US20040172769A1 - Method and apparatus for cleaning fabrics, floor coverings, and bare floor surfaces utilizing a soil transfer cleaning medium - Google Patents

Abstract

An apparatus and method for cleaning fabrics, floor coverings, and bare floor surfaces utilizing a soil transfer cleaning medium is disclosed. A method of mechanically removing soil from a surface intended to be cleaned includes the steps of successively and repeatedly: wetting a portion of a cleaning medium with a cleaning liquid; extracting any soil and at least some of the cleaning liquid from the previously wetted portion of the cleaning medium; and wiping the surface intended to be cleaned with the portion of the cleaning medium so as to transfer soil from the surface intended to be cleaned to the cleaning medium. Portable and vehicle-based devices may be utilized to practice the method of cleaning.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a continuation-in-part of U.S. Ser. No. 10/081,374, now U.S. Pat. No. ______, which claimed the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/299,561 filed June 20, 2001.[0001]
• This application is related to U.S. Ser. No. 10/371,940, which also claimed the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/299,561 filed June 20, 2001, wherein all of these related applications are incorporated by reference herein.[0002]
FIELD OF THE INVENTION
• The present invention relates generally to surface maintenance or conditioning machines, and more particularly to those machines employing one or more surface maintenance or conditioning appliances or tools to perform a surface cleaning task.[0003]
BACKGROUND OF THE INVENTION
• In general, proper carpet maintenance involves regular vacuuming and periodic cleaning to remove soil by methods such as hot water extraction, shampooing, bonnet cleaning, foam cleaning, etc. Some of the soil is loosely found between carpet fibers while other soil is held upon the carpet fibers by some means such as electrostatic forces, van der Waals forces, or oil bonding. Still other soil is mechanically trapped by carpet fibers. Regular vacuuming is essential as it removes some of the loose soil that damages the fibers. Vacuuming maintains the surface appearance of a carpet and keeps the level of soil in the pile at an acceptable level. Vacuuming removes only particulate soil and some unbound or loosely bound surface dirt; therefore, other methods of cleaning are periodically required to improve the appearance of the carpet. Wet cleaning methods are better for removing oils, greases, bound dirt, and other forms of matter that cause soiling on carpet. These methods are often used by professional cleaners and trained personnel.[0004]
• One type of surface maintenance machine for carpet cleaning is referred to as a bonnet cleaner. Bonnet cleaners employ an absorbent bonnet or pad (hereinafter referred to as the “pad”) attached to a rotary driver for rotating the pad about an axis generally perpendicular to the carpet surface. Cleaning liquid is sprayed directly onto the carpet followed by the rotating pad used to agitate the carpet and transfer soil from the carpet onto the bonnet, i.e., the pad. Since the pad is commonly two-sided, the pad may be reversed once one side of the pad gets soiled to a selected level. The pad may be periodically replaced and later cleaned depending upon the application and wear characteristics of the pad.[0005]
• The soil transfer process of the bonnet cleaners may be characterized as a “circular engagement process” since the pad rotates relative to the carpet surface. The method employed by bonnet cleaners does have the advantage of being fast drying if a relatively small amount of cleaning liquid is employed. However, limitations of bonnet cleaners include transferring soil from soiled areas to a relatively cleaner area, leaving much of the cleaning fluid in the carpet, and having the potential to damage the carpet. With respect to the latter, some carpets, particular twisted ply variations, may be damaged by aggressive engagement with the rotating pad. Additionally, the bonnet cleaning process is a relatively labor intensive process since the pad requires frequent soil monitoring and frequent removal of soiled pads.[0006]
• Yet another limitation of bonnet cleaners is the relatively uncontrolled use of cleaning liquid in the carpet cleaning process as some areas of the carpet may receive more cleaning liquid spray than other areas. Reliance on operator spraying of cleaning liquid to the carpet surface may result in overwetting of some areas and underwetting of other areas.[0007]
