, the rear portion 320 collects more debris than the front portion 330.

Fig. 5 is a bottom view of a pad 500 (e.g., pad 300 of fig. 3). The pad 500 has a length 510 that spans the width of a robot (e.g., the robot 110 of fig. 1), such as across and below the leading edge of the robot 100. The mat 500 has a width 515, the width 515 being divided into portions 530, 540, 550, 560, and 570 (collectively "portions 520"). The portion 520 of the pad 500 is formed by transition regions 580a-d (collectively "transition regions 580") that extend through the length 510 of the pad. Portions 520 may be considered pockets (pockets) separated by transition regions 580. Pad 500 includes a leading edge 590 (which is the same as leading edge 370 shown in fig. 3) and a trailing edge 595. Portion 530 forms a leading edge 590 and portion 570 forms a trailing edge 595. When the pad 500 is attached to a robot, the leading edge 590 is near the front of the robot 110. As the robot 110 moves forward during cleaning operations, the leading edge 590 first contacts the floor surface 310.

The length 510 and width 515 are sized such that the mat 500 may be secured to the mat holder of the robot 110. Other attributes of the pad 500, such as the vertical thickness, the planar width of each portion 530, 540, 550, 560, 570, may be enlarged or reduced to accommodate particular cleaning operations, such as larger or smaller floor surface areas and floor surface areas with more or fewer obstructions to traverse during a cleaning task. In one embodiment, the pad 500 has a width of about 5: 2 length 510 to width 515. The pad 500 may be of different sizes. In some embodiments, the pad 500 has a length 510 of about 27-32cm (e.g., 27cm, 30cm, or 32cm) and a width 515 of about 10-15cm (e.g., 10cm, 12cm, 15 cm). In an embodiment, the pad 500 has a length 510 of about 15-20cm (e.g., 15cm, 18cm, or 20cm) and a width of about 5-10cm (e.g., 5cm, 8cm, or 10 cm).

Portions 520 of pad 500 are defined by transition regions 580 a-d. Portion 520 extends across length 510 of pad 500. Portion 520 is a pocket formed between transition regions 580 and formed on one or both edges by transition regions 580. The transition region 580 is formed by bonding the various layers of the pad 500 (e.g., core 610, envelope 620, moisture resistant material 630) together, thereby defining the edges of the pocket forming portion 520. By securing the layers, each of the portions 520 generally has a thicker central region that tapers to a thinner transition region (e.g., region 580). In one aspect, the pad 500 includes five portions 530, 540, 550, 560, 570, although other configurations of the pad are possible. In an embodiment, the pad 500 includes less than five portions, e.g., two portions. For example, the first portion may be a forward portion that terminates at the leading edge 590. The second portion may be a rearward portion starting at the trailing edge 595 and ending at the beginning of the forward portion. Optionally, in an embodiment, the pad may have more than five sections to increase the surface area of the pad 500 and/or increase the number of transition regions 580 and thereby break contact (and thus break molecular suction) between the surface area of the wetting pad 500 and the floor surface 310 more frequently. Embodiments of the pad 500 with more transition areas 580 are less likely to adhere to a wet floor surface 310 during cleaning tasks because the adhesion of the wet pad on a wet floor is accompanied by non-contact areas. (e.g., the non-contact region is a transition region 580 recessed inward from a point of maximum thickness of each pocket of each portion 520).

Each transition zone 580 separates adjacent portions of the pad 500. The transition zone 580 is the area where the layers of the pad 500 are bonded together. The transition region 580 bonds the layers of the pad 500 together from the top surface of the pad to the bottom surface of the pad. The transition zone 580 prevents the material within the pad from bunching or sliding and ensures that the material of one or more layers of the portion 520 maintains their position relative to the rest of the pad 500. The transition zone 580 ensures that the pad 500 retains its shape during the cleaning operation; for example, the center of the pad 500 is thicker than the front of the pad 500. The transition region 580 may assist in drawing liquid from the floor surface and in transferring liquid to the liquid retention core 610, as described with respect to fig. 6. In some embodiments, the transition area 580 holds debris that has been loosened and scrubbed from the floor surface by the robot 100 by wetting the floor surface and moving the pad 500 in a forward-to-backward scrubbing motion.

The mechanical process forms the transition zone 580. For example, mechanical embossing (embossing) forms the transition region 580. The various layers of the pad 500 (e.g., core 610, envelope layer 620, moisture resistant material 630) are fed through a rotary embossing die (embossing dies) that compresses the layers of the pad together to form a mechanical impression belt along the transition zone 580. The layers of the pad 500 are mechanically bonded together because the indentations press through the thickness of the pad from one or both sides. In an embodiment, the mechanical indentation is formed by a hot stamping process that fuses the various layers of the pad 500 together along the transition region 580. The layers of the pad 500 are "sandwiched" together to form a bond at the transition zone 580. In an embodiment, the transition zone 580 is formed using ultrasonic welding. For ultrasonic welding, the layers of the pad 500 are held tightly together and a high frequency signal is applied to fuse the layers of the core 610, moisture resistant material 630, and encapsulant layer 620 together through the thickness of the pad 500 (e.g., from the top surface to the bottom surface). The transition region 580 adds stiffness to the pad 500 and helps to maintain the contoured shape of the pad 500 so that the layers of the core 610 and envelope 620 do not move laterally relative to each other. Because the transition zone 580 securely holds the layers of the pad 500, this enables the mobile robot 110 to apply a downward force on the top surface of the pad 500 and fully translate the applied force into the same force applied to the bottom surface of the pad 500 in contact with the floor surface 310. The greater the movement and force applied, the greater the scrubbing action to loosen debris from the floor surface.

