GB2510111A

GB2510111A - Vacuum cleaner head

Info

Publication number: GB2510111A
Application number: GB1301159.8A
Authority: GB
Inventors: Peter Fisher
Original assignee: SCOTFLOW RENEWABLE ENERGY Ltd
Current assignee: SCOTFLOW RENEWABLE ENERGY Ltd
Priority date: 2013-01-23
Filing date: 2013-01-23
Publication date: 2014-07-30
Anticipated expiration: 2033-01-23
Also published as: GB201301159D0; EP2948037B1; GB2510111B; EP2948037A1; WO2014114924A1

Abstract

A vacuum cleaning head 10 formed of a unitary body 12 through which extends a conduit 14, formed of a substantially uninterrupted, single contoured wall passageway 34 between a substantially oval inlet 16 at a first end and a substantially circular outlet 18 at a second end. The conduit contains a primary vortex expansion chamber 20, formed by first 42, second and third 44 cross-sectional areas with the second being greater than and bounded by the first and third. The outlet is arranged for a connection with a hose to a motor. The conduit 14 may have a substantially circular cross-section and any changes in the cross-sectional area may for formed as one or more undulations in the conduit wall 36. The cleaning head 10 may have a substantially planar bottom face 32, which may be rectangular. The front edge 24 of the cleaning head 10 may include a window 46 which may extend along the majority of the front edge 24. The cleaning head 10 may have one or more air inlet control ports 64, which may be channels on the bottom face 32 of the base 22 between the conduit and a side edge. The cleaning head 10 may have a gimbal joint at the outlet 18 which may include a vortex expansion chamber.

Description

HEAD

The present invention relates to vacuum cleaning devices and in particular, thcugh not exclusively, to a vacuum cleaning head with increased pick-up at low power.

Vacuum cleaning devices for cleaning floors work on the principle that air is drawn through the cleaner and dust receptacle using a draw' created by an impeller fan driven by an electric motor. The air is expelled via one or more filters to prevent small dust particles being emitted, with the collected dust and debris being retained in the dust receptacle.

There are two basic designs of vacuum cleaning devices, those where the motor is in the cleaning head, sometimes referred to as upright, and those where the motor and cleaning head are separated by a hose, commonly referred to as cylinder. In an upright vacuum cleaner, the motor is used to provide both the suction, or draw, and to power beaters, brushes or rollers to mechanically assist in bringing the debris up into the suction path by agitating the floor surface. These upright vacuum cleaners can be particularly heavy and it is known that they cause physical damage to carpet fibres shortening the lifespan of a carpet. Upright vacuum cleaners are also not suitable for use in small tight spaces such as under furniture or on staircases. To overcome this, a hose is supplied to which vacuum attachments in the form of nozzles are attached. This arrangement operates in the same way as the cylinder vacuum cleaner, where the motor is separated from the cleaning head by a hose. The motor is then solely used for suction of debris up the hose.

With the hose being a few metres in length, the cleaning head requires to make contact with the surface being vacuumed to efficiently pick-up debris.

A standard prior art cleaning head for connection to a hose is rectangular in shape with a rectangular suction port, extending only 10-20 mm laterally, located at the centre of the bottom face. The rectangular suction port enters a conduit which ends at a connection to the hose.

This connection to the hose may be rotatable to assist manoeuvrability of the head as, typically, the hose is a rigid cylindrical tube. Horizontal channels are formed from the rectangular suction port to the sides of the head to direct debris to the suction port and to provide an air flow to the suction port when the head is in contact with the floor so that the head can move across the floor. At the front and back edges of the head are arranged brushes and/or scrapers to assist in lifting debris from a carpet. These brushes are articulated so that they can be moved up and down relative to the head for selective use depending on the floor surface being vacuumed.

There are a number of disadvantages with this prior art cleaning head. The head will only pick-up debris immediately below the suction port and thus only a small area of floor is cleaned on each stroke of the head. The horizontal channels do not assist this as they are too shallow and draw air from the sides of the device perpendicular to the direction of cleaning with no leading edge air flow or suction present. The arrangement of brushes prevents air flow in the cleaning direction.

