Vacuum cleaner attachment

Abstract

An adaptor 100 for detachable attachment to a dust extractor attachment for a vacuum cleaner hose, the dust extractor attachment having a body and a tube for attachment to the hose, the body having a

Description

The present invention relates to attachments for a vacuum cleaner hose for use in combination with a variety of drills, cutters, grinders or the like, and that removably selfadheres to a surface to enable hands-free use of the drill, cutter, grinder etc. When undertaking construction tasks such as drilling, cutting and grinding, potentially hazardous airborne and static dust and debris is generated. The UK Health and Safety Executive (HSE) regulations now state that extraction needs to be used to help reduce respiratory diseases caused by inhalation of such dust and debris. For example, silica is a major constituent in bricks, tiles, concrete and mortar, and is the biggest risk to construction workers after asbestos. Dust is generated from these materials during many common construction tasks, including cutting, drilling, grinding and polishing. Some of this dust is fine enough to get deep into the lungs. The fine dust is known as respirable crystalline silica (RCS) and heavy and prolonged exposure can cause lung cancer and other serious respiratory diseases. As a result, there is a real need for effective dust extractors and their use at the point of construction tasks including cutting, drilling, grinding and polishing. Ideally, such an extractor should stand alone and not require the use of the hand that is not being used to wield the tool, thereby leaving both hands free for the task. Industrial dust collectors and extractors are usually akin to a vacuum cleaner and include a large inlet through which dust is extracted from the air and collected in a chamber for later emptying. Such devices are cumbersome and expensive for smaller tasks and someone working in a non-industrial or domestic environment. A vacuum cleaner cleans by the suction of an air current. When the vacuum cleaner is switched on, an electric motor starts to spin. This, in turn, turns a fan which creates a suction force. The dirt and dust are drawn into the vacuum cleaner through an intake port and are held within the vacuum cleaner in an air-porous bag. The suction motor creates vacuum pressure and suction by rotating the motor fan. The fan rotates at a speed of about 30,000 to 35,000 RPM, causing air inside the cleaner to move quickly, which lowers the air pressure and causes suction. The higher-pressure air from outside the vacuum is sucked in to replace the low-pressure air, bringing dirt and dust with it to be caught in the bag. In some vacuum cleaners, an extendible hose and / or tube is fitted to the intake port of the vacuum cleaner. Attachments or accessories are often fitted to the other end of the hose / tube to change the diameter of the hose and add features such as fixed and rotating brushes. Many of the branded tool manufacturers offer dust extractor attachments for attachment to a vacuum cleaner hose, the majority of which require the hose and attachment to be held in one hand while the tool creating the dust and debris is held in the other hand. However, attachments that removably self-adhere to a surface, leaving both hands free for working, are also available. For example, Bosch® offers an attachment that has a shaped plate including a central opening through which a drill bit (or the like) is located (Figure 1). The attachment snap-fits onto a vacuum cleaner hose and, once the vacuum cleaner is switched on in “suck” mode, a vacuum is created under the plate which holds the plate against a surface. Suction from the vacuum cleaner then draws dust and debris created by the drill bit located through the central opening. The circumference of the central opening is lined with bristles pointing into the centre of the opening which enables the use of drill bits that are larger than the central opening itself. The bristles also capture any debris issuing within the boundary of the plate. GB 1576224 and GB 2067106 describe devices that are similar to the Bosch design, having a central opening in a plate, with the opening being recessed into the plate. GB 2311598 describes a tear-drop shaped frame to which a vacuum hose is attached at right angles. Again, the device includes a (small) circular opening through which a drill bit is inserted. US 6053674 describes a yet similar device with a plate including an opening for a drill bit, the size of which can be changed according to the size of the drill bit being used. This particular device requires a hand hold when used on a ceiling, presumably because the vacuum provided by the suction of the vacuum cleaner is not sufficient to counter the weight of the device and enable the device to be retained against a ceiling. EP 1894653 describes a yet again similar device, this time one in which the cover plate is shaped to allow drilling into corners. A big drawback of existing hands-free extraction unit designs is that they are designed for small diameter drilling, being limited by the use of a central aperture or opening. There is also a fine balance when dividing the suction and vacuum provided by the attached vacuum cleaner in use: sufficient vacuum must be created to enable the device to remain adhered to the surface to be worked on and there must be sufficient vacuum to draw enough of the resulting dust and debris to make use of the device worthwhile. For example, existing devices typically allow drilling through a limited channel within the body of the device. Such devices typically have an extraction volume area of between 48 - 90 square millimetres. Not only does this put the vacuum cleaner’s motor under extreme duress, which can decrease the operational lifespan of the machine, but the extraction capability is also significantly reduced. This small size of extraction volume is also required for hold and stability and needs to counter the weight of both the tool and vacuum cleaner hose, thereby enabling the tool to adhere to the surface. This requires a vacuum and also means the device can only extract fine dust through this small area which, again, limits the use of both drill types and sizes. Large pieces of ejected debris can quickly block extraction ports of this dimension. DrillBuddy UK Ltd produces a dust-extracting device, marketed as The XtraHand, which attaches with a friction fit to a vacuum cleaner hose. Rather than having a central opening through which the drill bit or cutter must pass, this device has a semi-circular “mouth” which, in use, is sited close to the drill bit or cutter and into which debris and dust is drawn when the vacuum cleaner is switched on and in suction mode (Figure 2). The internal shaping of the device enhances the vacuum created by the suction and provides a strong but releasable adherence to a surface, as well as sufficient suction to capture most, if not all, dust and debris as it is produced by a drill. The device also has a rubber skirt around its lower boundary which allows the device to adhere to uneven surfaces. A version of this device is described in GB 2449463. While this device provides an excellent hands-free solution that is not restricted in its use by the size of drill bit, it is not suitable for use with larger tools, including cutters and grinders. The internal shape also has a tendency to capture and retain dust, especially damp dust, which then blocks extraction. Accordingly, the present invention aims to improve on existing and known devices and, in particular, is the result of development and improvement of the device from DrillBuddy UK Ltd. Thus, in one aspect the invention resides in a dust extractor attachment for a vacuum cleaner hose having a body and a