In addition, the portions 520 of the pad 500 can each have a size that further promotes debris collection during cleaning operations. Each portion 520 includes a vertical thickness and a planar width along the anterior-posterior axis of the pad 500, and these thicknesses and widths are varied such that the pad 500 has a tapered configuration, as described above with respect to fig. 3 and below with respect to fig. 6. For example, the width of portions 530 and 570 (as a percentage of width 515) is shorter than the width of portions 540, 550, and 560. The portion 530 forming the leading edge 590 is also thinner than the other portions 540, 550, 560, 570, as described below with respect to fig. 6. The width of portion 530 is 12-17% of width 515. Portions 540, 550, and 560 each have a width that is 20-25% of width 515. The width of portion 570 is 8-13% of width 515. This allows the mat 500 to have an approximately triangular profile which allows the mat 500 to wet the front and rear of the mat relatively evenly and collect debris from the floor surface.

Turning now to fig. 6, a side view of one embodiment of the mat 500 illustrates a tapered profile that allows the mat 500 to avoid motion-stop adhesion and enables the mat 500 to collect and retain debris loosened from the floor surface 500. As the pad 500 moves in the direction of motion indicated by arrow 670, portion 530 is the forward portion forming the leading edge 590 and portion 570 is the rearward portion forming the trailing edge 595. As described above with respect to fig. 5, each of the portions 530, 540, 550, 560, 570 is separated by a transition region, such as transition region 580. The top of the pad 500 is relatively flat. The bottom of the pad 500 is defined by varying the thickness of the portion 520 (e.g., thicknesses 640, 650, 660), such as with an increased thickness at the rear relative to the front. For example, thickness 660 of portion 550 is thicker than thickness 650 of portion 540, and thickness 650 of portion 540 is thicker than thickness 640 of portion 530. In some examples, thickness 640 is about 2-5mm, thickness 650 is about 4-7mm, and thickness 660 is about 8-12 mm. The thickness 640, 650, 660 of the pad 500 may be scaled up or down depending on the size of the pad 500 and the robot 110 driving the pad 500.

In an embodiment, the mat 500 includes a core 610, an encapsulation layer 620, and a moisture resistant material 630, all of which form one or more layers of the mat 500. Fig. 7 is an exploded perspective view of the pad 500 showing each layer in the stack 700 in relation to other layers.

Each portion 530, 540, 550, 560, 570 of the pad 500 includes one or more liquid-absorbent layers that form the liquid-retaining core 610 of the pad. In some portions 520, the core 610 is formed from a stack of liquid-absorbent layers that may be bonded together. The wick 610 absorbs liquid in contact with the wick, for example, by capillary action, and distributes the liquid throughout the wick. For example, the wick 610 wicks liquid from the outer surface of the pad 500 and retains the liquid. The surface tension of the liquid absorbent layer prevents the wicking liquid absorbed by the core 610 from leaking into the underlying layers of the pad 500 or onto the floor surface 310. The core 610 holds the liquid in one or more absorbent layers so that the fluid does not leak back onto the floor surface 310, for example when the mat 500 is pressed against the floor surface 310 by the mat holder of the robot 110. In one embodiment, when less than 1 pound of force is applied to the core 610, the core 610 retains about 90% of the liquid absorbed from the floor. The core 610 absorbs up to 8-10 times the weight of the pad 500. The core 610 may be formed from a single stack of bonded absorbent layers or the core 610 may be formed from two or more stacks of bonded absorbent layers.

In an embodiment, the stack of bonded absorbent layers comprises an airlaid material (airlaid material). The airlaid material includes a surface that is approximately isotropic. The airlaid material can be a non-electrostatic (non-static) non-fibrous material. Multiple airlaid layers, each comprising a stack of absorbent layers, may be bonded together by a mechanical embossing process (e.g., as used in transition zone 580). Airlaid materials include cellulose pulp non-woven material (cellulose pulp nonwoven) air bonded to biocomponent fibers (biocomponent fibers). The fibers of the cellulose pulp are thermally bonded to the biocomponent polyethylene, polypropylene, or both, which have a low melting point. The mixture forms the core 610 such that the core 610 is absorbent and semi-rigid, such that the core 610 retains its shape when wet. The airlaid material uniformly disperses the absorbed liquid, preventing the liquid from accumulating or pooling at the low points of the core 610.

In embodiments, the absorbent layers of the core 610 may be thermally bonded or bonded with an adhesive to form a multi-stack absorbent layer (e.g., a core layer). The spray adhesive is uniformly applied over the absorbent layer to bond the layers together without forming ridges or rigid regions of the core 610. The adhesive comprises a polyolefin. The adhesive enables fluid to wick between the absorbent layers of the core 610, promoting a substantially uniform dispersion of fluid within the core. Latex adhesive may be applied to the absorbent layer of the core 610 to reduce lint (threading) of the absorbent layer to minimize the absorbent layer from falling off the core.

