Robotic Carpet and Rug Deep Cleaner

This invention combines multiple tasks associated with carpet deep cleaning. It includes a self-propelled cleaner and guide system that will dispense, brush and retrieve a dry carpet cleaning pretreatment and powder across the surface of the carpet.

DETAILED DESCRIPTION

This invention combines multiple tasks associated with carpet deep cleaning. The robotic cleaner of the present invention is a self-propelled and self-guided system that will dispense, brush and retrieve a dry carpet cleaning pretreatment and/or powder across the surface of a carpet or rug. The robotic cleaner may dispense the pretreatment and/or powder substantially evenly across the surface of a carpet or rug. The robotic cleaner includes a stored power source, such as a battery, for operation. The powder source is preferably rechargeable. The cleaning system may also include a remote control for ease of use by an operator.

Prior to operation, the robotic cleaner is filled with one or more cleaning compositions and placed in the area to be cleaned. To determine the cleaning area, the cleaning system (i.e. the robotic cleaner and guidance system and any other parts that are used in connection with the robotic cleaner) will include a guidance system, such as a GPS and/or a combination of transmitters and receivers, that identify the perimeter of the cleaning area by sensing markers or transmitters that are present in the cleaning area. These sensing markers and/or transmitters help the robotic cleaner identify the perimeter reference points and are placed in the cleaning area by the operator prior to cleaning to aid the robotic cleaner in sensing the cleaning area.

As one exemplary embodiment, an internal mapping system with sensors (e.g. stairway sensors, bumper sensors, and the like), processors, and optionally at least one camera, may be employed as the guidance system that provides navigation information to the robotic cleaner. One such internal mapping system that may be ideal for use with the robotic cleaner of the present invention is disclosed in U.S. Pat. No. 7,805,220 to Taylor et al., which is entirely incorporated by reference herein.

After the robotic cleaner is powered up, it will sense the perimeter markers and begin moving within those markers. As it begins to move it will begin dispensing the pretreatment and/or cleaning composition (“cleaning materials”) onto the surface of the carpet or rug. A brushing mechanism may also be activated to brush the pretreatment and/or cleaning composition into the surface of the carpet or rug. The brushing mechanism may operate at the same time as the pretreatment and/or cleaning composition is being dispensed, or it may operate in a second pass over the carpet or rug after the dispensing step is completed

The robotic cleaner will dispense the pretreatment and/or cleaning composition in any pattern as it moves over the surface of the carpet or rug. For example, it may move in a back and forth pattern, a circular pattern, etc. It may move forward and backward or it may only move in a forward direction. The robotic cleaner will continue to move over the surface of the carpet until it has dispensed the cleaning materials over the entire area to be cleaned. The robotic cleaner may dispense the cleaning materials in a substantially uniform manner. Preferably, the robotic cleaner will avoid moving over areas that have already been passed over. If the robotic cleaner dispenses all of the cleaning materials prior to completing its course over the carpet or rug, it will signal the operator to add more cleaning materials.

The robotic cleaner may be programmed to operate in a rest state while the cleaning materials are given time to clean the carpet or rug and/or to allow the cleaning materials to dry. For example, the robotic cleaner may rest in an idle state for approximately 15 minutes, or 30 minutes, or 45 minutes, or one hour.

After the optional rest period has elapsed, the robotic cleaner will power back up and retrace its path in vacuum mode. While in vacuum mode, the robotic cleaner may move in any direction and/or pattern that allows it to retrieve the cleaning materials. For example, it may move forward and backward, or it may move in a circular pattern. In this manner, the robotic cleaner retrieves the cleaning materials that have been dispensed.

FIG. 1Aillustrates the top view of one embodiment of the robotic cleaner100of the present invention. As shown, the robotic cleaner has wheels109for ease of movement over a carpet or rug. Opening105is provided for adding the powder cleaning composition to the robotic cleaner100. Power buttons103are provided which are utilized by the operator to begin movement of the robotic cleaner100. A flip up cover107is provided which allows the use to empty the contents of the material that has been vacuumed up from the carpet or rug. Charging outlet101is provided so that the operator can re-charge the robotic cleaner after use.

FIG. 1Billustrates the bottom view of one embodiment of the robotic cleaner100of the present invention. Dispensing chamber106is provided as an opening for spreading the powder cleaning composition onto the surface of the carpet or rug. The powder cleaning composition is added to the robotic cleaner through opening105shown inFIG. 1A. Brushing mechanism108is provided to agitate the powder cleaning composition into the surface of the carpet or rug. Retrieval chamber110is provided to allow retrieval of the powder cleaning composition from the carpet or rug. The powder cleaning composition, and any other materials present on the carpet or rug, is vacuumed up through retrieval chamber110and is stored in an area which is accessed by flip up opening107shown inFIG. 1A.