tube for attachment to the hose. The body has a rear wall, two straight side walls, a flat top surface, an open base and a front opening for debris collection, the front opening having a semicircular profile in horizontal and vertical planes. The tube is attached to the rear wall, and the body defines a cavity which is divided into an upper and a lower cavity by a solid plate such that the cavities are not in fluid communication. The tube is attached to the body at an angle of between about 23 and 26 degrees to a horizontal plane, the plate divides the body cavity in a ratio of about 31:69 upper cavity to lower cavity, the plate extends centrally across the cavity by between about 70-80%, and the plate is inclined at an angle of about 27 degrees from the front opening to the rear wall. The colocation of the features of the dust extractor attachment provides an attachment that can be attached to a surface through a vacuum, like a limpet device, thereby leaving both hands free for hole drilling or the like. The tube is attached at a specific angle that ensures the attachment remains fixed to a ceiling in use and is not detached by the weight of a vacuum cleaner hose. In addition, the specific division ratio of the cavity in the attachment maximises suction to attach the attachment to a surface and suction for debris collection. The attachment has a semicircular front opening which, in a particular example, may have a radius of between about R30 and R40, optionally a particular radius of R37 or a diameter of about 75mm. The shape of the front opening allows a clear view of the drilling task (or the like) and enables the task to be carried out very close to the attachment, thereby maximising the catchment of dust and debris. The diameter of the attachment enables the use of most standard sizes of drill bits. In another example, the open base of the attachment may be defined by a downwardly extending flange that slopes away from the body, the flange including a plurality of perforations. Ideally the perforations are spaced at regular intervals in the flange around the base. These perforations act as mechanical anchors to fix a tapered elastic skirt over the flange. The flexibility and tapered shape of the skirt enables the attachment to be laid against even, uneven, wet or dry surfaces. Optionally, the skirt has convex curved upper and lower surfaces. In a particular example, the curve of the lower surface of the skirt has a radius of between about R3 and R4 and a depth of between about 1.3mm and 1.4mm. A particular radius is R3.4 and particular depth is 1.35mm. Such a curvature provides additional fixing of the attachment to a surface by way of a vacuum with the upwardly curved upper surface being pulled towards the gap underneath the skirt, thereby flattening the skirt. In a further example, the plate may have a curved profile at the front opening and a flat profile at the rear wall. Such a shape maximises the size of the front opening and volume of the upper cavity. In some examples, the plate extends into the tube. While it will be appreciated that the tube may attach to the hose by a friction fit, additional or alternative fixing means may be provided. For example, additional fixing means may be by way of one or more holes or openings in the tube which interact with biased fixings, such as sprung clips, found on the hose. In a second aspect the present invention resides in an adaptor for reversible attachment to a dust extractor attachment for a vacuum cleaner hose. The dust extractor attachment has a body and a tube for attachment to the hose, the body having a rear wall, side walls, a top surface, an open base and a front opening for debris collection. The tube is attached to the rear wall, and the body defines a cavity which is divided into an upper and a lower cavity by a solid plate so the cavities are not in fluid communication. The adaptor has a body with two straight sides and a top surface, and the top surface includes a curved, straight or circular opening for debris collection. It will be appreciated that the dust extractor attachment may be as described herein. In one example, the adaptor may include flexible fixing means located on the top surface opposite the opening, for reversible attachment of the adaptor to the dust extractor attachment. Such flexible fixing means may be a tab or the like. Optionally, the adaptor may include a flexible lug on the underside of the top surface, the flexible lug acting with the underside of the top surface to clip the adaptor to the front opening of the dust extractor attachment. Alternatively or in addition, the side walls and top surface of the adaptor may be shaped to be a friction fit over the side walls and top surface of the dust extractor attachment. In another example, the opening of the adaptor may include an upwardly curved lip or rim. In this way, the collection of dust and debris is maximised. In a particular example, the opening may be substantially semicircular and having a diameter of between about 70 and 80mm, such as about 73mm or a diameter of between about 130 and 140mm, such as about 134mm. In another example, the opening may be substantially straight having a length of between about 160 and 170 mm, such as about 165mm. In a yet further example, the opening may be circular and have a diameter of about 45mm. In a third aspect, the present invention provides a hose adaptor for reversible attachment to a dust extractor attachment for a vacuum cleaner hose. It will be appreciated that the dust extractor attachment may be as described herein. The hose adaptor may have an internal diameter of about 35mm at a first end and a larger internal diameter at its second, opposite end. For example, the second end may have an internal diameter of about 63mm. In one example, the hose adaptor may include resilient or biased means for attachment to the dust extractor attachment as described herein. Such resilient or biased means may be in additional or alternative to a friction fit and, ideally, mate with means, such as openings, on the dust extractor attachment. In another example, the diameter of the hose adaptor may widen evenly and in a straight, i.e. gradually, from the first end to the second end. Alternatively, the diameter of the hose adaptor may widen in a stepped manner from the first end to the second end. In a fourth aspect, the present invention resides in a kit of parts comprising a vacuum cleaner dust extractor attachment as described herein and an adaptor as described herein. The kit may optionally include a hose adaptor as described herein. In a fifth aspect, the present invention resides in a kit of parts comprising an adaptor a vacuum cleaner dust extractor attachment and a hose adaptor as described herein. In an example, the vacuum cleaner dust extractor attachment may be as described herein. The present invention will now be described in detail with reference to the figures in which: Figure 1 is a prior art device sold by Bosch®; Figure 2 is a prior art device sold by DrillBuddy UK Ltd; Figure 3 is a top view of the attachment of the present invention; Figure 4 is a view from underneath the attachment of the present invention; Figure 5 is a perspective side view of the attachment of the present invention; Figure 6 is a cross section through the flange and skirt of the attachment of the present invention; Figure 7 is a vertical cross section along the central axis A of Figure 4 looking from right to left of the figure as indicated by the arrows; Figure 8 is a vertical cross section through line B-B of Figure 4 looking from the front of the attachment of the present invention towards the tube as indicated by the arrows; Figure 9 is a detailed view of notch 15; Figure 10 is a top view of a first embodiment of the attachment