In embodiments, the core 610 may have a non-uniform density, for example, to promote wicking of liquid away from the surface of the core and toward the interior of the core. The surface of the core 610 may be slightly denser than the interior of the core. The denser surface of the core 610 is smoother and less absorbent than the interior of the core. The core 610 is configured to hold and disperse liquid throughout the center of the core.

The core 610 forms the base of the mat 500. The core 610 is semi-rigid to maintain the shape of the pad 500. The transition zone 580 stiffens the core 610 and helps the core maintain structure. The portions 520 of the mat 500 each include one or more layers of the core 610. Portions of the mat 500 have different numbers of layers comprised of the core 610 material. For example, portion 530 includes a single layer of core 610, while portions 540, 550, 560, and 570 each include two or more layers of core 610. In some embodiments, the single core 610 layer comprises an air-laid web. In some embodiments, the single core 610 layer includes latex.

In an embodiment, the encapsulation layer 620 encapsulates the core 610 of one or more layers and forms the outer surface of the pad 500. The encapsulating layer 620 comprises a flexible absorbent material that covers the core 610 and prevents direct exposure of the core to the floor surface 310. In an embodiment, the encapsulating layer 620 comprises a fiber entangled material. During the cleaning operation, the encapsulating layer 620 contacts the floor surface. During the cleaning operation, the encapsulating layer 620 absorbs liquid from the floor surface by capillary action. The encapsulating layer 620 transfers the liquid into the core 610 where it is retained by the pad 500.

The encapsulating layer 620 may be formed of a flexible, absorbent, and thin material, such as a spunlace material, a spunbond material, and the like. In some embodiments, the encapsulating layer 620 is formed by a fiber entanglement process applied to the precursor web (precusor web), such as hydroentanglement, jet entanglement, hydraulic needling, and the like. The precursor web is formed from textile-like staple fibers. The precursor web may be a single fiber web or a blend of many different fibers. The fibers may include one or more of polyester, viscose, polypropylene, cotton and other similar materials.

The encapsulating layer 620 is configured for use in wet, damp, or dry cleaning operations, such as for mopping or dusting a floor surface. The encapsulating layer 620 may include an outer coating composed of one or more cleaning materials, debris removal materials, and the like. Encapsulating layer 620 includes a detergent surfactant such as butoxypropionaldehyde, alkyl polyglycoside, dialkyl dimethyl ammonium chloride, polyoxyethylene castor oil, alkyl benzene sulfonate, glycolic acid, or other surfactant.

In some embodiments, the encapsulating layer 620 may include an outer coating consisting of antistatic agents, such as those based on long chain aliphatic amines (optionally ethoxylated) and amides, quaternary ammonium salts (e.g., behenyl trimethyl ammonium chloride or cocamidopropyl betaine), phosphate esters, polyethylene glycol esters, or polyols. Other aspects of the pad 900 configured for dry cleaning are described below in connection with fig. 9-10.

Returning to fig. 6 and 7, the pad 500 includes a moisture resistant material 630. The moisture resistant material 630 forms a moisture resistant layer and may be disposed between a portion of the encapsulant layer 620 and the core 610. The moisture resistant material 630 slows (e.g., slows the rate of) the transfer of liquid between the encapsulant layer 620 and the core 610. The rate of liquid transfer is controlled by the moisture resistant material 630 to control the rate of liquid absorption in the core 610. The moisture resistant material 630 improves the cleaning of the pad 500 because the pad 500 does not fill with liquid immediately upon cleaning, but leaves some liquid on the floor surface. For example, the envelope layer 620 wets before liquid is significantly absorbed into the core 610, thereby allowing the pad 500 to mop the floor surface 310. The moisture resistant material 630 is disposed between the core 610 and the envelope layer 620 such that liquid carried by the core 610 is not readily transferred back to the envelope layer 620, but is wicked to the interior of the core 610. The moisture resistant material prevents the encapsulating layer 620 from becoming saturated and this may cause the mat 500 to adhere to the floor surface 310 as moisture is adhered to the core 610. The adhesion of the pad 500 to the floor surface 310 prevents the pad from allowing debris and liquids to accumulate under the pad and prevent the robot 110 from moving on the floor surface 310.

In an embodiment, the moisture resistant material 630 comprises a batting material. The batting material includes loosely entangled fibers of low density relative to the core 610. The moisture resistant material 630 wicks fluid from the encapsulating layer 620 and transfers the liquid to the core 610 at a first rate that is slower than a second rate of liquid transfer that occurs when the encapsulating layer directly contacts the core. As described above, slowing the rate of liquid transfer enables the pad 500 to leave some liquid on the floor surface 310 during the cleaning operation, which enables the liquid to absorb stains or other debris on the floor surface for subsequent absorption into the pad 500 upon another mobile robot pass. In an embodiment, the mobile robot 110 traverses the floor surface 310 in overlapping parallel columns that stop at a 180 degree turn. In an embodiment, the robot 110 overlaps the previously traversed column, overlapping approximately two-thirds of the width of the robot 110 body, or two-thirds of the width of the pad 500 attached to the robot 110, such that every point on the floor surface is contacted three times by the pad 500. During these passes, liquid applied to the floor surface by the robot is wicked from the moisture resistant material 630 through the core 610. The low density of the moisture resistant material 630 prevents the moisture resistant material 630 from storing excess liquid and from transferring liquid from the core 610 back to the envelope layer 620. Such a configuration allows the encapsulating layer 620 to be drier to absorb more liquid from the floor surface 310 and improves wicking of liquid and suspended debris into the core 610. In an embodiment, the moisture resistant material 630 may include latex fibers. In an embodiment, the moisture resistant material 630 may comprise cotton batting.