The articulated brushes also mean that the head is composed of multiple parts resulting in a suction conduit which switches dramatically from a rectangular cross-section to a circular cross-section. These sudden changes in the cross-section of the conduit together with the dogleg path to the hose, cause the suction flow to fragment and reduce in air speed. This reduces the amount of debris which can be carried in the suction flow and consequently the head is inefficient at cleaning.

To overcome these disadvantages manufacturers have increased the power of the motor to increase suction. One disadvantage in increasing power is that the head becomes more difficult to manoeuvre across the floor as the increased suction across the small suction port will want to lift the carpet at the suction port. The horizontal channels seek to alleviate this, but if made too large, the desired increase in suction is lost.

A further disadvantage in increasing power is the effect on the environment by the increased energy consumption.

Indeed, there are currently proposals to provide an EU directive to ecodesign vacuum cleaners whereby the maximum power will be reduced from the current 2000 watts to 900 watts. Manufacturers are already concerned about the drop in efficiency and performance this will have on vacuum cleaners.

There is thus a need for a cleaning head which provides more efficient pick-up at lower motor power.

It is believed that heads which encourage laminar flow can give increased pick-up as the higher air speed through the head has a greater capacity to carry a load of particles. US 6,421,875 describes a cleaning head which is aerodynamically designed to increase efficiency based on creating a region in the vacuum head which produces high-speed laminar flow for particulate pickup, another area which provides for vortex formation, and another area which pulls air and particulates from the vortex region and forms them into a laninar flow air pattern. The head has an elongated, generally rectangular vacuum chamber comprising: a front side and an opposite spaced apart rear side, each side with a top edge and a bottom portion having a generally flattened floor contacting bottom edge, in which the bottom portion defines a number of air bypass channels for restricting a flow of air into the vacuum chamber, with the channels being generally perpendicular to the sides and those arranged in each side being offset to those on the opposite side; a right side and an opposite spaced apart left side, each side with a top edge and a bottom portion having a generally flattened floor contacting bottom edge, and attached to the front side and the rear side; and a top cover portion which attaches to the top edges of the sides, which defines a tube receiving orifice for connection to the hose, the portion having curved faces from each edge to form the vacuum chamber. In use, draw from the motor creates a negative pressure in the vacuum chamber, air passes into the vacuum chamber through the air bypass channels which are arranged to form multiple vortices in the vacuum chamber by the offset alignment of the front and rear air bypass channels and the laminar flow top cover portion provides an aerodynamically unobstructed path for air from the vacuum chamber to the tube receiving orifice.

The combination of laminar air flow with air bypass channels and the resulting multiple vortices in the head, claim to produce a loss of less than 3% in airflow through the head compared to efficiency losses of 13% to

30% in the prior art cleaning heads.

There are a number of disadvantages with this proposed cleaning head. The curved faces from the front, rear, left and right sides provide a conduit which is rectangular in cross section through the vacuum chamber to the tube receiving orifice, which will have a circular cross section. This will create a fragmented vortex in the chamber which will slow the air speed down and effectively allow debris to fall out' of the air flow.

The tube receiving orifice is arranged to be parallel with the floor contacting bottom edge and vertically above the rear edge. Thus the airflow will have to turn through approximately 90 degrees which again detrimentally reduces the speed. Though intended to combine three regions of air flow in the head, these regions are likely to interfere with each other creating regions of zero airflow where debris will fall-out' and not be drawn to the hose. Additionally, creating a high speed laminar flow requires a high suction or draw. This cleaning head is therefore likely to be designed to operate at maximum motor power i.e. 2000 watts and will thus be much less successful at lower power.

It is therefore an object of the present invention to provide a vacuum cleaning head which mitigates at least some of the disadvantages of prior art vacuum cleaning heads.

It is a further object of the present invention to provide a vacuum cleaning head which improves the efficiency of debris pick-up at low power.