• Another type of surface maintenance machine intended for carpet cleaning is referred to as an “extractor machine.” Extractor machines are commonly used for deep carpet cleaning. In general, an extractor is a transportable self-contained device which (i) sprays cleaning liquid directly onto the carpet to create a wetted carpet portion, (ii) agitates the wetted portion with a brush, and (iii) removes some of the cleaning liquid and soil in the carpet through a vacuum system. Generally, in the extraction process a relatively large quantity of cleaning liquid is applied on the carpet. While the vacuum system recovers a portion of the applied cleaning liquid, a significant portion is retained by the carpet. As a consequence, carpet drying times are substantially longer than in the bonnet cleaning process. Excessive carpet wetting may promote the growth of fungus and/or bacteria within the carpet. Additionally, carpet overwetting may also cause surface stains to appear or reappear as underlying soil or stains migrate from the bottom of the carpet to its surface. Additionally, extractors are generally limited to a single operational direction as the steps of wetting, agitation, and vacuuming are sequentially performed. As a result, extractor machines may be difficult to maneuver in some environments, i.e., complex floor layouts.[0008]
SUMMARY AND OBJECTS OF THE INVENTION
• An object of the present invention is the provision of a carpet cleaning machine promoting efficient use of cleaning liquid in carpet cleaning.[0009]
• Another object of the present invention is to enhance cleaning area per unit of cleaning solution.[0010]
• Another object of the present invention is to provide a cleaning method that permits a carpet to dry more rapidly.[0011]
• Yet another object of the present invention is to provide a carpet cleaning process that has the ability to lift carpet pile which exposes more of the carpet fibers to the surrounding drying air so as to permit the carpet to dry more rapidly than if the pile was not lifted.[0012]
• Yet another object of the present invention is the provision of a cleaning process and apparatus for cleaning a variety of surfaces, including but not limited to floor surfaces, stairways, walls, and upholstered furniture or other fabric surfaces.[0013]
• The present invention is directed both to a method of cleaning surfaces and an apparatus for performing the method. In a broad sense, the cleaning process is similar to a damp cloth wiping operation wherein soil from a surface is transferred to the damp cloth. More particularly, the cleaning process utilizes:[0014]
• In accordance with the present invention, a revolving cleaning medium, which after being wiped against a surface intended to be cleaned is wetted, followed immediately by the step of extracting so as to remove cleaning solution and any soil from the cleaning medium, and again wiped against the surface—the process revolving or repeating. In a preferred operation, one portion of the cleaning medium is wetted with cleaning liquid, while another portion is being extracted to remove soil and cleaning liquid therefrom, and while yet another portion is being wiped against the surface to transfer soil from the surface to the cleaning medium. The process continues in a revolving or cyclical manner so that each portion of the cleaning medium is sequentially wetted, extracted, and wiped against the surface.[0015]
• The method of cleaning surfaces in accordance with the present invention includes the steps of (i) wetting a revolving cleaning medium with a cleaning solution, (ii) followed by removing at least some of the cleaning liquid from the revolving cleaning medium directly after wetting by way of a moisture extraction device, and (iii) wiping the surface with the revolving cleaning medium so as to transfer soil from the surface to the revolving cleaning medium and subsequently removing transferred soil from the revolving cleaning medium.[0016]
• In accordance with present invention, a transportable device is utilized to perform the cleaning process on a carpeted surface. The device may be a relatively portable machine having a cleaning liquid tank, a soiled solution recovery tank, a vacuum system, and cleaning head. The cleaning head may include a revolving cleaning medium and associated drive mechanism. A vacuum extractor may be used to engage the cleaning medium to remove soil and at least some of the cleaning liquid from the cleaning medium.[0017]
• In accordance with one embodiment of the invention the revolving cleaning medium is configured as a pair of counter rotating cylindrical cleaning media having portions of each successively wetted, extracted, and wiped against a surface intended to be cleaned, with the process repeating or revolving.[0018]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective illustration of one embodiment of a cleaning machine according to the present invention.[0019]
• FIG. 2 is a perspective view of a cleaning head of the cleaning machine of FIG. 1.[0020]
• FIG. 3 is another perspective view of the cleaning head of FIG. 1.[0021]
• FIG. 4 is a side elevation view of the cleaning head of FIG. 1.[0022]
• FIG. 5 is a cross sectional view of the cleaning head of FIG. 2, taken along lines[0023]5-5.
• FIG. 6 is a detailed side elevational view of a portion of the cleaning head of FIG. 5.[0024]
• FIG. 7 is bottom plan view of the cleaning head of FIG. 1.[0025]
DETAILED DESCRIPTION OF THE INVENTION
• The present invention is directed both to a method of cleaning surfaces and an apparatus for performing the method. In a broad sense as will subsequently be described, the cleaning process in accordance with the present invention is similar to a damp cloth wiping operation wherein soil from a surface is transferred to the damp cloth.[0026]