The moisture resistant material 630 is disposed in the portion 520 in different amounts (e.g., different volumes but the same density). The moisture resistant material 630 imparts volume to one or more of the portions 520. The tapered cross-sectional shape of the pad 500 is formed by varying the amount of moisture resistant material 630 in each section 520 so that the rear portion of the pad is thicker than the front portion of the pad. In an embodiment, the density of the moisture resistant material 630 is approximately equal throughout the portions 520 of the pad 500, such that the rate of liquid absorption into the core 610 varies only with the volume of moisture resistant material in each portion 520. As in the embodiment of FIGS. 3, 5, and 6, portions 530 and 540 do not include the moisture resistant material 630 and portions 550, 560, and 570 include the moisture resistant material 630. The amount of moisture resistant material 630 in each portion controls how the mat 500 contacts the floor surface 310, for example, to promote even dispersion of debris collection on the bottom of the mat 500, as described above with respect to fig. 3.

The moisture resistant material 630 is disposed on a surface of the core 610, the surface of the core 610 facing the floor surface 310 during a cleaning operation. The top surface of the pad 500, including the pad backing (described in more detail below in connection with fig. 12-13), includes an encapsulation layer 620 in contact with the core 610. The moisture resistant material 630 is not required to reduce liquid transfer between the core 610 and the encapsulant layer 620 because the top surface of the pad 500 does not contact the floor surface 310.

Returning to fig. 5 and 6, the mat 500 has directly cut ends 525, 535 such that the core 610 is exposed at both ends of the mat 500. Because the encapsulating layer 620 is not sealed at the ends of the pad 500, the ends of the core 610 are not compressed and can absorb liquid. The full length 510 of the pad 500 is available for liquid absorption and cleaning. No portion of the core 610 is rendered incapable of absorbing liquid by compression by the envelope layer 620. Because the encapsulating layer 620 is not sealed at the ends 525, 535 of the pad, the core 610 is not compressed at the ends 525, 535 of the pad, and thus the ends 525, 535 are able to absorb as much liquid as the other portions of the core 610 of the pad 500 inward from the ends 525, 535. In addition, because the encapsulating layer 620 is not sealed at the ends 525, 535 of the pad, the used pad 500 does not have a wet-through, floppy end of the encapsulating layer 620 extending from the ends 525, 535 of the pad 500 at the completion of the cleaning operation. Rather, the liquid is absorbed and retained by the core 610, while dripping is reduced or prevented.

The thickness of the portion 520 promotes even distribution of debris collection on the pad 500. In some embodiments, the rear portion 320 of the pad is generally thicker than the front portion 330 of the pad 500 for the direction of movement 670 of the pad across a floor surface during a cleaning operation. The portions located at the front (such as portion 530) are thinner than the portions located at the rear (such as portions 540, 550, 560, and 570). For example, portion 530 includes a core 610 surrounded by an encapsulation layer 620 and has a first thickness 640. Portion 540 includes a core 610 of double thickness relative to portion 530, such as including two stacks of bonded absorbent material layers 710, 720. Portion 540 has a second thickness 650 that is greater than first thickness 640. The first thickness is about 5-10 mm. The second thickness is about 7-13 mm. Portion 530 includes a first thickness of core 610 and the other portions 540, 550, 560, and 570 each include a second thickness of core 610 that is approximately twice the first thickness 640.

In an embodiment, the pad 500 may include more than two portions. Portion 550 is located behind portions 530 and 540 and includes a moisture resistant material 630 between the encapsulating layer 620 and the core 610. Portion 550 has a third thickness 660 greater than second thickness 650 and first thickness 640. Portions 550, 560, and 570 each have a third thickness 630. The third thickness 630 is approximately 15-25 millimeters. Portions 550, 560, and 570 each increase in thickness. Each of the portions 550, 560, and 570 includes a moisture resistant material 630 disposed between the core 610 and the encapsulating layer 620.

The transition region 580 divides the width 515 of the mat 500 into a plurality of portions, as described above with respect to fig. 5. The transition region 580 is an area of width 515 in which the core 610, the encapsulant layer 620, and the moisture resistant material 630 (if applicable) are combined to form an indentation in the mat 500. Transition region 580 may have a thickness that is less than thickness 640 of the pocket of portion 520. The transition zone 580 helps prevent the pad 500 from sticking to the floor surface by creating intermittent locations across the surface area of the pad 500 where the pad 500 does not contact the floor surface 310 during cleaning operations. The intermittent transition regions 580 prevent the wet pad 500 from adhering to the floor surface 310 and reduce the amount of force required by the robot 110 to push the wet pad 500 across the floor surface, as they break the contact of the pad 500 with the floor surface 310. Additionally, the transition region 580 facilitates wicking between the core 610, the encapsulant layer 620, and the moisture resistant material 630 (if present). The wicking action provided by the transition zone 580 promotes uniform fluid absorption by the core 610 across the width 515 of the pad 500. For example, the mat 500 does not wet from front to back, but rather wets more evenly from the bottom of the mat 500 in contact with the floor surface to the top of the mat 500 that is secured to the mat holder of the robot 110.