adaptor of the present invention; Figure 11 is a perspective view from above of the attachment adaptor of Figure 10; Figure 12 is a vertical cross section through line C-C of Figure 10 looking from right to left of the figure as indicated by the arrows; Figure 13 is a view of the rear of the adaptor of Figure 10 in use, looking at the end that attaches to the attachment, towards the opening and front end of the adaptor; Figure 14 is a view of the front of the adaptor of Figure 10 in use, looking at the front opening end towards the end that attaches to the attachment; Figure 15 is a perspective view from underneath the adaptor of Figure 10; Figure 16 is a vertical cross-section illustrating the connection between the attachment and the adaptor of Figure 10; Figure 17 illustrates a second embodiment of the attachment adaptor of the present invention, in which Figure 17A is a plan view of the top, Figure 17B is perspective view from above, Figure 17C is a view of the rear of the adaptor in use, looking at the end that attaches to the attachment, towards the opening and front of the adaptor, Figure 17D is a view of the front of the adaptor in use, looking at the opening end towards the end that attaches to the attachment, and Figure 17E is a perspective view from underneath; Figure 18 illustrates a third embodiment of the attachment adaptor of the present invention, in which Figure 18A is a plan view of the top, Figure 18B is perspective view from above, Figure 18C is a vertical cross section through line D-D of Figure 18A looking from right to left of the figure as indicated by the arrows, Figure 18D is a perspective view from underneath, Figure 18E is a view of the rear of the adaptor in use, looking at the end that attaches to the attachment, towards the opening and front of the adaptor, and Figure 18F is a view of the front of the adaptor in use, looking at the opening end towards the end that attaches to the attachment; Figure 19 illustrates a fourth embodiment of the attachment adaptor of the present invention, in which Figure 19A is a plan view of the top, Figure 19B is perspective view from above, Figure 19C is a vertical cross section through line E-E of Figure 19A looking from right to left of the figure as indicated by the arrows, Figure 19D is a perspective view from underneath, Figure 19E is a view of the rear of the adaptor in use, looking at the end that attaches to the attachment, towards the opening and front of the adaptor, and Figure 19F is a view of the front of the adaptor in use, looking at the opening end towards the end that attaches to the attachment; Figure 20 is a side perspective view of the hose adaptor of the present invention; Figure 21 is a vertical cross section illustrating the connection between the attachment and the hose adaptor; Figure 22 is an exploded view showing the inter-relationship between the hose adaptor, the attachment and the attachment adaptor; and Figure 23 shows the hose adaptor, attachment and attachment adaptor linked together. A manufacturing tolerance of ± 0.5mm applies to all dimensions mentioned herein. The vacuum cleaner hose attachment described herein is designed and shaped to catch and remove dust when the attachment is attached to a vacuum cleaner hose, held or reversibly adhered to a surface near to a drilling, cutting, grinding, sawing or polishing site, and the vacuum cleaner is switched on in suck, vacuum or extraction mode. As shown in Figures 3, 4, 5 and 7, the vacuum cleaner attachment 1 of the present invention has a tube 3 moulded to a body 2. The attachment is described herein as if resting on a horizontal surface. The tube 3 has a length of about 40mm at its lower perimeter, increasing gradually to about 53mm at its upper perimeter. The length of the tube 3 is particularly selected to enable a sufficient and suitable friction fit with a vacuum cleaner hose, tube or pipe and that premature connection failure is minimised. The Applicant has found that a tube of longer length causes failure of fixing of the attachment to a surface because the tube 3 acts as fulcrum and so increases the chances of attachment failure due to increased torque, i.e. more length on the tube 3 means less effort from the attachment 1 to release from the surface to which it is attached. The circumference of the tube 3 is dimensioned to fit into or over the end of a vacuum hose that is not connected to the vacuum cleaner intake port, i.e. the end of the hose that is opposite to the vacuum cleaner intake port. For example, a tube 3 diameter of about 35mm fits inside a standard UK vacuum hose or attachment with a friction fit. Other hose diameters may be catered for by either flaring the tube 3 in a direction extending away from the body 2 or increasing the diameter in one or more discrete steps (see Figures 17 and 19-23). The tube 3 shown in Figure 3 has the same diameter along its length and a separate hose adaptor that increases or decreases in diameter may be provided as part of a kit. It will be appreciated that the attachment 1 may be attached to the vacuum cleaner hose by any suitable means, including friction fit, mating parts and sprung interlocking compression fittings. The attachment 1 shown in Figures 3 and 4 includes a pair of rectangular holes 4 in the wall of the tube 3 which are located opposite each other, one (4a) being on the upper or top side of the tube 3 in use, the other (4b) being on the lower or underside of the tube 3 when in use. The holes 4 are 6mm by 8mm in dimension, located 8mm from the end of the tube 3 furthest away from the body 2, and are specifically dimensioned to accept a protrusion attached to or part of a sprung clip to connect the tube 3 either to a vacuum hose or a tube adaptor (see Figures 17 and 19-23). In this way, the diameter of the tube 3 is changed thereby enabling attachment to a vacuum hose of a different diameter. For example, workshop and industrial vacuum cleaners, particularly in the USA and Canada use larger hoses, typically having a diameter of 63mm. This is in contrast to UK hoses for household use which are typically about 35mm in diameter. The tube 3 is moulded to the body 2 so the two parts form an integral device. The tube 3 is attached at a point on the body 2 that is closest to the vacuum cleaner hose in use. In effect, the body 2 extends from the tube 3. The tube 3 is attached to the body 2 at an angle of about 25.5 degrees to a horizontal axis which forms the base of the attachment 1 when on a horizontal surface. While an angle of about 23 degrees has been found to be effective, the increased angle in the embodiment described herein further enhances the ability of the attachment 1 to remain attached to a ceiling when in use, rather than be pulled off by the weight of an attached hose. Indeed. An angle of around 25.5 degrees has been found to be the best angle for both horizontal and vertical attachment. Any larger angle causes an increase in torque due to the fulcrum / lever effect and a smaller angle sees an increase in failure when trying to attach the attachment 1 to a ceiling. The body 2 essentially has a three upstanding side walls 5a, 5b, 5c - a rear and two side walls - and a top or upper surface 6 spanning between the upper edges of the three walls 5 and enclosing the space thereunder, in effect creating a box with three sides. The front and underside of the body 2 are open. The rear wall 5a is located below the tube 3 and the front is located parallel and opposite. The two side walls 5b, 5c extend from the rear wall 5a, diverging outwards from a central axis A of the tube 3. The cavity created by the three side walls 5a, 5b, 5c is divided by an air flow separator 7 into an upper cavity 8a and lower cavity 8b. The shape of the body 2 has a tapered design with straight edges