Field

[0001] The present disclosure relates to power-driven cleaning apparatus, and more particularly to power-driven surface cleaning apparatus.

Background

[0002] The earth is full of dust and dirt and surfaces of premises need to be cleaned from time to time to maintain cleanliness and hygiene. Conventionally, surfaces are cleaned by manual wiping. With the availability of wiping tools, surface cleaning and wiping can be made easier. However, known surface cleaning apparatus are either too powerful for everyday use or not good enough to facilitate good and effective cleaning.

Disclosure

[0003] There is provided a power-driven cleaning apparatus and a power-driven painting roller apparatus.

[0004] The power-driven cleaning apparatus comprising a main housing, a roller cleaner having a roller axis and mounted on the main housing, and a powered drive mechanism configured to drive the roller cleaner; wherein the roller cleaner is configured to be power driven by the drive mechanism to rotate relative to the main housing and about the roller axis, wherein the roller cleaner comprises a rigid roller core, a resiliently deformable outer portion extending around the rigid roller core, and an outermost surface surrounding the roller core; and wherein a retention device for touch fastening of a flexible wiper sheet is formed on the outermost surface.

[0005] In some embodiments, the outermost surface of the roller cleaner comprises a first surface portion which is an outer surface of the outer portion and a second surface portion which is a frictional portion configured to form a retention surface of a retention surface, and wherein the frictional portion is operable as the retention device for retaining a portion of a wiper sheet by touch or frictional engagement between the wiper sheet and the frictional portion.

[0006] In some embodiments, the second surface portion has a higher coefficient of friction than the first surface portion.

[0007] In some embodiments, the first surface portion has a first end and a second end, and wherein the second surface portion interconnects or is intermediate the first end and the second end of the first surface portion; and/or wherein the second surface portion has a first end and a second end, and wherein the first surface portion interconnects or is intermediate the first end and the second end of the second surface portion. [0008] In some embodiments, the outermost surface of the roller cleaner has an outer perimeter measured in a perimetric direction which is orthogonal to an axial direction which is parallel to the roller axis; wherein the first end and the second end of the first surface portion cooperate to define a gap, and the second surface portion is formed in the gap.

[0009] In some embodiments, the first end and the second end of the first surface portion cooperate to define an elongate gap, wherein the elongate gap extends along a gap axis which is parallel to the roller axis and has a gap width which is measured in the perimetric direction, and wherein the gap is a minor portion of the outer perimeter.

[0010] In some embodiments, the gap width is less than 5% or 10% of the outer perimeter, say less than 2%, 3%, 4% of the outer perimeter or less than 7%, 8%, 9% of the outer perimeter.

[0011] In some embodiments, the first surface portion has a first surface area and the second surface portion has a second surface area, the second area being less than 5% of the first surface area, say less than 2%, 3% or 4% of the first surface area.

[0012] In some embodiments, the first surface portion is a smooth and rubbery surface.

[0013] In some embodiments, the second surface portion is a rough surface which is configured to form a latching surface of a touch fastener.

[0014] In some embodiments, a plurality of hooks, a plurality of loops, or a plurality of hooks and loops are distributed to form a spurred surface defining the second surface portion, and wherein the spurred surface is to form an engagement surface of a touch fastener.

[0015] In some embodiments, the outer portion is devised as a cushioning portion, and wherein the cushioning portion is in friction contact with a target surface due to weight of the apparatus when the apparatus rests on the target surface, and is to rotationally rub against the target surface when the roller cleaner is power-driven to rotate relative to the target surface.

[0016] In some embodiments, the outer portion is formed of a resiliently deformable material selected from one or more of: a foamy material, a spongy material, a rubbery material.

[0017] In some embodiments, a flexible wiper sheet for cleaning a target surface is detachably attached to the outermost surface of the roller cleaner, wherein the wiper sheet is intermediate the outermost surface and the target surface during cleaning operations when the wiper is in friction contact with the target surface due to weight of the apparatus.

