Cleaning sheet

Disclosed is a cleaning sheet to be attached to a cleaning head. The cleaning sheet has an attachment sheet dimensioned to cover a nozzle head provided in the cleaning head. Liquid squirted from the nozzle head can be received by the attachment sheet and come between the cleaning head and the cleaning sheet. Since the cleaning sheet has a liquid permeable attachment surface, the liquid having reached the attachment surface can be absorbed by a liquid absorbent sheet of the cleaning sheet and gradually applied to a floor surface to be cleaned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning sheet which is intended to be used for cleaning as attached to a mop-like cleaning device or the like, and more particularly to a cleaning sheet which can absorb and retain liquid.

2. Description of the Related Art

There have been known cleaning sheets which should be used for cleaning the house floor as attached to a cleaning head of a mop-like cleaning device. Such conventional cleaning sheets are typically constructed of a single nonwoven fabric or by layering two or more nonwoven fabrics on top of one another and used in a dry state. When they are used in a dry state, dirt or dust can be trapped between fibers on the surface of the nonwoven fabric. Alternatively, an adsorbent lubricant is coated thereon to let dirt or dust adhere to the sheet surface.

However, such cleaning sheets to be used in a dry state are not effective in removing stains adhered to the floor surface, although they are effective in collecting fluffy dust.

Japanese Utility-Model Registration No. 3094858 discloses a cleaning device which has nozzles in a cleaning head for squirting water to the floor surface. After wetted with water, the floor surface is wiped off with a cleaning sheet attached to the cleaning head. Japanese Unexamined Patent Publication No. 2001-521432 also discloses a cleaning device with a liquid supply part on a handle which extends upward from the top face of a cleaning head.

The cleaning devices disclosed in the above-identified documents are used such that the nozzles provided in the cleaning head apply water or cleaning liquid to the outside of the cleaning head, and the floor surface wetted with the water or cleaning liquid is then wiped off with a cleaning pad. The cleaning pad, which is designed to be attached to the bottom face of the cleaning head, has a liquid permeable sheet on a cleaning surface side to be applied to the floor surface, or the like, and a liquid absorbent layer behind the liquid permeable sheet. It should be noted that the back side of the cleaning pad, which faces the cleaning head, is typically covered with a liquid impermeable sheet.

However, in the case where the cleaning head is provided with the nozzles, as in Japanese Utility-Model Registration No. 3094858, if the water or cleaning liquid flows down the cleaning head after being squirted out of the nozzles, it tends to spread between the cleaning head and the cleaning pad. Because the back side of the cleaning pad is impermeable to liquid, the water or cleaning liquid tends to remain between the cleaning head and the cleaning pad. When the cleaning pad is removed from the cleaning head, the water or cleaning liquid drips on the floor surface, and the cleaning head after removal of the cleaning pad remains soaked with the cleaning liquid.

Moreover, if the cleaning liquid remains between the cleaning head and the cleaning pad, the coefficient of friction between the cleaning head and the cleaning pad may be decreased and cause slippage between the back side of the cleaning pad and the cleaning head when the cleaning pad is slid on the floor surface.

In Japanese Utility-Model Registration No. 3094858, furthermore, the liquid is directly applied to the floor surface from the nozzles of the cleaning head. If the floor surface to be cleaned is a ceramic tile floor, a large amount of liquid may be directly applied to the floor surface without any problem, but if the floor surface is a wooden floor on which a finishing compound such as a paint is applied, a large amount of cleaning liquid may deteriorate the finishing compound.

SUMMARY OF THE INVENTION

The present invention has been developed to solve the problems in the prior art set forth above and has an object to provide a cleaning sheet which prevents a bottom face of a cleaning head from becoming soaked with liquid.

Another object of the present invention is to provide a cleaning sheet which permits application of a moderate amount of liquid to a surface to be cleaned.

According to the invention, there is provided a cleaning sheet having an attachment surface side to be applied to a cleaning head of a cleaning device and a cleaning surface side to be applied to an object to be cleaned, the cleaning sheet comprising a liquid permeable exterior sheet on the cleaning surface side and a liquid absorbent sheet behind the exterior sheet,

wherein the liquid absorbent sheet is permitted to absorb liquid applied to the attachment surface side.

According to the present invention, liquid coming between the cleaning head and the cleaning sheet can be absorbed by the liquid absorbent sheet of the cleaning sheet. This prevents the liquid from remaining between the cleaning head and the cleaning sheet.