so the attachment 1 is versatile in restricted areas and when used in small spaces such as cupboards, corners or reveals. As illustrated in Figures 3 and 4, the perimeter or outline of the body 2 and the tube 3 together have a shape similar to the letter Y, with the tube 3 providing the stem of the Y and the side walls 5a, 5b, 5c providing the arms of the letter. The perimeter of the body 2 is defined by the lower edge of the side walls 5a, 5b, 5c and provides a base on which the attachment 1 sits in use. The rear wall 5a below the tube 3 is about 27mm in length and has a convex curve towards the tube 3 and the outer side of the body 2 having a radius of about R50 (50mm). This particular curvature aids in the reduction of fixing failure of the attachment 1 to a surface. If the rear wall 5a was straight, it would form a pivot / tipping point thereby increasing the likelihood of detachment of the attachment 1 to separate from the surface. The curved shape of the rear wall 5a elongates the rear of the attachment 1 which, in turn, increases the footprint area and reduces the pivot / tipping point when suction is applied. Side walls 5b extend in a direction away from each end of rear wall 5a, in a straight line, at an angle of 48 degrees from the central axis A for a length of about 26mm on each side. Side wall 5c extends the perimeter further away from the tube 3 and rear wall 5a at an angle of 14 degrees from the central axis A or 34.5 degrees from the line of trajectory of side wall 5b towards central axis A. Side wall 5c is approximately 54mm in length and, at its ends furthest from the tube 3 and rear wall 5a, turns a rounded corner into two front walls 5d which are at 90 degrees to the central axis A and approximately 9mm in length. The front walls 5d are the furthest extremity from rear wall 5a and the tube 3 and form the front of the attachment 1. They also join to the air flow separator 7 within the cavity of the body 2. The perimeter of the body 2 is completed by a semicircular shape which is provided by the front edge 7a of the air flow separator 7. The front edge 7a curves into the body 2 with a radius of R36 and so the diameter of the curve is about 72mm. A horizontally orientated flange 9 extends outwards from the lower edge of the rear, side and front walls 5a-5d, as well as the front edge 7a, away from the body 2 by about 7mm. The flange 9 is angled downwards from the inside to the outside of the body 2 so the flange 9 is lower at its outermost edge. The downward angle assists the mechanical fixing of the flange 9 to a skirt 11 and keeps the flange 9 central to the skirt 11 thereby reducing any weak points and preventing premature failure or tearing of the skirt 11. As shown in Figure 3, the flange 9 includes 2mm diameter perforations 10 spaced evenly, approximately 8mm apart, around the flange 9. Moulded over and through the flange 9, via the perforations 10, is a flexible skirt 11 which runs all the way around the flange 9 (see Figure 4). While the skirt 11 may be made of any suitable material, thermoplastic elastomers have been found to be particularly suitable because the material is soft, so doesn’t leave marks on a surface, and is elastic so it can be deformed and return to its original shape. Moulding of the skirt material through the perforations 9 creates a strong bond between the skirt 11 and the body 2 which reduces the likelihood of unwanted and premature separation of the skirt 11 from the body 2 and prolongs the life of the attachment 1. As shown in Figure 6, the skirt 11 has a rear wall that abuts the wall 5 of the body 2, a convex upper surface and a curved lower or underneath surface that curves into the body of the skirt 11 with a radius of R3.4 and depth of 1,35mm. As such, the skirt 11 has a scallop shape and tapers from its rear wall to its outermost edge, which is rounded. The rounded shape on the uppermost surface creates a tension effect on the skirt 11. Because the skirt 11 is a continuous loop, this shape prevents it from distorting. In addition, the curve straightens out when suction is applied as the attachment 1 is pulled towards the surface to which it is to be attached. This elongates the front edge of the skirt 11, straightening it, which allows smoother flow and allows the skirt 11 to retain its shape. It is well known that, in engineering, an arc is the strongest structural shape. The shape of the skirt 11 also provides a malleable edge which adheres the body 2 to a surface via a vacuum created by the underneath curved surface when pressure is applied to the body. This vacuum creates an adhesive force which allows the body 2 to be adhered to almost any surface, notably uneven surfaces, and minimise the likelihood of premature detachment of the attachment 1 from the surface. When the vacuum is released, the body 2 can be removed from the surface. Importantly, the skirt 11 allows the attachment 1 to be used on flat, shallow curved or slightly uneven surfaces, such as internal or external walls and ceilings, as well as many porous construction surfaces including bricks and blocks. The strong seal created by the skirt 11 reduces the likelihood of debris travelling under the attachment 1, and preventing damage or marking to surfaces to which the attachment 1 is adhered. As shown in Figure 5, the rear wall 5a is shaped in its height from the flange 9 to the lowermost circumference of the tube 3. Side wall 5b increases in height from where it joins the rear wall 5a to where it meets the side wall 5c from about 26mm to about 35mm. Side wall 5c decreases in height continuously along its length from the side wall side 5b to the front wall 5d to a wall height of about 16mm at the front wall 5d. The top or upper surface 6 has a shape that mirrors the height of the walls, sloping upwards from the tube and then downwards towards front walls 5d. The front edge 6a of the top surface 6 mirrors the front edge 7a of the front walls 5d and the air flow separator 7, having a straight portion on either side of a curve having a radius of R36. As a result, the straight portion of the front edge 6a overhangs the front wall 5d by about 7mm. This overhang extends the top of the attachment to mirror the circumference of the skirt 11 which helps increase suction and extraction from the work area. The distance between the front edges 6a and 7a, defined by the height of the front walls 5d, provides an opening or mouth which is an inlet port for the attachment 1. The shape of front edges 6a and 7a allows an unobstructed view of the task in hand and maximises the catchment area for dust and debris. The radius of R36 gives an inlet area of about 74mm x 18mm. Features inside the body 2 are illustrated in Figures 7 and 8. In particular, inside the body 2 is the air flow separator 7. The separator 7 is a shaped plate that extends between the lower edges of front walls 5d to provide a front edge 7a and extends to within and across the diameter of the tube 3. The separator 7 rises from the front edge 7a to within the tube 3 at an angle of 27 degrees above the horizontal plane, thereby dividing the body 2 into two compartments, upper cavity 8a and lower cavity 8b. The angle of rise of the separator 7 results in division of the body 2 in a ratio of 69:31 with 31% of the space being the upper cavity 8a and 69% of the space being the lower cavity 8b. This division has been found to provide the optimum split of air flowing into the attachment 1 in use a) to provide sufficient suction to draw in dust and debris, including large pieces of debris, over the separator 7 and b) to provide sufficient vacuum below the separator 7 to enable the attachment 1 to be held against a surface by vacuum alone. Such a ratio also reduces stress on the vacuum cleaner when in operation, thereby prolonging