• More particularly, the cleaning process in accordance with the present invention utilizes a revolving cleaning medium which after being wiped against a surface intended to be cleaned is wetted, followed immediately by the step of extracting so as to remove cleaning liquid, in part, and any soil from the cleaning medium, and again wiped against the surface—the process revolving or repeating.[0027]
• In a preferred operation, one portion of the cleaning medium is wetted with cleaning liquid, while another portion is being extracted to remove soil and cleaning liquid therefrom, and while yet another portion is being wiped against the surface to transfer soil from the surface to the cleaning medium. The process continues in a revolving or cyclical manner so that each portion of the cleaning medium is sequentially wetted, extracted, and wiped against the surface.[0028]
• FIG. 1 illustrates an embodiment of a transportable floor[0029]surface cleaning machine10 according to the present invention. More particularly,machine10, for illustrative purposes, is illustrated as an AC powered (with power cord not shown) self-contained portable carpet extractor similar to those known in the art, including acleaning solution tank12 for containing a cleaningliquid13, such as a mixture of water and a cleaning chemical, arecovery tank14, a cleaninghead20, a cleaningliquid dispenser22, and a soiledsolution extraction system24 as further described herein. In operation,machine10 is supported upon theground surface25 byrear wheels26 andcaster wheel28. Representative examples of self-contained portable carpet extractors havingcleaning solution tank12,recovery tank14, cleaningliquid dispenser22, and soiled solutionvacuum extraction system24 include models1230 and1260 extractors manufactured by Tennant Company, Minneapolis, Minn. In an illustrated embodiment, cleaninghead20 in accordance with the present invention may be used in conjunction with one of such known walk-behind extractor machines and the like.
• [0030]Cleaning head20, in accordance with the present invention, includes a cleaningmedium40 and associateddrive assembly60 as is more particularly shown in detail in FIGS. 2 and 3. Driveassembly60 selectively revolves cleaningmedium40 relative to cleaninghead20 andsurface25. In operation, cleaningmedium40 is intended to be first wetted with cleaningliquid13 by cleaningliquid dispenser22 and immediately followed by a moisture extraction process before being wiped againstsurface25 so as to transfer soil fromsurface25 to cleaningmedium40. In the extraction process, soil, as well cleaning solution resulting from the step of wetting the cleaning medium just performed, is removed from cleaningmedium40 by soiledsolution extraction system24. As further explained herein, cleaningmedium40 revolves during operation so that different portions of the cleaningmedium40 are simultaneously being wetted with cleaningliquid13, extracted byextraction system24, or wiped against thesurface25.
• Referring to FIGS. 1 through 3, cleaning[0031]head20 is attached at a forward portion of themachine10 via acoupling structure48.Coupling structure48 includes a pair offasteners50engaging apertures52 in cleaninghead20 and permitting cleaninghead20 to pivot or rotate about an axis (not shown) passing throughapertures52.Cleaning head20 may include one or more assemblies which are movably connected together so that the assemblies may move relative to each other so as to facilitate operational contact of the cleaninghead20 across undulating floor surfaces. In the illustrated embodiment, cleaning head includes forward andrear assemblies54,56, respectively.Forward assembly54 includes cleaningmedium40 in the form of a pair of counter rotating cylindrical cleaning pads and/or brushes62 and64, andvacuum extractor42.Rear assembly56 includes cleaningmedium drive assembly60,coupling structure48, andcaster wheel28.Caster wheel28 is coupled to cleaninghead20 to support at least a portion ofmachine10 onsurface25.
• As described above, cleaning medium[0032]40 functions to transfer soil fromsurface25 to the cleaningmedium40. For a carpet surface, cleaning medium40 functions to wipe the carpet and transfer soil from carpet fibers to the cleaningmedium40. A variety of different materials may be utilized as a cleaning medium, including but not limited to fabrics and absorbent foams, i.e., being “foam rubber” like.Cleaning medium40 in one embodiment of the invention as illustrated in the Figures includes a pair of cylindrical devices, i.e., cylindrical cleaning pads and/or brushes62 and64, hereafter referred to as simply brushes. However, it should be noted herein that cylindrical brushes62 and64, i.e. the cleaningmedium40, may be a constructed from any combination of pad-like or bristle-like or foam-like materials, and the like, which serve to transfer soil from the surface intended to be cleaned unto the cleaning medium.