[0018] In some embodiments, the roller cleaner is driven by a motor having a motor axis, and wherein the motor is mounted inside the rigid roller core, with the motor axis parallel to the roller axis.

[0019] In some embodiments, the motor is mounted inside a rigid motor housing and the motor housing is mounted inside the rigid roller core; and wherein the motor is to drive the rigid roller core to rotate relative to the motor housing and the main housing during operations.

[0020] In some embodiments, the roller cleaner is driven by a motor via a belt drive mechanism.

[0021] In some embodiments, the rigid roller core comprises a first clam shell and a second clam shell, the first and second clam shells being fastened together to form the rigid roller core.

[0022] In some embodiments, a fastening means is distributed on an outer surface of the rigid roller core, the fastening means being for releasable attachment of a wiper sheet to surround the rigid roller core and form the cleaning surface.

[0023] In some embodiments, the fastening means comprises hook fasteners which are distributed in an axial direction and/or circumferentially on the outer surface of the rigid roller core.

[0024] In some embodiments, wherein the wiper sheet is an electrostatic sheet.

[0025] In some embodiments, the apparatus has a weight which is to cause slight deformation of the outer portion when the apparatus rests on the target surface.

[0026] In some embodiments, the motor is to rotate the roller cleaner relative to the target surface during normal operations when the cleaning surface is in abutment contact with the target surface.

[0027] In some embodiments, the motor is to rotate the roller cleaner relative to the target surface during normal operations so that the cleaning surface and the target floor has a relative translational speed of between 1 km/h to 2km/hr.

[0028] In some embodiments, the motor is to rotate the roller cleaner relative to the target surface during normal operations at between 150-250 rpm.

[0029] In some embodiments, the main housing comprises a base housing portion and a handle portion, and wherein the roller cleaner is mounted in the base housing portion and the handle portion is pivotally mounted to a rear end of the base housing portion.

[0030] In some embodiments, the apparatus comprises a power switch operable to supply power to the motor, wherein the power switch is mounted on the base housing portion or the handle portion.

[0031] The power-driven painting roller apparatus comprises the features of the power-driven cleaning apparatus, with the cleaning surface modified as a painting surface. [0032] The agitation by the roller against the contact surface has been found to significantly improve the intended purposes of the apparatus, that is, surface cleaning and painting.

Figures

[0033] The present disclosure is described by way of example and with reference to the accompanying figures, in which:

Figure 1 is a perspective view of an example surface cleaning apparatus of the present disclosure,

Figures 1A, 1 B, 1 C, 1 D and 1 E are, respectively, front, side, rear, top and bottom views of the apparatus of Figure 1 ,

Figure 1 A1 is a schematic perspective view of the hand-grip portion of the apparatus of Figure 1 showing a power switch mounted on the hand-grip portion,

Figures 2A and 2B are, respectively, schematic perspective and top views of the base housing portion of the apparatus of Figure 1 showing the motor and motor support structure,

Figures 3A and 3B are, respectively, schematic perspective and top views of the base housing portion of the apparatus of Figure 1 showing the motor but not the motor support structure,

Figure 4A is a partially exploded view of the roller body and the base housing portion,

Figure 4B is a further exploded view of Figure 4A, showing a motor support structure inside the roller body,

Figure 4C is a simplified schematic view of Figure 4B,

Figure 5A is a schematic top view of the apparatus of Figure 1 , with fastening means on the roller body exposed,

Figures 5B to 5D are schematic diagrams showing attachment of a wiper sheet to the roller body of the apparatus of Figure 1 ,

Figure 6 is a perspective view of another example surface cleaning apparatus of the present disclosure,

Figure 6A is a schematic perspective view of the base housing portion of the apparatus of Figure 6 showing a belt drive mechanism,

Figure 6B is a simplified schematic top view of the base housing portion of the apparatus of Figure 6 showing the motor and the belt drive mechanism,

Figure 7A and 7B are perspective and side views of the apparatus of Figure 6 with a guard mounted onto the base housing portion and showing the belt drive mechanism, and Figure 8 is an enlarged perspective view of the belt drive mechanism.