the life of the motor. Looking at Figure 4, the separator 7 has a front edge 7a that spans the distance between the two front walls 5d and extends through the body 2, tapering in width in a straight line towards the tube 3. At the tube end, the separator 7 extends beyond the body 2 and into the tube 3 by an amount that leaves a length of about 30mm of the tube 3 free from detail and obstruction. The separator 7 spans the diameter of the tube 3 and so has a width of about 31 mm. The maximum height above the separator 7 in the tube 3 is 9mm and the maximum depth below the separator 7 is 20mm, with the separator 7 having a thickness of 2mm. These distances have been found to be important, otherwise there is either too much suction to the underside of the separator 7 or too much suction above the separator 7. If the separator 7 ends before or where the tube 3 joins the body 2, a vortex is created in the lower cavity 8b which pulls airflow (and thus, dust) back into the cavity 8b. This, in turn, means the attachment 1 leaves dust marks on the surface to which it has been attached. Extension of the separator 7 into the tube 3 reduces the vortex in the lower cavity 8b thereby reducing the ingress of dust into the lower cavity 8b and the attachment 1 leaves faint if any mark on the surface to which it has been attached. The taper on the separator 7 means the separator 7 does not span the whole width of the body 2. Instead, the taper of the separator 7 is such that pockets 12 are created on either side of the separator 7, between the separator 7 and the side walls 5b and 5c. At each edge of the separator 7 is an upstanding wall 13 which separates the upper cavity 8a from the lower cavity 8b. There is no fluid communication between the two cavities 8a and 8b. The upper cavity 8a provides an area through which debris is sucked while vortices in the lower cavity 8b provided by suction from the vacuum cleaner adhere the attachment 1 firmly to a surface. In the embodiment illustrated, the wall 13 is the same height as the front wall 5d and reduces in height to zero where the angle of the separator 7 meets the rear wall 5a and the body 2 joins the tube 3. Such shaping funnels suction from the open mouth of the upper cavity 8a directly into the tube 3 and prevents the accumulation of dust and debris at the outer edges of the body 2 where the suction is at its least efficient. Looking from underneath (Figure 4), the upstanding wall 13 sits 9mm away from side wall 5c, creating a pocket 12 in the lower cavity 8b. Each pocket 12 is essentially a channel that, in the embodiment illustrated, increases in width from 9mm at the front wall 5d to 11mm where the side wall 5c changes angle and becomes side wall 5b. The pocket 12 then tapers to a point where the body 2 and tube 3 meet. In this way, the suction area in the lower cavity 8b is maximised. Indeed, the attachment 1 has an extraction volume area of 276 square millimetres and the strength of adhesion can be as much as 7.8lbs per square inch (about 53.78 kPa) with a standard UK regulation domestic 640Watt vacuum cleaner. This allows large debris from all types of natural and manmade materials to be extracted from a variety of different drill bit types as well as boring drills, cutting tools and grinding tools. Referring to Figures 4 and 8, the separator 7 has a curved portion 7b extending away from the front edge 7a and for the length of the side wall 5c. Travelling into the body 2 towards the tube 3, the separator 7 changes its shape from curved to flat at the point where the side walls 5 change shape from side wall 5c to side wall 5b. The flat portion 7c extends into the tube 3. The curved portion 7b has a downward curve of R200 which has the advantage of reducing the central distance between the surface to which the attachment 1 is attached in use and the upper cavity 8a through which debris is pulled, whilst also maximising the dimension of the mouth 14. The symmetrical shape to both the body 2 and front edges 6a and 7a maximises the dust and debris catchment area, allowing far more effective and efficient extraction of both dust and debris, including that of much larger debris from problematic material including wood, chipboard, medium density fibreboard (MDF) and composites, from a plethora of drill bit types, including larger flat bits, hole saws, diamond drill bits, core drills, auger and Forstner bits. To use the attachment, the flange 9, covered with the skirt 11, is placed against or on a surface near to where dust and debris will be generated. Suction by the vacuum cleaner pulls the curve of the skirt 11 against the surface and holds the attachment 1 securely in place. A vacuum created in the lower cavity 8b maintains the hold on the attachment. Air being sucked by the attached vacuum cleaner over the separator 7 independently pulls in dust and debris produced by drilling, cutting, grinding etc. through the mouth 14, into the upper cavity 8a, into tube 3 and then into the vacuum cleaner via an attached hose or tube (not shown). Because the attachment 1 is securely and strongly attached to the work surface, the operator is able to maintain optimum safety and control by having both hands free to use the power tool, while reducing the risk of respiratory diseases from dangerous airborne particles entering the lungs by efficient dust extraction. Once the task has been completed, the vacuum cleaner suction is switched off and the attachment 1 is removed from the work surface. The attachment 1 may then be placed over a newly drilled hole and the vacuum switched on again. Suction by the vacuum cleaner creates a vortex in the lower cavity 8b which will clean and remove the dust and debris from the hole. The shape of the attachment 1, in combination with the shape of the separator 7 and the pockets 12 in lower cavity 8b create a specific airflow through the attachment. In particular, the internal shaping of the attachment 1 channels the airflow not only from the front of the body 2, but also from above and behind the front edge 6a and 7a. This action pulls escaping dust and debris back into the upper cavity 8a if the debris is ejected or dispersed over the top of the attachment 1. Because the flow of suction is directed in this way, it provides exceptionally effective extraction for core drilling and cutting with both multi tools and angle grinders. When measured with an anemometer, the suction speed when positioned 18mm directly above the separator 7 and behind the front edges 6a and 7a creates a suction draw speed of between 7 and 8mph. As a result, the attachment 1 may be used with a multitude of drill bits and cutting tools that would not usually be possible. It will be appreciated that the attachment 1 is limited by the dimensions of the upper cavity 8a and the shape of the front edges 6a and 7a. Thus, in another aspect, the present invention resides in an adaptor 100 for the attachment 1 described herein that reversibly attaches to the body 2 and provides the option of a differently shaped front edge. As may be seen in Figures 3 and 7, the body 2 includes a notch 15 located about 17mm back from the edge of the front edge 7a at the midpoint in the top 6. In the embodiment illustrated, the notch 15 is 15mm long, 3mm wide and 1.5mm deep. As illustrated in Figure 9, the wall 15a of the notch 15 nearest the mouth 14 is orthogonal to the top 6. At its lowest point (1.5mm), the notch base 15b is orthogonal to the notch wall 15a and the rear wall 15c of the notch 15 is angled upwards from the base 15b to meet the top 6. Such a notch 15 is shaped to receive a reciprocal protrusion on a biased thumb clip, such as the one illustrated in Figures 10 to 19, as part of an adaptor 100. It will be appreciated that any suitable reversible connecting means may be