• An exemplary construction of[0033]brushes62 and64 includes a substrate, such as a woven synthetic fabric, having pile fibers tufted thereinto. In one embodiment of the invention, the substrate has an appearance and feel that is similar to the surface fabric used on a common paint roller. In some instances, it may be desirable to intersperse stiffer fibers, i.e., brush like bristles, into the substrate to enhance the agitation action of cleaningmedium40. A 0.75inch pile 100% nylon roller fabric may be utilized to cover an extruded PVC tubing to formbrush62,64. Other materials and tube forms may be utilized to formbrush62,64.
• With particular reference to FIGS. 4 through 7, brushes[0034]62,64 of cleaningmedium40 are rotatably driven by cleaningmedium drive assembly60. Driveassembly60 includesdrive belts70,72,74,76 andelectric motors80,82,84.Drive belt70 is coupled to a common rotatingjackshaft86 which is driven by three smallelectric motors80,82,84. Eachmotor80,82,84 has an associateddrive belt72,74,76 to thejackshaft86. In alternative embodiments, a single electric motor may be utilized to rotatably drive cylindrical brushes62 and64. As depicted in FIGS. 5 and 6, cleaning medium brushes62,64 are rotated in opposite directions during operation. To facilitate cleaninghead20 contact withfloor surface25 during operation, front andrear assemblies54,56 are pivotally coupled aboutjackshaft86.
• In an exemplary embodiment of the invention, cleaning[0035]dispenser22 includes apump30, shown fixed to the main assembly ofmachine10—see FIG. 1, for pumping cleaningliquid13 throughconduit32 andnozzle34 thereby delivering cleaningliquid13 tobrushes62,64. Appropriate fluid controls, such as switches, valves, etc. (not shown) are provided to control the application of cleaningfluid13. As depicted in FIGS. 5 and 6,nozzle34 spray is substantially directed to the cleaning medium brushes62,64, and not surface25. Alternative dispensing means may include drip bars or tubes (not shown) for transferring cleaningliquid13 to cleaningmedium40.
• As indicated earlier,[0036]extraction system24 is intended to remove cleaningliquid13 and any soil from the cleaningmedium40, for example brushes62 and64. In the embodiment of the invention illustrated in the drawings,extraction system24 includes avacuum extractor42 which engages brushes62,64, avacuum conduit44, and avacuum fan46 to remove soiled solution frombrushes62,64 and to transfer soiled solution torecovery tank14. As particularly illustrated in FIGS. 4 and 5,extractor42 includes a bifurcated end having a pair ofelongate vacuum apertures92,94 in operational contact with associated cleaning medium brushes62,64. Soiled solution and airflow throughelongate apertures92,94 is joined at an upper portion ofextractor42 for further removal throughhose44 torecovery tank14.Elongate apertures92,94 are sized in relation tobrushes62,64 to remove soiled solution across substantially the entire transverse length of the brushes. An alternative vacuum extractor may include two separate vacuum extractor heads each having separate conduits to the recovery tank. As depicted in FIG. 5,extractor42 defines aninterior region98 in whichnozzle34 is provided. A spray of cleaningsolution13 directed toward cleaningmedium40, namely brushes62 and64, fromnozzle34 is intended to be generally contained withininterior region98.
• FIGS. 5-7 disclose an additional feature of the invention, that of drip guards[0037]96. In the absence ofdrip guards96,large droplets97 of cleaning solution formed on thewalls98 of the cleaninghead20 will tend to drop onto thecarpet surface25. This may result in a speckled or uneven appearance. Drip guards96 serve to preventdroplets97 from reachingcarpet surface25 during the cleaning process. Drip guards96 extend substantially the entire length of cleaning brushes64,66 and are provided in contacting relation with cleaning brushes64,66. Drip guards96 function to redirect cleaning solution thrown frombrushes64,66 back ontobrush64. As a result,large droplets97 of cleaning solution are prevented from being dropped onto thecarpet surface25. Drip guards96 are illustrated as a generally planar form. Alternative embodiments ofdrip guards96 may include curved or other complex forms. Drip guards96 may be formed as an integral portion of cleaninghead20 or may be a separate attachment secured within cleaninghead20. In one embodiment, drip guards96 are formed from 0.060 inch thick steel. In other embodiments, drip guards96 may be formed from one or more different materials and may have thicknesses which are different than 0.060 inch think.
• In operation,[0038]machine10 is operator-propelled across a surface. In accordance with the present invention,machine10 may be bi-directionaly operated—i.e.,machine10 may be propelled forwardly or rearwardly during operation. To initiate a cleaning operation, appropriate controls, such as switches (not shown), are used to activatevacuum motor46, cleaningmedium drive60 and cleaningliquid pump30. Upon activation, brushes62,64 of cleaningmedium40 are revolved viadrive assembly60 and cleaningliquid13 is dispensed throughspray nozzle34 to cleaning medium brushes62,64.