Acccrding to a first aspect of the present invention there is provided a vacuum cleaning head comprising: a unitary body having a conduit passing therethough; the conduit being a substantially uninterrupted, single contoured walled continuous passageway with a substantially oval inlet at a first end leading to a substantially circular outlet at a second end; the inlet being arranged to face a surface to be cleaned; the outlet being arranged for connection of a hose to a motor; and the conduit including a primary vortex expansion chamber, the chamber being formed by variations in the cross-sectional area of the conduit between first, second and third cross-sectional areas wherein the second is greater than and bounded by the first and third.

In this way, a vortex is created in an expanded region of an uninterrupted airflow, this increases the air speed and consequently the pick-up.

Preferably the conduit is substantially circular in cross-section. The contoured wall provides curved or gentle slopes through the conduit rather than straight or flat surfaces and in particular no acute angles.

Preferably, the changes in the cross-sectional area of the conduit are undulatlons in the wall which may be considered as being convex in nature with a concave chanter there between.

In this way, the substantially uninterrupted, single contoured walled continuous passageway ensures that the air flow is not fragmented and that the vortex creates the greatest increase in air speed.

Preferably, the cleaning head has a substantially planar bottom face for contacting a surface to be cleaned. More preferably the bottom face is rectangular. In this way, the vacuum cleaning head has dimensions similar to the prior art cleaning heads with a front, rear, left side and right side edges. Additionally, the cleaning head can be swept across a floor or carpet in the same manner as

prior art devices.

Preferably, the body includes a window at a front edge. A window allows air to be drawn in to the conduit to create the air flow through the head. Advantageously the window has a length being a majority of a length of the front edge. Preferably the window is formed by removing a portion of the front edge so that the window is bounded on three sides by the body and on a fourth side, by the surface to be cleaned. In this way, the window can be considered as a cut-away or channel. By creating the window at the floor level, the air will be drawn in through the oarpet pile and aid in debris collection.

Preferably the inlet has a width at the bottom face which is approximately egual to the length of the window. The width of the inlet may be greater than the length of the window. In this way, the cleaning head can draw in air and debris across the majority of the width of the cleaning head.

Advantageously, the window forms a portion of the inlet.

In this way, the window becomes part of the conduit and one end of the substantially uninterrupted, single contoured walled continuous passageway. More preferably, the passageway is substantially centrally located in the body.

Preferably, the inlet is an elongate oval at the bottom face, having left and right portions extending towards the left and right sides respectively. Preferably the left and right portions are substantially part circular in cross-section to maintain the substantially uninterrupted, single contoured walled continuous passageway of the conduit. In this way, the air flow is not fragmented at the inlet.

Advantageously, a wall of each portion undulates to provide a region with a decreased cross-sectional area.

In this way, a restriction is provided in the conduit which assists in creating further opportunity to increase air speed in the conduit.

Preferably, there are provided one or more air inlet control ports in the body. An air inlet control port provides an aperture or channel in the body to allow air to enter the conduit other than through the window. In an embodiment there are arranged two air inlet control ports at the right and left edges of the cleaning head. The air inlet control ports may be channels on the bottom face between a side edge and the conduit respectively.

Alternatively, the air inlet control ports may be apertures in the body arranged towards the side edges.

The apertures are preferably countersunk on each side with the diameter of the aperture controlling air speed through the air inlet control port. Such air inlet control ports allow the head to be manoeuvred across a floor surface without wanting to stick' to the surface by controlling the down force.

Optionally there may be further vortex expansion chambers in the conduit. In this way the conduit can be considered as a tubular pathway with undulating walls to provide selective restrictions at which vortexes may be created to increase the air speed and hence the draw or suction through the cleaning head.

Preferably, the outlet is arranged at approximately sixty degrees to the bottom face. In this way, the hose will be located at thirty degrees to the surface being cleaned which is the preferred position of hoses on cleaning heads of the prior art. This ensures that the cleaning head of the present invention can be retrofitted to existing vacuum cleaners and used in an identical manner as is currently practised.