Description

[0034] A cleaning apparatus 100 comprises a main housing and a power-driven roller cleaner 120 which is mounted on the main housing. The example main housing comprises a base housing portion 140 and a handle portion 150. The base housing portion 140 is elongate and extends along a first longitudinal axis X-X’ which is also a center axis of the base housing portion 140. The handle portion 150 is elongate and extends along a second longitudinal axis Y-Y’ between an upper end and a lower end. The base housing portion 140 comprises a forward end, a rearward end, and a pair of side portions interconnecting the forward end and the rearward end. Each of the side portions 146 comprises a side panel 148. The side panel 148 has a height comparable to or larger than the height of the roller cleaner 120 and a width which is larger than the width of the roller cleaner 120. In example embodiments, the width of the base housing portion 140, defined by the width of the side panel portions, is 2-3 times the width of the roller body. The base housing portion 140 also comprises a bottom portion and an upper portion between which a hollow internal compartment is defined. The roller cleaner 120 is power-driven to rotate by a driving circuity and the driving circuitry is housed inside the base housing portion 140. The roller cleaner 120, the driving circuitry, and the base housing portion 140 collectively define a base portion of the cleaning apparatus 100. The handle portion 150 defines an upper portion of the cleaning apparatus 100.

[0035] The handle portion 150 is pivotally movable relative to the base housing portion 140 so that the upper end of the handle portion 150 can be elevated or lowered with respect to a surface on which the main housing is supported. The lower end of the handle portion 150 is pivotally joined to the rear end of the base housing portion 140, for example, by a hinged joint or by a universal joint. In example embodiments such as the present, the handle portion 150 is joined to a longitudinal mid-point on the base housing portion 140 and is swivel-able with respect to the base housing portion 140. In example configurations as depicted in Figures 1 A to 1 E, the handle portion 150 is orthogonal to the first longitudinal axis X-X’ of the base housing portion 140 and is swivel- able in a plane orthogonal and/or a plane parallel to the first longitudinal axis X-X’ of the base housing portion 140. In example embodiments such as the present, the handle portion 150 comprises a hand-grip portion 152 which is proximal the upper free end of the handle portion 150. As depicted in Fig. 1A1 , a power switch 154 which is operable, for example finger-operable, by a user to turn on or turn off the driving circuitry of the roller cleaner 120 is mounted on or near the hand-grip portion 152. [0036] The roller cleaner 120 comprises a roller and a cleaning surface 124. The roller is mounted on a front portion of the internal compartment defined by the base housing portion 140 and is rotatable about a rotation axis which is parallel to the first longitudinal axis X-X’ of the base housing portion 140. The roller comprises a first lateral end, a second lateral end and a roller body which extends in an axial direction between the first and second lateral ends and having a center axis, the axial direction being coaxial with the center axis of the roller body which is also the rotation axis. The roller body comprises a radially outermost surface which is to rotate about the center axis of the roller.

[0037] The main cleaning surface 124 of the roller cleaner 120 is an exterior surface of the roller cleaner 120 which is to rotate about the roller center axis (or roller axis in short) during operations. In example embodiments such as the present, the main cleaning surface 124 comprises a curved outer surface such as a cylindrical outer surface.

[0038] In use, the cleaning apparatus 100 is placed on a surface to be cleaned so that the main cleaning surface 124 is in abutment contact with the surface to be cleaned and in friction engagement therewith. The weight of the base portion is selected or designed so that there is sufficient frictional engagement between the main cleaning surface 124 and the surface to be cleaned.

