BACKGROUND

This present invention relates to a hand-held cleaning tool having a cleaning head which detachably receives a rotatably mounted cleaning element for scrubbing, buffing, scouring and the like

The invention has been developed primarily for use in domestic cleaning operations for example for the cleaning of oven interiors and will be described hereinafter with reference to this application However, it will be appreciated that the tool is not limited to this particular application and is also useful for scrubbing, cleaning, scouring and polishing various other surfaces, particularly those in tight or confined spaces and particularly where liquids are used in the cleaning which could contaminate the interior and especially the drive mechanisms of the tool

PRIOR ART

A wide variety of power-driven cleaning tools using rotary cleaning attachments are known for a range of purposes

These devices typically include a housing incorporating a power source, a drive motor, a gear and drive shaft assembly and a switch for activating a drive motor An output shaft generally extends outside the housing to receive and support a rotating or oscillating an attachment Examples of such tools are electrically driven or rechargeable hand held drills, power grinders and the like

However, these prior art devices suffer from a number of inherent disadvantages Firstly, many of these devices are relatively bulky, heavy and cumbersome Therefore, they do not lend themselves well to buffing, cleaning and polishing applications in confined spaces Certainly few are sized or shaped and ergonomically balanced such that it is

possible to conveniently clean the interior of ovens, baking dishes or the like and none of the smaller equivalent devices are sufficiently powerful to remove the built-up, baked-on grime normally found in oven interiors In any event, many of the prior art devices are not sealed against the ingress of water and other liquid contaminants and, as a result, are quite limited in their application and in fact could be dangerous to use in wet cleaning applications

Whilst attempts have been made to seal the housing of some prior art devices, sealed housings have brought their own set of problems In particular, sealing the housing has been found to increase the explosion risk due to the build up of hydrogen gas generated from the storage batteries within the housing

Accordingly, it is an object of the present invention to provide a lightweight, hand-held, portable cleaning device which is battery powered and specifically adapted for heavy duty cleaning and scrubbing of domestic ovens and the like, which avoids or at least ameliorates some of the disadvantages of known power-driven hand held cleaning devices

According to the invention, there is provided a portable hand-held cleaning device adapted for cleaning the interior of a confined spaces such as in an oven or domestic surfaces, said device comprising a housing having a handle portion and a cleaning head portion and a detachable cleaning element rotatably mounted at the head portion, said housing including a battery compartment for accommodating a storage battery, a motor, and a gear and drive shaft assembly associated with the motor for rotatably driving the cleaning head, wherein the housing is substantially closed to the ingress of water and other liquid contaminants and the device includes a gas control facility for reducing or removing from the housing unwanted gas generated by a storage battery accommodated therein

In one broad form the present invention comprises a portable hand-held cleaning device comprising,

a body comprising, a gripping handle which at least partially forms an inner compartment in which a power source is located, and, connected to said handle a cleaning head comprising a drive motor which imparts drive via a gear train to a drive member which detachably receives a rotatable cleaning element, said body further comprising a gas control facility, for neutralising the effect of or facilitating the escape of unwanted gases generated by said power source in and/or around said inner compartment, wherein the body is sealed to limit or prevent ingress into said device of water or other liquid or particulate contaminants

In a preferred embodiment, the gas control facility comprises a primary opening in communication with the inner compartment containing the power source This opening includes a recharging port which is concealed by a closure which seals the opening The body of the device may further incorporates a gas permeable waterproof membrane which allows constant egress of unwanted gas from the inner compartment to the external environment. In addition, the unwanted gas can be absorbed by gas purification pellets within the inner compartment

According to an alternative embodiment, the gas control system may comprise a gas flow-through passage which is in fluid communication with an integrally formed air intake and exhaust hole in an exterior wall of the housing wherein air flowing through the housing during operation flushes any gas generated by the storage battery through the gas flow-through passage and out of the housing

In an alternative embodiment, the gas flow passage comprises separate gas intake and exhaust passages and, during operation, a fan in the drive motor creates a negative pressure in the intake passage causing air to flow in through the air intake and an exhaust hole and into and through the intake passage past the storage battery, to the motor for cooling. The exhaust air from the motor ideally exerts a positive pressure on the air flowing through and out of the motor, causing it to flow out of the housing through the

exhaust passage Whilst the exhaust passage is open to the outside air it is water resistant and splash proof