Preferably, the inlet has a length, perpendicular to its width, which is a majority of half the width of the bottom face between the front and rear edges. More preferably the inlet is arranged near the front edge, with the outlet arranged to lie above the rear edge. In this way, the conduit will not be subjected to a ninety degree turn in direction between the inlet and outlet, thus reducing the chance of a drop in air speed.

In an alternative embodiment, the head includes a gimbal joint at the outlet. This provides rotation of the hose at the outlet. Advantageously, the gimbal joint includes vortex expansion chamber. In this way, air speed can be

increased at the joint as compared to prior art

arrangements wherein the air speed is decreased at the joint due to the dogleg arrangement.

Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings of which: Figure 1 is a perspective view of a vacuum cleaning head according to an embodiment of the present invention; Figure 2 is a cross-sectional view through a vacuum cleaning head according to an embodiment of the present invention; Figure 3 is a bottom view of a vacuum cleaning head according to an embodiment of the present invention; Figure 4 is a front view of a vacuum cleaning head according to an embodiment of the present invention; Figure 5 is an alternative cross-sectional view of a vacuum cleaning head according to a further embodiment of the present invention; and Figure 6 is an illustration of a gimbal joint for use in the vacuum cleaning head of the present invention.

Reference is made to Figures 1 to 4 of the drawings which illustrate a vacuum cleaning head, generally indicated by reference numeral 10, according to an embodiment of the present invention. Head 10 has a body 12 with a conduit 14 located therethrough between an inlet 16 and an outlet 18. The conduit includes a primary vortex chamber 20.

Body 12 is a single piece unit. The head 10 can be moulded from a toughened plastics material. This makes the head 10 relatively cheap to produce and durable as it has no moving parts. Body 12 has a generally rectangular footprint as for the prior art cleaning heads. This rectangular base 22 provides a front edge 24, rear edge 26, right side edge 28 and Left side edge 30. The base also has a bottom face 32 which is substantially planar and smooth excepting the space for the inlet 16.

Extending through the body 12 is a conduit 14. conduit 14 is a tubular passageway 34 without obstructions, tight corners or other interruptions to its continuous smooth wall 36. The conduit 14 is substantially circular in cross-section, but can become oval or elliptical with variations to the cross-sectional area appearing as undulations to the wall 36. The wall 36 may be oonsidered as contoured with curved or gentle slopes. Thus at smaller cross-sectional areas, the passageway 34 will be restricted with the wall 36 appearing to be convex around the circumference as compared to other larger cross-sectional areas appearing as concave.

The conduit 14 extends from an inlet 16 adjacent to the bottom face 32 to an outlet 18 on a top face 38 towards the rear side of the body 12. Within the conduit 14 is a primary vortex chamber 40. Chamber 40 is created by forming a section of the passageway 34 with a larger cross-sectional area, giving a convex or bulbous section, between two restrictions 42,44. The restrictions have a smaller cross-sectional area, perpendicular to the direction of the passageway, than the chamber 40, which they effectively bound. While one expansion chamber 40 is shown in the Figures, it will be apparent that more than one chamber 40 could be incorporated, if desired.

In order to draw air into the conduit 14, a window 46 is supplied in the body 12 at the front edge 24. Window 46 is created by removing a portion of the front edge so that a channel 48 is formed at the front edge 24. This provides a passageway for air to enter the head 10, at the surface being cleaned. It is noted that the channel 48 is long and thin with a width over a majority of the front edge 24 of the head 10. Ps the window 46 provides a front facing inlet for air to be drawn in this allows cleaning over the full width of the head 10. The walls of the channel 48 are contoured to provide smooth curves being also moulded in the body 12.

Behind the window 46, in the base 22, is provided the inlet 16. Inlet 16 is substantially oval, being elongated with a front side meeting the window 46, a rear side 50, narrower than half the depth of base 22, and left and right sides 52,54 being curved. The inlet 16 has a width between left 52 and right 54 sides at the bottom face 32 which is greater than the width of the window 46 and extends over almost the entire width of the base 22 of the head 10.