[0039] In example embodiments such as the present, the radially outermost layer of the roller body is resilient to enhance contact engagement with the surface to be cleaned. The resilient outermost layer may function as a soft cushion. The resilient outermost layer may be made of sponge, foam, silicone or rubber, and may be permanently attached to a rigid core roller body. The resilient outermost layer may have a thickness of between 1.5-3.5 mm (preferably between 2- 3mm) in the radial direction. The resilient outermost layer is resiliently deformable and is slightly deformed in the radial direction when the apparatus 100 is supported on a portion of the radially outermost layer of the roller body when the apparatus 100 rests on the surface to be cleaned during normal operations. The term slightly deformable herein means that the extent of deformation is closer to a no-radial deformation state when the roller body is at its free and resilient neutral state than a state of maximum radial resilient deformation. The resiliently deformable cleaning surface 124 facilitates cleaning operation resembling the rubbing action of a rubber eraser. In use, the roller is to rotate relative to the surface to be cleaned while in abutment contact therewith. The relative rotation between the roller cleaning surface 124 and the surface to be cleaned produces relative slip and a rubbing action which facilitates removal of dirt from the surface to be cleaned. [0040] The cleaning surface 124 of the roller cleaner 120 may be a permanent cleaning surface or a disposable cleaning surface. For example, the permanent cleaning surface 124 may be an integral portion of the resilient outermost layer of the roller body which is fastened onto the rigid core by fastening means such as screws, rivets or bolts. Disposable cleaning medium may be attached to the radially outermost layer of the roller body. Use of a disposable cleaning medium to form a cleaning surface 124 on the roller cleaner 120 can be advantageous since the cleaning medium may be changed at regular intervals or on a need basis so that the surface cleaning performance of the apparatus 100 can be maintained at a reasonable level. In addition, the capability to permit change of the cleaning medium also permits a user to select appropriate cleaning medium for different types of surfaces. For example, different cleaning mediums may be selectively used for, say, a wooden surface, a metal surface or a glassy surface.

[0041] The base housing portion 140 comprises a forward housing portion in which the roller body is mounted, as depicted in Figures 3A and 3B. The roller body is anchored on the main housing with the two longitudinal free ends rotatably supported on the two side portions 146 of the base housing portion 140. The longitudinal end of the roller body which is anchored on the side portion 146 of the base housing portion 140 has a substantially smaller radial dimension compared to the radial dimension of the roller body intermediate the longitudinal ends. With such a structure or configuration, the longitudinal ends are to function as a pair of supporting end axles in support of the intermediate portion of the roller body which is intermediate the longitudinal ends. Therefore, the intermediate portion of the roller body is in the form of a rotatable drum which is supported by a pair of end axles. The roller body may be resiliently supported on the base housing portion 140. In some embodiments, the pair of end axles is resiliently supported on a pair of bearings and the bearings are resiliently supported, for example, by spring means. In some embodiments, the roller body is spring biased to urge against the surface to be cleaned. For example, the spring may be biased to urge the roller body towards the surface-to-be-cleaned in order to foster compressive contact between the cleaning surface 124 of the roller cleaner 120 and the surface-to-be-cleaned. In use, a vertical downward component of the force applied on the handle portion 150 may also contribute to the downward compressive force to control the extent or level of compressive contact between the roller body outer surface and the surface to be cleaned. The elastic portion of the roller body may have an elasticity and adsorption properties or parameters comparable to that of an eraser rubber.

[0042] In example embodiments such as the present, a powered driving arrangement is mounted on the roller body, as schematically shown in Figures 2A, 2B, 3A and 3B. Powered herein means electrical-powered and powered driving arrangement herein means the driving arrangement is driven by electrical power. The example powered driving arrangement comprises a motor 162 having a motor casing 160 which is fixedly mounted on the interior of the roller body. The motor 162 has a motor shaft which is connected with the longitudinal end or the longitudinal ends of the roller body so that when the motor 162 rotates, the roller body is driven into rotation about the roller axis.