According to one embodiment of the present invention, a liquid permeable backing sheet may be provided on the attachment surface side to cover the liquid absorbent sheet. Alternatively, the liquid absorbent sheet may be exposed on the attachment surface side of the cleaning sheet without providing the backing sheet.

Preferably, first and second attachment sheets are provided to extend in opposite directions from longer sides of a rectangular main body in which the liquid absorbent sheet is present, the first attachment sheet being dimensioned to cover a liquid jetting part provided in the cleaning head. In this construction, liquid discharged from the liquid jetting part may flow down the first attachment sheet and be directed to and absorbed by the liquid absorbent sheet. The liquid thus applied to the liquid absorbent sheet can ooze out through the exterior sheet for cleaning the floor surface or the like.

Moreover, the second attachment sheet may have an indentation through which the liquid jetting part is able to squirt liquid out of the cleaning head. In this construction, the liquid may be squirted out of the cleaning head and applied to the floor surface by exposing the liquid jetting part through the indentation or may flow down the first attachment sheet to reach the liquid absorbent sheet by covering the liquid jetting part as set forth above.

Also preferably, the first attachment sheet dimensioned to cover the liquid jetting part has a water repellent interior surface for facing the liquid jetting part. If so, the liquid discharged from the liquid jetting part can flow down the first attachment sheet to quickly arrive at the main body of the cleaning sheet. This also prevents the liquid from remaining on the interior surface of the first attachment sheet.

According to the present invention, as has been described above, the liquid coming between the cleaning head and the attachment surface side of the cleaning sheet can be absorbed by the liquid absorbent sheet to prevent the liquid from remaining beneath the bottom face of the cleaning head. The liquid thus absorbed in the liquid absorbent sheet may be used for wiping the floor surface or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1is a perspective view of a cleaning device10to which a cleaning sheet1according to one embodiment of the present invention is suitably attached;FIG. 2is an enlarged perspective view showing a cleaning head11of the cleaning device10;FIGS. 3 and 4are perspective views showing states where the cleaning sheet1is attached to the cleaning head11in different orientations;FIG. 5is a side view showing a state where the cleaning sheet1is attached to the cleaning head11;FIG. 6is a bottom view showing a cleaning surface side of the cleaning sheet1;FIG. 7is a sectional view taken along line VII-VII ofFIG. 6; andFIG. 8is an exploded perspective view of the cleaning sheet1.

The cleaning sheet1according to one embodiment of the present invention is suitably used as attached to the cleaning head11of the cleaning device10. The cleaning sheet1has an attachment surface1bto be applied to a bottom face23of the cleaning head11and a cleaning surface1ato be applied to a floor surface or the like. As shown inFIGS. 7 and 8, the cleaning sheet1preferably has a main body1ewhich is constructed by stacking a first exterior sheet2, a second exterior sheet3, a liquid absorbent sheet4and a backing sheet5in the order mentioned above from the cleaning surface1ato the attachment surface1b.

As shown inFIG. 6, the main body1eis of a rectangular shape having parallel longer sides1c,1cand parallel shorter sides1d,1d. When the cleaning sheet1is used for cleaning the floor surface or the like, one of the longer sides1c,1cis to be situated forward in a wiping direction. First and second attachment sheets6,7are joined to the main body1ealong the longer sides1c,1c, respectively.

The individual sheets have an equal width W in a direction from side to side (hereinafter called the “transverse direction”). In a direction from front to rear (hereinafter called the “longitudinal direction”), on the other hand, the first exterior sheet2has a length L2, the second exterior sheet3has a length L3, the liquid absorbent sheet4has a length L4and the backing sheet5has a length L5. As shown inFIG. 6, the length L3of the second exterior sheet3is equal to the length of the shorter side1dof the main body1e.

The length L4of the liquid absorbent sheet4is preferably equal to the length L5of the backing sheet5, and the length L4/L5is preferably shorter than the length L3of the second exterior sheet3. As shown inFIG. 7, therefore, one longer side3aof the second exterior sheet3is at a distance from one longer side4aof the liquid absorbent sheet4. Likewise, the other longer side3bof the second exterior sheet3is at a distance from the other longer side4bof the liquid absorbent sheet4.

The length L2of the first exterior sheet2is preferably shorter than the length L3of the second exterior sheet3and the length L4of the liquid absorbent sheet4. In a side region9which extends along the longer side1cwith a length La, the cleaning surface side of the cleaning sheet1is not covered with the first exterior sheet2and the second exterior sheet3covering the liquid absorbent sheet4is exposed externally, as shown inFIG. 7. In a central region8, on the other hand, the cleaning surface side is covered with the first exterior sheet2.