As the conduit 14 is substantially circular in cross-section, the inlet 16 provides two horizontally arranged channels 56,58 between each side 50,52 respectively, and the centre of the inlet 16, leading through the conduit 14. Each channel 56,58 is open to the floor with a part circular wall when viewed from the side. The ends 60,62 of the horizontal channels 56,58 have a spherically shaped wall to maintain the smooth contoured surface of the conduit 14 throughout the body 12. Thus the conduit, through its entire length to the bottom face 32 provides an oval or circular cross-section.

At the left and right sides 52,54 of the inlet 16 are arranged air inlet control ports 64,66. These may be considered as down force control passages. Each port 64,66 at each end 52,54 is e channel providing a passage for air from the right and left side edges 28,30 to the inlet 16 and consequently the conduit 14. In this embodiment the ports are shaped like the window 46, with a side of the channel being represented by the surface to be cleaned. Each port has smooth walls which are contoured to the inlet 16.

Each horizontal channel 56,58 may have a uniform cross-sectional area along a majority of its length before opening into the conduit 14 circular cross-sectional area. In this embodiment, there is a restriction 68,70 in each channel 56,58 respectively. The restriction is as described with reference to the restrictions 42,44 at the primary vortex chamber 40, being an undulation in the wall of each channel which causes a reduction in the cross-sectional area of the part circular wall over a length of the channel 56,58.

The outlet 18, when viewed in the arrangement of Figure 2, is located at approximately sixty degrees to the bottom face 32. The outlet 18 sits vertically above the rear edge 26 and with the inlet 16 being towards the front edge 24, the depth of the head 10 is selected to ensure that the conduit 14 does not make any dogleg turns. At the outlet the conduit 14 will be of circular cross-section and sized to fit a regular hose of a cylinder or upright vacuum cleaner.

In use, the vacuum cleaning head 10 is fitted to a standard hose at the outlet 18. The hose will be connected to a motor and can preferably be run at low powers such as 800 watts compared to the 2000 watts of present machines. It should be noted that the hose will connect around the outside of the outlet 18, so that the conduit is not stepped into the air flow, which would create a wall upon which fragmentation of the air flow The cleaning head 10 is used in the same manner as the prior art cleaning heads, in which the bottom face 32 contacts the surface to be cleaned such as a floor or carpet. The head 10 is swept back and forth in strokes which maintain contact of the face 32 with the floor surface. Air is drawn into the head 10 via the window 46, from the draw of the motor through the conduit 14. This draw of air sucks in material immediately in front of the window 46 and across the heads entire width as the air flow is optimised and distributed over the head 10.

At the chamber 40, the expansion of area for the air to flow into causes a pressure drop which aids in drawing more air into the chamber 40 which effectively speeds up the air flow from the inlet 16 to the outlet 18 in the conduit 14. This increase in air speed can be likened to that occurring in the internal cylinder head structure of motor vehicles where nozzles are fitted. The increased draw is sufficient, even at low motor power, to pull debris from the pile of a carpet while picking up debris which lies in front of the head.

Primarily it can be considered that the shape of the expansion chamber allows for a large reduction in static pressure (draw) which, by Bernoulli's theorem, gives an equal rise in dynamic pressure (air speed) as the pressures maintain equilibrium. Thus the shape of the conduit at the chamber gives vortexial speed build-up inside the head.

The air inlet control ports 64,66 also provide an air intake point which is speeded up along the horizontal channels 56,58 by virtue of the restrictions 68,70 therein. This air intake controls the grip' which the draw has on the flocr surface and hence the manoeuvrability of the head 10 over the floor.

Additionally, the horizontal channels 56,58 work with the elongated input 16, to provide lateral pick-up across the entire width of the head 10. As the inlet 16 is both at the front edge 24 via the window and close to the side edges 28,30 by virtue of the inlet 16 dimensions, the head 10 can effectively be used up to walls and skirting boards for pick-up, areas which are traditionally missed

in using prior art cleaning heads.