FIG. 3illustrates the side view of one embodiment of the robotic cleaner100of the present invention. Storage bin306is shown as an area where the powder cleaning composition is stored in robotic cleaner100. Vacuum motor and retrieval bin310is an area of the robotic cleaner where the vacuum motor may be located and where a compartment or bin is separately located for collecting the material that is vacuumed up from the surface being cleaned. Robotic cleaner100includes a battery compartment304for storing a battery. The battery provides energy for operating the robotic cleaner. While wheels109are illustrated inFIG. 1Aas means for allowing movement of the robotic cleaner over the flooring surface, rubber track309is illustrated here inFIG. 3as an alternative means for allowing movement of the robotic cleaner over the flooring surface.

FIG. 2illustrates one embodiment of the operation of robotic cleaner100. A room200is shown that contains a carpet or rug210. A guidance system201is provided which communicates with the robotic cleaner100, allowing it to maneuver robotically over the surface of the carpet or rug. Robotic cleaner100is shown in operation mode moving in a back and forth pattern208over the surface of carpet or rug210.

The powder cleaning composition generally comprises an absorbent particulate material, a super absorbent polymer, and other ingredients. Other ingredients include, without limitation, organic liquids, surfactants, surface active agents, static reducing additives, dust suppressing additives, vacuum retrieval additives, metal ion chelators, stain resist agents, pH adjusters, fragrance, biocides, water, and the like. The absorbent particulate material, super absorbent polymer and other ingredients comprising the powder cleaning composition may be present in any of a number of combinations, as may be determined by the specific end-use of the powder cleaning composition.

The absorbent particulate materials may be selected from a wide variety of solid materials. The solid materials may include naturally occurring materials, such as wood particles (like sawdust or wood flour), particles made from grains and other vegetable matter, diatomaceous earth particles, cellulosic particles and inorganic particles (such as silicates, borates, etc.). The solid material may also be a synthetic material, such as a synthetic resin material. Synthetic resin materials include, for example, urea formaldehyde polymer, such as those disclosed in commonly assigned U.S. Pat. Nos. 4,434,067 and 4,908,149. Other synthetic resin materials include, for example, polyurethane, polystyrene, and phenol-formaldehyde resin particles, similar to the type disclosed in French Patent No. 2,015,972 assigned to Henkel Et Co Gmbh. Still other absorbent particulate materials include water insoluble inorganic salt adjuvants such as, for example, sulfates, carbonates (such as calcium carbonate), borates, citrates, phosphates, metasilicates and mixtures thereof.

The absorbent particulate material may be present in the composition in an amount between 0.1% and 75% by weight based on the total weight of the composition, more preferably between 10% and 65% by weight based on the total weight of the composition, and even more preferably between 25% and 60% by weight based on the total weight of the composition.

Average particle size of the absorbent particulate material may be from about 10 microns to about 300 microns in diameter as determined by sieve analysis. It may be more preferable that the average particle size of the particulate is from about 10 microns to about 200 microns in diameter as determined by sieve analysis. It may be even more preferable that the average particle size of the particulate material is from about 10 microns to about 105 microns in diameter as determined by sieve analysis. It may yet be even more preferable that the average particle size of the particulate is from about 35 microns to about 105 microns as determined by sieve analysis. In general, it may be preferable for some applications that the particle size distribution should be such that not more than about 10 percent of the particles are larger than about 105 microns and in general no more than about 5 percent of the particles are smaller than about 10 microns. Larger particles typically do not penetrate carpet material adequately, and use of such particles would result in only superficial cleaning at best. Larger particles also have insufficient surface area to absorb a large amount of soil per unit of weight. If the particles are smaller than about 10 microns in diameter, they may adhere to the individual carpet fibers and have a delustering or dulling effect on the color of the carpet. While particles between about 10 and 35 microns may be tolerated, they may not contribute to cleaning efficiency to any substantial extent so that the average particle size should be in excess of 35 microns.

The absorbent particles may be further characterized by the classical Critical Pigment Volume (CPV) effect, also known as the oil value or oil absorption value. This value may be determined by ASTM D281 and is described, for example, in U.S. Pat. No. 3,956,162 to Lautenberger. To remain a flowable powder, the maximum liquid content is restricted to below the oil absorption value. For particles of a certain shape, the oil absorption value is the volume between particles filled with air. As the air is displaced by a fluid, the flow properties of the powder are reduced until, at the oil absorption value, all the particles are surrounded by liquid. Accordingly, it may be preferred that the absorbent particles have an oil absorption value of at least 40. It may be more preferable that the absorbent particles have an oil absorption value of at least 60.

