WO1999018836A1

WO1999018836A1 - Self-wringing mop having improved cleaning element

Info

Publication number: WO1999018836A1
Application number: PCT/US1998/021185
Authority: WO
Inventors: Herman S. Howard
Original assignee: Media Group
Priority date: 1997-10-10
Filing date: 1998-10-08
Publication date: 1999-04-22
Also published as: AU1071299A

Abstract

A self-wringing mop (10) having a specially formed cleaning element (32) that has improved absorbency and a compact wringing mechanism (28) coupled to the mopstick (12). The cleaning element (32) is formed from a thermoplastic material formed with an antibacterial, detergent, or pharmaceutical agent incorporated therein during forming of the material into a desired shape for the cleaning element (32). Thus, the agent is embedded substantially uniformly throughout the material of the cleaning element (32) and is gradually released therefrom during use. The wringing mechanism (28) is fixed with respect to the mopstick (12). An actuating mechanism (42) couples the cleaning element (32) to the mopstick (12) via coupling legs (48) that are pivotally coupled to the mopstick (12). Lifting of the lever arm (52) lifts the coupling legs (48) and hence raises the cleaning element (32) between wringing elements (76) of the wringing mechanism (28) to effectuate wringing of the cleaning element. The coupling legs (48) and lever arm (52) have segments straddling the mopstick (12) to provide a compact design.

Description

SELF-WRINGING MOP HAVING IMPROVED CLEANING ELEMENT

BACKGROUND OF THE INVENTION

The present invention relates to a self-wring- ing mop. More particularly, the present invention relates to a self-wringing mop having an improved, highly absorbent cleaning element and a simple to use wringing mechanism that permits replacement of the cleaning element as necessary or desired. Mops are typically used to clean surfaces with a wet cleaning solution, or to absorb wet substances typically on a floor or other hard surface. When the cleaning element of the mop absorbs fluids, it must be wrung in order to release the fluids absorbed therein so that the fluids are not further spread on the surface being cleaned. Additionally, in order to assure that the mop cleans the surfaces intended to be clean, the cleaning element of the mop must be periodically rinsed to clean off any dirt, debris, or other undesired particles or fluids absorbed by the cleaning element so that the cleaning element is itself clean. Because the cleaning element typically is made from a fairly absorbent material, such as a sponge or mop strings formed from an absorbent fiber, the fluid absorbed by the cleaning element during rinsing must be wrung out. Otherwise, the cleaning element will deposit an undesired, albeit clean, amount of fluid on the surface to be cleaned.

A variety of wringing mechanisms have been designed to efficiently and effectively wring the cleaning element of a mop in a manner such that the user has little and preferably no contact with the wet, initially dirty cleaning element of the mop. Wringing mechanisms have been provided in the form of a mechanism separate from the mop and typically positionable over a bucket in which the cleaning element is rinsed and into which the fluid held by the cleaning element is wrung. In order to save space and facilitate use, self-wringing mops with built in wringing mechanisms may be used. Such mecha- nisms follow the mop wherever it goes, thus eliminating the need to separately retrieve a wringing mechanism. In order to facilitate use of self-wringing mops, it is desirable to provide as lightweight a wringing mechanism as possible. Additionally, it is desirable to form a wringing mechanism in as compact a configuration as possible such that the mechanism does not interfere with use or storage of the mop. Moreover, the wringing mechanism should be easy to use and not have parts that are likely to break off or get stuck or injure the user. Additionally, with the increased awareness of disease control and prevention, it has been desirable to provide as sanitary a wringing mechanism, as well as cleaning device, as possible. With the increasing popularity of self-wringing mops and structural improvements thereto, there has been a concurrent need for improved cleaning elements. The cleaning element often must be replaced before the self- wringing mop structure itself has worn. This is espe- cially true when the cleaning element is formed from a porous sponge, which is a particularly popular cleaning element because of its light weight and absorbency. Thus, there has been a need for a cleaning element that is strong enough to endure multiple cleaning jobs as well as multiple encounters with a wringing mechanism.

Additionally, the popularity of self-wringing mops has also been accompanied by the increased use of such mops in situations not normally associated with mop usage. Thus, there is a further need for improved clean- ing elements that are highly absorbent and lightweight, yet resistant to wear, corrosion and mildewing. The cleaning element preferably should also be usable on a variety of surfaces, such as carpets or other relatively rough and/or hard surfaces, without causing deterioration of the cleaning element material. Such a durable cleaning element should also be resistant to deterioration as a result of use to absorb materials which are acid or alkaline in nature. A variety of foam structures containing open and/or closed cells are known for use in mops for cleaning hard surfaces such as floors, walls, and counter tops. It is also known to include a material such as a pharmaceutical, detergent, antimicrobial agent which is deposited in the pores and/or cells of the foam structure as the structure is formed or by impregnation after forming and which can be removed from the structure when it is used. U.S. Patents 3,912,665 and 3,912,666 teach foam structures that include an agent which is deposited in the pores and/or cells of the structure and which can be removed when the structure is compressed or squeezed, thus liberating any deposited material.