In an alternative form the present invention comprises, a body including a gripping handle which at least partially defines an inner compartment in which a power source is located and a housing connected to the handle and having therein a motor which imparts drive via a gear train to a drive member which detachably receives a rotatable cleaning element, said device further comprising, a release mechanism for ejecting said cleaning element comprising, a release member which moves between an extended configuration in which said member engages and ejects the cleaning element and a retracted configuration in which the release member is free of the cleaning element, wherein said body is sealed to limit or prevent ingress of water or other liquid or particulate contaminants during use

In a further form the present invention comprises a cleaning element adapted for fitting to a hand-held cleaning device comprising a body comprising, a gripping handle which at least partially forms an inner compartment in which a power source is located, and, a housing connected to said handle and in which is located a cleaning head comprising a drive motor which imparts drive via a gear train to a drive member which detachably receives a rotatable cleaning element, said body further comprising a gas control facility, for neutralising the effect of or facilitating the escape of unwanted gases generated by said power source in and/or around said inner compartment, wherein the body is sealed to limit or prevent ingress of water or other liquid or particulate contaminants

According to a preferred embodiment of the aforesaid form of invention, there is provided a release mechanism for ejecting the detachable cleaning element and which moves between an extended configuration in which the release member engages the

cleaning element and a retracted configuration in which the release member is free of the cleaning element

The invention will now be described in more detail according to preferred but non- limiting embodiments of the invention wherein

Figure 1 shows a right side elevation view of a portable hand-held cleaning device according to one embodiment of the invention Figure 2 shows a front elevation view of the cleaning device of figure 1 Figure 3 shows a long-section view of the cleaning device of figures 1 and 2 (not all of the internal components in the apparatus are sectioned) Figure 4 shows a cross-sectional view of the cleaning device taken along lines IV-

IV of Figure 1 Figure 5 shows a cross-section view of the handle of the cleaning device of figure 1 , taken along lines V-V

Figure 6 shows a left side elevation view of the body of a portable hand-held cleaning device according to a preferred embodiment of the invention Figure 7 shows a long sectional view of the device of figure 6 showing internal components Figure 8 shows a cross-section of the device taken at line VI-VI of figure 7

Figure 9 shows a cross-section of the device taken at line VII- VII of figure 7

Figure 10 shows a cross-section of the device taken at line VIII- VIII of figure 7 Figure 11 shows a cross-section of the device taken at line IX-IX of figure 7 Figure 12 shows a cross-section of the device taken at line X-X of figure 7 Figure 13 shows a skirt according to one embodiment

Referring to figure 1, there is shown a portable hand-held cleaning device according to one embodiment of the invention Device 1 includes a lightweight plastics housing 2 formed from complementary left and right mating sections secured together by known means, for example screwing, gluing or snapping together to form an internal

compartment which is substantially or totally closed to the ingress of water and other particulate or liquid contaminants.

Housing 2 is ergonomically proportioned and balanced specifically for scrubbing and cleaning in confined spaces and includes a separate elongate handle portion 3 which allows the user to grip the device. A cleaning head portion 4 is contained in a housing which is integrally connected to the handle portion by way of neck portion 5 and supports a rotatably mounted interchangeable cleaning head element 6.

Figure 2 shows a front elevation of the device of figure 1 with corresponding parts numbered as for figure 1

Referring to figure 3 it can be seen that the neck portion 5 accommodates an electric motor 7, built into the body of the motor for driving the cleaning attachment 6. Motor 7 is supported in the housing by chassis 8 and anchorage 9 and is powered by one or more storage batteries or power cells 10 mounted in the handle 3 of housing 2.

Typically, storage cell 10 is a rechargeable battery such as nickel cadmium electrically connected to a recharging socket 1 1 into which a power plug can be inserted when the cleaning device is not in use, enabling the battery or batteries to be recharged. In this way, the battery or batteries can be recharged, thereby minimising the risk of liquid contamination of the interior components of the device and the inevitable corrosion which would follow given the wet and corrosive conditions under which the device would normally be operated.

Motor 7 has associated with it a gear and drive shaft assembly for rotatably driving the cleaning head element 6. A motor shaft 12 extends from the motor and has mounted thereon a first drive gear 13. A combination gear assembly 14 is rotatably mounted on gear shaft 15 which extends parallel to motor shaft 12 and includes a reduction sprocket 16 driven by the first drive gear 13. A second drive gear 17 is coaxially mounted with respect to reduction sprocket 16 for rotation at a speed reduced from that of the first

drive gear 13. Second drive sprocket 17 in turn drives a larger output gear 18 which is mounted on output shaft 19.