suitable, and the example described herein is purely for illustrative purposes. Referring to Figures 10 to 16, the adaptor 100 has a pair of upstanding side walls 105 and an upper or top surface 106 that spans the distance between the side walls 105. The bottom or lower surface (underside) of the adaptor 100 is open. The side walls 105 mirror each other in shape and flare from the point of attachment to the attachment body 2 to the front edge 106a of the top surface 106. The adaptor 100 has a flared shape when viewed from above, the line of which continues from the taper of the body 2. In this way, the attachment 1 and adaptor 100 widen from the narrowest point where the body meets the tube 3 to the widest point at the front edge 106a. As can be seen in Figures 10 and 11, the two side walls 105 are straight, continuing the line of side wall 5c with a 10 degree step outwards in width at a point 15mm from where the adaptor 100 meets the attachment 1. This slightly narrower section provides a compression fit with the attachment 1 by gripping the sides of the attachment 1, pulling the adaptor 100 backwards and forcing the mouth 14 of the attachment 1 into additional fixing means on the underside of the adaptor 100. After the 10 degree outward step, the side wall 105 extends for 52mm long before flaring outwards again at an angle of 17 degrees away from the centre of the adaptor 100. After this second outward step, the side wall 105 extends for 19mm. The side walls 105 terminate at the furthest extents of the front edge 106a. The upstanding edge of the side walls 105a is cut away and shaped to mirror the profile of the front of attachment 1. The adaptor 100 is about 80mm in length from its back edge where it meets the attachment 1 to the front edge 106a. The front edge 106a has an arcuate shape that curves in a horizonal plane and into the top surface 106, towards the attachment 1, with a diameter of about 134mm. When the flare of the side walls 105 is taken into account, the total extent or width of the front edge 106a is 155mm, thereby enlarging the catchment area of the attachment 1 by 34mm. The front edge 106a is also curved upwards in a vertical direction to maximise the catchment area for debris. As seen in Figure 11, beyond the upward and horizontal curvatures of front edge 106a, the top surface 106 is flat and angled 19 degrees above and to the horizontal plane. This shape mirrors the top surface 6 of the attachment 1 and enables the adaptor 100 to fit over the front of the attachment 1. Fitting to attachment 1 may be by way of a friction fit. In the example illustrated, the adaptor includes addition fixing means 110 which mates with the notch 15 on the attachment 1. In particular, the fixing means 110 is an upwardly curved, flexible tab. As shown in Figure 16, fixing to the attachment 1 is by way of a nub 110a on the underside of the flexible tab 110 that is shaped to fit into notch 15 on attachment 1. When the tab 110 is pulled backwards, the nub 110a lifts out of the notch 15. Similarly, when the adaptor 100 is attached to the attachment 1, the flexibility of the tab 110 allows the nub 110a to ride up and over top 6 and fall into notch 15 when the two parts meet. The adaptor 100 illustrated has additional means to fix it to the attachment 1. As shown most clearly in Figure 15, this is in the form of a substantially vertical wall 112, located at the point where the side walls 105 change direction and that depends from the underside of top surface 106. The wall 112 does not divide the cavity within the adaptor 100 but allows air to pass under the lower edge of the wall 112 and into upper cavity 8a of the attachment 1 when in use. The shape of the wall 112 along its vertical axis mirrors the shape and curve of front edge 6a of the attachment 1. Specifically, the wall 112 is orthogonal to the side walls 105 at each side for 18mm before curving towards the fixing tab 110 and rear of the adaptor 100. The straight portions depend from the underside of the top surface 106 by 6mm. The curved portion depends by 7mm and has a diameter of 64mm. The curved portion joins the underside of the top surface 106 at an angle of about 45 degrees. The curved portion of the wall 112 includes a flexible lip 112a that protrudes towards the rear of the adaptor and in a direction that is parallel to the top surface 106. This lip 112a enables a friction fit with front edge 6a of the attachment 1, the front edge 6a being gripped between the top surface 106 and the lip 112a. It will be appreciated from the above description that the adaptor 100 is fitted to the attachment 1 via a friction fit between side walls 5 and 105, gripping of the front edge 6 between the top surface 106 and the lip 112a, and clipping of the attachment means 110 in the notch 15. While any variation on the types and numbers of fixings are encompassed, the inventor has found that these three points of fixing provides the most secure and strong arrangement. The width and shape of the adaptor 100 finds particular use to capture debris and dust from 117mm and 127mm core drills. The adaptor 200 shown in Figures 17A-E provides an alternative debris catchment area and finds specific use with 65mm core drills. As seen in the figures, the adaptor 200 has essentially the same shape as the adaptor 100, having side walls 205, an upper or top surface 206 with an upwardly curved front edge 206a, and a flexible tab 210. The inner details of the adaptor 200 are also the same as for the adaptor 100, with a wall 212 depending from the top surface 206 to enable gripping of the front edge 6a between the top surface 206 and the lip 212a. The difference is seen in the front edge 206a of the adaptor 200. The front edge 206a has the same width as the front edge 106a of the adaptor 100 but instead of then flaring outwards as well as upwards, as in the front edge 106a, the side walls 206 curve in an orthogonal direction to their side direction to create front walls 205a which then flare outwards to form the front edge 206a. The curvature of the front edge 206a in the vertical plane has a length of 73mm and so is smaller than that of the front edge 106a of the adaptor 100. The additional flare at the ends of the front walls 205a maximises the debris catchment area of the opening of the adaptor 200. Figures 18A-F illustrates another adaptor 300 designed for use when chasing out openings for a double (two-gang) electrical socket back box. Like parts are labelled with like reference numerals and, as with the adaptor 200, the features of the adaptor 300 are essentially the same as the adaptor 100, with the difference being the shape of the front or mouth 314 of the adaptor 300. The slope of top surface 306 and flexible tab 310 are as per adaptors 100 and 200. The top surface 306 then extends in a flat plane, parallel to the horizontal axis, from the point at which the vertical wall 312 depends from the underside of the top surface 306 to the front edge 306a. In other words, the majority of the adaptor 300 is flat in profile and the side walls 305 are of a constant height - about 20mm - along the length of the adaptor 300. The top surface 306 has a width of about 95mm at its rear end where the adaptor 300 meets the attachment 1. The portion of the side walls 305 that grip the attachment 1 is about 15mm in length. At the end of this portion, the side walls step outwards at an angle of 10 degrees and have a straight length of 90mm before flaring outwards in a straight line at an angle of 42 degrees from the central axis. The flare has a length of 13mm and the top surface 306 is 105mm in length from the back where it meets the attachment 1 to the front 314. As a result, the adaptor increases in its width from 95mm where it attaches to the attachment 1 to about 165mm at the front