It is also known that antimicrobial agents or other desired agents can be incorporated into thermoplas- tic materials such as polyvinylalcohol, polyvinylacetate, polypropylene, polyamide, and polyvinylchloride. These resulting compositions are processed at relatively high temperatures and are exposed to the ambient atmosphere or other sources of oxygen (as when forming films or fibers the usual end products) . As disclosed in U.S. Patent 4,624,679, the thermoplastic materials containing antimicrobials can undergo degradation of the antimicrobial agent as a result of exposure of such compositions to heat .

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a self-wringing mop having a compact, lightweight, easy to use wringing mechanism. It is a further object of the present invention to provide a mop having an antimicrobial, pharmaceutical, or detergent agent incorporated into the composition comprising the cleaning element of the mop rather than simply being contained in the pores of a porous cleaning element .

It is another object of the present invention to provide a self-wringing mop that facilitates use, wringing, and replacement of a highly absorbent cleaning element that is durable and resistant to wear and corro- sion.

These and other objects are accomplished in accordance with the principles of the present invention by providing a mop having a compact, lightweight lever- actuated wringing mechanism thereon. In particular, the wringing mechanism is preferably formed with a lever arm that provides added leverage over a wringing mechanism pulled solely along the longitudinal axis of the mopstick. The wringing mechanism is further leveraged to permit positioning of the cleaning element between a use position, a wringing position, and a replacement position. Additionally, the wringing mechanism preferably is also formed such that the wringing elements which com- press and wring the cleaning element remain stationary with respect to the mopstick and thus are less likely to break. Preferably, the wringing mechanism is compact and the mopstick is collapsible to enhance storageability.

The cleaning element of the mop of the present invention is formed from a specially treated porous foam material that is highly resistant to corrosion and wear and extremely durable. Additionally, the composition comprising the cleaning element has an antimicrobial, detergent, or pharmaceutical agent incorporated therein, as hereinafter described, to provide as sanitary a cleaning system as possible. The agent is incorporated into the material of the cleaning element during formation of the cleaning element, rather than being deposited into the pores of the already formed cleaning element, with the result that the agent cannot readily be washed or squeezed out or scratched off.

The above and other objects, features, and advantages of the present invention will be readily apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings wherein like reference characters represent like elements, the scope of the invention being set out in the appended claims .

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings :

Fig. 1 is a front elevational exploded view of a self-wringing mop formed in accordance with the principles of the present invention; Fig. 2 is a side elevational view of the lower half of the self-wringing mop of Fig. 1, in a cleaning configuration;

Fig. 3 is side elevational view similar to that of Fig. 2, but with the mop in a wringing configuration,- Fig. 4 is a side elevational view of the lower half of a self-wringing mop similar to that of Fig. 1 but having a modified lever arm, the mop being shown in a neutral, cleaning configuration; and Fig. 5 is a side elevational view similar to that of Fig. 4, but with the mop in a release configuration.

DETAILED DESCRIPTION OF THE INVENTION A mop 10 formed in accordance with the principles of the present invention is shown in Fig. 1 as including a mopstick 12, a cleaning element 32, and a wringing mechanism 40. Preferably, mop 10 is collapsible to facilitate storage. In a preferred embodiment, as shown in Fig. 1, mopstick 12 that is formed in two parts, an upper mopstick section 12a and a lower mopstick section 12b. Upper mopstick section 12a has a proximal end 14 and a distal end 18. A handle 16 preferably is provided on proximal end 14. Handle 16 has a grip 17 pref- erably formed from a resilient but reasonably hard material (such as an elastomer) and shaped (such as ergonomi- cally) to enhance gripping and user comfort. A hook 20 or other such support element is preferably also provided at proximal end 14 of upper mopstick portion 12a. Preferably, upper mopstick section 12a is hollow such that an extension element 22 may be telescopingly fitted therein. Extension element 22 may be pulled out from distal end 18 of upper mopstick sec- tion 12a to the extent desired by the user and tightened to provide a mopstick of an appropriate length for a given user. Distal end 18 of upper mopstick section 12a preferably has a collar 24 positioned thereon to facili- tate grasping of section 12a during extraction of extension element 22. Additionally, collar 24 may be provided with a tightening element with respect to which extension element 22 is tightened so that extension element 22 and upper mopstick section 12a do not collapse or separate during use.

Extension element 22 is preferably provided with a connection portion 26a shaped in any desired manner for engaging a corresponding connection portion 26b on proximal end 28 of lower mopstick section 12b. In a preferred embodiment, connection portions 26a and 26b are threadedly interengaged. Additionally, lower mopstick section 12b may be provided with a collar 30 that preferably carries connection portion 26b.

An absorbent cleaning element 32 is coupled to lower mopstick section 12b such that cleaning element 32 is positioned adjacent distal end 34, ready for use once mopstick sections 12a and 12b have been coupled together. Cleaning element 32 preferably is shaped to facilitate cleaning. Thus, as may be seen in Figs. 2 and 3, clean- ing element 32 preferably is provided with a flat lower surface 34 and curved side surfaces 36. Additionally, the surface of cleaning element 32 may be provided with ridges 38 or other such surface shape to facilitate dirt and debris pick-up capabilities.