The dimensions of the main body1e(or the cleaning surface1a) are not particularly limited as long as the cleaning sheet1can be suitably used for wiping a floor surface or the like, but for instance, the length L3may be about 60 to 160 mm, the width W may be about 200 to 320 mm. The length La of the side region9is preferably 5 mm or more, more preferably 10 mm or more.

The first exterior sheet2and the second exterior sheet3both preferably contain heat-fusible synthetic resin fibers. In the central region8, as shown inFIGS. 6 and 7, the first exterior sheet2, the second exterior sheet3and the liquid absorbent sheet4may be joined together to have a plurality of parallel join lines71by heating under pressure, such as by heat embossing or ultrasonic embossing. The backing sheet5is bonded to the surface of the liquid absorbent layer4through a hot-melt type adhesive applied in such an amount as not to interfere with liquid transfer. Alternatively, the backing sheet5may be thermally bonded to the liquid absorbent layer4at the join lines71.

The first exterior sheet2and the second exterior sheet3are also fixed to each other at join lines72. The join lines72may be formed by heating under pressure, such as by embossing the first exterior sheet2and the second exterior sheet3. The join lines72are spaced inward from the longer sides2a,2bof the first exterior sheet2and extend parallel to the longer sides2a,2b.

Along the longer side2a, as shown inFIG. 7, the first exterior sheet2provides a flap61which is allowed to move freely while being fixed on the cleaning surface1aat the join line72. Along the longer side2b, likewise, the first exterior sheet2provides another flap61. When the cleaning sheet1is slid on the floor surface with the longer sides1c,1cdirected forward and rearward in the sliding direction, the flaps61,61function to remove dirt adhering to the floor surface. The flap61has a free length Lb which is preferably 0.5 mm or more, more preferably 1 mm or more. If the free length Lb is excessively long, the frictional resistance between the cleaning surface1aand the floor surface may be increased. Therefore, the free length Lb is preferably 10 mm or less, more preferably 5 mm or less.

At the transverse center, the attachment sheet6has an indentation6aon one edge6c. On the other hand, the attachment sheet7is rectangular without any indentation on its edge7a.

As shown inFIG. 7, the longer side6bof the attachment sheet6is aligned with the longer side3aof the second exterior sheet3, and the second exterior sheet3and the attachment sheet6, which are in face-to-face contact, are preferably bonded together through a hot-melt type adhesive to provide a join line73outside the longer side4aof the liquid absorbent sheet4. The join line73is parallel to the longer side3aof the second exterior sheet3and extends the entire length of the cleaning sheet1in the transverse direction. Likewise, the longer side7bof the attachment sheet7is aligned with the longer side3bof the second exterior sheet3, and the second exterior sheet3and the attachment sheet7are bonded together to provide another join line73outside the longer side4bof the liquid absorbent sheet4.

The first exterior sheet2is preferably a nonwoven fabric having a high fiber density, wherein at least 70 wt. % of constituent fibers are synthetic resin fibers treated to be hydrophilic or hydrophilic natural fibers, so that the first exterior sheet2is capable of being wetted by liquid and allows liquid applied to the sheet surface to pass through it toward the liquid absorbent sheet4. For example, the first exterior sheet2may be a spunbonded nonwoven fabric of synthetic resin fibers treated to be hydrophilic or a spunlaced or point-bonded nonwoven fabric of synthetic resin fibers treated to be hydrophilic by a surfactant and/or hydrophilic natural fibers such as cotton, rayon and pulp.

The second exterior sheet3is preferably a low-density nonwoven fabric containing at least 70 wt. % of hydrophobic fibers. For example, the second exterior sheet3may be a through-air bonded nonwoven fabric in which polyethylene (PE) resin fibers, polypropylene (PP) resin fibers, polyethylene terephthalate (PET) resin fibers, PE/PP bicomponent synthetic resin fibers, or PE/PET bicomponent synthetic resin fibers are thermally bonded together by hot air. The second exterior sheet3preferably has a basis weight of 10 to 50 g/m2and a lower fiber density than the first exterior sheet2.

The liquid absorbent sheet4may be a layered structure of a first absorbent sheet4dand a second absorbent sheet4e. Preferably, the first absorbent sheet4dand the second absorbent sheet4eare both an air-laid pulp which is manufactured by depositing pulp by air-laid process and then bonding the fibers through a resin binder. The liquid absorbent layer4preferably has a basis weight of about 50 to 200 g/m2. The liquid absorbent layer4may further contain superabsorbent polymer (SAP).