edge 306a. The side walls 306 also curve upwards at the point where the 42-degree flare of the side walls 305 occurs. The upward curve is at an angle of 136 degrees from the horizontal axis and has a height of about 29mm. It will be appreciated that this compound curve at the front of the adaptor 300 maximises the catchment area. The front edge 306a of the adaptor 300 is straight in profile, having no curve inwards as with adaptors 100 and 200. As with the adaptor 100, the front edge 306a flares outwards and upwards to maximise the debris catchment area. A yet further adaptor 400 is illustrated in Figures 19A to F. This adaptor is for particular use with 35mm Forstner Bits and 32mm Flat and Auger bits. Because these Bits tend to eject material everywhere at incredible speed, the adaptor 400 has a circular opening 414 in the top surface 406, rather than an open mouth. The circular shape means the suction flows 360degrees around the adaptor 400, thereby enabling the captures of debris from all angles. It will be appreciated that circular openings of larger (or smaller) diameter are also encompassed, for example to enable the adaptor to be used with a core drill. As with the adaptors 100, 200 and 300, the top surface 406 of the adaptor 400 slopes downwards at an angle of 160 degrees from the horizontal plane, from its rear edge 406b where the adaptor 400 meets the attachment 1 to the point at which the vertical wall 412 depends from the underside of top surface 406 inside the adaptor 406. At this point, the top surface 406 extends in a horizontal plane with the side walls 405 having the same height -about 26mm - around the entire periphery of the adaptor 400. The horizontal shape of the top surface 406 is essentially an inverted image of the shape of the top surface 206 at the same location of the adaptor 200. Specifically, rather than the top surface 206 defining a semicircle that curves into the top surface 206, the top surface 406 extends outwards in a semicircular shape, with this shape forming the circumference of a circular opening 414 having a diameter of about 45mm. The side walls 405 extend into an inwardly-projecting shoulder before meeting the semicircular outline of the top surface 406. The circumference of the circular opening 414 includes a raised rim 406a which curves upwards in a straight line from the top surface 406 at an angle of about 120 degrees from the horizontal plane, before turning into a straight, downwards slope at an angle of 134 degrees from the horizontal plane. As a result, the rim 406a has an inverted ‘V’ shape, as seen particularly in Figure 19C. The lower, free edge of the rim 406a terminates when level with the top edge of the side walls 405. The shape of the rim 406a produces a restrictive suction which pulls air in from outside the adaptor 400, retains the debris and prevents material from escaping when in use while maximising visibility of the job in hand. The present invention also encompasses a hose adapter to enable connection of a hose of a different diameter to that of the tube 3 of the attachment 1. While the tube 3 on the embodiment illustrated herein has an outer diameter of about 35mm, vacuum cleaners in the other countries, notably the US and Canada, typically use larger diameter hoses. The hose adaptor 500 is shown in Figures 20 and 21 and has a collar 501 having an internal diameter of about 35mm so that the adaptor 500 fits snuggly over the outside diameter of the tube 3. The adaptor 500 then flares outwards in a straight line (502), ending in an end tube 503 having an internal diameter of about 63mm, with the adaptor 500 resembling a funnel in its shape. The internal diameter of the end tube 503 tapers very slight, down to about 62mm, so the connection between the adaptor 500 and the tube 3 is by way of a friction fit. Included in the collar 501 is a pair of resilient compression thumb clips 504 that are disposed on the upper and lower surfaces of the collar 501 when in use. The clips 504 interact with the holes 4a and 4b in the tube 3 to secure the adaptor 500 to the tube 3. Inside the adaptor 500, at the point where the collar 501 ends and the flare 502 begins, is a rebated stop 505 that prevents the tube 3 from being inserted too far into the collar 501. The attachment 1, adaptors 100, 200, 300 and 400, and hose adaptor 500 described herein are designed to be fitted to and used with the majority of corded and cordless hose-mounted vacuums, or vacuum cleaners that use HVLP suction hoses. It will be appreciated that the suction at the base of the attachment (and adaptor), even when using a cordless, low powered HVLP vacuum, will produce enough suction to hold the attachment 1 securely in place and to extract dust and debris to both vertical and horizontal surfaces like walls and ceilings. Due to the design of the air flow separator 7, a vortex of airflow above in upper cavity 8a pulls airflow from above and behind the mouth 14, allowing escaping and / or ejected debris to be drawn back into the mouth 14 for extraction into the vacuum cleaner. In addition, the division of the cavity of the body 2 is such that the section velocity at the mouth 14 is increased which provides a rapid draw into the attachment and away from the work site. Indeed, the air speed in the upper cavity 8a has been measured using an anemometer at 8mph when the attachment 1 is attached, via a hose, to a standard 650W vacuum cleaner. Such strength of suction allows the attachment 1 to be used effectively with a wide variety of tools, including both metal and stone cutting discs on small 115mm and 125mm angle grinders, and oscillating multitools when cutting metal, stone, wood, MDF and composite materials. The shape of the attachment allows the very close proximity of drilling, boring and cutting tools, as well as a complete and unrestricted view of the operation or task in hand. The shape also enable the attachment 1 to be used effectively and efficiently with all sizes of: masonry drill bits up to and including 25mm, bullet-type drill bits for wood, MDF and composite materials up to and including 10mm, flat drill bits for wood, MDF and composite materials up to and including 32mm, Forstner Drill / Boring Bits for wood, MDF and composite materials up to and including 35mm, Auger Drill Bits for wood, MDF and composite materials up to and including 32mm, and wood, stone and metal hole saw bits up to and including 69mm. The size and shape of the mouths of the attachment 1 and adaptors 100, 200, 300 and 400 allows a large amount of airflow through the attachment which reduces the risk of premature wear and tear on the vacuum cleaner’s operating motor, as well as reducing the likelihood of premature motor failure due to stress and overheating. The strength of the suction in the lower cavity 8b, in combination with the seal around the perimeter of attachment 1 created by the flexible skirt 11, also enables the attachment 1 to adhere to damp and moisture-covered surfaces and prevents both further moisture (and dust) from penetrating the seal or moisture (and dust) from escaping underneath the seal. The suction in the lower cavity 8b is also such that it can be used to clean out a newly drilled hole by locating the attachment over the hole. In the same way, the suction may also be used to extract smoke, gas and / or water / fluid from a puncture pipe without the need to remain holding the attachment 1 in place. Also described herein are adaptors 100, 200, 300, 400 to change the size, shape and extraction volume of the attachment 1, and an adaptor 500 to enable the attachment 1 to be fitted to vacuum cleaner hoses of different diameters. Connections to these adaptors is by way of secure “clip” fittings, rather than simply relying on a friction fit, to ensure secure attachment.