In accordance with the principles of the present invention, cleaning element 32 is formed from an absorbent resilient material such as a thermoplastic synthetic sponge incorporating an antimicrobial, deter- gent, or pharmaceutical agent therein, the agent being embedded in the material of the sponge and not deposited in the pores or cells of the sponge from which it is quickly released during use. In a preferred embodiment of the present invention, cleaning element 32 is formed from a specially treated thermoplastic material such as polyvinylalcohol, polyvinylacetate, polypropylene, poly- amide, or polyvinylchloride formed into a dense porous material with pores formed sufficiently small and spaced together that the resultant sponge material is particu- larly durable. Preferably, the sponge material is formed such" that it hardens on drying and thus is less likely to tear during storage or undergo bacterial, fungal etc. attack. In accordance with the principles of the present invention, an antimicrobial agent in an amount effective to release the antimicrobial over the life of the cleaning element formed therefrom and to control antimi- crobial growth in and on the cleaning element is incorporated into the composition comprising the thermoplastic (polypropylene, polyvinylalcohol, polyamide, polyvinylacetate or polyvinylchloride) of the cleaning element while the composition is being melt processed so that the incorporated agent is embodied substantially uniformly throughout the plastic. It will be understood that a detergent or pharmaceutical agent may be incorporated in addition to or instead of an antimicrobial agent, the principles of incorporation of such additional or substitute agent being understood by those of skill in the art from a review of the disclosure pertaining to incorporation of the antimicrobial agent.

The present invention resides in the discovery that the aforesaid compositions comprising a thermoplas- tic synthetic polymer or copolymer and an antimicrobial agent, can be further processed to form foamed structures which can then be used as cleaning elements for cleaning floors, walls, counter tops and other hard surfaces and which will provide a desired level of antimicrobial activity, or a given amount of the antimicrobial agent over a prolonged period of time. In addition to the antimicrobial activity generated by the gradual release of the antimicrobial agent to the surface to be cleaned, the antimicrobial agent embedded in the thermoplastic material inhibits the growth of bacteria, mold, and mildew in the cleaning element, particular during storage or non-use. The antimicrobial agent cannot be washed or squeezed out or scratched off of the cleaning element because it is embedded in the plastic material comprising the cleaning element during formation of the cleaning element. In particular, as aforenoted, the antimicrobial agent is embedded in the thermoplastic material from which the cleaning element is formed and is released therefrom over time, migrating from within the material of the cleaning element to the surface to be cleaned to substantially eliminate the growth of microorganisms thereon. It should be understood that it is a requirement that the compositions be effective to control micro- bial growth throughout the intended life of the finished cleaning element.

Antimicrobial agents which are suitable for incorporation into the thermoplastic material from which the cleaning element is formed include, but are not limited to, 10, 10 ' -oxybisphenoxarsazine (OBPA) , 10,10'- oxybisphenarsazine, bis-n-tributyltin oxide, zinc omadine, N- (trichloromethylthio) cyclohexenedicarboxamide, mycostatin, methiolate, hexa- chlorophene, tribromasalicylanilide, trichlorocarbanilide and undecylenic acid. Quaternary ammonium salts for example, hexamethonium chloride, octadecyldimethylbenzyl ammonium chloride, alphyl imidazoliniumchloride and the like are preferred examples of compounds having antimi- crobial activity and particularly as germicides, disinfectants, mildewicides, and fungicides.

The amount of antimicrobial is not critical and is chosen to meet the need for the particular application of the cleaning element, usually from about 0.005% to about 15% by weight being adequate. Preferably the thermoplastic material composition contains at least about 90% of the thermoplastic material and preferably about 98% and most preferably 99% of the thermoplastic material, and a minor portion of the antimicrobial agent and other additives. The antimicrobial agent most desirably comprises 0.2% to 1% by weight of the thermoplastic material composition.

The invention is applicable to any polymer or copolymer that is capable of being foamed and that forms a cohesive foam structure. Thermoplastic polymers as a class can be used. Alkyl acrylate and alkyl methacrylate polymers and copolymers, such as ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 50/50 n-bu- tyl/isobutyl methacrylate copolymer, 2575 lauryl/isobutyl methacrylate copolymer, 30/70 stearyl/t-butyl methacrylate copolymer, 50/50 ethyl/n-butyl methacrylate copolymer, [copolymers of acrylic and vinyl compounds, such as] 50/50 vinyl toulene/isobutyl methacrylate copolymer, 50/35/15 vinyl toluene/t-butyl methacrylate/stearyl methacrylate terpolymer, 50/50 ethyl acrylate/vinyl acetate copolymer, certain other vinyl polymers, such as polyvinyl acetate, vinyl toluene-butadiene copolymers, carboxylated vinyl acetate, [certain cellulose deriva- tives, such as] ethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyrate and cellulose acetate propionate are examples of suitable polymers . Particularly preferred are the vinyl polymers and most preferred are polyvinylalcohol, polyvinylacetate, and polyvinylchloride. The polymer should have a molecular weight within the range from about 10,000 to about 1,000,000. Polymers of molecular weights below about 10,000 may not have sufficient cohesive strength to form a cohesive foamed structure. Polymers having molecular weights within the range from about 25,000 to about 600,000 are preferred.