• Wetted portions of[0039]brushes62,64 may be defined as those brush portions which receive cleaning liquid from thespray nozzle34. Regardingbrush62, which rotates in a referenced clockwise manner, the wetted portion is generally that portion ofbrush62 between approximately 9 o'clock and 12 o'clock. Regardingbrush64, which rotates in a referenced counterclockwise manner, the wetted portion is generally that portion ofbrush64 between approximately 3 o'clock and 12 o'clock. Referring to FIG. 6, wetted portions ofbrushes62,64 are designated asnumerals100,102. The relative dampness or wetness of wettedportions100,102 is of course dependent upon the quality of thespray exiting nozzle34 and the rate of rotation of cylindrical brushed62 and64. For example, increased wetness ofbrushes62 and64 may be achieved by a slower rate of rotation and/or increased spray throughnozzle34.
• Prior to wetted[0040]brush portions100,102 being rotated into contact withcarpet surface25, the relative dampness is reduced by operation ofvacuum extractor42.Vacuum extractor42 engages eachbrush62,64 to remove some of the just deposited cleaningliquid13 and soil previously transferred from the carpet surface. Eachbrush62,64 of the cleaningmedium40 is engaged byrespective vacuum apertures92,94 ofvacuum extractor42 to reduce the local wetness ofbrushes62,64. As a result, rotatingbrushes62,64 have a wettedportion100,102 as defined above, and a reducedwetness portion104,106 which engages the carpet surface and transfers soil from the carpet tobrushes62,64.
• As[0041]brushes62,64 are revolved, reducedwetness brush portions104,106 engage the carpet fibers and cause soil to be transferred from the carpet fibers tobrushes62,64. As brushes62,64 are further rotated, the reduced wetness portions104,106 (having received soil from the carpet) are sprayed with cleaning liquid throughnozzle34 and subsequently vacuum extracted throughextractor42 to convey soiled cleaning liquid frombrushes62,64 into soiledsolution recovery tank14.
• The cleaning process, in accordance with the present invention, thus includes the steps of wetting a portion of cleaning[0042]medium40 with cleaningliquid13, reducing the relative wetness of the wetted portion of the cleaning medium by extraction, and then wiping the surface intended to be cleaned with the cleaning medium so as to transfer soil from the surface intended to be cleaned to the cleaningmedium40. Soil upon the cleaningmedium40 is subsequently removed as the revolving cleaning medium is rewetted and extracted. In turn, the aforesaid cleaning process repeats as a cycle with cleaningmedium40 revolving, cleaningliquid13 being conveyed to cleaningmedium40,extractor42 reducing the relative wetness of a portion of the cleaning medium40 (and removing soiled solution therefrom), and cleaningmedium40 wiping the carpet to transfer soil from the carpet to the cleaningmedium40.
• Additional aspects of the present invention will be addressed. It is envisioned that the cleaning process according to the present invention may be performed on a variety of different machines, ranging from small manually operated devices, to large self-propelled vehicles. The illustrated device is a self-contained portable cleaning machine, more particularly an operator propelled unit with solution, pump, brush, and vacuum recovery tank. In alternative embodiments, machine[0043]11 may include a vehicle, such as a ride-on or towed-behind vehicle, or be a hand held machine performing a cleaning operation as described herein.Machine10 may be powered through an on-board power source, such as batteries or an IC engine.
• In alternative embodiments, cleaning[0044]head20 may be provided as an accessory or optional item for use with other cleaning machines. In other embodiments, cleaninghead20 may be utilized upon larger, operator driven machines.
• Embodiments of the present invention may be utilized for cleaning a variety of floor surfaces, including but not limited to carpets, rugs, tile, vinyl, terrazzo, wood floors, and concrete surfaces. Additional surfaces which may be cleaning through a process as described herein include walls, stairways, upholstered furniture or fabric, such as curtains and the like. In a particularly preferred embodiment and as described herein with reference to[0045]machine10 operation, the present invention is utilized for cleaning floor coverings.
• [0046]Surface cleaning medium40 may be one or more elongated cylindrical elements, as depicted in the Figures, wherein each elongated cylindrical element rotates about a generally horizontal axis of rotation generally in parallel with the surface intended to be cleaned. The axis of rotation in a particularly preferred embodiment being aligned generally transverse to the direction of intendedmachine10 operation. Alternatively, cleaningmedium40 may be one or more disk-shaped elements which rotate about one or more generally vertical axes of rotation generally transverse to the surface intended to be cleaned.