Output shaft or spigot 19 extends out through an aperture in the floor of housing 2 for releasable engagement with a selected and interchangeable cleaning element 6, which is provided with an upwardly extending central sleeve 20 which engages output shaft or spigot 19 and is rotated thereby. The device is also provided with sealing means 21 around output shaft 19 for sealing against liquid ingress during cleaning. A resilient splash skirt and bumper 22 is mounted at or adjacent to the rim of the cleaning head 4 and about cleaning element 6. The splash skirt and bumper restricts splashing and spraying of cleaning liquids when the device is in use and also minimises mechanical damage to walls and vulnerable surfaces adjacent to the surfaces being cleaned.

Typically, cleaning elements may take any one of a number of forms, for example a rotary brush, sponge or polisher. The cleaning head is attached by simple snap fitting and is removed by actuation of release mechanism 23 which includes release member 24 causing the ejection of cleaning element 6.

Figure 4 shows a cross-section of the device of figure 1 taken along lines IV-IV of figure 1 with the numbering corresponding to that used to identify identical components shown in figures 1 and 3.

Figure 5 shows a cross section of the device of figure 1 taken across V-V.

Device 1 is further provided with a gas control facility for both removal of unwanted and dangerous gases generated by the storage battery or batteries, and cooling the motor The gas control facility includes a gas flow-through passages comprising separate gas intake and exhaust passages, 25 and 26 respectively (see figure 5). As shown in figure 4, circumferential formation 27 disposed about motor 7 provides a barrier which results in a pressure differential across cavities 28 and 29. In the embodiment illustrated, lower cavity 28 is in fluid communication with gas intake passage 25 and upper cavity 29,

which receives exhaust air from motor exhaust 30 under positive pressure, is in fluid communication with gas exhaust chamber 26

During operation, the fan in the motor creates a negative pressure in intake passage 25 causing fresh air to flow into the housing through air intake and exhaust hole 31 and into and through intake passage 26 (see figure 5) As the air flows past each storage battery, it flushes any unwanted gases generated thereby The air and gas mixture continues its passage through intake passage 26 entering motor 7 via air holes 32 for cooling purposes The exhaust air and gases, which are expelled from the motor through motor exhaust 30, exert a positive pressure on the air flowing through the motor causing the air and gases to flow into and through exhaust passage 26, exiting the device through exhaust hole 31

The passage of water and other liquid contaminants through the intake and exhaust hole is largely prevented under normal operating conditions by a series of baffle plates in the rear of the housing

Figure 6 shows a left side view of hand-held cleaning device 50 according to a preferred embodiment of the invention Although device 50 is shown with an alternative profile of body 51 it is functionally similar to the device described in figures 1 to 7 except that the gas control facility operates an entirely different way. As for the figure 1 embodiment previously described, housing 51 is proportioned specifically for convenient hand-held use particularly within confined spaces Device 50 includes handle gripping portion 52 which allows the user to comfortably grip the device during use and further comprises cleaning head 53 which is contained in a housing integrally connected to handle portion 52 by neck 54 Cleaning head 53 detachably receives as described below via a drive member a cleaning attachment Cleaning head 53 is further defined by a skirt 55

Figure 7 shows a profile of the left half of housing 51 and as the left half is essentially a mirror image of the right half, the device will be described solely with reference to the left half The profile shown includes strengthening ribs 56 distributed throughout and