In addition to the foaming agent which can be any of the conventional foaming (blowing) agents such as sodium bicarbonate, ammonium carbonate, halocarbons such as CC1₃F, hydrazine, air, etc., there may also be solvents for the polymer, plasticizers for the polymer, coloring agents, fillers for the polymer which modify the polymer component of the foamed structure, and a curing agent for the polymer, if the polymer is in a partially polymerized condition so that the polymerization of the polymer can be completed after the foamed structure has been formed to set the structure in a desired configuration. Plasticizers which may be used include butyl phthalyl butyl glycolate, tributyl citrate, acetyl tributyl citrate, tricresyl phosphate, dibutyl tartrate, dibutyl phthalate, di-2-ethylhexyl azelate, chlorinated biphenyl and methyl abietate. Fillers for the polymer can be used as extenders for the polymer, and may also modify the physical properties of the foamed structure. The filler usually has a small particle size, although fibrous material also can be used. Satisfactory fillers include chalk, talc, silica, diatomaceous earth, clay, asbestos, magnesium silicate, calcium silicate, kaopolite powdered polyethylene and powdered polystyrene. The filler can comprise 0% to 300% by weight of the polymer. Coloring agents in- eluding dyes and pigments are used in small proportions, ranging from 0% to 10% by weight of the polymer.

Conventional foaming techniques may be utilized as follows. A blend of the selected plastic compound and antimicrobial agent is prepared. The blend is then mixed with the desired foaming or blowing agent and modifiers (fillers, colors and the like) under conditions under which foaming will occur. The foaming may take place in a confined space, such as a mold, preferably closed, the foamed structure will acquire the configuration of the mold and a molded object obtained. The molding can be carried out at room temperature without application of external pressure, since a pressure sufficient to ensure that the structure conforms to the configuration of the mold is obtained upon liberation of the foaming agent, for example C0₂, to ensure that the structure conforms to the configuration of the mold at atmospheric pressure and temperature. The foamed structures are formed very quickly, and the cleaning elements are ready for use within minutes after the procedure has begun. The struc- tures formed are shape retaining because of the nature of the polymer used and are also flexible because of the foam structure, even if no plasticizer is present, i.e., if the polymer is a rigid polymer. Preferably the compo- sition from which the cleaning element is formed is one which undergoes hardening when the resultant foam which has been wetted in use undergoes hardening.

The antimicrobial is retained, i.e., is embedded in the polymer from which it is slowly released, to provide a desired level of antimicrobial activity. It will be appreciated that the amount of the antimicrobial agent employed will depend on the selection of the antimicrobial agent, the identity and amount of the thermoplastic material and modifiers selected, the processing condition and other factors .

Practice of the invention comprising the improved cleaning element taught herein is described or self evident from the preceding composition description and following examples :

Examples 1-3:

Polyvinylalcohol (PVA) was mixed with processing additives as defined below and with a concentrate of an antimicrobial agent to achieve the blend compositions shown.

TABLE I

The blend compositions were introduced into a closed mold in the shape of the desired cleaning element, the temperature raised to about 60»C. Shortly thereafter the mold was opened and the foamed cleaning elements were removed. The foamed structures were subsequently evaluated for their biological activity by wetting with water and then placing samples of each of the wet structures on a microbiological growth medium solidified with agar which had previously been inoculated with an actively growing culture of Staphylococcus aureus .

After allowing the media to incubate for 24 hours, the biological activity of each sponge sample was evaluated by measuring the width of the region around the samples on the agar surface where no visible bacterial growth was evident. This width is defined as a Zone of Inhibition. Another evaluation of biological activity was made by extracting a specimen of each of the test samples with methanol. The extracted material was assayed by high performance liquid chromatography for recovery of the active antimicrobial agent. These results are tabulated in Table II.

TABLE II

These examples show that the antimicrobial is delivered in an inhibiting concentration and that a portion of the OBPA remains in the processed compositions.

In order to release dirty or contaminated fluids from absorbent cleaning element 32, or any other fluids thereby absorbed, mop 10 is preferably formed as a self-wringing mop having a wringing mechanism 40 by which cleaning element 32 may be wrung to extract fluids there- from. Preferably, wringing mechanism 40 and cleaning element 32 are mounted with respect to lower mopstick section 12b such that cleaning element 32 is moved with respect to substantially stationarily mounted wringing mechanism 40 to effectuate the wringing operation, as described below. It will be understood, however, that arrangements other than the described preferred embodiment may also be used with the improved cleaning element 32 of the present invention. For example, cleaning element 32 may remain stationary as a wringing element is moved with respect thereto to effectuate wringing. Alternatively, cleaning element 32 may be folded or otherwise distorted (such as by twisting) to wring fluid therefrom. In accordance with the principles of the present invention, cleaning element 32 is mounted on a cleaning element carrier 42 by which cleaning element 32 is coupled to mopstick 12. Carrier 42 may be a substantially elongated channel-shaped element having grasping legs 44 between which an upper portion 46 of cleaning element 32 is grasped. Carrier 42 is preferably formed from a rigid, inflexible material, such as metal, that can securely hold cleaning element 32 during cleaning operations without being distorted. Grasping legs 44 may be specially formed or crimped to enhance grasping of upper portion 46 of cleaning element 32 therebetween. For example grasping legs 44 may be shaped such as the carrier legs shown in U.S. Reissued Patent Re. 35,005, which is hereby incorporated by reference in its entirety.