Turning now to the type of cleaning application, FIG. 8 is a cut-away perspective view of an embodiment of a pad 500 for use in a wet cleaning operation (such as removing liquid from a floor surface 310). As discussed above with respect to fig. 6, the first layer 810 of the core 610 of the mat 500 extends across the width 515 of the mat, through each of the portions 530, 540, 550, 560, 570 and the transition region 580. The second layer 840 of the core 610 of the pad 500 extends across the portions 540, 550, 560, and 570. The core 610 is thinner in the front located portion 530 than in the rear located portions 540, 550, 560, 570. The encapsulating layer 820 extends under the entire core 610 for all portions 530, 540, 550, 560, 570, and encapsulates the core 610 above to surround the core 610. A moisture resistant material 630 is encapsulated into portions 550, 560, and 570.

The moisture resistant layer 830 gives the pad 500 bulk (e.g., vertical thickness) in the rear-located portions 550, 560, 570 and reduces or eliminates the contact area between the front-located portions 530, 540 on the floor surface relative to the contact area between the floor surface and the portions 550, 560, 570. The moisture resistant layer 830 suspends the portions 530, 540 just above the floor surface during the cleaning operation, with the pad 500 and robot 100 resting on the portions 550, 560, 570. Moisture resistant layer 830 is thicker in portion 570 than in portion 560 and thicker in portion 560 than in portion 550. The encapsulation layer 820 surrounds the moisture resistant layer 830, the first core layer 810, and the second core layer 840. The transition region 580 bonds the first core layer 810, the second core layer 840, the encapsulant layer 820, and the moisture-resistant layer 830 together (if applicable). Each portion 530, 540, 550, 560, 570 defines a pocket with an encapsulating layer 820 surrounding the first core layer 810 and the second core layer 840. For portions 550, 560, and 570, the encapsulating layer 820 forms a pocket around the moisture resistant layer 830.

Under the weight of the robot 110, the pad holder (e.g., the pad holder 1300 of fig. 13 described below) applies more pressure to the center of the pad 500 than to the edges 1295a, 1295b of the pad 500 because the pad 500 extends beyond the length of the pad holder 1300. Applying a pressure differential to the center and edges of the pad 500 promotes uniform wetting and debris accumulation on the pad 500 by allowing debris and liquid to pass under the pad to be absorbed and retained by the center portion of the pad. For example, as the robot 110 rotates, debris may traverse the length of the pad 500 from the sides to the center of the pad 500 and be collected and retained there, rather than being pushed by the sides or leading edge of the pad 500 and remaining on the floor surface 310 or merely accumulating on the edges of the pad. In an embodiment, the center of the mat 500 is 60-90% of the surface area of the mat 500 inward from the edges 1295a, 1296b and in contact with the floor surface 310. In an embodiment, the center of the pad 500 is located along a longitudinal axis 1280 that spans the lateral (e.g., left and right) edges 1295a, 1295b of the pad 500 and bisects the pad 500. In an embodiment, the pad holder 1300 of the robot 110 applies uniform pressure to the rear 320 of the pad 500, the rear 320 of the pad 500 spanning the length of the pad holder 1300 and contacting the floor surface 310. The pad holder 1300 is described in more detail below.

In this embodiment, portions 530 and 540 either do not contact the floor surface at all or have as much pressure as the rearwardly located portions 550, 560 due to the varying thickness of portions 530, 540, 550, 560 and 570. For example, core 610 is thinner in portion 530 than in portions 540, 550, 560, and 570. Portion 530 gently contacts or is suspended above floor surface 310 and allows some debris and liquid to pass under pad below portion 530, allowing the rearward located portions 540, 550, 560, 570 to wet and clear debris from the floor surface evenly, as described above. In addition, portion 540 does not include moisture resistant layer 830 and is thinner than portions 550, 560, 570 that include moisture resistant layers. Portion 540 allows some debris and liquid to pass under portion 540, which allows portions 550, 560, and 570 to clear debris and liquid from the floor surface. The pad 500 is configured to uniformly wet and collect debris uniformly on each portion 530, 540, 550, 560, 570 during a cleaning operation.

In other embodiments, the pad 900 is configured for a dry cleaning operation. Fig. 9 is a side view of pad 900. For example, the mat 900 is suitable for dusting floor surfaces. The pad 900 includes a front portion 910, a middle portion 920, and a rear portion 930. The front portion 910 is configured to form a leading edge 955 of the pad 900. The rear portion 930 is configured to form a rear edge 965 of the pad 900. The middle portion 920 connects the front portion 910 and the rear portion 930. Similar to pad 500, pad 900 includes an approximately triangular profile.

The core 940 extends across the width 950 of the pad 900. The core 940 may include a bonded absorbent layer that forms a semi-rigid base for the pad 900. Core 940 may be similar to core 610 of mat 500. For example, the core 940 may include one or more airlaid layers. Core 940 may be a different material that is less absorbent or not absorbent at all than core 610.