However, the liquid absorbent layer4may be formed of other materials as long as it is capable of absorbing and retaining liquid. For example, there may be used a structure of deposited pulp, a spunlaced nonwoven fabric including rayon and pulp, a layered structure of the spunlaced nonwoven fabric, or an air-laid nonwoven fabric which is manufactured by depositing pulp and synthetic resin fibers treated to be hydrophilic by air-laid process and then bonding the fibers through a binder.

The backing sheet5is permeable to liquid and may be formed of the same through-air bonded nonwoven fabric as used for the second exterior sheet or a spunlaced nonwoven fabric including rayon and pulp. In an alternative, there may be used a spunbonded or point-bonded nonwoven fabric of synthetic resin fibers treated to be hydrophilic. In another alternative, a resin film (e.g., PE film) formed with a large number of liquid passage apertures may be used. Preferably, a spunbonded nonwoven fabric is used, formed of synthetic resin fibers treated to be hydrophilic and having a basis weight of 20 g/m2.

The attachment sheets6,7may be a point-bonded or spunbonded nonwoven fabric of synthetic resin fibers. The attachment sheets6,7are preferably impermeable to liquid and, for example, their interior surfaces facing the main body1einFIG. 8may be treated to be water-repellent. In an alternative, a synthetic resin film (e.g., PE film) may be used for the attachment sheets6,7. If the attachment sheet is treated to be water-repellent, liquid applied to the interior surface can be easily directed into the clearance between the cleaning head11and the cleaning sheet1and absorbed by the liquid absorbent sheet4. This also prevents liquid from remaining on the interior surface of the attachment sheet.

As shown inFIG. 1, the cleaning device10comprises the cleaning head11, a shaft13connected to the top face of the cleaning head11through a universal joint12, and a grip14secured on the top end of the shaft13. In the present embodiment, the shaft13and the grip14constitute a handle15.

As viewed from above (FIG. 2), the cleaning head11has a generally rectangular contour. The cleaning head11has a front face11aalong one longer side of the rectangle and a rear face11balong the other longer side. Moreover, the cleaning head11has a right end face11calong one shorter side and a left end face11dalong the other shorter side. The front face11and the rear face11bhave a length almost equal to the width W of the main body1eof the cleaning sheet1, while the right end face11cand the left end face11dhave a length almost equal to or slightly shorter than the length L3of the main body1e.

The cleaning head11is preferably constructed of a rigid holder21injection molded of a synthetic resin, such as acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc., and a pad22secured beneath the holder21. The pad22is preferably formed of a flexible elastic material such as ethylene-vinyl acetate (EVA), urethane, or rubber. Alternatively, the pad22may be formed of soft PP or PE. The pad22and the holder21are preferably bonded and secured together. The bottom face of the pad22, i.e., the bottom face23of the cleaning head11is generally flat.

In the top face, the holder21has sheet retainers24inside four corners of the rectangle, i.e., the corner between the front face11aand the right end face11c, the corner between the front face11aand the left end face11d, the corner between the rear face11band the right end face11c, and the corner between the rear face11band the left end face11d. The sheet retainer24is preferably constructed by forming an opening21ain the top face of the holder21and covering the opening21awith a deformable sheet25made of PE, PP, PET, etc. The deformable sheet25has a cut25a.FIGS. 3 and 4show states where the cleaning sheet1is retained on the cleaning head11such that the attachment sheets6,7are pushed into the cuts25a.

As shown inFIG. 2, a liquid jetting part30is mounted on the holder21. The liquid jetting part30is preferably located at the midpoint between the right end face11cand the left end face11dof the holder21and in front of the universal joint12. The liquid jetting part30may be constructed of two components: a base31and a nozzle head32. The nozzle head32has a front face (squirt surface)33where three nozzles35,36,37have orifices.

As shown inFIG. 1, the shaft13is provided with a container holder41for holding a container42filled with a liquid. In the embodiment of FIG.1, the container holder41and the container42constitute a liquid retention part40. Inside a lower part41aof the container holder41, there is provided an interrupting mechanism with a valve. The grip14is provided with an operating part43so that the valve of the interrupting mechanism can be opened by pressing the operating part43.

Hereinbelow, how to use the cleaning sheet1will be described. The cleaning sheet1may be used in at least two ways.

FIG. 3shows a first usage. According to a first usage, the main body1eof the cleaning sheet1is laid on the bottom face23of the cleaning head11with the attachment sheet6located on the side of the front face11aof the cleaning head11and the attachment sheet7located on the side of the rear face11b. The cleaning sheet1is fixed on the cleaning head11by placing the attachment sheets6,7on the top face of the cleaning head11and tucking them into the sheet retainers24. Here, since the attachment sheet6has the indentation6a, the squirt surface33of the nozzle head32remains exposed externally, as shown inFIG. 6.