Preferably, legs 44 of carrier 42 are formed such that cleaning element 32 may be released therefrom, for replacement as necessary or desired. Such replacement capability is particularly desirable if cleaning element 32 having an antimicrobial agent incorporated therein, as described above, has substantially completely delivered the embedded antimicrobial, at which time, the cleaning element may be replaced with a new cleaning element containing a supply of antimicrobial agent. Legs 44 may be provided with a lock and release mechanism, such as by a latch or debent mechanism, that permits locking of legs 44 into a grasping position in which legs 44 firmly hold cleaning element 32 therebetween, and a release position in which legs 44 do not securely grasp cleaning element 32 so that cleaning element 32 may readily be removed from between legs 44. Alternatively, the upper surface of cleaning element 32 (grasped by carrier 42) may be provided with a connection element that is slid in and out of engagement with carrier 42, such as shown in U.S. Patent 4,322,865, which is hereby incorporated by reference in its entirety.

At least one coupling leg 48 couples carrier 42 to lower mopstick section 12b via lever arm 50. As may be seen in Fig. 1, in a preferred embodiment, a pair of coupling legs 48 are mounted on carrier 42 on either side of mopstick 12 coupled between cleaning element 32 and lever arm 50. The provision of a pair of coupling legs 48 distributes pulling forces on cleaning element carrier 42 more evenly than forces that would be exerted by a single coupling leg. Preferably, coupling leg 48 is substantially straight and pivots with respect to lever arm 50. Most preferably, in order to transmit lifting forces as directly as possible to carrier 42, with as little energy loss as possible, coupling leg 48 is fixedly connected to carrier 42 such that connecting ends 52 do not pivot with respect to carrier 42 as coupling legs 48 lift carrier 42. As shown in Fig. l, connecting ends 52 may be bent to be substantially parallel to carrier 42 and screwed or bolted thereto. However, any other type of connection between connecting ends 52 and carrier 42 may be used, such as shown in aforementioned U.S. Reissued Patent Re. 35,005 incorporated herein. Coupling legs 48 pivotally couple cleaning element 32 to lever arm 50, which, in turn, is pivotally coupled to mopstick 12. Movement of lever arm 50 with respect to mopstick 12 causes movement of cleaning ele- ment 32 with respect to mopstick 12 and thus wringing mechanism 40 as follows.

Pivot ends 54 of coupling legs 48 are pivotally coupled to lever arm 50 at a coupling axis support 56 (Fig. 1) via any desired pivot element. In a preferred embodiment, a bolt is used as a pivot axis 58 that is passed through coupling axis support 56. A nut may then be used at one end to secure coupling legs 48 to pivot axis 58. Coupling axis support 56 is proximally located with respect to pivot ends 60 by which lever arm 50 is coupled to lower mopstick section 12b. Pivot ends 60 pivotally couple distal end 62 of lever arm 52 to lower mopstick section 12b via any desired pivot element. In a preferred embodiment, a bolt that is passed through collar 30 of lower mopstick section 12b is used as a pivot axis 64. A nut secures pivot ends 60 of lever arm 50 to the bolt.

As may be seen in Fig. 2, the point at which lever arm 50 pivots with respect to lower mopstick section 12b (pivot axis 64) is spaced apart from the point at which coupling legs 48 pivot with respect to lever arm 50 (pivot axis 58) . Thus, a moment arm is formed by a distal portion 66 of lever arm 50 between coupling axis support 56 and pivot ends 60. The remainder of lever arm 50 extending away from mopstick 12 forms a proximal portion 68 having a proximal end 70 at which a handle 72 is formed. Proximal portion 68 is lifted in order to pivot lever arm 50 about pivot axis 64 and lift cleaning element 32 with respect to wringing mechanism 40 to put mop 10 into the wringing configuration shown in Fig. 3 and described in further detail below. In order to facilitate lifting of lever arm 52, handle 72 is preferably formed with an ergonomically shaped gripping portion 74. Lever arm 52 and cleaning element 32 are shown in the neutral, cleaning configuration in Fig. 2. In order to provide a self-wringing mop 10 that is as compact as possible when in the cleaning configuration, handle 72 is positioned below pivot axis 64 when mop 10 is in the cleaning configuration, as may be seen in Fig. 2. Preferably, proximal portion 68 of lever arm 52 is angled or bent with respect to distal portion 66 to bring handle 72 even closer to mopstick 12 when in the cleaning configuration, as may be seen in Fig. 2. Thus, the acute angle formed between proximal portion 68 of lever arm 50 and mopstick 12 is smaller than the acute angle formed between distal portion 66 and mopstick 12. Additionally, distal and proximal portions 66, 68 of lever arm 52 are preferably formed as a pair of substantially parallel arms that may straddle lower mopstick section 12b when in the neutral, cleaning position, as may be seen in Fig. 1. The provision of a pair of distal and proximal portions 66, 68 forming lever arm 52 distributes pulling forces on cleaning element carrier 42 more evenly than forces that would be exerted by a lever arm not so configured.