[0043] The motor 162 may be configured to drive the end axle or end axles so that the entire roller body rotates relative to the base housing portion 140. Alternatively, the end axle or end axles may be fixedly mounted on the base housing portion 140 and the motor 162 is connected to rotate relative to the fixed end axle or end axles so that the intermediate portion of the roller body is driven into rotation relative to the base housing portion 140 by the motor 162. The rotation speed of the roller body relative to the main housing is set to be different to the speed of movement of the base housing portion 140 relative to the surface in contact, so that there is relative movement or slip between the cleaning surface 124 of the roller cleaner 120 and the surface in contact with the roller cleaner 120. The slip between the cleaning surface 124 of the roller cleaner 120 and the surface in contact with the roller cleaner 120 is to generate rubbing actions to facilitate surface cleaning. In some embodiments such as the present, the speed of the roller body outermost surface is higher than the speed of the base housing portion 140 relative to the surface in contact. In other embodiments, the speed can be lower. The difference in speed needs not be large. For example, the difference may be in the region of 50 to 85 cm-per-second. The speed of the roller body outermost surface herein is the speed in the tangential direction of the portion of the roller body outermost surface which is in instantaneous contact with the surface to be cleaned and in contact.

[0044] The roller cleaner 120 is to rotate at a relative low speed, for example, at around 150-250 rpm (revolution-per-minute) to facilitate slip cleaning of a smooth surface in contact. The motor shaft may be connected to a set of output gears. The output gears may comprise a set of speed reduction gears to reduce the motor speed and to increase turning torque. The motor 162 may be a brushless DC motor (BLDC). In some embodiments, the motor 162 may be integrally formed on the roller body. For example, stator windings may be formed along an axial length portion of the roller body and distributed circumferentially along the inner periphery of the roller axial and the permanent magnet strips are similarly arranged on the rotor. The motor 162 may be driven by low- frequency DC voltages, for example, using PWM pulses at 2-10 Hz, and the driving voltage and frequency may be adaptively adjusted according to the application, for example, according to the surface conditions, such as extent of smoothness, cleanliness etc.

[0045] In use, a cleaning medium in the form of a wiper sheet 124A may be attached to the radially outermost layer of the roller body to form a wiping or cleaning surface 124 of the roller cleaner 120. In example embodiments, the wiper sheet may be fastened on the roller body outermost surface by snap fastening means or touch fastening means, such as hook-and-loop fastening means or pairs (better known by the trade name“Velcro”).

[0046] In example embodiments such as the present, a hook-fastening means 128 is disposed on the outermost surface of the roller body, as depicted in Figures 5A to 5D. The fastening means is distributed along the length of the roller body outermost surface. A wiper sheet is to be attached to the roller body outermost surface. The wiper sheet may be a wiper cloth or a wiper paper. The paper may be tissue paper and the wiper cloth may be made of microfiber or non-woven cloth. The wiper sheet may be dry or wet. An example wiper sheet suitable for use is a floor wiping sheet sold under the brand name Scotch- Brite™.

[0047] In the example shown in Figures 5A to 5D, the hook-fastening means is distributed along the length of the roller body outermost surface and extends in a direction parallel to the roller axis axial direction. An example wiper sheet, which is porous and having loop-fastening means distributed substantially uniformly on its entire wiping surface, is attached to the roller body. To attach the wiper sheet, a user is to hold an end edge of the wiper sheet parallel to the hook fastening means to bring the wiper sheet in alignment with the fastening means on the roller body. The user then attaches the aligned end edge of the wiper sheet so that the complementary fastening means on the roller body and on the wiper sheet will enter into fastening engagement. After the wiper sheet has been initially attached to the fastening means on the roller body, the roller body is turned and the entire wiper sheet is attached on the roller body.