The encapsulating layer 960 encapsulates around one or more layers of the core 940 and forms the outer surface of the pad 900. Encapsulation layer 960 may be the same as or similar to encapsulation layer 620, as described above with respect to fig. 6. The encapsulating layer 960 may be different from the encapsulating layer 620, for example, comprising a non-absorbent or semi-absorbent material. In an embodiment, the encapsulating layer 920 includes an electrostatic coating that promotes the collection of debris by the encapsulating layer from the floor surface, as described above with respect to fig. 6. The encapsulating layer 960 is adhered to the core 940 using an adhesive such as glue. Pad 900 does not have a transition region, such as transition region 580 of pad 500. Rather, the portions 910, 920, 930 may be defined based on the amount of core 940 and volume layer 970 materials present in each respective portion 910, 920, 930. Since wet attractive (e.g., adhesive) molecular forces are not an issue in dry pad embodiments, the layers of the pad 900 are less likely to adhere and prevent the robot 110 from moving and/or the application of forces from the top of the pad 900 to the bottom of the pad 900.

In an embodiment, the pad 900 includes a bulk layer 970. The volume layer 970 is low density batting. The bulk layer may include a moisture resistant material 630, such as latex batting as described above with respect to fig. 6. The bulk layer 970 increases the thickness of the pad 900 in the rear portion 930 relative to the thickness of the front portion 910 and the middle portion 920. Bulk layer 970 forms a soft pillow-like surface in rear portion 930 that contacts the floor surface with greater pressure than the surfaces of front portion 910 and middle portion 920. The front portion 910 may be suspended above a floor surface, similar to the portion 530 of the pad 500 described above.

Each portion of the pad 900 includes a different amount of material such that the thickness of the pad varies from the front of the pad 900 to the back of the pad 900. The front portion 910 includes a core 940 surrounded by an encapsulation layer 960. The middle portion 920 includes a core layer having an increased thickness relative to the core layer of the front portion 910 and surrounded by an encapsulant layer 960. The back portion 930 comprises a core layer, a bulk layer 970, and an encapsulant layer 960, wherein the core layer of the back portion 903 has a greater thickness than the core layer of the front portion 910.

The pad 900 includes a thickness that increases from the front of the pad to the back of the pad 900. The front portion 910 has a first thickness 980, the first thickness 980 being thinner than a second thickness 985 of the middle portion 920. The second thickness 985 of the middle portion 920 is thinner than the third thickness 990 of the rear portion 930. In an embodiment, the first thickness 980 of the front portion 910 is 40-60% of the second thickness 985 of the middle portion 920. In an embodiment, the second thickness 985 of the middle portion 920 is 20-30% of the third thickness 990 of the rear portion 930. During a cleaning operation, the front portion 910 and the middle portion 920 contact the floor surface with less pressure than the rear portion 930, allowing debris to reach the rear portion without pushing the debris across the floor surface under the robot 110. The front portion 910 and the middle portion 920 allow some debris to pass through the lower portion of the pad 900 during cleaning operations, which promotes uniform collection of debris for each of the front portion 910, the middle portion 920, and the rear portion 930.

Fig. 10 is a perspective bottom view of the pad 900. The pad 900 increases in partial width in the direction of the pad width 950 from the front portion 910 to the rear portion 930. In an embodiment, the front portion 910, the middle portion 920, and the rear portion 930 may each have a different width, as measured along a fore-aft direction of the pad 500 corresponding to fore-aft movement of the robot 110 during travel. In an embodiment, the combined widths of the front portion 910 and the middle portion 920 together are about 30% -40% (e.g., 30%, 32%, 34%, 36%, 38%, or 40%) of the width 950, and in an embodiment, the rear portion 930 is about 60% -70% (e.g., 60%, 62%, 64%, 66%, 68%, or 70%) of the width 950. As described above, in embodiments, pad 900 does not include indentations that form transition regions 580 of pad 500, and does not require liquid wicking from encapsulant layer 960 to core 940.

FIG. 11 is a schematic diagram illustrating example end views of wet and dry pads according to an embodiment of the invention. Pad 1100 represents a wet pad (e.g., pad 500 of fig. 5-6). Pad 1130 represents a dry pad (e.g., pad 900 of fig. 9-10). Both pads 1100, 1130 include a "tapered" front portion and a "non-tapered" rear portion. During a cleaning operation, the front of the pad 1100, 1130 contacts the floor surface with less pressure than the rear of the pad 1100, 1130. For example, the front portion 1120 of the wet pad 1100 allows some fluid and debris to contact the rear portion 1110 of the pad 1100 from the floor surface. As described above, the difference in thickness between the front portion 1120 and the back portion 1110 promotes even wetting and debris dispersion across the length of the wet pad 1100. For the wet pad 1100, the ratio of the front 1120 width to the back 1110 width is approximately 1: 4 such that the front portion 1120 is about 20-30% (e.g., 20%, 22%, 25%, 26%, 28%) of the width of the wet pad 1110 and the back portion is about 70-80% (e.g., 70%, 72%, 74%, 75%, 76%, 78%, or 80%) of the width of the pad. The width of each pad is the dimension across the leading and trailing edges of the pad.