As discussed above, lever arm 50 is pivoted about pivot axis 64 to effectuate wringing of cleaning element 32. Lever arm 52 and cleaning element 32 are shown in an elevated, wringing position in Fig. 3. Lift- ing of handle 72 to pivot lever arm 52 about pivot axis 64 causes coupling axis support 56 on lever arm 50 to be lifted and to pivot about pivot axis 64. As coupling axis support 56 is lifted and pivoted with lever arm 50, coupling legs 48, which are pivotally coupled to coupling axis support 56, are lifted and pivoted with respect to lever arm 50. Coupling ends 54 of coupling legs 48 thus rise as handle 72 is lifted, thereby pulling cleaning element 32 upward with respect to mopstick 12 and thus wringing mechanism 40 to effectuate a wringing operation as described below. Cleaning element carrier 42, coupling legs 48, and lever arm 50 thus act as an actuating mechanism 41 for wringing mechanism 40.

In a preferred embodiment, wringing mechanism 40 includes a plurality of wringing elements 76 coupled to distal end 34 of lower mopstick section 12b via mounting bracket 78. Preferably, wringing elements 76 are in the form of rollers mounted on roller axles 80. Rollers 76 are constructed of resilient, sturdy material that is hard enough to retain its shape while wringing cleaning element 32. Preferably, rollers 76 have a specially formed wringing surface 82, such as a ridged or knurled surface, that enhances the wringing of a cleaning element 32 contacted by rollers 76. Preferably, mounting bracket 78 is provided with a mounting collar 84 fixedly coupled to distal end 34 of lower mopstick section 12b such as by a nut and bolt connection 86. Coupling legs 48 pass through holes 88 in mounting bracket 78. Through holes 88 are dimensioned to accommodate the full range of motion of coupling legs 48 as they are pivoted with respect to mopstick 12 from the neutral position shown in Fig. 2 to the wringing position shown in Fig. 3. Additionally, mounting bracket 78 is preferably formed with two pairs of mounting legs 90 on which wringing elements 76 are mounted. The legs of each pair of mounting legs 90 are spaced apart and wringing elements 76 and cleaning element 32 are dimensioned to permit cleaning element 32 to be squeezed between wringing elements 76 as cleaning element 32 is lifted with respect thereto, as shown in Fig. 3, to effectuate a wringing operation.

As will be appreciated with reference to Fig. 2, legs 44 of carrier 42 are positioned between wringing elements 76 when mop 10 is in the neutral, cleaning configuration. Thus, legs 44 firmly grasp upper portion 46 of cleaning element 32 therebetween. If cleaning element 32 is formed with an antimicrobial or other embedded agent, cleaning element 32 typically will require period- ic replacement. Thus, actuating mechanism 41 of mop 10 is preferably formed such that actuating mechanism 41 may be positioned into a release configuration in which carrier 42 is positioned below wringing mechanism 40 so that cleaning element 32 may be released from carrier 42. One modification that may be made to actuating mechanism 41 to permit a release configuration to be attained is the replacement of pivot axis support 56 of Fig. 1 with a pair of support pivot axes on either side of mopstick 12, without an axle passing across mopstick 12 as shown in Fig. 1. Additionally, handle 72 is preferably formed with a removable gripping portion 74. Thus, lever arm 50 may be pivoted closer to mopstick 12 than the position shown in Fig. 2, putting actuating mechanism 41 into a release configuration. Lever arm 50 and coupling legs 48 are dimensioned so that upon complete lowering of lever arm to a release position substantially parallel to mopstick 12, carrier 42 is positioned below wringing mechanism 40 so that legs 44 may be released to release cleaning element 32 therefrom for replacement .

In a preferred embodiment shown in Fig. 4, distal portion 66 of lever arm 50 is substantially horizontal when mop 10 is in a cleaning configuration (with cleaning element 32 positioned below wringing mechanism 40, ready to clean a surface) . Such orientation of distal portion 66 permits the further lowering of lever arm 50 (even if pivot axis support 56 and handle 72 extend across mopstick 12) and thus further lowering of cleaning element 32 into a release position below wringing mechanism 40, as shown in Fig. 5. Cleaning element 32 can thus be released from carrier 42 and replaced as necessary or desired. In order to provide a self-wringing mop 10 that is as compact as possible when in the cleaning configuration, proximal portion 68 of lever arm 50 is preferably pivotable with respect to distal portion 66 into a posi- tion substantially parallel to mopstick 12, as shown in Fig. 4. Proximal portion 68 of lever arm 66 must be capable of being straightened and locked with respect to distal portion 66, as shown in Fig. 5, in order to place actuating mechanism 41 and mop 10 into a release configu- ration. Any locking mechanism known in the art may be provided to proximal portion 68 with respect to distal portion 66 for such operation. Additionally, the lock mechanism should proximal and distal portions 66, 68 of lever arm 50 into the straightened lifting position of Fig. 3, to place actuating mechanism 41 and mop 10 into the wringing configuration to perform a wringing operation. If desired, instead of forming the locking mechanism to lock portions 66, 68 for upward movement of lever arm 50, a shoulder may be provided to prevent further upward rotation of proximal portion 68 with respect to distal portion 66.