• Yet another embodiment of cleaning[0047]medium40 may include a belt, with an outward belt surface being a cleaning medium, trained between two or more rollers, the belt moving as the rollers rotate. With this belt-type cleaning medium, it should be appreciated that the belt is intended to revolve so that the outward belt surface having the cleaning medium thereon sequentially passes a wetting operation, followed by an extraction process, followed by a soil transfer process—i.e., wiping the intended surface to be cleaned with cleaning medium surface of the belt. Additional embodiments of cleaning mediums are of course possible as may be appreciated by those skilled in the relevant arts.
• In another[0048]embodiment cleaning medium40 may be a cylindrical shaped element having a combination of foam and bristle surfaces. (not shown) In alternative embodiments, cleaningmedium40 may comprise a revolving belt as aforesaid.Cleaning medium40 may include a variety of different materials including fabrics, synthetic scouring pads and foam elements and the like which serve the intended function of transferring soil from a surface being wiped onto the cleaning medium.
• [0049]Extractor42 may be provided by a wide array of structures and techniques as may be appreciated by those skilled in the relevant arts including, including but not limited to non-vacuum techniques such as pressing or squeezing, all of which are intended to be within the true spirit and scope of the present invention.
• Further, although cleaning[0050]solution dispenser22 is illustrated as being operated by a pump on the main assembly ofmachine10, other arrangements are of course possible so as to achieve the intended function. As used herein, and the appended claims, the cleaning liquid may comprise any cleaning solution which assists the transfer of the soil on the surface intended to be cleaned unto the cleaning medium. For example, cleaningliquid13 could also be in the form of a foam, vapor, liquid with suspended solids, a granular cleaning material, plain water, and the like. Of course,liquid dispenser22 would be of different form than that as illustrated in order to accommodate the selected cleaning liquid or material. Therefore, as used herein and the appended claims, wetting of the cleaning medium encompasses, but not limited to, depositing, applying, or conveying such material onto the cleaningmedium40.
• In alternative embodiments of the present invention, cleaning[0051]head20 may be coupled tomachine10 via a plurality of pivot points, a four bar linkage, or alternative structures which facilitate head movement and cleaning medium engagement across both even and uneven floor surfaces.
• Other modifications to the described embodiment may also be practicable. One or more cleaning liquid dispensing devices may be utilized in alternative embodiments of the invention. Additionally, the vacuum extractor may be alternatively configured and include a different extractor structure. For example, a plurality of vacuum extracting locations may be practicable, i.e., a first vacuum extraction location for reducing the relative dampness of the rotating cleaning medium prior to contact with the floor surface, and a second vacuum extraction location for removing soiled solution from the cleaning medium. In yet another example, a rotating belt machine may include a first cleaning liquid dispensing device, a first extraction device for reducing the dampness of the belt prior to contact with carpet, a second cleaning liquid dispensing device, and a second extraction device for removing soiled solution from the belt. As various changes could be made in the above methods and devices without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Definitions are provided herein with reference to terms used in the specification and appended claims:[0052]
• “Revolving”: 1. Tending to revolve or happen repeatedly. 2. Available at regular intervals. As used herein, the term broadly describes a cyclical movement of the cleaning medium relative to the surface. A cylindrical shaped “revolving” cleaning medium may be rotated about an axis of rotation. A belt shaped “revolving” cleaning medium may be supported for movement about a pair or more rotating elements, e.g., rollers, etc. More complex motions or movements of the cleaning medium relative to the floor are also intended to be included within the broad definition of the term revolving, including but not limited to oscillatory and/or motions.[0053]
• “Extracting”: 1. Drawing or pulling out, using force or effort. 2. To remove or obtain from a substrate by mechanical action, as by mechanical pressure or vacuum. As used herein, the term broadly describes the step of removing cleaning liquid and/or soil from the cleaning medium. The step of extracting may be achieved through a mechanical shearing type operation, or a vacuum removal operation, or both.[0054]
• “Wiping”: 1. Engaging, contacting. As used herein, the term broadly describes physical engagement between the cleaning medium and the surface being cleaned. Each of a rotating elongated cylindrical brush, disk brush or pad when engaging a surface to be cleaned is considered to be in “wiping” contact with the surface. Wiping does not necessarily imply or suggest removing liquid from a surface. In a carpet cleaning device of the present invention, a cleaning medium being wiped against the carpet surface would transfer some amount of cleaning liquid to the carpet surface.[0055]