One potentially preferred, non-limiting solid material for use in such compositions is the type which has been disclosed in U.S. Pat. No. 4,013,594 to Froehlich et al. wherein particulate, polymeric urea formaldehyde particles were proposed for use in dry-type cleaning compositions. These particulate urea formaldehyde materials were distinguished in the Froehlich patent from those of the earlier French Patent No. 2,015,972 based upon a fairly broad range of parameters. Of particular interest was the disclosure that the particles described in the Froehlich patent, as compared to the particles of the French patent, possessed a somewhat higher bulk density of at least about 0.2 grams per cubic centimeter. Such higher bulk density characteristics resulted in generally increased cleaning effectiveness as compared to the prior art particles. With respect to urea formaldehyde particles, it is noted that these particles may contain approximately 35-40% moisture content when manufactured.

Super absorbent polymers (“SAPs”) may include those polymers made from partially neutralized, lightly cross-linked poly(acrylic) acid compounds. Several commercially available super absorbent polymers that may suitable for incorporation into the present cleaning composition include the Luquasorb® products available from BASF, such as Luquasorb® 1010, Luquasorb® 1003, Luquasorb® MA 1110 and the Hysorb™ products available from BASF such as Hysorb™ 8400.

It has also been noted that some super absorbent polymers change color over time and exhibit shades of yellow or brown. These particular SAPs may be less desirable for use, since it is intended that the powdered cleaning composition remain white in color.

It is believed that smaller particle size SAPs absorb liquid much faster due to increased surface area. Thus, particle size of the dry SAPs may be in the range of 20-600 microns in diameter, more preferably in the range of 40-300 microns in diameter, and even more preferably in the range of 40-100 microns in diameter. It may be most preferable that the particle size of the SAPs is in the range of 60-80 microns in diameter. After absorbing liquid, the wet SAPs may swell to a size of 80-100 microns in diameter.

Super absorbent polymers may be present in the composition in an amount between 0.1% and 20% by weight based on the total weight of the composition, more preferably between 1% and 10% by weight based on the total weight of the composition, and even more preferably between 3% and 8% by weight based on the total weight of the composition.

Typically, the presence of between 3% to 8% of SAP in the composition allows the water content of the composition to be in the range of 55% to 80% and still maintain a powdered cleaning composition that has good flow properties. The presence of the SAP in the composition does not detrimentally affect the cleaning properties of the composition. Rather, it has been found that the cleaning properties are as good as that observed from cleaning substrates with the comparison composition that does not contain the SAP. Additionally, the retrieval properties (the ability to remove all, or nearly all, of the composition from the substrate being cleaned) are improved over the composition that does not contain the SAP.

The following other ingredients or additives may be present in the powder cleaning composition in amounts ranging between 0.01% and 10% by weight based on the total weight of the composition. Other ingredients include, without limitation, organic liquids, surfactants, surface active agents, static reducing additives, dust suppressing additives, vacuum retrieval additives, metal ion chelators, stain resist agents, pH adjusters, fragrance, biocides, water, and the like. However, as will be discussed below, the amount of water may be present in amounts that are higher than this range.

Examples of organic liquids which can be used include, without limitation, C1to C4aliphatic alcohols, high boiling hydrocarbon solvents, and mixtures thereof. The hydrocarbon solvents are generally the petroleum distillates with a boiling point between about 100° C. and about 300° C. Low boiling organic liquids are generally unsuitable from a standpoint of vapors and flammability, and higher boiling organic liquids do not evaporate from the textile substrate at an adequately rapid rate. Examples of commercially available hydrocarbon solvents include Stoddard solvent and odorless hydrocarbon solvent. These solvents usually consist of a petroleum distillate with a boiling point between about 105° and about 200° C. Properties of these solvents are comparable to those of British Standard White Spirits and domestic mineral spirits. Chemically, these solvents consist of a number of hydrocarbons, principally aliphatic, in the decane region. One potentially preferred, non-limiting organic liquid is a high boiling hydrocarbon solvent. Organic liquids may be present in the powder cleaning composition in amounts ranging between 0.01% and 10% by weight.

Surfactants of a number of classes are satisfactory for use in the powder cleaning composition. The selection of a surfactant is not critical but the surfactant should serve to lower the surface tension of the water in the composition to about 40 dynes per centimeter or less. Preferred anionic surfactants are long chain alcohol sulfate esters, such as those derived from C10-C18alcohols sulfated with chlorosulfonic acid and neutralized with an alkali. Also preferred are alkylene oxide additives of C6-C10mono and diesters of ortho-phosphoric acid. Representative nonionic surfactants that can be used have the formula:

where n is 0 or 1, m is 3 to 20, R1is OH or OCH3, R is C12to C22alkyl or phenyl or naphthyl optionally substituted by C1to C10alkyl groups.