Thus, in accordance with the principles of the present invention, an improved cleaning element is used in a self-wringing mop to result in an improved compact mopping unit. The self-wringing mechanism of the present invention is compact in design and easy to operate. Because the cleaning element is pulled upwardly through stationary wringing elements, fluid is extracted from the top to the bottom of the cleaning element, so that dirty fluid is progressively wrung from cleaning element 32 and efficient cleaning of cleaning element 32 is effected. While the foregoing description and drawings represent the preferred embodiments of the present inven- tion, it will be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope of the present invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, proportions, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. For instance, the cleaning element may be fixedly coupled to the mopstick and the wringing mechanism may be movably coupled to the mopstick by the actuating mechanism such that pushing down of the lever arm handle causes the wringing mechanism to move downwardly with respect to the mopstick and cleaning element to thereby wring the cleaning element. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and not limited to the foregoing description.

Claims

WHAT Is CLAIMED Is :

1 . A self -wringing mop comprising : a mopstick having a proximal end and a distal end ; an absorbent, compressible cleaning ele- ment coupled to said mopstick and positioned adjacent said distal end of said mopstick; a wringing mechanism having a pair of wringing elements shaped and positioned to compress said cleaning element when said cleaning element is moved with respect to said wringing elements; and an actuating mechanism coupled between said cleaning element and said mopstick and movable between^': a neutral configuration in which a portion of said cleaning element suffi- cient for use in cleaning a surface is positioned in a cleaning position below said wringing mechanism and a portion of said cleaning element is positioned be- tween said wringing elements; a wringing configuration in which said cleaning element is lifted between said wringing elements such that fluid held by said cleaning element is extracted therefrom; and a release configuration in which said cleaning element is positioned below said wringing elements for removal from said actuating mechanism.

2. A self-wringing mop as claimed in claim 1, wherein said actuating mechanism comprises: a carrier element coupled to said cleaning element; a lever arm having a distal pivot end pivotally coupled to said mopstick and a proximal end; and a coupling leg pivotally coupled to said lever arm and fixedly coupled to said carrier element such that said coupling arm and said carrier element are not pivotable relative to each other; wherein: said lever arm is pivotable between a neutral position, a wringing position, and a release position; in said neutral position, said proximal end of said lever arm is in a rest position below said distal pivot end and said coupling leg, carrier element, and cleaning element are in a cleaning position; in said wringing position, said proximal end is raised above said rest position and said coupling leg, carrier element, and cleaning element are raised above said cleaning position; and in said release position, said proximal end of said lever arm is in a release position below said distal pivot end and said carrier element and cleaning element are positioned below said wringing mechanism.

3. A self-wringing mop as claimed in claim 2, wherein: said coupling leg is pivotally coupled to said lever arm at a coupling leg pivot axis proximally spaced from said distal pivot end of said lever arm; said lever arm comprises a distal portion between said distal pivot end and said coupling leg pivot axis and a proximal portion between said coupling leg pivot axis and said proximal end; and said distal portion and said proximal portion of said lever arm are angled with respect to each other such that said proximal end of said lever arm is bent toward said mopstick.

4. A self-wringing mop as claimed in claim 3, wherein said distal portion and said proximal portion of said lever arm are pivotable with respect to each other so that said proximal portion is positionable into a sub- stantially vertical orientation when said lever arm is in said neutral position.

5. A self-wringing mop as claimed in claim 2, wherein: said lever arm comprises a pair of por- tions straddling said mopstick; and said coupling leg comprises a pair of legs straddling said mopstick and coupled to respective por- tions of said lever arm.

6. A self-wringing mop as claimed in claim 2, wherein said wringing mechanism comprises : a mounting bracket coupled to said distal end of said mopstick and having a through hole through which said coupling leg passes and a pair of spaced apart mounting legs; and at least one roller mounted on each said mounting leg, said rollers being spaced apart and shaped to wring said cleaning element as said lever arm is pulled into said wringing position, thereby raising and angling said coupling leg with respect to said through hole to thereby lift said cleaning element with respect to and between said rollers.

7. A self-wringing mop as claimed in claim 1, wherein: said mopstick comprises an upper mopstick section separably coupled to a lower mopstick section,- said upper mopstick section is substan- tially hollow; said mopstick further comprises an exten- sion element telescopically positioned within said upper mopstick section,- and said mopstick has a length that varies as said extension element is progressively telescoped out from within said upper mopstick section and coupled to said lower mopstick section.