Claims (22)

We claim:

1. A method of mechanically removing soil from a surface intended to be cleaned, said method being performed by a surface maintenance machine and comprising the steps of repeatedly:

wetting a portion of a revolving cleaning medium with a cleaning liquid;

extracting some soil and some of the cleaning liquid from the previously wetted portion of the cleaning medium; and

wiping the surface intended to be cleaned with the portion of the revolving cleaning medium so as to transfer soil from the surface intended to be cleaned to the cleaning medium.

2. The method ofclaim 1 further comprising the step of extracting soil and cleaning liquid on the portion of the cleaning medium previous wiped against the surface intended to be clean and prior to again wetting the same portion.

3. An automated method of removing soil from a surface intended to be cleaned by a movable machine having a revolving cleaning medium comprising the steps of repeatedly:

wetting a portion of the revolving cleaning medium with a cleaning liquid;

extracting some soil and some of the cleaning solution from said previously wetted portion of the revolving cleaning medium; and

wiping the surface with said portion of the revolving cleaning medium previously extracted so as to transfer soil from the surface intended to be cleaned to the revolving cleaning medium.

4. The method ofclaim 3 further comprising the step of extracting soil and cleaning solution from the portion of the cleaning medium previously wiped against the surface intended to be clean prior to again wetting the same portion.