Similarly, dry pad 1130 includes a front portion 1150 that is thinner than a rear portion 1140. For example, the front portion 1150 of the dry pad 1130 allows some debris to contact the rear portion 1140 of the pad from the floor surface. As described above, the difference in thickness between the front portion 1150 and the rear portion 1140 promotes uniform debris dispersion across the length of the pad 1100. The difference in thickness between the front portion 1150 and the rear portion 1140 prevents debris from accumulating on the dry pad 1130, particularly in a small area known as a "debris hot spot" that collects debris while the rest of the pad 1130 remains clean. For example, in an embodiment, the ratio of the width of the front portion 1150 to the width of the rear portion 1140 of the dry pad 1130 is about 1: 3 such that the front portion 1150 is approximately 25-35% of the width of the dry pad 1130 and the back portion is approximately 65-75% of the width of the pad.

The respective ratios of the front portions 1110, 1140 and the back portions 1120, 1150 are different for the wet pad 1100 and the dry pad 1130. Dry crumb is more abundant and less adherent than wet crumb. The dry debris covers a greater portion of the dry pad 1130 during the cleaning operation relative to the portion of the wet pad 1100 covered by the wet debris. The dry pad 1130 includes a greater ratio of front width to back width relative to the wet pad 1100. The dry pad 1130 allows for a larger debris space to pass under the front portion 1150 of the dry pad and collect and compress the larger debris so that some portion of the debris is compact enough to be captured by the rear portion 1140 pressing against the floor surface 310. Because dry debris is more abundant and less compact than wet debris, dry pad 1130 has a more overhanging leading edge than wet pad 1100. By having a larger front portion 1150, the dry pad 1130 presses over the fluffy dry debris and collects much of the dust and debris below the front portion 1150, rather than pushing the larger debris around the front of the robot 110.

Turning now to the assembly of the pads 300, 500, 900 to the robot 110, as shown in the embodiment of fig. 12, a backing layer 1210 can be secured to the pad, with the backing layer 1210 serving as an interface between the pad and the robot 110. Fig. 12 is a top view of the pad 1200 showing the backing layer 1210 of the pad. The pad 1200 may include any of the pads described above. The backing layer 1210 includes a rigid or semi-rigid layer secured to the pad body 1220. The pad 1200 uses the backing layer 1210 as a base to attach to the robot 110. The backing layer 1210 includes one or more openings (e.g., openings 1230a and 1230b) for engaging with protrusions on the pad holder 1300 of the robot 110. The backing layer 1210 is attached to a pad holder of the robot 110, such as described below in fig. 13. In an embodiment, the backing layer 1210 is a paperboard material. In other embodiments, the backing layer is plastic and the pad is a reusable and/or washable material.

In some embodiments, the backing layer 1210 does not protrude beyond the edges 1295a, 1295b of the pad 1200 (edges 1295a, 1295b correspond to edges 525, 535 in the embodiment of the pad 500 of fig. 5). In an embodiment, pad holder 1300 of robot 110 holds backing layer 1210 by gripping edges 1250a, 1250b of backing layer 1210. In some embodiments, the longitudinal edges 1255a, 1255b protrude from the edges of the pad 1200. In some embodiments, the longitudinal edges do not protrude from the edges of the pad 1200. In an embodiment, the backing layer 1210 is shaped to engage with the pad holder 1300 in a single orientation and represents a pad type (e.g., wet, dry, etc.). For example, the shape of the backing layer 1210 can communicate to the robot 110 what type of pad (e.g., dry pad 1130 or wet pad 1100) is attached to the robot. For example, the shape of the backing layer 1210 may be asymmetric about the longitudinal axis of the pad such that the pad 1200 fits into the pad holder in a single orientation. In an embodiment, a printed arrow or other symbol indicates a preferred or desired orientation of the pad 1200 in the pad holder of the robot 110.

In an embodiment, the backing layer 1210 includes keyed apertures 1230a, 1230b that receive protrusions 1320a, 1320b of the pad holder 1300 of the robot 110 for securing the pad 1200 to the robot 110. In some embodiments, the apertures 1230a, 1230b are located at a symmetrical distance from the edges 1295a, 1295b such that the pad 1200 may be secured to the pad holder in more than one orientation. The aperture 1240 provides an opening for sensors on the robot 110 to detect pad type indicia on the top surface of the pad 1200 and transmit a signal to the robot 110 indicating the type of pad 1200. For example, pad types include wet pad 1100, dry pad 1130, hybrid dry and wet pads, and the like. In an embodiment, the aperture 1240 may be replaced with another type of indicator for communicating pad type information to a sensor or otherwise in communication with a controller of the robot 110. Such indicators include, for example, RFID tags, QR codes or other data-rich symbols, and the like.

The backing layer 1210 includes a pair of end stops 1260a, 1260b and a groove 1270 that help orient and attach the pad 1200 to a pad holder (e.g., the pad holder 1300 of fig. 13) of the robot 110. The end stops 1260a, 1260b extend beyond the edges 1250a, 1250b of the backing layer 1210 only on one end of the backing layer 1210, such that the backing layer 1210 slides into a pair of retention rails (e.g., the retainers 1340a, 1340b of fig. 13) in only one direction. This ensures that the leading edge 370, 590, 955 of the pad 300, 500, 900 is towards the front of the robot 110. The end stops 1260a, 1260b fit into recesses 1330a, 1330b, respectively, in the pad holder 1300 on the robot. For example, the embodiment of the backing layer of FIG. 12 has a planar profile that is "T" shaped and the end stops 1260a, 1260b form the top horizontal cross-member of the "T". The top of the "T" of the backing layer 1210 cannot fit under the retention rails 1340a, 1340b, and therefore the backing layer 1210 only engages the pad holder 1300 in a single orientation.