8. A self-wringing mop as claimed in claim 1, wherein said cleaning element is formed from a sponge product comprising a thermoplastic synthetic material having embedded in the polymer an antimicrobial agent selected from the group consisting of 10,10'- oxybisphenoxarsazine (OBPA) , 10, 10 ' -oxybisphenarsazine, bis-n-tributyltin oxide, zinc omadine, N- (trichloromethylthio) cyclohexenedicarboxamide, mycostat- in, methiolate, hexachlorophene, tribromasalicylanilide, trichlorocarbanilide and undecylenic acid.

9. A self-wringing mop as climed in claim 1, wherein said cleaning element is formed from a sponge product comprising a thermoplastic synthetic material having embedded in the polymer as an antimicrobial agent a quaternary ammonium salt .

10. A self wringing mop as claimed in claim 9 wherein said quaternary ammonium salt is a member select - ed from the group consisting of hexamethonium chloride, octadecyldimethylbenzyl ammonium chloride and alkyl imidazolium dichloride .

11. A self-wringing mop as claimed in claim 8, wherein said polymer is a member selected from the group consisting of alkyl acrylate and alkyl methacrylate poly- mers and copolymers, such as ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 50/50 n-bu- tyl/isobutyl methacrylate copolymer, 2575 lauryl/isobutyl methacrylate copolymer, 30/70 stearyl/t-butyl methacry- late copolymer, 50/50 ethyl/n-butyl methacrylate copoly- mer, 50/50 vinyl toluene/isobutyl methacrylate copolymer, 50/35/15 vinyl toluene/t-butyl methacrylate/stearyl methacrylate terpolymer, 50/50 ethyl acrylate/vinyl acetate copolymer, certain other vinyl polymers, such as polyvinyl acetate, vinyl toluene-butadiene copolymers, carboxylated vinyl acetate, ethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate butyr- ate, and cellulose acetate propionate.

12. A self-wringing mop as claimed in claim 11, wherein said polymer is a vinyl polymer.

13. A self-wringing mop as claimed in claim 11, wherein said polymer is a member selected from the group consisting of polyvinylalcohol, polyvinylacetate, and polyvinylchloride .

14. A self-wringing mop as claimed in claim 13, wherein said antimicrobial agent is present in an amount of from about 0.005% to about 15% by weight of the sponge product .

15. A self-wringing mop as claimed in claim 8, wherein there is additionally dispersed in said polymer at least one member selected from the group consisting of plasticizers, filling agents, dispersants, coloring agents and anti-corrosion agents.

16. A mop comprising: a mopstick having a proximal end and a distal end; and a cleaning element coupled to said mopstick and adjacent said distal end of said mopstick; wherein said cleaning element comprises: a sponge product as claimed in claim 8.

17. A self-wringing mop comprising: a mopstick having a proximal end and a distal end; a cleaning element coupled to said mopstick and positioned adjacent said distal end of said mopstick; a wringing mechanism coupled to said mopstick adjacent said cleaning element; and a wringing actuating mechanism; wherein: said cleaning element is formed from a sponge product as claimed in claim 8 ,- said wringing actuating mechanism moves said cleaning element and said wringing mechanism rela- tive to each other from between a cleaning position and a wringing position.

18. A self-wringing mop as claimed in claim 16, wherein: said actuating mechanism comprises: a carrier element coupled to said cleaning element; a lever arm having a distal pivot end pivotally coupled to said mopstick and a proximal end; and a coupling leg pivotally cou- pling said carrier element to said lever arm; said lever arm is pivotable between a neutral position and a wringing position,- in said neutral position, said proximal end of said lever arm is in a rest position below said distal pivot end and said coupling leg, carrier element, and cleaning element are in a cleaning position,- in said wringing position, said proximal end is raised above said rest position and said coupling leg, carrier element, and cleaning element are raised above said cleaning position,- and said wringing mechanism comprises: a mounting bracket coupled to said distal end of said mopstick and having a through hole through which said coupling leg passes and a pair of spaced apart mounting legs,- and at least one roller mounted on each said mounting leg, said rollers being spaced apart and shaped to wring said cleaning element as said lever arm is pulled into said wring- ing position, thereby raising and angling said coupling leg with re- spect to said through hole to thereby lift said cleaning element with re- spect to and between said rollers.

19. A self-wringing mop as claimed in claim 18, wherein said lever arm is further positionable into a release position in which said proximal end of said lever arm is in a release position below said distal pivot end and said carrier element and cleaning element are posi- tioned below said wringing mechanism.

20. A method of forming a self-wringing mop comprising the steps of: providing a cleaning element formed by introducing a composition comprising a thermoplastic syn- thetic polymer in admixture with an antimicrobial agent into a mold having the shape of said cleaning element, introducing a foaming agent into said mold, maintaining the composition in said mold under conditions to foam the synthetic polymer and form a foamed structure containing the antimicrobial agent embedded in the synthetic poly- mer,- and coupling said cleaning element to a mopstick.