[0048] To have an even wiping surface, the length of the wiper sheet is larger than the diameter of the roller body. In the example embodiment, the wiper sheet has a size comparable to A4 paper. In some embodiments, the user is to operate the power switch 154 to turn on the motor 162 for slightly over one complete turn, say 1.5-2 turns, so that the roller body rotates in the direction of wiping operation (which is counterclockwise in the present example, as depicted in Figure 5C) to cause the wiper sheet to follow the curvature of the roller body outermost surface and gets fully attached on the roller body. The elastic portion of the roller body is adsorptive and the adsorption properties is to facilitate closely-fitted attachment of the wiper sheet on the roller body outermost surface. In some embodiments, the elastic portion of the roller body is static electrically charged and this further facilitates better attachment. In some embodiments, the hook-fastening means is helically or spirally distributed along and around the roller body outermost surface.

[0049] After the wiper sheet has been well attached on the roller body and wraps around the roller body, the apparatus 100 is in operation mode and ready for operation.

[0050] To operate the apparatus 100 to clean a surface, the base housing portion 140 is placed on the floor, as an example of a smooth surface to be wipe-cleaned, with its bottom portion in close proximity to the floor surface. The user then moves the base housing portion 140 to a location requiring cleaning and then operates the power switch 154 to turn on the motor 162 to drive the roller body to rotate in the direction of operation. To move the apparatus 100, the user holds the hand-grip portion 152 of the apparatus 100 so that the handle portion 150 is at an acute elevation angle with respect to the floor surface and with the hand-grip portion 152 elevated above the base housing portion 140. When the apparatus 100 is so moved, a vertically downward component of the moving force applied on the handle portion 150 will result in a downward compressive force on the roller body to act on the floor surface. When the motor 162 is turned on, the speed of the roller body outermost surface or the roller cleaner 120 cleaning surface 124 is higher than the speed of movement of the base housing portion 140, which is moved by a user at a typical speed of around 2-3km per hour. The faster movement of the roller cleaner 120 wiping surface compared to the speed of translational movement of the base housing portion 140 results in a relative slip between the roller cleaner 120 wiping surface and the floor surface. The relative slip helps to enhance cleaning by rubbing in addition to wiping. The static electricity charged roller body also helps to pick up dry dust in the vicinity of the roller body. The wiper sheet may be soaked with a cleaning liquid, for example, bleaching liquid, antiseptic liquid, polishing or waxing liquid, etc. without loss of generality. During surface wiping operations, the exterior surface of the roller body is to rotate about the rotational axis, the cleaning surface 124 is to engage with the floor surface, which is an example surface to be cleaned and to rotate relative to the surface in abutment with slip to effect cleaning or wiping with rubbing. It is noted that the cleaning performance are exceptional compared to conventional surface cleaning apparatus.

[0051] After use, the wiper sheet may be detached and the apparatus 100 is put back in storage.

[0052] The example roller comprises a rigid roller body and a resilient outer lining on the rigid roller body. The rigid roller body is formed from a first clam shell 126 and a second clam shell which are fastened to form a rigid and cylindrical core body of the roller body, as defined in Figure 4A. The clam shell is molded, for example, of hard plastics. The motor 162 is mounted on a rigid motor housing 160 which is inside an internal compartment defined by the first and second clam shells. The motor housing 160 is generally cylindrical along its length. The motor 162 is mounted at about a longitudinal center of the motor housing 160. A set of driving gears is mounted longitudinally adjacent the motor 162. Lead wires 164 to provide driving power to the motor 162 enter the motor housing 160 from a wire entry aperture which is on a longitudinal end of the motor housing 160 distal from the gears. In some embodiments, the motor housing 160 is rotationally fixed relative to the base housing portion 140 and the rigid roller body is rotatable relative to the motor housing 160. As depicted in Figure 4B, the set of driving gear has an output shaft 166 and the output shaft 166 is to drive a driving blade 168 to rotate relative to the motor housing 160 and/or the base housing portion 140. The driving blade 168 and the rigid core body of the roller body are fixedly connected so that the rigid core body is to rotate relative to the base housing portion 140 during cleaning operations when the motor 162 is driven into rotation. The motor 162 may be battery operated and the battery may be stored inside the rear portion of the base housing portion 140 or in the handle portion 150 without loss of generality.