The cleaning head 10 was tested against a standard manufacturer's head, of similar dimensions, with the

RTM

corresponding vacuum cleaner (Hoover Whirlwind 300 Airwatts' , Hepa Filter rated to 2000 watts) . The test was that specified by the Industry as 60312. On a Wilton type carpet, 24 grams of sand (0 to 250 micron sized) is sprinkled on a test area 700 mm long and the width of the cleaning head. The sand is then rolled into the carpet to embed in the pile and left for 10 minutes to settle. Five timed test strokes are allowed over the test area, with the area having an additional 200mm and 300mm at each end, for acceleration and deceleration of the head being tested. Three sets of stokes were performed and the weight of sand collected was measured tc determine the percentage of collection and hence the pick-up.

The vacuum cleaner was set at its lowest power rating, this being 800 watts. On testing, the manufacturers head provided an average pick-up of 26% over three separate tests as compared to 46% for the head of the present invention as described in Figures 1 to 4. Thus the vacuum cleaning head can operate effectively at power levels of less than 1 kW. Preferably it can operate in the power region of 500 to 700 watts with no less than the pick-up levels of currently commercially available models.

Reference is now made to Figure 5 of the drawings which illustrates a cleaning head, generally indicated by reference numeral 110, according to a further embodiment of the present invention. Like parts to those in Figures 1 to 4, have been given the same reference numeral, with the addition of 100, to aid clarity.

Head 110 is formed as a single unitary modelled body of contoured surfaces with a conduit 114 passing there through. In this arrangement the primary vortex chamber is located higher on the conduit towards and adjacent to the outlet 118. This does not affect the performance and illustrates that the chamber 120 may be located at any point in the conduit 114. Indeed, if desired more than one chamber can be arranged in the conduit 114. The pick-up through the head 110 is controlled by the ratios between the cross-sectional areas of the restrictions 142,144 and the cross-sectional area and volume of the chamber 120.

A further feature of the embodiment of Figure 5 is in the air inlet control ports 72,74. These do not open out on the bottom face 132, but instead are apertures through the roof 76 of the horizontal channels 156,158, respectively. Each aperture is countersunk from both the roof 76 and the top face 138 to form a nozzle whose diameter determines the air inlet to each horizontal channel 156,158. The ports 72,74 are located at the ends 160,162 of the horizontal channels 156,158. In this embodiment, there is an end face 78 on the side edge 128,130 to each horizontal channel 156,158. This embodiment illustrates that the air inlet control ports may be arranged at different positions at the ends of the horizontal channels.

The Figures show embodiments wherein the outlet 18,118 is arranged at a fixed angle with respect to the base 22,122. On some prior art vacuum cleaners the hose is allowed to rotate within the outlet. This can be designed into the present invention. Alternatively a gimbal joint 80 can be used as illustrated in Figure 6.

As is known in the art such a joint 60 comprises two cups 84,88 being part spheres in which the lower cup 84 sits within the upper cup 88, with each having the ability to rotate around The other cup. Each cup has a base 82,84 from which a conduit 90,92 extends respectively. The conduits 90,92 join together at a spherical chamber 94 formed by the cups 84,88. In this way, the lower cup 84 is fixed in position on the head 10, while the upper cup 88 can rotate so that the conduit 90 extending from the upper cup 88 can be adjusted to sit at any chosen angle with respect to the bottom face 32. Thus the head 10,110 of the present invention can provide an adjustable attachment to the hose, the hose being attached to the upper conduit 90, as found in present vacuum cleaning heads.

In this arrangement with the joint 80, the outlet 18 can be considered to be at the base 82 of the lower cup 84 or at the base 86 of the upper cup 88. In either configuration, the chamber 94 will provide an expansion chamber, in the same manner as chamber 20. Thus this may be arranged as the only expansion chamber, with outlet 18 considered to be at the base 86. Alternatively, this may be a second chamber, with the outlet 18 considered to be at the base 82.

The principle advantage of the present invention is that it provides a vacuum cleaning head with improved debris pick-up at low power.

A further advantage of the present invention is that it provides a vacuum cleaning head which draws in debris across the entire width of the head.