5. A method of removing soil from a surface intended to be cleaned using a movable machine, said method comprising the steps of:

moving the movable machine across the surface while performing the steps of:

wetting a portion of a revolving cleaning medium with a cleaning liquid;

extracting soil and cleaning liquid from said portion of the revolving cleaning medium; and

wiping the surface with said portion of the revolving cleaning medium so as to transfer soil from the surface intended to be cleaned to the cleaning medium

6. The method ofclaim 5 wherein the step of wetting the portion of the revolving cleaning medium includes spraying cleaning liquid onto the cleaning medium.

7. The method ofclaim 5 wherein the step of extracting soil and cleaning liquid from the portion of the cleaning medium is achieved through a vacuum extractor.

8. The method ofclaim 5 wherein the cleaning medium includes at least one elongated generally cylindrical shaped element rotating generally about an axis of rotation.

9. The method ofclaim 8 wherein the cleaning medium includes a pair of elongated generally cylindrical shaped elements which are counter-rotated relative to each other, and wherein said axis of rotation is generally parallel with the surface intended to be cleaned.

10. The method ofclaim 9 wherein the step of extracting is achieved through a pair of vacuum apertures, each of said pair of vacuum apertures being associated with a different one of the counter-rotated elongated generally cylindrical shaped elements.

11. The method ofclaim 8 wherein the axis of rotation is aligned in a direction generally transverse to an operational direction of device movement across the surface.

12. The method ofclaim 5 wherein the surface is a carpet surface, and wherein the step of wiping the surface transfers soil from fibers of the carpet surface to the cleaning medium.

13. The method ofclaim 5 wherein the surface is a fabric surface, and wherein the step of wiping the surface transfers soil from fibers of the fabric surface to the cleaning medium.

14. The method ofclaim 5 wherein the movable machine includes at least one drip guard in contact with at least a portion of the cleaning medium for redirecting cleaning solution within a cleaning head toward the cleaning medium.

15. A method of cleaning a carpeted surface, said method being performed by a surface maintenance machine and comprising the steps of repeatedly:

spraying a portion of a revolving cleaning medium with a cleaning liquid;

removing some soil and some of the cleaning liquid from the previously wetted portion of the cleaning medium using a vacuum device; and

wiping the carpeted surface with the portion of the revolving cleaning medium so as to transfer soil from the carpeted surface to the cleaning medium.

16. The method ofclaim 15 wherein the step of spraying involves pumping a cleaning liquid from a reservoir carried by the surface maintenance machine.

17. The method ofclaim 15 wherein the step of removing involves applying a vacuum to the previously wetted portion of the cleaning medium so as to convey soil and cleaning liquid to a receptacle of soiled solution carried by the surface maintenance machine.

18. The method ofclaim 15 wherein the step of wiping involves rotating a cylindrical cleaning medium in contact with the carpeted surface.

19. The method ofclaim 18 wherein the cylindrical cleaning medium is rotated about an axis which is generally perpendicular to a direction of machine use.

20. The method ofclaim 15 wherein the surface maintenance machine either a self-propelled machine or a non-propelled machine.

21. The method ofclaim 15 wherein the movable machine includes at least one drip guard in contact with at least a portion of the cleaning medium for redirecting cleaning solution within a cleaning head toward the cleaning medium.

22. A method of cleaning a carpeted surface, said method being performed by a surface maintenance machine and comprising the steps of repeatedly:

spraying a portion of a revolving cleaning medium with a cleaning liquid;

removing some soil and some of the cleaning liquid from the previously wetted portion of the cleaning medium using a vacuum device;

wiping the carpeted surface with the portion of the revolving cleaning medium so as to transfer soil from the carpeted surface to the cleaning medium, said step of wiping causing an amount of cleaning liquid to be thrown from the cleaning medium into contact with interior surfaces of a cleaning head; and

redirecting the amount of cleaning liquid thrown from the cleaning medium back toward the cleaning medium so as to minimize the dropping of large droplets of cleaning solution onto the carpeted surface.

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