[0053] Referring to Figure 5A, an example roller cleaner comprises a roller core which is a core portion and a roller outer which is an outer portion of the roller cleaner. The roller core is rigid and is configured as a support structure to hold the roller cleaner on the main housing of the cleaning apparatus. The roller cleaner has a roller axis and the roller cleaner is rotatable relative to the main housing about the roller axis as a rotational axis. The roller core has an inner surface which surrounds the roller axis and an outer surface which surrounds its inner surface. The outer surface of the roller core is proximal to or in abutment with the roller outer.

[0054] The roller outer has an inner surface which is proximal to and surrounds the roller core, and an outer surface which surrounds its inner surface. In some embodiments, the inner surface of the roller outer is fixedly attached or bonded to the outer surface of the roller core.

[0055] The roller outer comprises a first portion having a first surface portion 130A and a second portion having a second surface portion 130B. The first surface portion and the second portion cooperate to define an outer surface or an outermost surface of the roller cleaner. In example applications wherein the cleaner roller is to engage directly with a target surface to be cleaned, the outer surface of the roller cleaner is also the outermost surface of the roller cleaner.

[0056] The roller cleaner has a length which is measured in an axial direction which is parallel to the roller axis and a perimeter which is measured in a perimetric direction orthogonal to the axial direction. The perimeter of the roller cleaner is also the perimeter of the roller outer in the present example.

[0057] In example applications where a flexible wiper sheet is attached to the roller head, the outermost surface will be a surface of the wiper sheet. [0058] The first portion of the roller outer is a resiliently deformable portion. The resiliently deformable portion may be made of an elastomeric material, a spongy material, a foamed material, a rubbery material, or a combination of any of the aforesaid.

[0059] The second portion is to define a retention portion on outer surface of the roller cleaner. The retention portion is configured to hold a flexible cleaning attachment such as a piece of cleaning towel, a piece of cleaning fabric, or a sheet of cleaning paper. To facilitate ease of use, the retention portion may be configured as a touch fastening portion or a touch fastening means for holding a cleaning attachment by touch fastening or contact fastening. The cleaning attachment may be in the form of a sheet, such as a wiper sheet 124A.

[0060] The retention portion is configured to firmly hold the cleaning attachment so that when the cleaning attachment is held on the roller cleaner, the cleaning attachment surrounds the perimeter of the roller cleaner, as shown in Figure 5D.

[0061] In example embodiments, the first portion of the roller outer extends in a perimetric direction between a first end and a second end, and defines a gap between the first and second ends.

[0062] In example embodiments, the second portion of the roller outer is formed in the gap. In example embodiments, fastening components are distributed in the gap to form a distributed touch fastening device exposed on the outer surface of the roller outer. The fastening components may be made of a flexible and resilient material such as a flexible and resilient material fabric. The fastening components may be in the form of hooks, piles, or loops. In example embodiments, the fastening components may be densely populated or distributed in the gap to provide a firmer grip on the cleaning attachment. The fastening components are densely populated or distributed when all or a majority of the components are in physical abutment. A majority herein means more than 70%, 80%, 90% of the fastening components are in physical abutment. The fastening components are densely populated or distributed in the gap such that a large majority of the gap area is filled with the fastening components. A larger majority herein mean smore than 70%, 80%, 90%, 95%. The fastening components may protrude above the first surface portion. The end of the fastening components is further away from the roller axis than the first surface portion.

[0063] In example embodiments such as the present, the gap is an elongate gap extending in a gap direction which is parallel to the roller axis.

[0064] In example embodiments such as the present, the second portion may comprise a plurality of discrete sub-portions which are separately distributed within the first portion. [0065] In general, the retention portion is devised such that when the cleaning attachment is firmly held on the roller cleaner, the cleaning attachment covers a full revolution or more of the roller cleaner.