A yet further advantage of the present invention is that it provides a vacuum cleaning head which operates effectively without brushes or scrapers and thus does not require adjustment to operate on any surface to be cleaned.

It will be appreciated by those skilled in the art that modifications may be made to the invention herein described without departing from the scope thereof. For example, though described with reference to a cylinder vacuum cleaner, the vacuum cleaning head could be used on a hand held device such as those used for cleaning the interior of oars or on wet oarpet shampoo devioes where water is sucked up with the debris. Additionally, the outer surface of the head can be of any form or S arrangement as desired. Brushes and scrapers may also be added, if desired.

Claims

CLAIMS1. A vacuum cleaning head comprising: a unitary body having a conduit passing therethough; the conduit being a substantially uninterrupted, single contoured walled continuous passageway with a substantially oval inlet at a first end leading to a substantially circular outlet at a second end; the inlet being arranged to face a surface to be cleaned; the outlet being arranged for connection of a hose to a motor; and the conduit including a primary vortex expansion chamber, the chamber being formed by variations in the cross-sectional area of the conduit between first, second and third cross-sectional areas wherein the second is greater than and bounded by the first and third.
2. A cleaning head according to claim 1 wherein the conduit is substantially circular in cross-section.
3. A vacuum cleaning head according to claim 1 or claim 2 wherein changes in the cross-sectional area of the conduit are formed as one or more undulations in the wall of the conduit.
4. A vacuum cleaning head according to any preceding claim wherein the cleaning head has a substantially planar bottom face for contacting a surface to be cleaned.
5. A vacuum cleaning head according to claim 4 wherein the bottom face is rectangular.
6. A vacuum cleaning head according to any preceding claim wherein the body includes a window at a front edge.
7. A vacuum cleaning head according to claim 6 wherein the window has a length being a majority of a length of the front edge.
8. A vacuum cleaning head aocording to claim 6 or claim 7 wherein the window is formed by removing a portion of the front edge so that the window is bounded on three sides by the body and on a fourth side, by the surface to be cleaned.
9. A vacuum cleaning head according to any one of claims 6 to 8 wherein the inlet has a width at the bottom face which is approximately egual to the length of the window.
19. A vacuum cleaning head according to any one of claims 6 to 9 wherein the window forms a portion of the inlet.
11. A vacuum cleaning head according to any preceding claim wherein the passageway is substantially centrally located in the body.
12. A vacuum cleaning head according to any preceding claim wherein the inlet is an elongate oval at the bottom face, having left and right portions extending towards the left and right sides respectively.
13. A vacuum cleaning head according to claim 12 wherein the left and right porcions are substantially part circular in cross-section.
14. A vacuum cleaning head according to claim 12 or claim 13 wherein a wall of each portion undulates to provide a region with a decreased cross-sectional area.
15. A vacuum cleaning head according to any preceding claim wherein there are provided one or more air inlet control ports in the body.
16. A vacuum cleaning head according to claim 15 wherein there are arranged two air inlet control ports at the right and left edges of the cleaning head.
17. A vacuum cleaning head according to claim 16 wherein the air inlet control ports are channels on the bottom face between a side edge and the conduit respectively.
18. A vacuum cleaning head according to claim 16 wherein the air inlet control ports are apertures in the body arranged towards the side edges.
19. A vacuum cleaning head according to any preceding claim wherein there are one or more further vortex expansion chambers in the conduit.
20. A vacuum cleaning head according to any one of claims 4 to 19 wherein the outlet is arranged at approximately sixty degrees to the bottom face.
21. A vaouum cleaning head according to any one of claims 4 to 20 wherein the inlet has a length, perpendicular to its width, which is a majority of half the width of the bottom face between front and rear edges.
22. A vacuum cleaning head according to claim 21 wherein the inlet is arranged near the front edge, with the outlet arranged to lie above the rear edge.
23. A vacuum cleaning head according to any preceding claim wherein the head includes a gimbal joint at the outlet.
24. A vacuum cleaning head according to claim 23 wherein the gimbal joint includes vortex expansion chamber.