The surfactant can be a nonionic surfactant or a mixture of a nonionic surfactant and either an anionic surfactant or a cationic surfactant. Mixtures of anionic and cationic surfactants are suitable only in carefully selected cases. A preferred composition contains from about 1 to about 4% nonionic surfactant. A satisfactory mixture of commercial anionic surfactants comprises (1) 0.4% of the sodium salt of a mixture of C10-C18alcohol sulfates, predominantly C12, (2) 0.4% of the diethylcyclohexylamine salt of the same sulfate mix, and (3) 0.2% of the product formed by reacting a mixture of n-octyl mono and diesters of ortho-phosphoric acid with sufficient ethylene oxide to form a neutral product, ordinarily about 2 to 4 moles of ethylene oxide per mole of phosphoric ester.

Surfactants may be present in the powder cleaning composition in amounts ranging between 0.01% and 10% by weight. However, the surfactant may more preferably be present in amounts ranging from about 0.5 to about 5.0% by weight.

Vacuum retrieval additives include, for example, compounds such as polyoxyalkylene materials (such as dipropylene glycol), aluminum silicate clay, hydrolyzed styrene maleic anhydride, and mixtures thereof. Polyoxyalkylene materials (such as dipropylene glycol), as well as non-volatile organic solvents (such as mineral oil), and mixtures thereof may also be used as dust suppressing additives. Aluminum silicate clay may also be used as a static reducing additive. Metal ion chelators include such compounds, for example, as ethylene diamine tetraacetic acid (EDTA). Stain resist agents include such compounds as, for example, acrylic stain blockers. Such compounds as aqua ammonia, citric acid, and mixtures thereof may be included as pH adjusters. Biocides may be included to prolong the shelf life of the cleaning composition. These may include, for example, compounds such as potassium sorbate, isothiazolones and mixtures thereof. Fragrances may also be included in the composition to impart a desirable odor to the composition. Any of the above ingredients or additives may be present in the powder cleaning composition in amounts ranging between 0.01% and 10% by weight.

The amount of water added to the cleaning composition may depend on the amount of super absorbent polymer adding to the powder cleaning composition. However, in general, it may be desirable that the amount of water added to the composition is between 20% and 90% based on the total weight of the composition. It may be more preferable that the amount of water added to the composition is between 30% and 70% based on the total weight of the composition. It may be most preferable that the amount of water added to the composition is between 40% and 60% based on the total weight of the composition. In some instances, it may ideal that the amount of water is greater than the amount of absorbent particulate material present in the composition.

Thus, it may be ideal that the powder cleaning composition is comprised of between 0.1% and 75% by weight of at least one absorbent particulate material; between 0.1% and 20% by weight of at least one super absorbent polymer; between 20% and 90% by weight of water, wherein the water may also contain a surfactant sufficient to provide a surface tension of less than about 40 dynes per centimeter; and between 0.01% and 10% by weight of at least one additive selected from an organic liquid, a stain resist agent, a pH adjuster, a biocide, a static reducing additive, a dust suppressing additive, a vacuum retrieval additive, a metal ion chelator, and a fragrance.

It may be more preferable that the cleaning composition is comprised of between 10% and 65% by weight of at least one absorbent particulate material; between 1% and 10% by weight of at least one super absorbent polymer; between 30% and 70% by weight of water, wherein the water may also contain a surfactant sufficient to provide a surface tension of less than about 40 dynes per centimeter; and between 0.01% and 10% by weight of at least one additive selected from an organic liquid, a stain resist agent, a pH adjuster, a biocide, a static reducing additive, a dust suppressing additive, a vacuum retrieval additive, a metal ion chelator, and a fragrance.

Further, it may be preferable that the cleaning composition is comprised of between 25% and 60% by weight of at least one absorbent particulate material; between 3% and 8% by weight of at least one super absorbent polymer; between 40% and 60% by weight of water, wherein the water may also contain a surfactant sufficient to provide a surface tension of less than about 40 dynes per centimeter; and between 0.01% and 10% by weight of at least one additive selected from an organic liquid, a stain resist agent, a pH adjuster, a biocide, a static reducing additive, a dust suppressing additive, a vacuum retrieval additive, a metal ion chelator, and a fragrance.

In preparing the powdered cleaning composition, it may be desirable to add the super absorbent polymer to the absorbent particulate material and then immediately add the water. This may prevent the super absorbent polymer from dehydrating the absorbent particulate itself. Also, it may be ideal that the super absorbent particulate is properly hydrated, prior to its addition to the composition.

The present invention eliminates the need for a hands-on operator to clean carpets and rugs. The self-propelled and guided robotic cleaner requires very little supervision. Essentially, it transforms s a very difficult and physical cleaning experience into a simple and easy to use tool.