[0066] An example cleaning apparatus 200 depicted in Figures 6 and 6A is substantially identical to that of the cleaning apparatus 100 and the description thereon is incorporated by reference and applied mutatis for the benefit of succinctness, with like numerals representing like features but increased by 100.

[0067] The cleaning apparatus 200 comprises a main housing and a power-driven roller cleaner 220 which is mounted on the main housing. The example main housing comprises a base housing portion 240 and a handle portion 250. A power switch 254 which is operable to turn on or turn off the driving circuitry of the roller cleaner 120 is mounted on the base hosing portion 240. The power switch 254 works as a foot stepping on/ off switch, which is operable, for example by foot, by a user standing up-right.

[0068] In some embodiments, the cleaning apparatus comprises two power switches, one mounted on or near the hand-grip portion and one mounted on the base housing portion.

[0069] In some embodiments, a powered driving arrangement is mounted on the base housing portion as depicted in Figure 6A. The powered driving arrangement comprises a motor 262 and a belt drive mechanism 270 comprising a set of gears and a transmission belt 272. The belt drive mechanism 270 is mounted on a side portion 246 of the base housing portion 240 and the motor is fixedly mounted on a rearward end opposite to the roller cleaner 220, as depicted in Figure 6B The motor 262 has a motor shaft which is to drive the set of gears into motion via the transmission belt of the belt drive mechanism 270. The transmission belt may be a flat belt or a timing belt. In the present example, the belt drive mechanism comprises a transmission belt 272, a large intermediate gear 274, a small intermediate gear 276 and an output gear 278. When the motor shaft of the motor 262 rotates, the driving force is transmitted to the large intermediate gear 274 via the transmission belt 272. The large intermediate gear 274 is coupled to the small intermediate gear 276 by an intermediate shaft such that they rotate together. The small intermediate gear 276 drives the output gear 278 into motion. The output gear 278 is connected to the roller body. As a result, when the motor 262 rotates, the roller body is driven into rotation about the roller axis.

[0070] In some embodiments, a guard 280 is mounted onto the base housing portion as depicted in Figure 7A. The guard 280 comprises a cover member and a body member. The cover member covers an upper and front portion of the roller cleaner. The body member is configured to cover the space between the pair of side portions 246 of the base housing portion. The body member may comprise a debris collection compartment pending into the space between the base housing portion 240 and the roller cleaner 220.

[0071] In some embodiments, the material of the cleaning medium is chosen such that one end of the cleaning medium is attachable to the cleaning medium itself, for examples, electrostatically or through microstructure on the surface of the cleaning medium. The guard 280 may be configured to exert a force onto the cleaning medium to facilitate continued attachment of the cleaning medium on the roller cleaner.

[0072] While floor has been used as an example of surface to be cleaned, the surface to be cleaned may be a wall, for example, a glass wall, or other surfaces, for example, smooth surfaces, and cleaning operations are adjusted mutatis mutandis without loss of generality.

[0073] While the disclosure has been described with reference to example embodiments, it is expected that persons skilled in the art will understand that the embodiments serve as examples and shall not be taken to restrict the scope of disclosure.

[0074] For example, while the example apparatus 100 comprises a handle portion 150, the apparatus 100 may not have a handle portion 150. For example, the apparatus 100 may be microprocessor-based with machine visions and driven automatically by a microprocessor in cooperation with sensors, similar to vacuum cleaners which are known as robotic vacuum cleaners without loss of generality.

[0075] While the example apparatus 100 is for cleaning a surface, especially a smooth surface, the apparatus 100 may be adapted to be used as a painter. When adapted as a painter, the outermost surface of the roller body may be adapted to operate as a painting roller. The rubbing action is expected to produce a good paint effect. When adapted to function as a painter, the apparatus 100 may comprise a paint egress nozzle for dispensing paint on the outermost surface. Alternatively, the outermost surface may be a spongy surface which can store paint for dispensing.

[0076] Table of numerals