Claims

1. An adaptor for detachable attachment to a dust extractor attachment for a vacuum cleaner hose, the dust extractor attachment having a body and a tube for attachment to the hose, the body having a rear wall, side walls, a top surface, an open base and a front opening for debris collection, the tube is attached to the rear wall, and the body defines a cavity which is divided into an upper and a lower cavity by a solid plate so the cavities are not in fluid communication, the attachment being for use in catching and removal of water and dust and debris generated during drilling, cutting, grinding, or sawing, wherein the adaptor has a body with two straight sides and a top surface, and wherein the top surface includes a curved, straight or circular opening for debris collection.

2. The adaptor of claim 1, wherein the adaptor includes flexible fixing means located opposite on the top surface opposite the opening for attachment of the adaptor to the dust extractor attachment.

3. The adaptor of claim 1 or claim 2, wherein the adaptor includes a flexible lug on the underside of the top surface, the flexible lug acting with the underside of the top surface to clip the adaptor to the front opening of the dust extractor attachment.

4. The adaptor of any one of claims 1 to 3, wherein the side walls and top surface of the adaptor are shaped to be a friction fit over the side walls and top surface of the dust extractor attachment.

5. The adaptor of any one of claims 1 to 4, wherein the opening includes an upwardly curved lip or rim.

6. The adaptor of any one of claims 1 to 5, wherein the opening is substantially semicircular and has a diameter of between 70 and 80mm.

7. The adaptor of any one of claims 1 to 5, wherein the opening is substantially semicircular and has a diameter of between 130 and 140mm.

8. The adaptor of any one of claims 1 to 6, wherein the opening is substantially straight and has a length of 165mm.

9. The adaptor of any one of claims 1 to 6, wherein the opening is circular and has adiameter of 45mm.

10. A kit of parts comprising:i) a vacuum cleaner dust extractor attachment for attachment to a vacuum cleaner hose having a body and a tube for attachment to the hose, the body having a rear wall, side walls, a top surface, an open base and a front opening for debris collection, the tube is attached to the rear wall, and the body defines a cavity which is divided into an upper and a lower cavity by a solid plate so the cavities are not in fluid communication; andii) an adaptor as claimed in any one of claims 1 to 9.

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