comprises at end 57 a charge cover 58 which seals the inside of housing 51 End 57 also comprises vent membranes 59 which allow/s escape of gases from the inside of housing 51 to the external environment Charge cover 58 according to the embodiment shown is pivotally attached to housing 51 via pivot 60 which enables free rotation of charge cover 58 for access to the inside of housing 51 Alternatively, charge cover 58 can be adapted to snap fit to housing 51 Device 50 includes internal cavity 61 which receives and accommodates batteries 62 which are in electrical contact with electric motor 63 via switching assembly 64 Switch assembly 64 comprises switch cover 65 which is squeeze actuated by the user's finger Located immediately inside cover 65 is trigger 66 which pivots about switch frame 67 Motor 63 is mounted within passage 68 and is secured by anchorage assembly 69 and spur gear 70 Spur gear 70 is in turn connected to spur gear 71 anchored about gear shaft 72 Gear shaft 72 locates in spur gear 73 which in turn engages internal spur gear 74 Spur gear 74 is rotatable with the assistance of ball¬ bearing 75 responsive to actuation of electric motor 63 Beneath ball-bearing 75 is a shaft seal 76 which prevents water ingress into the gear train assembly during use Drive shaft 77 receives nylon brush 78 which rotates in response to the rotation of shaft 77 Head 53 further comprises splash guard or bumper 79 which provides resistance against lateral loads and minimises damage to the machine therefrom Nylon brush 78 is releasable by means of actuation of release assembly 80 Assembly 80 comprises cover 81 which abuts release member 82 which in turn engages and compresses biasing spring 83 When nylon brush 78 is to be removed the user applies finger pressure to cover 81 which in turn causes release member 82 to advance in the direction of drive shaft 77 Due to the configuration of release member 82 and in particular V formation 84, this impinges on gradient surface 85 of nylon brush 78 causing nylon brush 78 to release from drive shaft 77 Release member 82 is naturally biased by means of spring 83 away from engagement with brush 78 Using this release mechanism, different heads can be used for a variety of different cleaning needs In order to replace nylon brush 78 this is simply a matter of pushing it into position on shaft 77 by snap-fit engagement or equivalent mechanical means The handle, neck and housing for the cleaning head are formed by engagement of mirror image halves separated along the longitudinal axis of the device The halves are preferably fitted together by means of screws which are

typically located at fixation points 86, 87, 88, 89, 90 and 91 In addition to ensure the integrity of the waterproof seal a gasket and/or a bonding compound is preferable

The gas control facility in the above described preferred embodiment of the invention works in the following way Batteries contained in inner compartment 61 are prone to produce unwanted hydrogen gas making the device potentially dangerous to users without appropriate gas control To avoid the dangers of potentially explosive gas build up, in compartment 61 according to the preferred embodiment of the invention, there is provided in the body of the cleaning device 50 a primary opening 92 which allows gas generated in compartment 61 to escape therefrom Opening 92 is located adjacent recharging port 93 so that when cover 58 is free of handle 52 for the purpose of enabling electrical access to the recharging port, gas evacuates from inner compartment 61 to the external environment reducing or eliminating unwanted gas build up Thus, primary opening 61 provides for intermittent expungement of dangerous gas build up but only when closure 61 is removed or partially separated from handle 52 For more permanent ventilation of inner compartment 61 and as an adjunct to primary opening 92 there is provided according to the preferred embodiment a gas permeable waterproof membrane 59 located on handle 52 which allows permanent ventilation of inner compartment 61 In addition to the primary opening 92 and gas permeable membrane 59 there may further be provided gas absorbing pellets which may be placed in the inner compartment or in a region where the pellets will be in contact with unwanted gas Thus, the gas control facility may comprise individually or in any combination, the primary opening 92, gas permeable membrane 59 or gas absorption pellets Preferably however, the gas control facility will comprise at least gas permeable membrane 59 and preferably the primary opening 92

In an alternative form of the invention there is provided a cleaning element which preferably comprises a brush 78, pad scourer or the like (not shown) which detachably fits to the cleaning head 53 Each cleaning element preferably includes male or female profile parts which complement female or male profile parts in or on the cleaning head 53 In the embodiment of figure 7 cleaning brush 78 is adapted with female profile part

94 which receives drive shaft 77 providing said male profile part Shaft 77 is adapted with a selected cross sectional profile which keys the cleaning brush 78 to the shaft 77. Thus cleaning elements for use with the cleaning devices hereinbefore described will include a formation mutually compatible with the corresponding formation on the drive shaft. For example, the shaft may have a three sided, square, five sided hexagonal octagonal or polygonal cross section adapted to provide a key for cleaning brush profile part 94

Figure 8 shows a cross section of device 50 of figure 7 taken at line VI - VI. This shows the fixation screw 60 securing handle 52 Figure 9 shows a cross section of the device taken at line VII - VII showing handle 52 secured by fixation screw 86 and internal compartment 61 containing batteries 62 where unwanted gas build up may take place

Figures 10 and 11 show cross sections taken at lines VIII - VIII and IX - IX respectively. Figure 10 shows a narrower profile of handle 52 with batteries 62 fitting snugly within compartment 61 Figure 1 1 shows the profile of finger operable switch cover 65.

Figure 12 shows a cross section taken at line X - X of figure 7 showing generally drive motor 63 cleaning head 53 and skirt 79

Figure 13 shows typical skirt configurations

The foregoing describes only two embodiments of the invention and although the invention has been described with reference to those embodiments, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms without departing from the spirit or scope of the invention.