The groove 1270 depicted in the embodiment of the backing layer 1210 in fig. 12 engages a spring-loaded latch (not shown) below the retention rail 1340b of the pad holder 1300 on the robot 110. The spring loaded latch is a detent (not shown) that holds the pad 1200 in place during operation of the mobile robot 110. The stopping mechanism provides tactile feedback to the user to know when the backing layer 1210 is fully and securely inserted into the pad holder 1300.

In some embodiments, the pad 1200 includes one or more chemical preservatives that are applied to the backing layer 1210 or fabricated within the backing layer 1210. The preservative is selected to prevent wood spores, which may be present in the wood-based backing layer 1210. The backing layer is about 5-7 mm thick, 68-72 mm wide, and 92-94 mm long. Backing layer 1210 is coated on both sides with a water resistant coating, such as a wax or polymer, or a combination of water resistant materials, such as wax, polyvinyl alcohol, polyamine. The backing layer 1210 does not disintegrate when wetted, for example by liquid wicked from the floor surface by the pad 1200.

To secure the backing layer 1210 of the pad 1200, the robot 110 includes a pad holder 1300. Fig. 13 is a bottom view of an example pad holder 1300 on the robot 110. The pad holder 1300 is connected to the cleaning robot 110 and is configured to secure any of the above-described pads 300, 500, 900 to the robot 110. The pad holder 1300 includes a pad release mechanism 1310. The pad release mechanism is shown in an upper position or pad securing position. The pad release mechanism 1310 includes a movable retention rail 1340a (e.g., a lip) that holds the pad in place by supporting the edges (e.g., edges 1250a-b) of the backing layer 1210. The retention rail 1340b is a movable retention clip. In an embodiment, a toggle switch button may move a spring actuator that rotates the pad release mechanism 1310, thereby moving the retention clip 1340 away from the backing layer 1210. In an embodiment, the switch button is a pad release button located in a shock absorbing section on the front of the robot 110 or on the top of the robot 110. In an embodiment, the pad holder includes retractable protrusions 1320a, 1320b, the protrusions 1320a, 1320b retracting into the pad holder 1300 when the pad release mechanism 1310 is activated. In an embodiment, the pop-up projection 1350 slides upward through the slot 1352 or opening in the pad holder 1300. When the pad is to be ejected, the ejection protrusion 1350 extends through the slot 1355 and pushes against the backing layer 1210 to push the pad 300, 500, 900, 1200 from the pad holder 1300.

Under the weight of the robot 110, the pad holder 1300 is configured to apply different pressures against the floor surface (e.g., floor surface 310) to different portions of the pad (e.g., pad 500). The pad retainer 1300 can apply more pressure to the rear portion (e.g., rear portion 320) of the pad 500 so that the front portion (e.g., front portion 330) of the pad does not adhere to the floor surface 310 and push debris into the front portion of the pad 500 without entraining debris. Also, applying greater pressure to the rear of the pad 500 can promote even wetting and debris accumulation on the pad by allowing liquid and debris to pass under the front 330 of the pad to contact the rear 320 of the pad 500.

In an embodiment, the pad holder 1300 applies greater pressure to the center of the rear portion 320 of the pad rather than the edges 1295a, 1295b of the pad, where the edges 1295a, 1295b extend beyond the edges of the pad holder 1300 (the numbered cells refer to the individual embodiments of the pad shown in fig. 3 and 5). Since the pad holder does not extend beyond the width of the robot 110, the weight of the robot 110 presses directly on the portion of the pad 500 that is in contact with the pad holder 1300 rather than extending beyond the portion of the pad holder 1300. The center of the pad 500 includes a portion of the pad 500 that is disposed inwardly from the lateral edges 525, 535 of the pad 500. The lateral edges of the pad 500 are flexible. In an embodiment, the lateral edges extend beyond the body of the robot 110 and may curve to press against along a wall or surface of other objects directly adjacent to the robot 110. The pad holder 1300 applies uniform pressure to the center of the rear portion 320 of the pad 500 so that the pad 500 uniformly collects debris. Applying differential pressure to the center and edges of the pad can promote uniform wetting and debris accumulation on the pad 520 by allowing debris and liquid to pass under the pad 500 to the center of the pad 500. For example, as the robot 110 rotates, debris may pass the length of the pad 500 from the sides and reach the center of the pad 500 where it is collected by the pad 500, rather than being pushed by the sides of the pad 500 and left on the floor surface or merely accumulating on the edges of the pad 500. In an embodiment, the center of the pad 500 is 60-90% of the surface area of the pad 500 centered about the lateral axis 1290 (e.g., running fore and aft), inward from the edges 1295a, 1295b and in contact with the floor surface 310. In an embodiment, the center of the pad is located along a longitudinal axis 1280, the longitudinal axis 1280 spanning the lateral (e.g., left and right) edges of the pad 500 and bisecting the pad 500.

A number of embodiments have been described above. Accordingly, other implementations are within the scope of the following claims.