As shown inFIG. 5, the main body1eof the cleaning sheet1thus attached to the cleaning head11can be kept generally flat on the bottom face23of the cleaning head11.

By pressing the operating part43with the grip14being held by hand, the valve of the interrupting mechanism provided in the lower part41aof the container holder41can be opened to permit the space above the liquid within the container42to communicate with the atmosphere. As a result, the liquid pressure within the nozzle head32is increased through a hollow13aof the shaft13and a pipe44in accordance with the liquid level within the container42, and the liquid is squirted forward from the nozzles35,36,37and applied to the floor surface in front of the cleaning head11. After the floor surface is wetted with the liquid, the cleaning head11is moved forward to wipe the floor with the cleaning sheet1.

The liquid in the container42may be plain water, or may contain a detergent for cleansing a floor surface, a high gloss wax, etc.

As the cleaning head11is slid on the floor surface, the liquid, which is foul with fine dust on the floor surface, passes through voids between the constituent fibers of the second exterior sheet3and is absorbed and retained by the liquid absorbent sheet4. This controls the amount of liquid between the first exterior sheet2and the floor surface so that the first exterior sheet2can retain a moderate amount of water to efficiently wipe off fine dust or dirt. Here, the flaps61,61, which are provided on the cleaning surface1aof the cleaning sheet1and which are able to move freely at boundaries between the central region8and the side regions9, also facilitate removal of the dirt adhering to the floor surface.

If the liquid drips from the nozzles35,36,37, the dripping liquid can be received by the top face of the base31. The upper face of the base31is inclined to approach the bottom face23of the cleaning head11as it extends toward the front face11a. Therefore, the liquid dripping on the top face of the base31is directed to the front face11awhich is covered with the attachment sheet6and then to the attachment surface1bof the cleaning sheet1. Since the liquid applied to the attachment surface1bcan pass through the backing sheet5and be absorbed by the liquid absorbent sheet4, the bottom face23of the cleaning head11is prevented from being soaked with the liquid.

This also prevents the liquid from dripping on the floor surface when the cleaning sheet1is removed from the cleaning device10. In addition, since the detergent is also prevented from remaining between the bottom face23of the cleaning head11and the cleaning sheet1, slippage due to the detergent can be prevented from occurring between the bottom face23and the cleaning sheet1.

FIG. 4shows a second usage of the cleaning sheet1. According to a second usage, the main body1eof the cleaning sheet1is laid on the bottom face23of the cleaning head11and the attachment sheet7is tucked into the sheet retainers24while covering the front face11aof the cleaning head11. The attachment sheet7is rectangular and dimensioned to be able to cover the squirt surface33of the nozzle head32, as shown inFIG. 4. On the other hand, the attachment sheet6formed with the indentation6ais tucked into the sheet retainers24while covering the rear face11bof the cleaning head11.

According to the second usage, when the liquid is squirted from the nozzles35,36,37of the nozzle head32by pressing the operating part43of the grip14, the liquid is received by the attachment sheet7, conducted to the bottom face23of the cleaning head11and then absorbed by the liquid absorbent sheet4of the cleaning sheet1through the backing sheet5.

When the cleaning head11is pressed against the floor surface, therefore, the liquid absorbed in the liquid absorbent sheet4is applied to the floor surface through the second exterior sheet3in the side regions9, which results in that the first exterior sheet2, which is inferior in liquid-permeability to the second exterior sheet3, is moderately wetted to remove the dirt from the floor surface.

In the second usage, the liquid, which is not directly applied to the floor surface but to the liquid absorbent sheet4, can be gradually applied to the floor surface in accordance with a pressure between the cleaning head11and the floor surface, i.e., a force exerted to push the cleaning head11against the floor surface. Accordingly, even if the floor surface is a wooden floor on which a finishing compound is applied, the amount of liquid between the cleaning sheet1and the floor surface can be easily controlled to prevent deterioration of the finishing compound.

Although the present invention has been illustrated and described with respect to exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omission and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. For example, the main body1eof the cleaning sheet1where the liquid absorbent sheet4is present may be of an oval or elliptical shape. The attachment sheets6,7may be integral with one of the sheets constituting the main body1e.

Therefore, the present invention should not be understood as limited to the specific embodiments set out above but should be understood to include all possible embodiments which can be embodied within a scope encompassed and equivalent thereof with respect to the features set out in the appended claims.